Dissertations / Theses on the topic 'Dynamic Virtual Power Plants'

The growing number of micro generation devices in the electrical network is leading many to consider that these devices can no longer be considered as fit and forget, but should instead be considered as having a demonstrable network impact which should be predicted and utilised. One of the techniques for considering the impacts of these devices is the Virtual Power Plant (VPP). The VPP is the aggregation of all the Distributed Generation (DG) connected into the network up to and including the connection voltage of the VPP, such that the cumulative power up the voltage levels can be seen in the single VPP unit, rather than across a broad spread of devices. One of the crucial tasks in characterising the VPP, developed in this work, is the ability to correctly predict and then aggregate the behaviour of several technology types which are weather driven, as a large proportion of DG is weather driven. Of this weather driven DG, some can only typically be dispatched with modification and the rest cannot be dispatched at all. The aggregation of the VPP as part of the electrical network is also developed, as the constraints of the network and the reliability of the network cannot be overlooked when considering the aggregation of the VPP. From a distribution network operator's (DNO) perspective, these characterisation models can be used to highlight problems in the network introduced by the addition of DG, but are also generally utilitarian in their role of predicting the power output (or negative load) found throughout the network due to DG. For a commercial agent interested in selling energy, these models allow for accurate predictions of energy to be determined for the trading period. A VPP agent would also be adversely affected by line failure in the network, leading to the development of an N-1 analysis based upon reliability rates of the network, which is used as the basis for a discussion on the impacts of single line failure and the mitigation available through feedback from the DNO.

I confini delle risorse di energia distribuita sono in continua espansione negli ultimi anni con conseguenti cambiamenti nella gestione ottimizzata di energia nelle Smart Grid per soddisfare la domanda di energia, apportare miglioramenti alle condizioni ambientali e minimizzare i prezzi. Per raggiungere questo obiettivo si utilizza un Virtual Power Plant con al suo interno un gestore di energia che coordina le unit`a distribuite relative al sistema di energia elettrico. Questo lavoro di tesi sviluppa un modello per la gestione energetica all’interno di un Virtual Power Plant per decidere come e con quali fonti energetiche soddisfare la domanda di energia elettrica. Le decisioni riguardanti le quantita` ed il tipo di risorse energetiche utilizzate ad intervalli orari nell’arco di una giornata avvengono dinamicamente e dipendono da fattori variabili provenienti dalla disponibilit`a delle risorse di energia rinnovabili, dal costo dell’energia elettrica acquistata dalla rete esterna, dal costo del diesel, dai carichi associati ad utenze domestiche e dalla possibilit`a di immagazzinare o rilasciare energia all’interno dell’unit`a di storage. La soluzione `e calcolata mediante l’utilizzo di una funzione costo minimizzata la quale prende in considerazione solo i costi diretti relativi all’impianto VPP. Le conclusioni teoriche e le aspettative sono verificate mediante una simulazione di uno scenario reale.

Hydro-electricity plays an important role in the safe, stable and efficient operation of electric power systems. Frequency stability of power systems refers to the ability to maintain steady frequency following a severe system upset resulting in a significant imbalance between generation and load. In order to suppress power grid frequency fluctuations, generating units change their power output automatically according to the change of grid frequency, to make the active power balanced again. This is the primary frequency control (PFC). PFC of electrical power grids is commonly performed by units in hydropower plants (HPPs), because of the great rapidity and amplitude of their power regulation. A hydropower generation system is a complex nonlinear power system including hydraulic, mechanical, electrical and magnetic subsystems. Nowadays, the size of HPPs and the structure complexity of systems have been increasing, especially in China. The proportion of electricity generated by intermittent renewable energy sources have also been growing. Therefore, the performance of HPPs in terms of frequency control is more and more important. The research on control strategies and dynamic processes of HPPs is of great importance. The frequency stability of hydropower units is a critical factor of power system security and power quality. The power response time for evaluating the frequency regulation quality, is also a key indicator. In recent years, there is a tendency that the new turbines experience fatigue to a greater extent than what seem to be the case for new runners decades ago, due to more regulation movements caused by increasingly more integration of intermittent renewable energy sources. In some countries, as in Sweden, PFC is a service that the transmission system operator buys from the power producers. In other countries, as in Norway and China, there is also an obligation for the producers to deliver this service, free of charge. However, there are costs related to this, e.g. due to design constraints and auxiliary equipment when purchasing a new unit or system, and due to wear and tear which affects the expected life time and maintenance intervals. Hence the specific research on wear and tear of hydro units due to PFC is exceedingly necessary.

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xviii, 218 p.; also includes graphics. Includes abstract and vita. Advisor: Jean Michael Guldmann, City and Regional Planning Graduate Program. Includes bibliographical references (p. 130-133).

Current flow in the electrical grid is changing due to the introduction of new generators and loads.Specifically, weak Overhead lines, are a constraint for the introduction of wind farms located farfrom the central network. The current situation requires smart solutions to improve the transportationcapabilities of these grid’s components. Among the different possibilities, Dynamic Line Rating(DLR), is emerging as the most interesting solution from both the economic and technical points ofview. The presented Thesis work investigates the performance of DLR from both the theoretical andpractical perspectives.The theory behind DLR is based on the development of a thermal model able to estimate the precisetemperature experienced by OHLs conductor under different climate conditions. Since 1972, whenthe first investigation on DLR have been published, different thermal models have been developed,each with a different precision level. The first part of the thesis concerns the investigation of IEEE738 standard accuracy.The standard analysis highlighted weaknesses on the theoretical approach employed on the forcedconvective cooling calculation. Specifically the wind direction effect is estimated as the conductorwas a perfect cylinder. A wind tunnel test has been performed in order to verify the effect of theconductor’s strands on the total thermal equilibrium. The results show that an inclined wind-conductor relative direction can have a more important impacton the line rating than foreseen with the IEEE thermal model. Since the wind tunnel test has been thefirst experience of this kind pursued at KTH, the presence of few different laboratory set-updeficiencies did not allow to draw a definitive and precise conclusion on the necessary IEEE formulacorrection.The practical side of the Thesis project includes an extensive literature research on the differentdevices that can be employed for dynamic line rating and a real-case study analysis. The analysis isperformed in order to evaluate which can be the best solution when the introduction of new windenergy supply increase the load on a pre-existent OHL. Results show that, in the selected region,Värmland, in the southwestern Sweden, DLR has the prerequisites to allow the exploitation of thehigh wind energy resource at the lower expenses. Wind energy production is often associated with anincreased cooling on the line’s conductors. This means that higher current levels can be withstoodavoiding the need for expensive lines’ upgrading. For the selected hot-spot, in 2015, DLR wouldhave allowed a transport capability improvement of 69.6% during the summer and of 26.7% duringthe winter. It is also reported that a load equal to the SLR during the winter period would have causedserious overheating transients of the conductor. Overall DLR proved to allow technical and economicbenefit for the system operator.
Flödet genom elnätet förändras på grund av införandet av ny generering och nya typer av laster.Specifikt är svaga luftledningar en begränsning för installation av vindkraft som ligger långt fråndet centrala nätet. Den nuvarande situationen kräver smarta lösningar för att förbättratransportkapaciteten i elnätet. Bland de olika möjligheterna finns Dynamic Line Rating (DLR) somframstår som den mest intressanta lösningen från både ekonomiska och tekniska synvinklar. Det härexamensarbetet behandlar resultatet av DLR från både teoretiska och praktiska perspektiv.Den teoretiska grunden för DLR är baserad på utvecklingen av en termisk modell som kan skattatemperaturen i luftledningar under olika klimatförhållanden. Examensarbetets första del behandlaren undersökning av IEEE 738 standarden (DLR standard). IEEE 738 standarden utgår från ledarensom en perfekt cylinder. Något som har en effekt bland annat i effekten av vindriktning. Ettvindtunnel test har utförts för att verifiera effekten av fler kardelers effekt på den totala termiskajämvikten. Resultaten visar att antalet kardeler har en betydande effekt på den termiska jämviktenoch då alltså även på DLR.Den andra delen av examensarbetet innehåller en omfattande litteratursökning på de olikaapparaterna som kan användas till DLR samt en praktik undersökning/analys. Analysen utförs föratt utvärdera vilken lösning som kan vara den bästa vid införandet av mer vindkraft, som ökarbelastningen på en redan existerande luftledning. Resultaten visar att, i det valda området,Värmland, i sydvästra Sverige, har DLR förutsättningar för att medge ökat utnyttjandet av den storavindkraft resurs som finns där till relativt låga kostnader. Slutsatsen av examensarbetet är att DLR ger tekniska och ekonomiska fördelar tillsystemoperatören.

The main contribution of this thesis is an investigation of model predictive control(MPC) for marine diesel electric power plants. Recommendations and new ideasfor further development are emphasized.The motivation of the thesis is to develop a controller for diesel electric power plantsthat can control the plant in a more efficient way. This includes reducing wear andtear, fuel consumption, and emissions. However, the safety aspect is always themost important factor and must be handled with care.The case plant to be studied is a diesel electrical power plant consisting of severaldiesel driven generators (genset). These gensets produce electrical power to servethe electrical demands on a marine vessel. The consumers can be propulsion units,heave compensators, drilling equipment, and hotel loads. These highly dynamicconsumers are large compared with the producers. This gives unwanted fluctuationof frequency. In some vessels this effect is so large that more gensets are requiredfor transients than for peak demands. This can be avoided with better controlstrategies.The controller developed in this thesis adjusts the local controllers on the dieselengines. The objective is to keep the genset at a given load sharing, while keepingthe frequency within rules and regulations. In addition is the plant controlled to astate where a single point failure does not lead to blackout.Blackout is prevented by calculating a failure case in addition to the normal case.The failure case may be a disconnection of the largest genset on the power bussegment. The case is calculated in the controller to make sure that if the caseoccurs the plant is able to handle the failure without a blackout. A normal case,where everything goes as normal, is calculated to optimize the current operation.The controller is verified by simulation done in MATLAB/Simulink. Theimplemented controller performs well during all of the simulated cases. However,the predictions made by the controller are in some cases conservative. This is dueto the choice of the fuel rate constraints. Lastly, suggestions for how to improvethe performance of the controller are included. The most important suggestionsare to include a model of the turbocharger in the control plant model and toinclude more failure cases.

The expansion of renewable energies and the deregulations of the energy market are increasing the demand of regulating power. In absence of hydropower, thermal power is often used for this purpose instead. This thesis focuses on the Vattenfall owned power plant Jänschwalde located in Germany. The goal is to optimize the start-up procedure, so that the start-up time is reduced without causing too much thermal stress on the important thickwalled components in the boiler. By reducing the start-up time, the plant can become more protable, 　exible and better suited to regulate the electricity market. A start-up model was built in Dymola and validated against measurement data and a simulation model of Jänschwalde, which is too complex to use for optimization purposes. The JModelica.org platform was used for the optimization part of the project. It was possible to nd optimal solutions for the start-up process of the Jänschwalde power plant, but the convergence of the optimization algorithm was very dependent on the optimization options used and the scaling of the plant model. Further work includes development of the components used in the start-up model, rening the discretization and scaling for the optimization problem.

As the largest global renewable source, hydropower shoulders a large portion of the regulation duty in many power systems. New challenges are emerging from variable renewable energy (VRE) sources, the increasing scale and complexity of hydropower plants (HPPs) and power grid. Stable and efficient operation of HPPs and their interaction with power systems is of great importance. Theoretical analysis, numerical simulation and on-site measurement are adopted as main study methods in this thesis. Various numerical models of HPPs are established, with different degrees of complexity for different purposes. The majority of the analysis and results are based on eight HPPs in Sweden and China. Stable operation (frequency stability and rotor angle stability) and efficient operation are two important goals. Regarding the stable operation, various operating conditions are analysed; the response time of primary frequency control (PFC) and the system stability of isolated operation are investigated. A fundamental study on hydraulic-mechanical-electrical coupling mechanisms for small signal stability of HPPs is conducted. A methodology is proposed to quantify the contribution to the damping of low frequency oscillations from hydraulic turbines. The oscillations, with periods ranging from less than one up to hundreds of seconds, are analysed. Regarding the efficient operation, a description and an initial analysis of wear and tear of turbines are presented; a controller filter is proposed as a solution for wear reduction of turbines and maintaining the frequency quality of power systems; then the study is further extended by proposing a framework that combines technical plant operation with economic indicators, to obtain relative values of regulation burden and performance of PFC. The results show that the coupling between the hydraulic-mechanical subsystem and the electrical subsystem can be considerable and should be considered with higher attention. Effectiveness and applicability of different numerical models are shown, supplying suggestions for further model optimization. For the influence from power systems on HPPs, the dynamic processes and corresponding control strategies of HPPs under diverse disturbances and requirements from power systems are addressed. For the influence from HPPs on power systems, quantifications of frequency quality and the hydraulic damping are conducted utilising proposed methodologies.

In the current climate crisis, there is an increasing need for the integration of renewableenergy in higher penetration indexes, which is boosting innovation not only in the technology but also in new business models.  Virtual Power Plants (VPPs) are an aggregation model for generation that is said to be able to decrease imbalances from renewable generation while improving economic performance.  While the regulation in some countries still does not allow this type of activity there are also many others in which aggregation of demand and even VPPs are growing in numbers. This study aims to prove the previous statement and quantify the amount of imbalances that can be offset and the consequent penalties avoided for a VPP located  in  the  north  of  Portugal  composed  of  a  pumped-storage  hydro  plant  and  onshore wind generation.  In order to do so, two case studies have been compared:  a baseline case in which each unit is operated independently and another in which all the units are aggregated under the VPP model.  With this aim, a simplified bidding strategy has been simulated for both cases and three different error levels, to finally compare the results through four key performance indicators (KPIs):  increase in profit, increase revenues, decrease in imbalance and decrease in penalty cost.  The optimization problem was formulated as a mixed-integer linear programming (MILP) problem and it was carried out in two steps:  one for the day ahead session and a second for the intraday market.  It aims to diversify the generation port- folio of the hydro power plant and divide it among the available products:  energy sold in the day ahead market, capacity reserves for the secondary reserves, and energy sold as tertiary reserves.  It was decided to follow a deterministic approach, considering in the strategy a tree of scenarios and their associated probabilities.  In order to formulate this scenarios historical data was used, due to the high dependence between the market variables.  The results show that an average annual 16% decrease in energy deviations could be achieved which implies a 16.3% decrease in the penalty costs.  Moreover, it was also found that the combined oper- ation of the assets in the intraday market, together with the penalty reduction, would lead to a 1% increase in profit with a 0.1% decrease in revenues, concluding that a more detailed and data intensive model would be required to analyse the full advantage of the VPP modelwhen operating the assets together also during the day ahead session.
I den nuvarande klimatkrisen finns det ett ökande behov av integration av en högre andel förnybar energi, vilket ökar behovet av innovationer inte bara inom tekniken utan också i nya affärsmodeller. Virtuella kraftverk (Virtual Power Plants VPP) är en aggregeringsmodell för produktion som sägs kunna minska obalansen från förnybar produktion samtidigt somden förbättrar det ekonomiska utfallet. Ä ven om förordningen i vissa länder fortfarande intetillåter denna typ av verksamhet finns det också många andra där aggregering av efterfrågan och till och med VPP växer i antal. Denna studie syftar till att visa på nyttan av VPP och kvantifiera mängden obalanser som kan kompenseras och de orsakade obalans-kostnader som undviks för en VPP som ligger i norra Portugal som består av ett vattenkraftverk med pumplagring och vindkraft på land. För att göra det har två fallstudier jämförts: ett basfall där varje enhet drivs oberoende och en annan där alla enheterna är aggregerade enligt VPPmodellen. Med detta syfte har en förenklad budstrategi simulerats för båda fallen och tre olika nivåer på fel i prognoser för att slutligen kunna jämföra resultaten genom fyra olika indikatorer (KPI:er): vinstökning, ökning av intäkter, minskning av obalans och minskning av obalanskostnader. Optimeringsproblemet formulerades som ett mixed-linear-integer programmeringsproblem (MILP) och det genomfördes i två steg: ett för dagenföremarknaden och ett andra för intradagsmarknaden. Detta syftar till att diversifiera produktionsportföljen för vattenkraftverket och dela den mellan de tillgängliga produkterna: energi som säljs i den kommande marknaden, kapacitetsreserver för sekundära reserver och energi som säljs som tertiära reserver. I studien har vi valt en deterministisk strategi med beaktande av ett scenarioträd med respektive sannolikheter. För att formulera dessa scenarier användes historiska data på grund av den stora korrelationen mellan marknadsvariablerna. Resultaten visar att en genomsnittlig årlig minskning av energiavvikelserna med 16% skulle kunna uppnås vilket innebär en minskning av obalanskostnaderna med 16,3%. Dessutom konstaterades det att den kombinerade driften av tillgångarna på intradagsmarknaden, tillsammans med minskningen av obalanser, skulle leda till en vinstökning på 1% med en minskning av intäkterna på 0,1%, från vilket vi drar slutsatsen att en mer detaljerad och datakrävande modell skulle krävas för att analysera VPP-modellens fulla potential när mananvänder tillgångarna tillsammans även under dagenföremarknaden.

Electricity is an essential good, which can hardly be replaced. It can be produced thanks to a wide rangeof sources, from coal to nuclear, not to mention renewables such as wind and solar. In order to meetdemand at the lowest cost, an optimisation is made on electricity markets between the differentproduction plants. This optimisation mainly relies on the electricity production cost of each technology.In order to include long-term constraints in the short-term optimisation, a so-called use value (oropportunity cost) can be computed and added to the production cost. One long-term constraint thatEDF, the main French electricity producer, is facing is that its gas plants cannot exceed a given numberof operation hours and starts between two maintenances. A specific software, DiMOI, computes usevalues for this double constraint but its parameters needs to be tested in order to improve thecomputation, as it is not thought to work properly.DiMOI relies on dynamic programming and more particularly on an algorithm called Bellman algorithm.The software has been tested with EDF R&D department in order to propose some modellingimprovements. Electricity and gas market prices, together with real plant parameters such as startingcosts, operating costs and yields, were used as inputs for this work, and the results were checkedagainst reality.This study gave some results but they appeared to be invalid. Indeed, an optimisation problem wasdiscovered in DiMOI computing core: on a deterministic context, a study with little degrees of freedomwas giving better profits than a study with more degrees of freedom. This problem origin was notfound precisely with a first investigation, and the R&D team expected the fixing time to be very long.The adaptation of a simpler tool (MaStock) was proposed and made in order to replace DiMOI. Thisproject has thus led to DiMOI giving up and its replacement by MaStock. Time was missing to testcorrectly this tool, and the first study which was made was not completely positive. Further studiesshould be carried out, for instance deterministic ones (using real past data) whose results could becompared to reality.Some complementary studies were made from a fictitious system, in order to study the impact of someparameters when computing use values and operations schedules. The conclusions of these studiesare the little impacts that changes in gas prices and start-up costs parameters have on the global resultsand the importance of an accurate choice in the time periods durations used for the computations.Unfortunately these conclusions might be too specific as they were made on short study periods.Further case studies should be done in order to reach more general conclusions.

Electrical demand flexibility is a key component to enabling a low cost, low carbon grid. In this study, residential electricity demand and flexibility is explored from the lens of a virtual power plant operator. Individual and aggregate asset consumption is analysed using a pool of >10,000 household assets over 6 years. Key safety, comfort and availability limitations are identified per asset type. Pool flexibility is analysed using a combination of past data and principled calculations, with flexibility quantified for different products and methods of control. A machine learning model is built for a small pool of 200 assets, predicting consumption 24 hours in advance. Calculated flexibility and asset limitations are then used within an optimisation model, leveraging flexibility and combining the value of self consumption and day ahead price optimisation for a residential home.
Flexibilitet i efterfrågan av elektricitet är essentiellt för att möjliggöra ett elnät med låga kostnader och utsläpp. I denna studie undersöks elanvändning av en bostad samt flexibilitet i perspektiv från en virtuell kraftverksoperatör. Individuell och sammanlagd konsumtion analyseras genom tillgång av data från >10 000 bostäder över 6 år. Begränsningar av säkerhet, komfort och tillgänglighet identifieras per tillgångstyp. Sammanlagda flexibiliteten analyseras genom en kombination av tidigare data och principiella beräkningar, med flexibilitet kvantifierad för diverse produkter och kontrollmetoder. En modell för maskininlärning utvecklades för 200 bostäder och förutser konsumtion 24 timmar i förväg. Den beräknade flexibiliteten och tillgångsbegränsningar används sedan i en optimeringsmodell som utnyttjar flexibilitet och kombinerar värdet av självkonsumtion och optimerat pris för nästkommande dag för ett bostadshus.

The Turkish TSO (TEIAS) has been leading a project that aims the synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA (former UCTE) System. For this purpose, this study concentrates on the specific problems related to the electromechanical systems of large size hydroelectric power plants regarding low frequency inter area oscillations, which are prone to occur once the interconnected operation is established. The expected frequency of inter area oscillations after interconnected operation is close to 0.15 Hz, which is in the frequency range of the speed governing structures of turbines, as explained in the first two sections of the thesis. In the third section, the nonlinear turbine governor model used throughout the study is explained. In the following part, the governor parameter tuning study with regard to the defined performance objectives is explained. Afterwards, the effect of the retuned governor settings of the sample hydroelectric power plants on a simple multi machine power system is shown. Following that, the system wide effect of removing the sources of negative damping, which are strongly dependent on the governor settings of the major hydroelectric power plants of the Turkish Power System, is shown. In the final part, conclusions are made on the operation of the hydroelectric power plants regarding the frequency stability of the system after synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA System.

Renewable energy resources are projected to claim a larger part of the Swedish power mix in coming years. This could potentially increase frequency fluctuations in the power grid due to the intermittency of renewable power generating resources. These fluctuations can in turn cause issues in the power grid if left unchecked. In order to resolve these issues, countermeasures are employed. One such countermeasure is for private actors to regulate power; in exchange they are financially compensated through reserve markets. The reserve market studied in this thesis is called Frequency Containment Reserve – Normal (FCR-N). Currently hydroelectric power provides almost all regulated power within this market. As the need for power regulation is expected to increase in the coming years, there exists a need to study other technologies capable of power regulation. This thesis focuses on one such technology called, virtual power plants. While virtual power plants are operating in other parts of the world, there were no virtual power plants operating in Sweden. As a result, the nature of an optimized virtual power plant and the economic benefits of optimization had not been previously investigated. To answer such questions, this thesis modelled and optimized the revenue of a virtual power plant. The examined virtual power plant consisted of cooling chillers, lighting, ventilation fans and a battery energy storage system. Where varying their total power demand allowed for them to provide power regulation. With the virtual power plant market in Sweden being in its infancy, this thesis serves as a first look into how an optimized virtual power plant using these components could function. To put the economic results of the optimization into context, a comparative model was constructed. The comparative model was based on a semi-static linear model. This is what the thesis’s industry partner Siemens currently uses. For the simulated scenarios, the optimized model generated at least 85% higher net revenues than the semi-static linear model. The increase in revenue holds potential to increase the uptake of virtual power plants on the Swedish market, thus increasing stability in the power grid and easing the transition to renewable energy.
Då förnyelsebara energiresurser antas omfatta en större roll av den svenska elproduktionen inom kommande år, så kan detta leda till att frekvensfluktueringar i elnätet ökar. Detta sker på grund av att den oregelbundna elproduktionen från förnyelsebara energiresurser inte matchas med konsumtion. Om dessa fluktueringar inte hanteras kan det i sin tur leda till skadliga störningar inom elnätet. För att motverka detta och således stabilisera elnätet används diverse lösningar. Ett sätt att åstadkomma ökad stabilisering i elnätet är att låta privata aktörer kraftreglera. De privata aktörerna som står för kraftregleringen gör detta i utbyte mot ekonomisk kompensation, genom att delta i reservmarknader. Den reservmarknad som studerades inom detta examensarbete kallas Frequency Containment Reserve – Normal (FCR-N). I nuläget står vattenkraft för nästan all reglerad kraft inom den här marknaden. Men då behovet av kraftreglering antas öka inom kommande år så behövs nya teknologier studeras som kan bistå med kraftregleringen. Den studerade teknologin inom detta examensarbete var ett virtuellt kraftverk. Då inga virtuella kraftverk var i bruk i Sverige då denna uppsats skrevs fanns det osäkerheter kring hur man optimalt styr ett virtuellt kraftverk och de ekonomiska fördelarna som detta skulle kunna leda till. Detta examensarbete modellerade och optimerade ett virtuellt kraftverk ur ett vinstperspektiv. Det virtuella kraftverket var uppbyggt utav kylmaskiner, ljus, ventilationsfläktar och ett batterisystem. Deras kraftkonsumtion styrdes på ett sådant sätt som lätt de bidra till kraftreglering på reservmarknaden. För att kunna analysera de ekonomiska resultaten från det optimerade virtuella kraftverket, så byggdes en jämförelsemodell. Denna jämförelsemodell är baserad på en semistatisk linjär modell, vilket är det som examensarbetets industripartner Siemens använder. Den ekonomiska jämförelsens resultat påvisade att inkomsten från den optimerade modellen var minst 85% högre än den semistatiskt linjära modellen, inom de studerade scenarierna. Denna inkomstökning skulle potentiellt kunna öka användningen av virtuella kraftverk på den svenska reservmarknaden vilket i sin tur skulle medföra högre stabilitet på elnätet. Genom att öka stabiliteten på elnätet kan således förnyelsebara energiresurser i sin tur lättare implementeras.

Thesis (M.S.)--Missouri University of Science and Technology, 2008.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 12, 2008) Includes bibliographical references (p. 64-66).

Nuclear power plays a crucial role in energy supply in the world: around 15% of the electricity generated worldwide is provided from nuclear stations avoiding around 2.5 billion tonnes of CO2 emissions. As of January 2016, 442 reactors that generated 380+ GW were in operation and 66 new reactors were under construction. The seismic design of new nuclear power plants (NPPs) has gained much interest after the high-profile Fukushima Dai-ichi accident. In the UK, a tectonically stable continental region that possesses medium-to-low seismic activity, strong earthquakes capable of jeopardising the structural integrity of NPPs, although infrequent, can still occur. Despite that no NPP has been built in Great Britain after 1995, a New Build Programme intended to build 16 GW of new nuclear capacity by 2030 is currently under way. This PhD project provides a state-of-the-art framework for seismic probabilistic safety assessment and risk control of NPPs in Northwest Europe with particular application to the British Isles. It includes three progressive levels: (i) seismic input, (ii) seismic risk analysis, and (iii) seismic risk control. For seismic input, a suitable model to rationally define inputs in the context of risk assessments is proposed. Such a model is based on the stochastic simulation of accelerograms that are compatible with seismic scenarios defined by magnitude 4 < Mw < 6.5, epicentral distance 10 km < Repi < 100 km, and different types of soil (rock, stiff soil and soft soil). It was found to be a rational approach that streamlines the simulation of accelerograms to conduct nonlinear dynamic analyses for safety assessments. The model is a function of a few variables customarily known in structural engineering projects. In terms of PGA, PGV and spectral accelerations, the simulated accelerograms were validated by GMPEs calibrated for the UK, Europe and the Middle East, and other stable continental regions. For seismic risk analysis, a straightforward and logical approach to probabilistically assess the risk of NPPs based on the stochastic simulation of accelerograms is studied. It effectively simplifies traditional approaches: for seismic inputs, it avoids the use of selecting/scaling procedures and GMPEs; for structural outputs, it does not use Monte Carlo algorithms to simulate the damage state. However, it demands more expensive computational resources as a large number of nonlinear dynamic analyses are needed. For seismic risk control, strategies to control the risk using seismic protection systems are analysed. This is based on recent experience reported elsewhere of seismically protected nuclear reactor buildings in other areas of medium-to-low seismic activity. Finally, a scenario-based incremental dynamic analysis (IDA) is proposed aimed at the generation of surfaces for unacceptable performance of NPPs as function of earthquake magnitude and distance. It was found that viscous-based devices are more efficient than hysteretic-based devices in controlling the seismic risk of NPPs in the UK. Finally, using the proposed scenario-based IDA, it was found that when considering all controlling scenarios for a representative UK nuclear site, the risk is significantly reduced ranging from 3 to 5 orders of magnitude when using viscous-based devices.

Being able to detect and describe hardware deterioration in nuclear power plants benefits the nuclear industry tremendously as it would enable appropriate outage and maintenance planning. Being able to detect and describe this faulty behaviour also assists in fault analysis of nuclear power plants. This thesis describes the development of narrow band dynamic operating envelope that makes use of real-time simulated plant measurements and control operations to compare with actual plant measurements and control operations. By simulating the plant behaviour in real-time whilst comparing it with the real-time transient the plant is following, a second set of plant measurements is generated. The newly generated plant measurements represent plant measurements if the control system did not introduce control operations to nullify the effect of the fault. This enables the calculation of the unknown disturbance introduced into the plant as a fault condition. The benefit of such a system is that plant faults that are too small to detect (especially during transients when the plant operating point is moving around) can be identified. The behaviour of the control system is also continuously predicted so the effect of the control system compensating for fault effects (which in most cases hides the fault condition) is used to characterise the fault condition in terms of magnitude, position and subsystem being affected. The combination of the fault detection and fault characterisations produces a complete fault identification system. The approach is verified by making use of an implementation of the fault identification system on a simulated plant. Typical faults (small enough to go undetected for an extended period of time during a typical transient) are introduced into the virtual plant and continuously compared with another plant simulation, producing the same transient without the introduction of the fault. A comparison is done to evaluate the speed and detail provided by the fault identification system as opposed to the conventional plant protection system. Using the described methodology, the fault is detected and characterised before plant design limitations are reached or the fault is detected by the conventional protection system. In addition to the fault identification system, this research develops the functional requirements for a full scope engineering and training simulator that would allow the simulator to be fully utilised to simulate postulated accident scenarios, plan plant modification procedures as well as provide an in- transient real time reference for plant diagnostic systems. To ensure practical implementation of the system in the regulated nuclear industry, an implementation framework that keeps the conventional plant protection system intact, is created. It allows the implementation of narrow band dynamic operating envelope operating within the conventional operating envelope. The framework allows the implementation of the developed fault identification system and other plant diagnostic systems on existing nuclear power plants without impacting on existing nuclear power plant licences as well as the licensing process of new nuclear power plants.
Thesis(PhD (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2013.

This report explores the impacts of variable renewable energy (VRE) on power trading in the European wholesale electricity market. The intricate operation of a typical power exchange in Europe is accompanied by an equally complex balancing system. The increasing amount of VRE in the power system, such as wind and solar power, has far-reaching impacts for power traders in both this electricity market and the corresponding balancing system. As a result, the electricity market is evolving in unprecedented ways and new participants are entering the playing field to capitalize on the changing dynamics caused by VRE generators. One novel participant, the virtual power plant (VPP), possesses an advantage over other market participants by aggregating VRE generators with controllable renewable energy generators, like biogas and hydro plants, into one entity. This allows the VPP to both gain access to live VRE production data that larger plants don’t have, which it then utilizes to remotely dispatch various subpools of assets, and to provide balancing services to the grid. Subsequently, VPPs are able to trade VRE and other renewable electricity superiorly on the same spot markets and balancing systems as large central power plants and industrial consumers. The report asserts that VPP traders can earn profits through means of innovative trading strategies that exploit predictable market impacts caused by VRE power through a robust understanding of the electricity market and their unique access to data.
Denna rapport undersöker effekterna av variabel förnybar energi (VRE) på krafthandeln på den europeiska elhandelsmarknaden för stora aktörer. Den komplicerade driften av ett typiskt kraftutbyte i Europa åtföljs av ett lika komplicerat balanseringssystem. Den ökande mängden VRE i kraftsystemet, såsom vind- och solkraft, har långtgående effekter för krafthandlare på både denna elmarknad och motsvarande balanseringssystem. Som ett resultat utvecklas elmarknaden på enastående sätt och nya deltagare kommer in på spelplanen för att dra nytta av den förändrade dynamiken som orsakas av VRE-generatorer. En ny spelare, det virtuella kraftverket (VPP), har en fördel jämfört med andra marknadsaktörer genom att samla VRE-generatorer med styrbara förnybara energiproducenter, som biogas och vattenkraftverk, till en enhet. Detta gör att VPP både kan få tillgång till live VRE-produktionsdata som större anläggningar inte har, som den sedan använder för att distribuera olika underpooler av tillgångar och för att tillhandahålla balanstjänster till nätet. Därefter kan VPP: er handla med VRE och annan förnybar el på ett överlägset sätt på samma spotmarknader och balanseringssystem som stora centrala kraftverk och industrikonsumenter. Rapporten visar att VPP-handlare kan göra vinster genom innovativa handelsstrategier som utnyttjar förutsägbara marknadseffekter orsakade av VRE-kraft genom en detaljerad förståelse för elmarknaden och unik tillgång till data för produktionen av förnybar energi

QC 20201118

La technologie d’électrolyse à oxydes solides (SOE) pourrait permettre d’améliorer l’efficacité des installations de conversion d’électricité en gaz naturel de synthèse (SNG) et de réduire leur coût, grâce à une integration thermique performante, à l’industrialisation de la technologie et une flexibilisation des unités pour la pénétration de l’électricité renouvelable. Une analyse énergétique détaillée de trois concepts d’installations power-to-SNG innovants est d’abord réalisée avec une intégration thermique détailllée. Les installations intégrant des unités SOE et produisant du GNC ou du GNL présentent des rendements d’au moins 78,5% sur base PCS, bien plus élevés que pour les installations intégrant des unités d’électrolyse PEM qui produisent du GNC avec un rendement de 64,4%. La réponse thermique des unités SOE soumises à des variations de charge électrique est ensuite étudiée sur la base d’un modèle dynamique 1D à l’échelle d’une cellule (SOEC). Les cellules « électrolyte support » sont thermiquement plus stables que les « électrode support » et donc plus adaptées à des charges électriques variables. Le modèle est ensuite étendu à une unité entière de production et de stockage d’H2 et couplé à différents profils électriques. L’unité affiche une consommation énergétique de 3,4-3,8 kWh·Nm-3 H2 et un rendement élevé de l’électricité vers l’H2 (93-103%) par récupération de la vapeur de méthanation. Un dimensionnement du réservoir d’H2 et de l’unité de méthanation est réalisé avec un profil électrique éolien. Les charges électriques variables réduisent l’efficacité des installations power-to-SNG, en augmentent les coûts et en complexifient l’opération. Les installations multifuels semblent être l’option la plus prometteuse pour gérer l’intermittence de la production d’électricité. Etendre la gamme d’opération des SOECs aux modes exotherme et endotherme améliorerait les rendements de l’électricité vers l’H2 en comparaison au mode marche/arrêt. Pour une charge électrique constante, les SOECs doivent préférablement être opérées au thermoneutre ou en mode exotherme. Enfin, les coûts de production du SNG sont évalués, en commençant par une estimation ascendante des coûts d’investissement d’unités SOE. Les coûts de production du SNG des concepts étudiés vont de 82 à 89 €·MWh-1 CH4 (PCS) avec des unités SOE, valeurs plus faibles que pour des unités PEM, mais qui restent deux fois supérieures au prix moyen du gaz naturel en France
The solid oxide electrolysis technology (SOE) could improve the conversion efficiency of power-tosynthetic natural gas (SNG) plants and reduce their costs, provided that i) a performant thermal integration is implemented ii) the technology is implemented at industrial scale, and iii) plants can absorb the intermittency of renewable power sources. First, the energy analysis of three innovative power-to-SNG plant concepts is implemented. For each concept, a full explicit thermal integration is proposed. Plants with integrated SOE units show efficiencies higher than 78.5% (based on the HHV of the SNG) for the production of CNG and LNG, significantly higher than plants with PEM units with a 64.4% efficiency for CNG production. Second, the thermal response of SOE units to electrical power loads is investigated with a 1D dynamic model at the cell level (SOEC). Electrolyte support cells present a higher thermal stability than electrode support cells and should be preferred for fluctuating power applications. The model was then extended to a full H2 production and storage unit and coupled with different electrical power profiles. The units shows an energy consumption of 3.4-3.8 kWh·Nm-3 H2 and a high power-to-H2 conversion efficiency (93-103%) because of the steam recovery from the methanation unit. A first dimensioning of the H2 storage tank and the methanation unit is proposed, assuming a windmill power profile. Fluctuating power profiles reduce the efficiency of power-to-SNG plants, increase their costs and complexify their operation. Multifuel plants seem to be the most promising option to tackle the issue of intermittent power production. Extending the operation range of SOECs to exothermic and endothermic modes would improve power-to-H2 conversion efficiencies compared to on/off operation. In case of constant power load though, SOECs should preferably be operated at the thermoneutral point or in exothermic mode. Third, SNG production costs corresponding to the aforementioned plant concepts are evaluated, starting with a bottom-up cost evaluation of SOE units. The SNG production costs are in the range of 82-89 €·MWh-1 CH4 (HHV) with SOE units, which is lower than with PEM units, but remains two times higher than the average price of conventional natural gas for all sectors in France

The topic of unit commitment has been and continues to be of interest to many researchers and is a primary operation for most utilities. Past research has utilized integer programming, dynamic programming, linear programming, gradient, and heuristic techniques. This research combines both linear programming and dynamic programming for unit commitment decisions within a weekly time frame. The result provides most of the advantages of linear programming and dynamic programming with less stringent requirements on the pre solution information needed for unit transition sequences. Further, the research yields a new tool for the solution of the Transaction Evaluation problem.
Ph. D.
incomplete_metadata

In this thesis we have explored the co-designed paradigm to show alternative processor design points. Specifically, we have provided HW/SW mechanisms for instruction fusion, issue and commit for modern processors. We have implemented a co-designed virtual machine monitor that binary translates x86 instructions into RISC like micro-ops. Moreover, the translations are stored as superblocks, which are a trace of basic blocks. These superblocks are further optimized using speculative and non-speculative optimizations. Hardware mechanisms exists in-order to take corrective action in case of misspeculations. During the course of this PhD we have made following contributions. Firstly, we have provided a novel Programmable Functional unit, in-order to speed up general-purpose applications. The PFU consists of a grid of functional units, similar to CCA, and a distributed internal register file. The inputs of the macro-op are brought from the Physical Register File to the internal register file using a set of moves and a set of loads. A macro-op fusion algorithm fuses micro-ops at runtime. The fusion algorithm is based on a scheduling step that indicates whether the current fused instruction is beneficial or not. The micro-ops corresponding to the macro-ops are stored as control signals in a configuration. The macro-op consists of a configuration ID which helps in locating the configurations. A small configuration cache is present inside the Programmable Functional unit, that holds these configurations. In case of a miss in the configuration cache configurations are loaded from I-Cache. Moreover, in-order to support bulk commit of atomic superblocks that are larger than the ROB we have proposed a speculative commit mechanism. For this we have proposed a Speculative commit register map table that holds the mappings of the speculatively committed instructions. When all the instructions of the superblock have committed the speculative state is copied to Backend Register Rename Table. Secondly, we proposed a co-designed in-order processor with with two kinds of accelerators. These FU based accelerators run a pair of fused instructions. We have considered two kinds of instruction fusion. First, we fused a pair of independent loads together into vector loads and execute them on vector load units. For the second kind of instruction fusion we have fused a pair of dependent simple ALU instructions and execute them in Interlock Collapsing ALUs (ICALU). Moreover, we have evaluated performance of various code optimizations such as list-scheduling, load-store telescoping and load hoisting among others. We have compared our co-designed processor with small instruction window out-of-order processors. Thirdly, we have proposed a co-designed out-of-order processor. Specifically we have reduced complexity in two areas. First of all, we have co-designed the commit mechanism, that enable bulk commit of atomic superblocks. In this solution we got rid of the conventional ROB, instead we introduce the Superblock Ordering Buffer (SOB). SOB ensures program order is maintained at the granularity of the superblock, by bulk committing the program state. The program state consists of the register state and the memory state. The register state is held in a per superblock register map table, whereas the memory state is held in gated store buffer and updated in bulk. Furthermore, we have tackled the complexity of Out-of-Order issue logic by using FIFOs. We have proposed an enhanced steering heuristic that fixes the inefficiencies of the existing dependence-based heuristic. Moreover, a mechanism to release the FIFO entries earlier is also proposed that further improves the performance of the steering heuristic.
En aquesta tesis hem explorat el paradigma de les màquines issue i commit per processadors actuals. Hem implementat una màquina virtual que tradueix binaris x86 a micro-ops de tipus RISC. Aquestes traduccions es guarden com a superblocks, que en realitat no és més que una traça de virtuals co-dissenyades. En particular, hem proposat mecanismes hw/sw per a la fusió d’instruccions, blocs bàsics. Aquests superblocks s’optimitzen utilitzant optimizacions especualtives i d’altres no speculatives. En cas de les optimizations especulatives es consideren mecanismes per a la gestió de errades en l’especulació. Al llarg d’aquesta tesis s’han fet les següents contribucions: Primer, hem proposat una nova unitat functional programmable (PFU) per tal de millorar l’execució d’aplicacions de proposit general. La PFU està formada per un conjunt d’unitats funcionals, similar al CCA, amb un banc de registres intern a la PFU distribuït a les unitats funcionals que la composen. Les entrades de la macro-operació que s’executa en la PFU es mouen del banc de registres físic convencional al intern fent servir un conjunt de moves i loads. Un algorisme de fusió combina més micro-operacions en temps d’execució. Aquest algorisme es basa en un pas de planificació que mesura el benefici de les decisions de fusió. Les micro operacions corresponents a la macro operació s’emmagatzemen com a senyals de control en una configuració. Les macro-operacions tenen associat un identificador de configuració que ajuda a localitzar d’aquestes. Una petita cache de configuracions està present dintre de la PFU per tal de guardar-les. En cas de que la configuració no estigui a la cache, les configuracions es carreguen de la cache d’instruccions. Per altre banda, per tal de donar support al commit atòmic dels superblocks que sobrepassen el tamany del ROB s’ha proposat un mecanisme de commit especulatiu. Per aquest mecanisme hem proposat una taula de mapeig especulativa dels registres, que es copia a la taula no especulativa quan totes les instruccions del superblock han comitejat. Segon, hem proposat un processador en order co-dissenyat que combina dos tipus d’acceleradors. Aquests acceleradors executen un parell d’instruccions fusionades. S’han considerat dos tipus de fusió d’instructions. Primer, combinem un parell de loads independents formant loads vectorials i els executem en una unitat vectorial. Segon, fusionem parells d’instruccions simples d’alu que són dependents i que s’executaran en una Interlock Collapsing ALU (ICALU). Per altra aquestes tecniques les hem evaluat conjuntament amb diverses optimizacions com list scheduling, load-store telescoping i hoisting de loads, entre d’altres. Aquesta proposta ha estat comparada amb un processador fora d’ordre. Tercer, hem proposat un processador fora d’ordre co-dissenyat efficient reduint-ne la complexitat en dos areas principals. En primer lloc, hem co-disenyat el mecanisme de commit per tal de permetre un eficient commit atòmic del superblocks. En aquesta solució hem substituït el ROB convencional, i en lloc hem introduït el Superblock Ordering Buffer (SOB). El SOB manté l’odre de programa a granularitat de superblock. L’estat del programa consisteix en registres i memòria. L’estat dels registres es manté en una taula per superblock, mentre que l’estat de memòria es guarda en un buffer i s’actulitza atòmicament. La segona gran area de reducció de complexitat considerarada és l’ús de FIFOs a la lògica d’issue. En aquest últim àmbit hem proposat una heurística de distribució que solventa les ineficiències de l’heurística basada en dependències anteriorment proposada. Finalment, i junt amb les FIFOs, s’ha proposat un mecanisme per alliberar les entrades de la FIFO anticipadament.

La complexité croissante des dispositifs en électronique de puissance nécessite l'intervention de la conception assistée par ordinateur. Le développement de systèmes électriques/électroniques est effectué à l'aide du prototypage virtuel dans lequel les logiciels de simulation sont utilisés pour prédire le comportement des composants. De ce fait, le prototypage virtuel permet une économie de temps et d'argent pour la réalisation de prototypes. La demande croissante d'appareils à faible puissance et à haut rendement a obligé les concepteurs à analyser précisément les pertes de chaque composant constituant du système. Les composants magnétiques constituent une partie importante des appareils en électronique, par conséquent la modélisation précise des matériaux magnétiques est nécessaire afin de prédire leur comportement réaliste dans des conditions de fonctionnement variables selon l'application. Notre travail s'inscrit dans ce contexte et propose un modèle dynamique non linéaire de composants magnétiques pour une utilisation dans des simulateurs de circuits électriques. Ce modèle de composant magnétique inclut le comportement d'hystérésis non linéaire du matériau et permet une modélisation précise des pertes fer et des pertes joule avec de plus la prise en considération des effets thermiques qui, généralement, ne sont pas pris en compte par les modèles existants. Le modèle est basé sur le principe de la séparation des contributions statiques et dynamiques des pertes fer et s'appuie sur la théorie de Bertotti. Le langage de programmation VHDL-AMS est utilisé en raison de sa fonctionnalité de modélisation multidomaines, permettant un couplage avec un modèle thermique. Le modèle de composant magnétique est mis en oeuvre dans le logiciel de simulation de circuit "Simplorer". Il est ensuite testé dans une application de convertisseur de puissance, le convertisseur abaisseur qui permet de fournir une excitation non-conventionnelle. Le modèle est validé pour différents noyaux d'inductances, différentes ondulations de courant et niveaux de charge, différentes températures et une large gamme de fréquence
The increasing complexity of power electronic devices requires the intervention of computer-aided design in electrical engineering. Development of electric/electronic systems nowadays is carried out by the help of virtual prototyping, in which simulation software are used to predict components behavior without investing time and money to build physical prototypes. The increasing demand of low power, high efficiency devices forced designers to precisely analyze losses in each component constituting the system. Magnetic components constitute a major part of electronics devices. Therefore accurate modeling of magnetic materials is mandatory in order to predict their realistic behavior under variable operating conditions. Our work takes place in this context by proposing a non-linear dynamic model of magnetic components for use in circuit simulators. It includes the material nonlinear hysteretic and dynamic behaviors with accurate modeling of winding and core losses in addition to thermal effects that are not taken into account by existing models. The model is based on the principle of separation of static and dynamic contributions as well as Bertotti’s theory. VHDL-AMS is used as a modeling language due to its multi-domain modeling feature, allowing coupling with a thermal model. The magnetic component model is implemented in circuit simulation software “Simplorer” It is then tested in a widely used power converter application, the buck converter, to ensure non conventional excitation. The model is validated for different core inductors, different current ripples, different loads, different temperatures and a wide frequency range

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Tese(Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

The objective of the proposed research is to investigate feasible approaches to dynamic control of the power grid. Growth in the demand for electric power, and an increase in the penetration of renewable energy resources are causing congestion on an already aging power grid. Conventional grid control involves the use of static assets that operate on long time scales. These assets provide no dynamic control on the grid, and are typically used for scheduled support. Existing solutions (FACTS devices) to dynamic grid control have seen minimal market penetration because of high cost and low reliability. The proposed research provides a solution for dynamic control of the power grid that augments existing grid assets with a thin AC converter (TACC) to realize enhanced dynamic control. The TACC is a direct AC converter with filter elements and no bulk energy storage that dynamically reflects the asset value on the grid. The converter has a fail-normal mode of operation that returns the asset to its initial operating state, thereby not degrading system reliability. Some applications of TACCs include Inverter-Less STATCOMs and Controllable Network Transformers, which are realized by augmenting shunt VAR capacitors and load tap changers respectively. The principle of virtual quadrature sources is proposed to enable conditioning of AC voltages and currents. The concept is a novel method to realize control of phase angle and, or harmonics in single-phase AC converters, with no bulk energy storage. This concept is used to control the TACC and provides the asset with significantly enhanced control capabilities. Scaling of the TACC to utility voltage and power levels has been addressed by proposing a novel multilevel direct AC converter. The concept proposes the use of commercially available low cost semiconductor devices to realize high power converters. The specific application chosen to validate the concept of TACCs, through a medium voltage design, is the Inverter-less STATCOM.

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.14.02 - електричні станції, мережі і системи (141 – електроенергетика, електротехніка та електромеханіка). – Національний технічний університет «Харківський політехнічний інститут» МОН України, Харків, 2019. Зміст анотації. Дисертація присвячена розв’язанню актуальної науково- прикладної задачі у галузі забезпечення заявлених графіків видачі потужності у вузлі генерації електричних станцій на відновлювальних джерелах енергії (ВДЕ), шляхом використання систем акумуляції та концепції віртуальних електричних станцій. Актуальність теми дисертаційної роботи полягає у наступному, сучасні тенденції в розвитку електроенергетичних систем передбачають суттєве збільшення частки електричних станцій на відновлювальних джерелах енергії в загальній структурі генерації розвинутих країн, що призводить до необхідності їх додаткового резервування. З гідно статті 71.5 закону про «Ринок електричної енергії України», Гарантований покупець повинен придбати всю енергію від виробників з ВДЕ, що працюють за «Зеленим тарифом». Особливістю режимів роботи електричних станцій на відновлювальних джерелах є майже пряма залежність від погодних умов, що призводить до відхилень значення потужності в точках генерації від заявлених значень. Отже виникає необхідність в компенсації виникаючих небалансів. Використовуючи концепцію віртуальних електричних станцій, що поєднують електричні станції на ВДЕ, активних споживачів та системи акумуляції в єдину станцію зі спільною системою управління, можливо зменшити небаланси в точці генерації. Це потребує створення методів вибору оптимальної компоновки систем накопичення; алгоритмів систем управління для віртуальних електричних станцій та розподілених систем акумулювання; рекомендацій по їх застосуванню для електричних мереж, які тільки починають перехід від традиційних до інтелектуальних і мають дефіцит маневрових потужностей. Розробка технічних заходів для забезпечення заявлених графіків роботи сонячних електростанцій (СЕС) та вітряних електростанцій (ВЕС) дозволить їх інтегрувати до графіку генерації в якості базових станцій. Це дасть можливість виконати зобов‘язання всіх учасників процесу та не порушувати заплановані режими роботи інших станцій. Мета і задачі дослідження. Мета дослідження полягає у забезпеченні заявлених графіків видачі потужності у вузлі генерації електричних станцій на відновлювальних джерелах енергії, шляхом використання систем акумуляції та концепції віртуальних електричних станцій. Для досягнення поставленої мети визначені задачі дослідження: – проаналізувати основні методи та засоби забезпечення графіків видачі потужності електричних станцій на відновлювальних джерелах енергії в Україні та світі і фактори, що впливають на них; – розробити математичну модель для дослідження режимів роботи електричних станцій гібридної генерації на основі сонячної та вітроелектростанції та провести перевірку адекватності розробленої математичної моделі; – уточнити методику розрахунку вартості електричної енергії від систем акумулювання у вузлі генерації з урахуванням втрат при передачі та перетворенні енергії; – вдосконалити методику оптимізації конфігурації систем акумулювання для балансування генерації СЕС та ВЕС за умови мінімізації питомої вартості електричної енергії; – провести комп‘ютерне моделювання роботи електричних станцій на відновлювальних джерелах енергії на основі погодних даних обраного адміністративного району України з метою визначення необхідної конфігурації системи акумулювання на основі розробленої методики; – розробити комп‘ютерну модель віртуальної електричної станції, що поєднує в собі удосконалені математичні моделі генерації активної потужності СЕС і ВЕС, комп‘ютерні моделі систем накопичення енергії, імітацію активних споживачів і енергетичного ринку, а також елементи апаратно-комп‘ютерного моделювання. – розробити алгоритм роботи інформаційно-керуючої системи віртуальної електричної станції, на основі уточненого методу розрахунку вартості електричної енергії та провести його апробацію на комп‘ютерній моделі віртуальної електричної станції. – дослідити можливість застосування концепції віртуальних електричних станцій для забезпечення добових графіків генерації з урахуванням вимог Гарантованого покупця. Об’єктом досліджень – електромагнітні процеси в мережах з електричними станціями на основі відновлювальних джерел енергії. Предметом досліджень – електричні та інформаційні параметри режимів обладнання електричних станцій на відновлюваних джерелах енергії. Наукова новизна одержаних результатів: 1) Отримала подальший розвиток математична модель віртуальної електричної станції, яка відрізняється від існуючих тим, що додано елементи для зв‘язку з реальним програмованим логічним контролером ОВЕН 110-60 та на основі регресійного аналізу враховано додатковий коефіцієнт співвідношення вхідних погодних умов та результуючої потужності для встановлення відповідності з реальними характеристиками обладнання, що дозволило застосувати апаратно-програмне моделювання, збільшити точність розрахунку вихідної активної потужності сонячної електричної станції на 5% та проводити моделювання роботи вітряної електричної станції на швидкостях вітру більших за номінальні. 2) Отримав подальший розвиток метод розрахунку вартості електричної енергії яка використовується для забезпечення добових графіків генерації ВДЕ на основі акумуляції в межах однієї віртуальної електричної станції, який відрізняється від відомих врахуванням витрат пов‘язаних з розташуванням, встановленням та роботою додаткового обладнання, що дозволяє підвищити точність виконання розрахунків і підвищити енергоефективність таких систем за рахунок задіяння найбільш доцільних їх елементів. 3) Науково і технічно обґрунтовано використання концепції віртуальних електричних станцій для забезпечення добових графіків генерацій сонячних та вітроелектростанцій в умовах енергетичного ринку України, що дозволить забезпечити функціонування механізму Гарантованого покупця з мінімальним застосуванням додаткових маневрових потужностей. Практичне значення одержаних результатів. Для електроенергетичної галузі України полягає в тому, що на підставі виконаних досліджень визначені способи оптимізації режимів роботи електричних станцій на відновлювальних джерелах енергії за допомогою акумуляції. Такий підхід дозволить встановити відповідність між діючим та прогнозним значенням потужності у точці генерації, сформувати графік навантаження для традиційних електричних станцій без необхідності додаткового їх маневрування для компенсацій електростанцій на відновлювальних джерелах енергії. Окрім того, результати досліджень допоможуть збільшити точність розрахунків вартості електричної енергії у точці генерації від систем акумулювання. Розроблена методика вибору конфігурації систем акумуляції дозволяє визначити мінімально необхідну ємність накопичувачів енергії та їх потужність, що забезпечить мінімізацію вартості устаткування. Запропонований алгоритм управління розподіленою системою акумулювання дозволяє вирішити задачу розподіленого балансування, а також враховує можливість залучення активних споживачів та енергетичного ринку до процесу балансування. Результати дисертаційної роботи були впроваджені: - у ТОВ «ЛЕО» для розрахунку мінімально необхідного об’єму систем накопичення енергії, що будуть рекомендовані для забезпечення заявлених графіків генерації електричних станцій на ВДЕ які працюють за зеленим тарифом; - у навчальному процесі кафедри електричних станцій Національного технічного університету “Харківський політехнічний інститут” для студентів спеціальностей 141 спеціальності за спеціалізаціями: 141-01 «Електричні станції» та 141-05 «Енергетичний менеджмент та енергоефективні технології» під час викладання курсів лекцій з дисциплін «Електрична частина станцій та підстанцій», «АСУТП станцій та підстанцій», «Системи відновлюваної енергетики та вторинні енергоресурси» , під час написання дипломних проектів, випускних кваліфікаційних робіт. Дисертація виконана згідно планів наукових досліджень кафедр електричних станцій та загальної електротехніки Національного технічного університету «Харківський політехнічний інститут» у відповідності до договору «Методи удосконалення електроенергетичних систем» (ДР № 0116U000885).
Dissertation for the degree of candidate of technical sciences (doctor of philosophy) in specialty 05.14.02 - Electric power stations, networks and systems (141 - Power engineering, electrical engineering and electromechanics). – National Technical University "Kharkiv Polytechnic Institute", Ministry of Education and Science of Ukraine, Kharkiv, 2019. Annotation content. The dissertation is devoted to solving the actual scientific and applied problem in the providing the stated schedules of power generation at renewable energy sources (RES) through the use of storage systems and the concept of virtual power plants. According to the legislation of Ukraine, the Guaranteed Buyer must purchase all energy from renewable energy producers operating under the Green Tariff. The peculiarity of the operating modes of power plants on renewable sources is almost a direct dependence on weather conditions, which leads to deviations of the power value at the points of generation from the declared values. Therefore, there is a need to compensate for emerging imbalances. Using the concept of virtual power plants that combine RES, active consumers and storage systems into a single station with a common control system, it is possible to reduce imbalances at the generation point. This requires the creation of methods for selecting the optimal layout of the accumulation systems; control systems algorithms for virtual power plants and distributed storage systems; recommendations for their application to power grids that are just beginning to transition from traditional to intelligent and have a lack of maneuverability. The development of technical measures to ensure the declared schedules of solar power plants (SPP) and wind power plants (WPP) will allow them to be integrated into the generation schedule as base stations. This will make it possible to fulfill the obligations of all participants of the process and not violate the planned operating modes of other stations. The purpose and tasks of the study. The purpose of the study is to provide the stated schedules of power generation at the generation site of renewable energy sources through the use of storage systems and the concept of virtual power plants. To achieve the goal, the research objectives are defined: – to analyze the basic methods and means of providing the schedules of power outputs of renewable energy sources in Ukraine and the world and the factors that influence them; – to develop a mathematical model for the study of operating modes of hybrid power plants based on solar and wind power plants and to check the adequacy of the developed mathematical model; – clarify the methodology for calculating the cost of electricity from storage systems at the generation site, taking into account losses in energy transmission and conversion; – improve the method of optimization of the configuration of accumulation systems for balancing the generation of SES and WPP, while minimizing the specific cost of electricity; – carry out computer simulation of the operation of renewable energy power plants based on the weather data of the selected administrative district of Ukraine in order to determine the required configuration of the accumulation system based on the developed methodology; – to develop a computer model of a virtual power plant that combines advanced mathematical models of SES and WPP power generation, computer models of energy storage systems, imitation of active consumers and the energy market, as well as elements of hardware and computer modeling. – to develop an algorithm of operation of the information and control system of the virtual power plant, based on the specified method of calculating the cost of electricity, and to test it on a computer model of the virtual power plant. – explore the possibility of applying the concept of virtual power plants to provide daily generation schedules, taking into account the requirements of the Guaranteed Buyer. The object of research is the electromagnetic processes in grids with power plants based on renewable energy sources. Subject of research – electrical and information parameters of modes of equipment of power plants on renewable energy sources. Scientific novelty: 1) The mathematical model of the virtual power plant has been further developed, which differs from the existing ones by adding elements for communication with the real programmable logic controller OVEN 110-60 and based on the regression analysis the additional coefficient of the ratio of incoming weather conditions and the resulting power is taken into account the real characteristics of the equipment, which allowed to apply hardware and software modeling, to increase the accuracy of the calculation of the output active power of solar panels at 5% and conduct simulations of wind power station at wind speeds greater than nominal. 2) The method of calculating the cost of electricity, which is used to provide daily schedules of generation of RES on the basis of accumulation within one virtual power station, which differs from the known costs related to the location, installation and operation of additional equipment, which improves the accuracy of calculations, was further developed. and to increase the energy efficiency of such systems by utilizing their most relevant elements. 3) It is scientifically and technically grounded to use the concept of virtual power plants for providing daily schedules of generation of solar and wind power plants in the conditions of the energy market of Ukraine, which will allow to ensure the functioning of the Guaranteed Buyer mechanism with minimal use of additional maneuvering capacities. Practical value: The practical value of the work lies in the fact that methods of optimization of modes of operation of power plants on renewable energy sources by means of accumulation are determined on the basis of the performed researches. This approach will allow to establish the correspondence between the current and the predicted value of power at the point of generation, to form a schedule of load for traditional power plants without the need for additional maneuvering for compensation of power plants on renewable energy sources. In addition, research findings will help to increase the accuracy of electricity cost calculations at the point of generation from storage systems. The developed method of choosing the configuration of accumulation systems allows to determine the minimum required capacity of energy storage and their capacity, which will minimize the cost of equipment. The proposed algorithm for managing a distributed accumulation system allows to solve the problem of distributed balancing, and also takes into account the possibility of involving active consumers and the energy market in the balancing process. The results of the dissertation work were introduced: - at LEO LLC to calculate the minimum required volume of energy storage systems that will be recommended to provide the stated generation schedules of power plants than work based on green tariff; - in the educational process of the National Technical University "Kharkiv Polytechnic Institute" for students of specialties 141 specialties in specialization: 141- 01 "Power Plants" and 141-05 "Energy Management and Energy Efficient Technologies" during the teaching of lectures on disciplines "Electrical part of stations and substations "," ACTSP of stations and substations "," Renewable energy systems and secondary energy resources ", during writing of diploma projects, final qualification works. The dissertation is executed according to the plans of scientific researches of the National Technical University "Kharkiv Polytechnic Institute" of the Department of Power stations and general electrical engineering in accordance with the economic agreement « Methods of improvement of power systems» (state registration number - 0116U000885).

Esta dissertação apresenta uma contribuição aos estudos de planejamento do sistema elétrico do Estado de São Paulo, ressaltando os benefícios que se obteria, com uma maior integração das fontes renováveis à matriz elétrica desse estado (notadamente as fontes de energia solar fotovoltaica, eólica, aproveitamento dos resíduos sólidos urbano RSU e vinhaça), visando o aumento da segurança e independência energética, redução de perdas, e benefícios ambientais. Para tanto, apresenta-se o conceito das usinas virtuais, cujo propósito é obter um melhor e maior aproveitamento dos recursos energéticos normalmente dispersos espacialmente - incluindo nesse rol a microgeração distribuída, a autoprodução e cogeração, e mesmo as fontes não renováveis que se encontram perto dos centros de consumo - com o objetivo de coordenar o seu funcionamento conjunto para satisfazer os requisitos da demanda de energia, por meio do uso da Tecnologia da Informação e Telecomunicações ou das Redes Inteligentes (Smart Grid), e, além disso, configurando a usina virtual de maneira que ela atue , no que diz respeito ao sistema interconectado de energia elétrica, rede de transmissão ou distribuição, como se fosse uma planta de geração de grande porte. Apresenta-se uma análise e projeções da operação e do suprimento do subsistema Sudeste/Centro Oeste (SE/CO), com foco especial no Sistema Elétrico do Estado de São Paulo, com suas interações com o SIN.
This Thesis presents contributions for the planning of the electrical system of São Paulo State Brazil, emphasizing benefits obtained with a better integration of renewables (mainly solar photovoltaics, wind energy, from municipal solid waste and sugarcane vinasse) aiming energy security and independence, loss reduction and environmental benefits. For this, the concept of VPP Virtual Power Plant is introduced, in which a better and broader use of energetic resources, geographically dispersed, including distributed microgeneration, autoproduction, cogeneration, and even nonrenewable sources, is facilitated. Those disperse energy resources, in general located near the consumer, are grouped and jointly managed, in order of to satisfy the demand requirements, using Smart Grid and Information and Telecommunication Technologies, and making the VPP to act, for the transmission or distribution system point of view, as a conventional large electrical power plant. An analysis and forecasts of the operation of the Brazilian Southeast/Center West (SE/CO) subsystem, with special focus on São Paulo State electrical system, and its interactions with the Brazilian Interconnected Electrical System (SIN), is presented.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 - електричні станції, мережі і системи. – Національний технічний університет «Харківський політехнічний інститут», Харків, 2019. Дисертаційна робота присвячена розв’язанню актуальної науково-прикладної задачі у напрямку забезпечення заявлених графіків генерації електричних станцій на відновлюваних джерелах енергії на основі концепції віртуальних електричних станцій. У дисертаційній роботі досліджено методи забезпечення заявлених графіків генерації електричних станцій на ВДЕ та обґрунтована доцільність використання концепції віртуальних електричних станцій для вирішення поставленої задачі. Досліджено застосування різних типів систем акумуляції, як одного з елементів віртуальної електричної станції. Проведено аналіз існуючих методів впровадження інтелектуальних мереж, що дозволило вибрати шаблон Smart Grid Architecture Model за основу для створення необхідної інфраструктури. Проведено аналіз існуючих методів визначення оптимальної ємності систем акумуляції та їх компоновки. Розроблено комп‘ютерну модель для дослідження роботи віртуальних електричних станцій, що дозволяє оцінити потенційні небаланси при генерації, перевірити достатність обсягу систем акумуляції для різних задач, а також провести апробацію роботи системи управління. Уточнено методику розрахунку вартості електричної енергії від систем акумулювання з урахуванням вартості втрат енергії при передачі та трансформації, а також додаткових факторів пов‘язаних з орендою та обслуговуванням. Розроблено, реалізовано та апробовано алгоритм управління віртуальною електричною станцією, що базується на задіянні найбільш дешевого джерела енергії для балансування з урахуванням обмежень електричних мереж, доступу до енергетичного ринку та можливості залучення активних споживачів. Показана можливість забезпечення заявлених графіків генерації електричних станцій на основі концепції віртуальних електричних станцій на прикладі умов одного з адміністративних центрів України.
Dissertation for the degree of candidate of technical sciences in specialty 05.14.02 - power plants, networks and systems. - National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. The thesis is devoted to the solution of the current scientific and applied problem in the field of providing the declared schedules of generating power plants with renewable energy sources based on the concept of virtual power plants. In the dissertation work, the methods of providing the declared schedules of generating power plants on renewable energy sources are investigated. The expediency of using the concept of virtual power plants to solve the problem is justified. The use of various types of accumulation systems as one of the elements of a virtual power plant is investigated. The analysis of existing methods and state-of-the-art-practices of implementing intelligent networks was carried out, which made it possible to select the Smart Grid Architecture Model pattern as the basis for creating the necessary infrastructure. The analysis of existing methods for determining the optimal capacity of accumulation systems and their layout has been carried out that was used to calculate minimal capacity for providing the declared schedules of generation of PV and wind power plant each 1 MW for one of the administrative centers of Ukraine. The developed computer model for studying the operation of virtual power plants that include PV and wind power with energy storage and connections to PLC allows assessing potential unbalances during generation, checking the sufficiency of the capacity of accumulation systems for various tasks, as well as testing the operation of the control system. The methodology for calculating the cost of electrical energy from storage systems has been refined, taking into account the cost of energy losses during transmission and transformation, as well as additional factors associated with renting and servicing. An algorithm for managing a virtual power plant was developed, implemented and tested with real PLC connected to mathematical model, based on using the cheapest energy source for balancing taking into account the limitations of electrical networks, power lines and transforming equipment, access to the energy market for buying and selling energy and the ability to attract active consumers. The possibility of providing the declared schedules of generation of power plants based on the concept of virtual power plants on the example of conditions of one of the administrative centers of Ukraine is shown.

Les Etudes Probabilistes de Sûreté (EPS) de niveau 2 en centrale nucléaire visent à identifier les séquences d’événements pouvant correspondre à la propagation d’un accident d’un endommagement du cœur jusqu’à une perte potentielle de l’intégrité de l’enceinte, et à estimer la fréquence d’apparition des différents scénarios possibles.

Ces accidents sévères dépendent non seulement de défaillances matérielles ou d’erreurs humaines, mais également de l’occurrence de phénomènes physiques, tels que des explosions vapeur ou hydrogène. La prise en compte de tels phénomènes dans le cadre booléen des arbres d’événements s’avère difficile, et les méthodologies dynamiques de réalisation des EPS sont censées fournir une manière plus cohérente d’intégrer l’évolution du processus physique dans les changements de configuration discrète de la centrale au long d’un transitoire accidentel.

Cette thèse décrit l’application d’une des plus récentes approches dynamiques des EPS – la Théorie de la Dynamique Probabiliste basée sur les Stimuli (SDTPD) – à différents modèles de déflagration d'hydrogène ainsi que les développements qui ont permis cette applications et les diverses améliorations et techniques qui ont été mises en oeuvre.

Level-2 Probabilistic Safety Analyses (PSA) of nuclear power plants aims to identify the possible sequences of events corresponding to an accident propagation from a core damage to a potential loss of integrity of the containment, and to assess the frequency of occurrence of the different scenarios.

These so-called severe accidents depend not only on hardware failures and human errors, but also on the occurrence of physical phenomena such as e.g. steam or hydrogen explosions. Handling these phenomena in the classical Boolean framework of event trees is not convenient, and dynamic methodologies to perform PSA studies are expected to provide a more consistent way of integrating the physical process evolution with the discrete changes of plant configuration along an accidental transient.

This PhD Thesis presents the application of one of the most recently proposed dynamic PSA methodologies, i.e. the Stimulus-Driven Theory of Probabilistic Dynamics (SDTPD), to several models of hydrogen explosion in the containment of a plant, as well as the developed methods and improvements.

Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

Cette thèse aborde les formalismes pour la modélisation multi-physique en support au cycle en V deconception. Ce travail a été réalisé dans le cadre du projet ANR-MoCoSyMec, selon la méthodologie duprototypage virtuel fonctionnel (PVF) et illustré sur des systèmes électromagnétiques.Nous nous sommes principalement intéressés au langage VHDL-AMS, en tant que support aux différentsniveaux de modélisation apparaissant dans le cycle en V de conception. Cela nous a conduits à traiter laportabilité et l'interopérabilité en VHDL-AMS de diverses méthodes et outils de modélisation. Nous avonsproposé et validé, via le formalisme des composants logiciels ICAr, des solutions aux limites de l'utilisation deVHDL-AMS pour modéliser certains phénomènes physiques reposants sur des calculs numériques.Nous avons étendu la norme ICAr pour supporter des modèles dynamiques décrits par des équationsdifférentielles algébriques (DAE) ; et pour des besoins de co-simulation, nous pouvons également y associer unsolveur. Ces développements sont désormais capitalisés dans le framework CADES.Enfin, nous avons proposé une architecture pour le portage de modèles d'un formalisme à un autre. Elle a étédéfinie et mise en oeuvre plus particulièrement pour des modèles magnétiques réluctants (Reluctool) et desMEMS magnétiques (MacMMems) vers le VHDL-AMS.Ces formalismes et méthodologies sont mis en oeuvre autour du PVF d'un contacteur électromagnétique.

Global economy growth, continuous development and the extensive use of technologies by consumers is increasing the demands of consumers for a reliable and efficient energy supply. Along with the rising energy consumption in the world, new technologies will influence the way we generate, distribute and consume energy. Alongside others, distributed energy generation is expected to become a major trend in many countries. The fast upward penetration of Distributed Energy Resources (DER) and the ongoing trend towards a more competitive electricity market requires new technologies and policies to handle emerging technical and economic issues. In order to handle distributed generation and to increase its participation within power markets, the idea of a Virtual Power Plant (VPP) has emerged. The concept of a VPP is recognized as an effective option to aggregate and operate DER and allowing for wholesale energy market participation to provide the required flexibility services to the local grid. Also, many DERs are available in urban areas and exploiting the flexibility of a VPP and developing a robust business case requires advanced considerations on their technical and commercial constraints and trade-offs in developing the VPP's operations regarding flexibility when simultaneously participating in the market. Considering the potential of activating commercial consumers in demand response programs, this paper proposes a new framework for energy scheduling of a distribution grid based on the concept of a technical virtual power plant (TVPP). This concept aims to enhance the flexibility of the grid, while contributing to an increase in the quality and reliability of the system, which also brings economic benefits. In this paper, a stochastic mixed-integer linear programming (MILP) optimization model was developed, which guarantees that the global optimum solution is obtained, in this case, maximizing the total profit of a TVPP. Regarding operational constraints, the TVPP allows the presence of commercial buildings and other distributed energy resources a day-ahead (DA) electricity market, as a price maker agent. In this context, this paper presents a comprehensive, integrated techno-economic approach that assesses the technical constraints and commercial flexibility opportunities. The case study includes the VPP's energy scheduling, improving system reliability by improving the voltage profile, and demand response and main commercial customers' assets (electric vehicles (EVs) parking lots and Heating Ventilation and Air Condition (HVAC) systems) aggregation and management. The model is tested using the IEEE 119-Bus test system, and results show that with the optimal management of DER, EVs parking lots and HVAC systems in commercial buildings allows the TVPP to increase its profit, by a percentage of 49,23%.

Global economy growth, continuous development and the extensive use of technologies by consumers is increasing the demands of consumers for a reliable and efficient energy supply. Along with the rising energy consumption in the world, new technologies will influence the way we generate, distribute and consume energy. Alongside others, distributed energy generation is expected to become a major trend in many countries. The fast upward penetration of Distributed Energy Resources (DER) and the ongoing trend towards a more competitive electricity market requires new technologies and policies to handle emerging technical and economic issues. In order to handle distributed generation and to increase its participation within power markets, the idea of a Virtual Power Plant (VPP) has emerged. The concept of a VPP is recognized as an effective option to aggregate and operate DER and allowing for wholesale energy market participation to provide the required flexibility services to the local grid. Also, many DERs are available in urban areas and exploiting the flexibility of a VPP and developing a robust business case requires advanced considerations on their technical and commercial constraints and trade-offs in developing the VPP's operations regarding flexibility when simultaneously participating in the market. Considering the potential of activating commercial consumers in demand response programs, this paper proposes a new framework for energy scheduling of a distribution grid based on the concept of a technical virtual power plant (TVPP). This concept aims to enhance the flexibility of the grid, while contributing to an increase in the quality and reliability of the system, which also brings economic benefits. In this paper, a stochastic mixed-integer linear programming (MILP) optimization model was developed, which guarantees that the global optimum solution is obtained, in this case, maximizing the total profit of a TVPP. Regarding operational constraints, the TVPP allows the presence of commercial buildings and other distributed energy resources a day-ahead (DA) electricity market, as a price maker agent. In this context, this paper presents a comprehensive, integrated techno-economic approach that assesses the technical constraints and commercial flexibility opportunities. The case study includes the VPP's energy scheduling, improving system reliability by improving the voltage profile, and demand response and main commercial customers' assets (electric vehicles (EVs) parking lots and Heating Ventilation and Air Condition (HVAC) systems) aggregation and management. The model is tested using the IEEE 119-Bus test system, and results show that with the optimal management of DER, EVs parking lots and HVAC systems in commercial buildings allows the TVPP to increase its profit, by a percentage of 49,23%.

Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. In order to determine how realistic model performance is, the performance of the one of the models (doubly fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.
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The advent of smart meter technology has enabled periodic monitoring of consumer energy consumption. Hence, short term energy forecasting is gaining more importance than conventional load forecasting. An Accurate forecasting of energy consumption is indispensable for the proper functioning of a virtual power plant (VPP). This paper focuses on short term energy forecasting in a VPP. The factors that influence energy forecasting in a VPP are identified and an artificial neural network based energy forecasting model is built. The model is tested on Sydney/ New South Wales (NSW) electricity grid. It considers the historical weather data and holidays in Sydney/ NSW and forecasts the energy consumption pattern with sufficient accuracy.

碩士
國立中興大學
應用經濟學系所
104
The core value of virtual power plants is that they can integrate dispersed and sporadic virtual peaking capacity to lower the power demand with the power plant during the peak time, to achieve the goal of lower the power demand of the electricity system during the peak time. The effective function of virtual power plants depends on whether the majority of electric power customers are willing to participate the integration program of distributed generations and flexible pricing program programs or not. Due to the conditions of different types of electric power customers (such as whether their electrical behavior is flexible or not, whether they have own distributed power generation equipment or not, etc.), they will have different benefits and costs when they take part in the flexible pricing program which were executed by virtual power plants. Therefore, this study aims to use a quantitative economic benefit model to identify low-voltage lighting customers’, high-voltage customers’ and the whole society’s economic benefits and opportunity costs when they participate in virtual power plants’ operation, and continuously assess whether the participation of the electric power customers and whole society have economic feasibility or not, and make related policy recommendation base on the simulation result. According to the empirical analysis of this study, it shows that whether low-voltage lighting customers are willing to involve in the operation of virtual power plants or not, the most relevance is the discount of the demand charge of the flexible pricing program, and the economic benefits of participate in the operation of virtual power plant can’t be raised by changing the behavior (in basic simulation scenario, when the low-voltage lighting customer only participate the flexible pricing program, his BCR is 0.8732. The demand charge discount and energy charge discount were raised around 1.5 times in alternative plan, BCR were1.24 and 0.91；if we double the curtails times and the curtails kW number in summer months, the BCR would become 0.5 and 0.526); if the high-voltage customer can integrate and utilize his own distributed power generation equipment effectively to participate the operation of virtual power plants, under our simulation result, his NPV will be 2667931(NTD), and BCR will be 1.53, then it will have huge economic benefits. Moreover, from the holistic viewpoint of the society, if we can encourage electric power customers to join the flexible pricing program actively and construct more renewable energy generation equipment to supply power use, or store the electricity energy storage system further for emergency, it will help to slow down the building of peak load power plants, save the capacity avoided cost, and help to reduce the carbon emission at the same time. According to the simulation result of our empirical analysis, we have three mainly policy recommendations. The first is Taiwan Power Company should properly raise the current discount of basic demand charge in the Demand Bidding Program up to 100 (NTD / per kW per month) or more, to increase the incentive compatibility and make customers have motivations to coordinate with the energy conservation policy of the government. The second is the government can develop virtual power plant or similar industries like Aggregator, to integrate the low-voltage lighting customer of low electric demand and let the low-voltage lighting customer have more opportunities of the self-selection pricing scheme. In short, by implementing crowdsourcing to achieve the energy conservation policy. The last one is the plan of the electricity policy should be state with cross-system idea, not just enhance the connection among renewable energy itself but the connection between renewable energy, energy storage system and flexible pricing program, using the new technology of the energy management to systematically integrate the supply and demand agent.

碩士
國立中山大學
通訊工程研究所
102
In recent years, the concept of the virtual power plant is receiving a great deal of attention in the literature because of owing the following two potentials. One is that the virtual power plant can protect the power system by controlling the demand response customers and the energy storage systems to confine the power demand to the power system restriction. The other is that the virtual power plant can integrate the renewable power with the power system. By controlling the energy storage systems, the virtual power plant can solve the harmful impact of the renewable power. Although the virtual power plant benefits the power system, the investigators are wondering about the profit of running the virtual power plant. For this reason, we aim to study a way on earning the profit by controlling the demand response customers and the energy storage systems. With the proposed method, the business owners can understand how to run the virtual power plant.

博士
國立成功大學
電機工程學系
107
In light of the development of renewable energy and concerns over environmental protection, renewable energy resources have become a trend in distribution systems. Accordingly, the dispatch strategy of the system need to be changed. As an aggregator involved in various renewable energy sources, energy storage systems, and loads, a virtual power plant plays a key role as not only a consumer but a prosumer. The structure also transform the traditional one-direction power delivery to bi-direction. The virtual power plant thus can enable itself to supply energy and ancillary services to the utility grid to maximize its profit. To deal with the security, dispatch, operation and bidding issues faced by VPP, this dissertation proposes an overcurrent protection strategies with distributed generations and fault current limiters, the demand response potential analysis, elasticity demand response model construction, and operation and bidding strategy determination. By scheduling the energy storage systems, demand response, and renewable energy sources, virtual power plants can join bidding markets to achieve maximum benefits. The potential uncertainties caused by renewable energy sources and the demand response are considered in a robust optimization model. Moreover, a bi-level game theory model is introduced to modify the bidding environment among market operators and all the participants. The numerical results demonstrate the stable operation and profit maximized can be achieved through the proposed adaptive protection scheme and operation and bidding strategy optimization. By involving the uncertainty consideration and thus getting rid of penalty due to failing to provide the winning ancillary service quantity, the economic efficiency is proved to be increased.

碩士
國立成功大學
電機工程學系
86
This thesis investigates the application of static condensers (STATCON)to enhance dynamic stability of nuclear power plants in Taiwan PowerSystem. The studied system containing identical parallel operatedturbogenerators is employed to analyze the effectiveness of the proposed STATCON with reactive power modulation. Two proportional-integral-derivative (PID) controllers using speed deviations of the studiedgenerators as feedback signals are designed by modal control theory to modulate the var flow of the STATCON. In order to have a complete and detailed research, a frequency-domain approach based on eigenvalue analyses and a time-domain approach based on nonlinear model simulation are both performed to validate the effectiveness of the proposed damping method. It can be concluded from the simulation results that the proposed damping scheme can both effectively enhance the dynamic stability of the studied system and increase the maximum transferred power of the transmission line.

A dynamic MEA absorption process model has been developed to study the operability of this process in a dynamic fashion and to develop a control strategy to maintain the operation of the MEA scrubbing CO2 capture process in the presence of the external perturbations that may arise from the transient operation of the power plant. The novelty in this work is that a mechanistic model based on the conservation laws of mass and energy have been developed for the complete MEA absorption process. The model developed in this work was implemented in gPROMS. The process response of the key output variables to changes in the key input process variables, i.e., the flue gas flow rate and the reboiler heat duty, are presented and discussed in this study. In order to represent the actual operation of a power plant, the dynamic response of the MEA absorption process to a sinusoidal change in the flue gas flow rate was also considered in the present analysis. The mechanistic dynamic model was applied to develop a basic feedback control strategy. The implementation of a control strategy was tested by changing the operating conditions for the flue gas flow rate. The controlled variables, i.e., the percentage of CO2 absorbed in the absorber column and the reboiler temperature, were maintained around their nominal set point values by manipulating the valve stem positions, which determine the lean solvent feed flow rate at the top of the absorber column, and the reboiler heat duty, respectively. For the sinusoidal test, the amplitude of the oscillations observed for the controlled variables was smaller than those observed for the open-loop tests. This is because the variability of the controlled variables was transferred to the manipulated variable in the closed loop. The mechanistic dynamic model developed in this process can be potentially used as a practical tool that can provide insight regarding the dynamic operation of MEA absorption process. The model developed in this work can also be used as a basis to develop other studies related to the operability, controllability and dynamic flexibility of this process.

In diesel-hybrid autonomous power systems, a reduced number of diesel generators supply the power to the load and control the frequency of the system in isolation from the utility grid. In these type of systems, frequency variations of consequence are more likely to occur than in large interconnected power grids, since they feature a relatively small generation capacity and rapid changes in power demand. If generators are not able to maintain frequency within prescribed operational limits during a transient, the assistance of other components is required in order to avoid major disruptions in the power system. In this thesis the use of a virtual synchronous machine (VSM) to support dynamic frequency control in a diesel-hybrid autonomous power system was investigated. The proposed VSM consisted in the control of the grid-interface converter of an energy storage system in order to emulate the inertial response and the damping power of a synchronous generator. Furthermore, the damping function of the proposed VSM used an estimated value of the stabilization frequency of the grid, which allowed it to provide proper damping power when the system operated in frequency droop mode. Theoretical and experimental results showed a satisfactory performance of the proposed VSM, which effectively reduced the frequency nadir in 34 %, on average, for different values of the droop factor of the grid-forming genset. Finally, self-tuning algorithms were designed to find optimal parameters for the VSM in order to minimize the amplitude and rate of change of the frequency variations, and the power flow through the energy storage. Simulations results showed that the self-tuning VSM achieved a performance similar to the constant parameters VSM, while reducing the power flow through the energy storage in up to 58 %.

碩士
國立中興大學
高階經理人碩士在職專班
103
The development of heat pump system and virtual power plant in Taiwan has not yet mature. However, as domestic communities are gradually paying more attention to renewable energy, the framework of virtual power plant will be formed. The good opportunity for the development of heat pump system will be coming soon. In Taiwan, it is very important to explore the issue of how the heat pump system will be developed with the current trend of renewable energy to respond to market changes and adjust related innovative business model and its strategies. The study adopted “Delphi Method” to explore the business model of innovative management of heat pump system under framework of virtual power plant in Taiwan and plan the strategies in response to changes in the market. The author interviewed eight experts and scholars, including two professors from academia, the Secretary-General of Taiwan Heat Pumps Association, and five decision makers in supply chains of heat pump system. Interviewees filled in two rounds of questionnaires and provided professional opinions. According to the result of first-round survey: 1. The development of heat pump system in Taiwan has potential for steady growth, subject to the market niche. In particular, if Taiwan can follow the practice of advanced countries in terms of the innovative management of heat pump system under framework of virtual power plant and consider the development of renewable energy an indispensible part, the heat pump system will have a promising future in Taiwan; 2. The trend of global energy, governmental policy of energy, consumer awareness, and scale of market are key factors which affect the development of heat pump system in Taiwan; 3. It is recommended that the heat pump system in Taiwan develop its own brand to expand the scale of market, manage core technologies, and improve competitiveness; 4. It is feasible to rent the equipment or save the energy expenses to pay the purchase cost of equipment. However, the best way is to take individual clients’ best interest into account and provide different programs and increase customers’ willingness to purchase a heat pump system based on the concept of investment; and 5. It is feasible to consider the heat pump as distributed power under the framework of virtual power plant, combined with the demand response program proposed by the power company in the innovative business model, which focuses on the degree of consumers’ awareness and the attraction to consumers. Due to different professional backgrounds of experts and scholars, the focuses on questions varied. Accordingly, the second round of questionnaire was compiled based on the result of first round and provided for interviewees to choose answers to questions. According to the result of second-round survey: 1. The price is the most important key to the promotion of heat pump system, followed by market visibility, standard of governmental regulations, and subsidies; 2. Sales of heat pump system could be improved by providing after-sale service, reducing the price of heat pump system, and helping clients obtain premium demand response programs; and 3. The reason why consumers resisted the business model of integration of heat pump system and demand response program was that consumers did not understand the actual benefits generated from the heat pump system. Moreover, such business model was so complicated that consumers tended to remain status quo and resist the heat pump system. The study obtained the applicable business model of innovative management of heat pump system under the framework of virtual power plant with a favorable price in the demand response program. In addition, the study also proposed necessary strategies for development of heat pump system in response to gradually popular trend of renewable energy and distributed generation facilities. The core value of heat pump system is that the heat pump is one of renewable energy which is obtained from air, waters, soil in nature as well as a distributed generation facility which can store energy. Since the power supply from renewable energy is not steady, the energy storage system like heat pump is required to serve as an indispensable component during high-proportion power generation of renewable energy. Keywords: Virtual power plant, Heat pump system, Delphi method, Innovative business model, Energy service company, Aggregator, The third party