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Kirkby, Nicholas (Nicholas J. ). "Reuse of hybrid car power systems." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98967.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (page 37).
Used hybrid car power systems are inexpensive and capable of tens of kilowatts of power throughput. This paper documents a process for using the second generation Toyota Prius inverter module to drive a three phase permanent magnet synchronous motor/generator from Ford hybrid vehicle. A lightweight housing and a rotor position sensor for the motor/generator are constructed to allow it to be used outside of the original bulky transaxle. Field oriented control is implemented on a microcontroller which interfaces with the motor/generator and the Prius inverter module. The motor, inverter, and controller are installed on a demonstration vehicle for the purpose of load testing.
by Nicholas Kirkby.
S.B.
2
Lim, Pei Yi. "Power management strategies for off-grid hybrid power systems." Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/2503.
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At present, there are still a large number of people living in isolated areas, particularly in developing countries, who have no immediate access to the main electricity grid. Most of the energy demands of these remote communities are met by diesel-operated power systems, which are relatively affordable and available. With the ever increasing awareness of climate change, many local authorities have taken initiatives to reduce the carbon footprint of certain energy sectors. In some rural applications, diesel generator power systems are augmented by single or multiple renewable energy supply units to form an off-grid hybrid power system.Generally, the majority of off-grid hybrid power systems include a massive battery bank to store excess renewable energy to supply the user load demand during the period when renewable energy is deficient. In the charging and discharging processes, energy losses may occur due to the inefficiency of the charger and the battery cells. Also, inclusion of an energy storage element into a hybrid power system incurs additional investment costs and involves recycling issues. Therefore, it is necessary to minimise the size of storage, whenever possible, and operate the system under an appropriate power management strategy to ensure efficient system operation.The chosen power management strategy impacts long-term performance of a system as well as components’ longevity. The research presented in this thesis describes the development of an advanced power management concept for the operation of a photovoltaic-variable speed diesel generator hybrid power system.A general introduction regarding the research background to hybrid power system applications and fundamentals of solar energy is presented. A component sizing and control program is developed to facilitate hybrid power system design. Then, various off-grid power system configurations are further discussed with emphasis on the system performances and economic aspects.A prediction technique, namely the Hourly-based Prediction Model for solar irradiance and load demand forecasts is discussed. Forecast algorithms for the hourly solar irradiance and load demand predictions are presented. The proposed prediction models are implemented in the power management strategy for the off-grid photovoltaic-variable speed diesel generator hybrid power system. Assessments of the prediction models through comprehensive analyses of statistical measures are presented.HOMER simulation software has been adopted for time series generation and economic analyses for several off-grid power system configurations. Also, the HOMER simulation results for electrical aspects are used as a benchmark to evaluate the component models developed in this thesis. Due to the fact that HOMER offers limited choices of power management strategy and users do not have access to modify the control algorithms, it is impossible to determine the performance of a system under advanced power management strategy. Therefore, analytical performance models of system components have been developed using the MATLAB/Simulink software to allow the implementation of the proposed power management strategy.The concepts and flow charts of the predictive power management strategy are described. This power management strategy consists of predictive and adaptive dispatch. The time step of the predictive dispatch is fixed to one hour while the time step of the adaptive dispatch is one minute. Operation of the additional generator capacity of the hybrid power system is based on the predicted net load. The adaptive dispatch supports the predictive dispatch to handle fluctuations of net load that occur in between prediction intervals.Simulation results of the performance of hybrid power systems using different types of diesel generator and power management strategies are presented. Particular emphasis is on the comparisons of the system performances using non-predictive and predictive power management strategies. These simulations allow quantitative assessment of the system performances in terms of electrical output, fuel consumption and carbon dioxide emission.Last but not least, the entire research is summarised and concluded with suggestions for future research. In short, the photovoltaic-variable speed diesel generator hybrid power system topology and the proposed power management strategy offer an alternative to the off-grid hybrid power system design, with the aims of overcoming the complex technical issues associated with energy storage and of contributing to market extension of hybrid power systems, particularly in remote locations where financial and technical issues are the major concerns.
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Anderson, Glenn Warwick Jan. "Hybrid simulation of AC-DC power systems." Thesis, University of Canterbury. Electrical and Computer Engineering, 1995. http://hdl.handle.net/10092/1176.
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Transient stability studies are primarily concerned with the generator response of ac power systems and use only steady state type equations to model HVdc converter terminals. These equations are adequate for small disturbances at the converter terminals but cannot accurately represent a converters behaviour during, and through its recovery of, a significant transient disturbance. A detailed three phase electromagnetic analysis is necessary to describe the converters correct behaviour. This thesis describes an accurate and effective hybrid method combining these two types of studies, for analyzing dynamically fast devices such as HVdc converters within ac power systems. Firstly, conventional techniques are reviewed for both a transient stability analysis of power systems and for an electromagnetic transient analysis of HVdc converters. This review deals in particular with the two programs that constitute the hybrid developed in this thesis. Various techniques are then examined to efficiently and accurately pass the dynamic effects of an HVdc link to an ac system stability study, and the dynamic effects of an ac system to a detailed HVdc link study. An optimal solution is derived to maximise the inherent advantages of a hybrid. Finally, the hybrid is applied to a test system and its effectiveness in performing its task is shown.
4
Das, Debosmita. "Advanced power electronics for hybrid energy systems." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1412940298.
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Alawhali, Nasser. "CONTRIBUTIONS TO HYBRID POWER SYSTEMS INCORPORATING RENEWABLES FOR DESALINATION SYSTEMS." UKnowledge, 2018. https://uknowledge.uky.edu/ece_etds/115.
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Renewable energy is one of the most reliable resource that can be used to generate the electricity. It is expected to be the most highly used resource for electricity generation in many countries in the world in the next few decades. Renewable energy resources can be used in several purposes. It can be used for electricity generation, water desalination and mining. Using renewable resources to desalinate the water has several advantages such as reduce the emission, save money and improve the public health. The research described in the thesis focuses on the analysis of using the renewable resources such as solar and wind turbines for desalination plant. The output power from wind turbine is connected through converter and the excess power will be transfer back to the main grid. The photo-voltaic system (PV) is divided into several sections, each section has its own DC-DC converter for maximum power point tracking and a two-level grid connected inverter with different control strategies. The functions of the battery are explored by connecting it to the system in order to prevent possible voltage fluctuations and as a bu er storage in order to eliminate the power mismatch between PV array generation and load demand. Computer models of the system are developed and implemented using the PSCADTM / EMTDCTM software.
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Meegahawatte, Danushka Hansitha. "A design method for specifying power sources for hybrid power systems." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1215/.
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Many efforts have been made in recent years to address issues surrounding the use of fossil fuels for energy. However, it must be conceded that world’s dependence on fossil fuels cannot cease overnight. In reality, the switch is expected to be a relatively slow migration of technologies over many decades. During this transition period the world will need bridging technologies to aid in the transition to alternate energy sources. One such technology, which shows much promise in boosting energy efficiency while reducing emissions and costs, is the adoption of hybrid power systems. This thesis investigates the motives behind seeking alternate energy sources and discusses the future need to move away from fossil fuels and the likely role hybrid power systems will play in the future. A general outline of a hybrid power system is presented, and its key subsystems identified and discussed, paying attention to power generation, energy storage technologies and the performance of these systems. A novel method of specifying the power sources in bespoke hybrid power systems are presented. A custom software tool aimed at evaluating how different hardware configurations and output duty cycles affect the performance of a hybrid power system is then presented and used in several case studies to investigate the effectiveness of the presented method in specifying power sources for a given application. It was found that the hardware, output application and control strategy of a hybrid power system affects the overall performance of the system. Furthermore, if the output duty cycle of a hybrid power system is repetitive and predictable in nature, it was found that the hardware and control strategy of the system can be fine-tuned using simple techniques to optimise the overall system configuration and performance.
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Yan, Wenguang. "Multilevel sliding mode control in hybrid power systems." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1172766787.
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Natsheh, Emad Maher. "Hybrid power systems energy management based on artificial intelligence." Thesis, Manchester Metropolitan University, 2013. http://e-space.mmu.ac.uk/314015/.
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This thesis presents a novel adaptive scheme for energy management in stand-alone hybrid power systems. The proposed management system is designed to manage the power flow between the hybrid power system and energy storage elements in order to satisfy the load requirements based on artificial neural network (ANN) and fuzzy logic controllers. The neural network controller is employed to achieve the maximum power point (MPP) for different types of photovoltaic (PV) panels, based on Levenberg Marquardt learning algorithm. The statistical analysis of the results indicates that the R2 value for the testing set was 0.99. The advance fuzzy logic controller is developed to distribute the power among the hybrid system and to manage the charge and discharge current flow for performance optimization. The developed management system performance was assessed using a hybrid system comprises PV panels, wind turbine, battery storage, and proton exchange membrane fuel cell (PEMFC). To improve the generating performance of the PEMFC and prolong its life, stack temperature is controlled by a fuzzy logic controller. Moreover, perturb and observe (P&O) algorithm with two different controller techniques - the linear PI and the non-linear passivity-based controller (PBC) - are provided for a comparison with the proposed MPPT controller system. The comparison revealed the robustness of the proposed PV control system for solar irradiance and load resistance changes. Real-time measured parameters and practical load profiles are used as inputs for the developed management system. The proposed model and its control strategy offer a proper tool for optimizing the hybrid power system performance, such as the one used in smart-house applications. The research work also led to a new approach in monitoring PV power stations. The monitoring system enables system degradation early detection by calculating the residual difference between the model predicted and the actual measured power parameters. Measurements were taken over 21 month’s period; using hourly average irradiance and cell temperature. Good agreement was achieved between the theoretical simulation and the real time measurement taken the online grid connected solar power plant.
9
Cheng, Carol Shaoyu. "A hybrid approach to power system voltage security assessment." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/15469.
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kollappillai, Murugan Sai Varun. "Analysis of Hybrid Offshore Floating Wind and Marine Power." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-36861.
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Wind energy is a major part of renewable energy production. With fossil fuel depletion and climate change at the cusp, it is an absolute need to implement or evolve the current source or utilization of renewable energy. The wind has been dominating the onshore for many decades and offshore wind turbines are available at shallow depths. To extract more wind energy source deep sea location is recommended. Also, in deep seas, ocean current energy is utilized very sparsely compared to the dominating wind and solar energy. So far no hybrid offshore horizontal axis and ocean current system are in existence. Based on the depth of the sea water the offshore floating structure is classified. Usually, for any floating structure stability is an apprehension. In an offshore floating structure, the damping with respect to the thrust force exerted on the wind turbine will affect the life of the wind turbine. During high wind speed, the angle of inclination would go up to about 4 degrees. The time required for the floating structure to come to rest may also be high. We present an analysis based on an existing floating structure which is a ballast stabilized the floating structure. In this paper, we add an additional submerged turbine and do a 2D analysis on the floating structure to find out whether the structure’s oscillation is well damped or not. We also discuss whether the weight of the submerged will influence the stability or by changing the radius of blades of the submerged turbine will affect the damping.
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Boghossian, John G. "Dual-temperature Kalina cycle for geothermal-solar hybrid power systems." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68995.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 47-48).
This thesis analyzes the thermodynamics of a power system coupling two renewable heat sources: low-temperature geothermal and a high-temperature solar. The process, referred to as a dual-temperature geothermal-solar Kalina hybrid cycle, is analyzed in detail and then compared to appropriate single-heat source power systems, in order to assess any thermodynamic synergies. With increasing demand for more efficient renewable sources of power generation, a plant design where the working fluid is heated (and partially vaporized) by low- to medium-temperature geothermal brine, before being further vaporized by solar heat, presents an opportunity for efficient operation of the power plant. Given a set of design parameters and the constrained optimization of decision variables, a design basis plant configuration is first chosen. Then, the power output attained by the Kalina hybrid is compared to that attained by a combination of a geothermal organic Rankine cycle and a solar standalone steam cycle, with the same boundary conditions. The Kalina hybrid plant is found to produce 9.5 MW of power, with 100 kg/s of geothermal brine and a solar-to-geothermal heat input ratio constrained to 1. The system performance is increasing in the working fluid low pressure and decreasing in the ammonia molar concentration, at the cost of a corresponding increase in solar-to-geothermal heat input ratio. On a design power comparison basis, the hybrid configuration displays no thermodynamic synergy between geothermal and solar energy modes. Specifically, the hybrid plant produces 29% less net power than the combined single-energy mode plants. No assessment of possible economic synergies is attempted. Potential changes to the current Kalina hybrid cycle that can lead to higher thermodynamic performance include regenerating heat within the cycle; using the solar high quality heat source in alternative locations in the cycle; employing one pressure-turbine loop instead of two; using reheat between the two turbines; and investigating other plausible working fluid mixtures including hydrocarbons and refrigerants.
by John G. Boghossian.
S.B.
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Kazuz, Ramadan. "Hybrid solar thermo-electric systems for combined heat and power." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/72508/.
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Solar energy has been extensively used in the renewable technology field, especially for domestic applications, either for heating, electrical generation or for a combination of heat and power (CHP) in one system. For CHP system solar photoelectric/thermal (PV/T) is the most commonly used technology for roof top applications. However, combination between solar hot water and thermoelectric generators has become an attractive for CHP system, this is due to its simplicity of construction and its high reliability. Moreover, this technology does not rely simply on sunlight and it can work with any other heat source, such as waste heat. However, its main drawback is its low efficiency. Recent publications by Kraemer et al (2011) and Arturo (2013) have shown that the efficiency of solar thermoelectric systems has improved dramatically, especially when combined with a solar concentrator system, as well as within a vacuum environment. The project recorded in this thesis focused on the design, construction and investigation of an experimental solar thermoelectric system based on a flat plate solar absorber. The aim was to study the technical feasibility and economical viability of generating heat and electric power using a solar thermoelectric hot water system. The design procedure involved on determining the heat absorbed and emitted, as well as the electrical power that was generated by the system. It began by obtaining the efficiency of the solar absorber, including selecting its paint, this was done through an experimental technique to determine the heat absorbed by the absorber, and the results obtained were verified by direct measurements of the light intensity. xvi An intensity meter was used, and results from both the experimental and theoretical models showed good agreement. The process also included calculating the heat from the system that was gained, lost and generated, as well as the electrical power provided. This was done to provide the system optimal size optimization to obtain the best and most economical system. Further improvement was made to the system by assembling a vacuum cavity, to improve the system’s efficiency. Although the maximum electrical efficiency obtained was relatively low (0.9%), compared to results recorded in the literature (Kraemer et al ,2011 and Arturo, 2013). However, the results of the electrical power output, under a vacuum level of 5 x 10-2mbar, increased approximately three times compared to the results obtained under normal (atmospheric) conditions. Additionally, the thermal power increased by 37% at this level of vacuum. The process involved determining the best thermoelectric geometries to achieve the optimum power outcome under different environmental conditions. The results showed that the system, which included the Thermoelectric device (TEG) with a larger geometric size, produced the best thermal power among other sizes. It was concluded that the system with the smallest TEG geometric size provided the best electrical power output.
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Basurto, M. T. "Study of fuel cell and gas turbine hybrid power systems." Thesis, Cranfield University, 2002. http://dspace.lib.cranfield.ac.uk/handle/1826/10514.
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Environmental awareness and the interest in distributed generation caused by
electricity market de-regulation are factors that promote research on renewable energies.
Fuel cells transform the chemical energy stored in fuel into electricity by
means of electrochemical reactions. Among the different fuel cell types, high temperature
fuel cells (HTFCS) have many advantages: high efficiency, low emissions,
fuel flexibility, modularity and high quality waste heat. The main disadvantage is their
high cost - however, this will be reduced when HTFCS are commercialised.
The
synergy between HTFCS and gas turbines (GTS) makes HTPC/GTS very
efficient
power systems for the generation of electricity, from kilowatts to just a few
megawatts.
The
present work focuses on HTFC/GT power systems, analysing their
performance, studying some particular applications, and making an economic
assessment. The final objective of this Thesis is to define a procedure to assist in the
preliminary design of HTFC/GT systems.
The authors main contribution is the definition of the Green-Cell Code
capable of simulating HTFC/GT systems, the study of their interest for several
applications, and the generation of a decision-making method for the preliminary design
of HTFC/GT
systems.
The
design and off-design simulation of HTFC/GT cycles have been carried
out with the integration of a code developed by the author to simulate HTFC
performance, and a commercial code to simulate GT performance. This work is even
more valuable
given the lack of commercial tools to analyse the system.
All of the technical and economic work is collected in a set of charts that
assist the
procedure of HTFC/GT cycle selection.
These charts show that HTFC/GT systems currently achieve thermal
efficiencies of about 60%, and will be capable of achieving up to 73% in the future.
This is of great interest for power generation applications. The use of a recuperate is
required to optimise the performance of the gas turbine and the fuel cell; it is also
interesting to use it to generate the maximum amount of power from the HTFC, in order
to reduce emissions and increase overall efficiency. Results show that Pressurised
MCFC/GT
Cycles achieve better performance and economic results that Atmospheric
MCFC/GT
Cycles. For Pressurised MCFC/GT Cycles, the optimum stack operating
pressure is between 5 and 10 bars. The installation of a combustor in Pressurised
MCFC/GT
cycles leads to higher specific power, higher unit costs of electricity, higher
CHP
efficiency, and lower thermal efficiency.
The use of HTFC/GT
cycles to generate heat and power must be seen as a
way to improve HTFC/GT efficiency by using the waste heat of exhaust gases, rather
than as an
optimum application.
Results also show that SOFC/GT systems achieve slightly higher results than
MCFC/GT
systems. Thus, the choice between MCFCs and SOFCs will be based on
durability and cost issues rather than on performance issues.
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Darbyshire, James. "Multi-function power electronic interface for hybrid mini-grid systems." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/2394.
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In the past five years, global interest regarding the development of renewable energy technologies has significantly increased. The conventional electric power generation methods sourced from fossil fuels is now problematic, from both the supply and emission points of view. Fossil fuels are non-renewable limited resources that have taken millions of years to form; eventually they will be exhausted and the current cost of automotive fuel is evidence of them becoming diminished. The carbon dioxide emissions created through the energy conversion process are causing an increase in the overall atmospheric concentrations, which through global warming may have serious consequences for humanity.Natural sources of energy production can be derived from the Sun through the use of solar and wind generation methods. Converting these sources to electricity requires the technology of power electronics, the central area of research for this dissertation. Solar energy can most easily be harnessed through the photo-electric effect which creates DC electricity. However, the majority of electric loads and transmission require AC electricity. The inverter is the electronic device required for this power conversion. Wind turbines usually create variable voltage and frequency AC that is rectified to DC and then converted to grid type AC through an inverter.Voltage source inverters, their topologies and control are investigated within this dissertation. Voltage control methods are adopted for both stand-alone and grid connected techniques where control of active and reactive power is required. Current control techniques in the form of PI and hysteresis are applied to allow novel interfaces between generation sources to be achieved. Accurate control of the power electronics allows an enhancement in the power production from the renewable energy source. The power electronic device of the DC-DC converter, either buck or boost is controlled to allow the renewable resource to operate at its optimum power point. The control aspects and algorithms of these converters are central to this research. The solar algorithms of perturb and observe, and incremental conductance are developed with the latter being more favourable to changing levels of irradiation. The author draws a parallel between rapidly changing solar conditions with normally changing wind states. This analogy with an understanding of the mechanics of PMSG allows a novel wind MPPT algorithm to be developed which is simulated in PSIM. Methods to analyse the usefulness of the algorithm are developed and general conclusions are drawn.Another aim central to the research is the efficient combination of renewable energy sources into a single reliable power system. This forms the multi-function aspect of the research. The interconnection of the sources on the AC or DC sides is investigated for both stand-alone and grid connected topologies. A requirement of the stand-alone system is to provide power when no renewable resources are available causing some form of energy storage to be utilised. Conventional batteries are used, causing the VC-VSI to become bi-directional allowing charging. This is simulated in PSIM and demonstrated as part of the Denmark and Eco Beach projects. Many differing topologies of stand alone, grid connected and edge of grid systems are developed, simulated and some are demonstrated.While investigating the currently used topologies the author invents the novel complimentary hybrid system concept. This idea allows a single inverter to be used to feed energy from either the wind or solar resource. With careful engineering of the PV array and wind turbine characteristics only a small loss of energy is caused, deemed the crossover loss. This original concept is mathematically modelled, simulated and demonstrated with results presented from the Denmark project. The strength of this idea is from the quite complimentary nature of wind and solar resources, for only a small proportion of the year are high solar and strong wind conditions occurring simultaneously.Compared to a solar resource, the wind resource is much more complicated to model. An analysis of readily available wind source data is presented with a statistical analysis of the scaling methods; a novel box and whiskers plot is used to convey this information. New software is presented to allow a more accurate and digital model of a power curve to be recreated, allowing a more precise annual energy generation calculation. For various wind turbines a capacity factor analysis is presented with its disadvantages explained. To overcome these issues the concepts of economic efficiency and conversion efficiency are explained. These prevent some of the typical methods to enhance the standard capacity factor expression. The combination of these three methods allows selection of the most suitable wind turbine for a site.The concept of a mini-grid is an isolated power generation and distribution system, which can have its renewable energy sources, centralised or decentralised. The methods used to coalesce conventional generation with renewable energy technology forms another key piece of this research. A design methodology for the development of a hybrid power system is created with examples used from projects attributed to the author. The harmonising of the renewable energy sources with the conventional generation while providing a stable and robust grid is explained in detail with respect to the generator loading and control. The careful control of the renewable resource output is shown to allow a greater overall penetration of renewable energy into the network while continuing network stability. The concept of frequency shift control is presented, simulated and demonstrated with reference to the Eco Beach project. This project epitomises much of the research that has been presented in this dissertation. It combines centralised and decentralised inverters, with battery storage and the control of diesel generators. An overall controller dictates the optimum times to charge or draw from the battery based upon the local environmental and time of day variables. Finally, the monitoring aspects of this project are representative of a future smart grid where loads may be shed on demand through under frequency or direct control.
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Kong, Suyao. "Advanced passivity-based control for hybrid power systems : application to hybrid electric vehicles and microgrids." Thesis, Bourgogne Franche-Comté, 2020. http://indexation.univ-fcomte.fr/nuxeo/site/esupversions/a01b06c5-fb6c-452d-bd16-02b269cd0bb9.
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Un système hybride à base de pile à combustible (PàC) est une solution efficace pour faire face aux problèmes de pollution atmosphérique et de pénurie des combustibles fossiles. Cette thèse se concentre sur la conception de la commande pour les systèmes d'alimentation hybrides à base de PàC, et appliquée à deux applications : le véhicule électrique et le centre de données alimenté par un micro-réseau.Tout d'abord, cette thèse propose une commande basée sur la passivité pour un système hybride PàC/supercondensateurs (SCs). Cette commande a été conçue via la méthode de conception IDA-PBC (Interconnection and Damping Assignment - Passivity Based Control), afin de résoudre le problème de coordination des convertisseurs. L'état de charge des SCs ainsi que toutes les limitations sont intégrés directement dans la loi de commande. Un banc d'essais PHIL (Power Hardware-in-the-loop) est utilisé pour la validation. Ensuite, un filtre de Kalman étendu (EKF) est combiné avec la commande proposée, pour prévoir l'état de santé (SoH) de la pile à combustible. Enfin, un banc d'essais HIL (Hardware-in-the-loop) basé sur un FPGA INTEL / ALTERA est conçu afin de valider le fonctionnement des algorithmes en temps réel pour un véhicule commercial.Pour l'application à un micro-réseau, une commande passive est proposée pour un système hybride comprenant des panneaux photovoltaïques, une PàC, des SCs et un électrolyseur. La faisabilité de cette commande est validée par les résultats expérimentaux sur un banc d'essai PHIL. Ce travail est intégré au projet ANR DATAZERO.La nouveauté principale de cette commande est qu'elle intègre certaines contraintes de composants directement dans la loi de commande, en préservant la stabilité de l’ensemble du système, en boucle ferméeA Fuel cell (FC) hybrid power system is a promising solution to deal with the atmospheric pollution and fossil fuels shortage problems. This thesis focuses on the controller design for FC hybrid power systems, towards two applications: the hybrid electrical vehicle and the microgrid-powered datacenter.Firstly, this thesis proposes an advanced passivity-based control for a FC/super-capacitors (SCs) hybrid system. In order to solve the converters coordination problem, a controller designed using the design method Interconnection and Damping Assignment - Passivity-Based Control (IDA-PBC) is applied, which considers the state-of-charge of the SCs as well as voltage and current limitations. The proposed controller is validated on a Power Hardware-in-the-loop (PHIL) platform. Then an Extended Kalman Filter (EKF) is applied to forecast the State-of-Health (SoH) of the fuel cell and is combined with the proposed controller. Finally, a Hardware-in-the-loop (HIL) platform based on an INTEL/ALTERA FPGA is designed in order to validate the real-time operation of the algorithms for a specific case study with a commercial vehicle.For microgrid applications, a passivity-based controller for a hybrid power supply system for a green datacenter is proposed, including photovoltaic panels, a fuel cell, SCs and an electrolyzer. The feasibility of this non-linear controller is proven by the simulation results and experimental validation on a PHIL test bench. This work is integrated into the ANR DATAZERO project.The main novelty of the proposed controller is that it integrates some component constraints directly into the controller equations, while the locally asymptotic stability of the whole closed-loop system is preserved
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Moleli, Christopher Teboho. "Hybrid field generator controller for optimised perfomance." Thesis, Port Elizabeth Technikon, 2003. http://hdl.handle.net/10948/236.
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Battery charging wind turbines like, Hybrid Field Generator, have become more popular in the growing renewable energy market. With wind energy, voltage and current control is generally provided by means of power electronics. The paper describes the analytical investigation in to control aspects of a hybrid field generator controller for optimized performance. The project objective is about maintaining the generated voltage at 28V through out a generator speed range, between 149 rpm and 598 rpm. The over voltage load, known as dump load, is connected to the control circuit to reduce stress on the bypass transistor for speeds above 598 rpm. Maintaining a stable voltage through out the speed range, between 149rpm and 598rpm, is achieved by employing power electronics techniques. This is done by using power converters and inverters to vary the generator armature excitation levels hence varying its air gap flux density. All these take place during each of the three modes of generator operation, which are: buck, boost and permanent magnet modes. Although the generator controller is power electronics based, it also uses software to optimize its performance. In this case, a PIC16F877 microcontroller development system has been used to test the controller function blocks.
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Kusakana, Kanzumba. "Optimal operation control of hybrid renewable energy systems." Thesis, Bloemfontein: Central University of Technology, Free State, 2014. http://hdl.handle.net/11462/670.
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Thesis (D. Tech. (Electrical Engineering)) -- Central University of Technology, Free State, 2014For a sustainable and clean electricity production in isolated rural areas, renewable energies appear to be the most suitable and usable supply options. Apart from all being renewable and sustainable, each of the renewable energy sources has its specific characteristics and advantages that make it well suited for specific applications and locations. Solar photovoltaic and wind turbines are well established and are currently the mostly used renewable energy sources for electricity generation in small-scale rural applications. However, for areas in which adequate water resources are available, micro-hydro is the best supply option compared to other renewable resources in terms of cost of energy produced. Apart from being capital-cost-intensive, the other main disadvantages of the renewable energy technologies are their resource-dependent output powers and their strong reliance on weather and climatic conditions. Therefore, they cannot continuously match the fluctuating load energy requirements each and every time. Standalone diesel generators, on the other hand, have low initial capital costs and can generate electricity on demand, but their operation and maintenance costs are very high, especially when they run at partial loads. In order for the renewable sources to respond reliably to the load energy requirements, they can be combined in a hybrid energy system with back-up diesel generator and energy storage systems. The most important feature of such a hybrid system is to generate energy at any time by optimally using all available energy sources. The fact that the renewable resources available at a given site are a function of the season of the year implies that the fraction of the energy provided to the load is not constant. This means that for hybrid systems comprising diesel generator, renewable sources and battery storage in their architecture, the renewable energy fraction and the energy storage capacity are projected to have a significant impact on the diesel generator fuel consumption, depending on the complex interaction between the daily variation of renewable resources and the non-linear load demand. V This was the context on which this research was based, aiming to develop a tool to minimize the daily operation costs of standalone hybrid systems. However, the complexity of this problem is of an extremely high mathematical degree due to the non-linearity of the load demand as well as the non-linearity of the renewable resources profiles. Unlike the algorithms already developed, the objective was to develop a tool that could minimize the diesel generator control variables while maximizing the hydro, wind, solar and battery control variables resulting in saving fuel and operation costs. An innovative and powerful optimization model was then developed capable of efficiently dealing with these types of problems. The hybrid system optimal operation control model has been simulated using fmincon interior-point in MATLAB. Using realistic and actual data for several case studies, the developed model has been successfully used to analyse the complex interaction between the daily non-linear load, the non-linear renewable resources as well as the battery dynamic, and their impact on the hybrid system’s daily operation cost minimization. The model developed, as well as the solver and algorithm used in this work, have low computational requirements for achieving results within a reasonable time, therefore this can be seen as a faster and more accurate optimization tool.
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Othman, Mohd Fauzi. "A hybrid systems approach to control and fault detection and accommodation in power systems." Thesis, University of Sheffield, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412141.
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Shaheen, Murtadha A. "POWER MAXIMIZATION FOR PYROELECTRIC, PIEZOELECTRIC, AND HYBRID ENERGY HARVESTING." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4462.
Full textAbstract:
The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters.
A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance Cp and resistance Rp can be calculated at a frequency of 1 mHz to 1 Hz. This method demonstrates that for pyroelectric materials the impedance depends on two major factors: average working temperature, and the heating rate.
Design and implementation of a hybrid approach using multiple piezoelectric cantilevers is presented. This is done to achieve mechanical and electrical tuning, along with bandwidth widening. In addition, a hybrid tuning technique with an improved adjusting capacitor method was applied. An toroid inductor of 700 mH is shunted in to the load resistance and shunt capacitance. Results show an extended frequency range up to 12 resonance frequencies (300% improvement) with improved power up to 197%.
Finally, a hybrid piezoelectric and pyroelectric system is designed and tested. Using a voltage doubler, circuit for rectifying and collecting pyroelectric and piezoelectric voltages individually is proposed. The investigation showed that the hybrid energy is possible using the voltage doubler circuit from two independent sources for pyroelectrictity and piezoelectricity due to marked differences of optimal performance.
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Roe, Curtis Aaron. "Power system impacts of plug-in hybrid electric vehicles." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29636.
Full textAbstract:
Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.Committee Chair: Dr. A. P. Meliopoulos; Committee Member: Dr. David Taylor; Committee Member: Dr. Ronald Harley; Committee Member: Dr. Shijie Deng. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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LaBella, Thomas Matthew. "A High-Efficiency Hybrid Resonant Microconverter for Photovoltaic Generation Systems." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/50526.
Full textAbstract:
The demand for increased renewable energy production has led to increased
photovoltaic (PV) installations worldwide. As this demand continues to grow, it is
important that the costs of PV installations decrease while the power output capability
increases. One of the components in PV installations that has lots of room for improvement
is the power conditioning system. The power conditioning system is responsible for
converting the power output of PV modules into power useable by the utility grid while
insuring the PV array is outputting the maximum available power. Modular power
conditioning systems, where each PV module has its own power converter, have been
proven to yield higher output power due to their superior maximum power point tracking
capabilities. However, this comes with the disadvantages of higher costs and lower power
conversion efficiencies due to the increased number of power electronics converters. The
primary objective of this dissertation is to develop a high-efficiency, low cost
microconverter in an effort to increase the output power capability and decrease the cost of
modular power conditioning systems.
First, existing isolated dc-dc converter topologies are explored and a new topology
is proposed based on the highly-efficient series resonant converter operating near the series
resonant frequency. Two different hybrid modes of operation are introduced in order to
add wide input-voltage regulation capability to the series resonant converter while
achieving high efficiency through low circulating currents, zero-current switching (ZCS)
of the output diodes, zero-voltage switching (ZVS) and/or ZCS of the primary side active
switches, and direct power transfer from the source to the load for the majority of the
switching cycle. Each operating mode is analyzed in detail using state-plane trajectory
plots. A systematic design approach that is unique to the newly proposed converter is
presented along with a detailed loss analysis and loss model. A 300-W microconverter
prototype is designed to experimentally validate the analysis and loss model. The converter
featured a 97.7% weighted California Energy Commission (CEC) efficiency with a
nominal input voltage of 30 V. This is higher than any other reported CEC efficiency for
PV microconverters in literature to date.
Each operating mode of the proposed converter can be controlled using simple
fixed-frequency pulse-width modulation (PWM) based techniques, which makes
implementation of control straightforward. Simplified models of each operating mode are
derived as well as control-to-input voltage transfer functions. A smooth transition method
is then introduced using a two-carrier PWM modulator, which allows the converter to
transition between operating modes quickly and smoothly. The performance of the voltage
controllers and transition method were verified experimentally.
To ensure the proposed converter is compatible with different types of modular
power conditioning system architectures, system-level interaction issues associated with
different modular applications are explored. The first issue is soft start, which is necessary
when the converter is beginning operation with a large capacitive load. A novel soft start
method is introduced that allows the converter to start up safely and quickly, even with a
short-circuited output. Maximum power point tracking and double line frequency ripple
rejection are also explored, both of which are very important to ensuring the PV module is
outputting the maximum amount of available power.
Lastly, this work deals with efficiency optimization of the proposed converter. It
is possible to use magnetic integration so that the resonant inductor can be incorporated
into the isolation transformer by way of the transformer leakage inductance in order to
reduce parts count and associated costs. This chapter, however, analyzes the disadvantages
to this technique, which are increased proximity effect losses resulting in higher conduction
losses. A new prototype is designed and tested that utilizes an external resonant inductor
and the CEC efficiency was increased from 97.7% to 98.0% with a marginal 1.8% total
cost increase. Additionally, a variable frequency efficiency optimization algorithm is
proposed which increases the system efficiency under the high-line and low-line input
voltage conditions. This algorithm is used for efficiency optimization only and not control,
so the previously presented simple fixed-frequency modeling and control techniques can
still be utilized.Ph. D.
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Trivedi, Manas. "Multi-objective generation scheduling with hybrid energy resources." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202498690/.
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Miwa, Brett Andrew. "Hybrid construction of a 10MHz DC-DC converter for distributed power systems." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/41583.
Full textAbstract:
Thesis (Elec. E.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.Includes bibliographical references (leaves 204-208).
by Brett Andrew Miwa.
Elec.E.
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Erbes, Teodora. "Stochastic Learning Feedback Hybrid Automata for Dynamic Power Management in Embedded Systems." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/9709.
Full textAbstract:
Dynamic Power Management (DPM) refers to the strategies employed at system level to reduce energy expenditure (i.e. to prolong battery life) in embedded systems. The trade-off involved in DPM techniques is between the reductions of energy consumption and latency incurred by the jobs to be executed by the system. Such trade-offs need to be decided at runtime making DPM an on-line problem. In this context, the contributions of this thesis are two-fold. Firstly, we formulate the DPM problem as a hybrid automaton control problem. We model a timed hybrid automaton to mathematically analyze various opportunities in optimizing energy in a given system model. Secondly, stochastic control is added to the automata model, whose control strategy is learnt dynamically using stochastic learning automata (SLA). Several linear and non-linear feedback algorithms are incorporated in the final Stochastic Learning Hybrid Automata (SLHA) model. Simulation-based experiments show the expediency of the feedback systems in stationary environments. Further experiments are conducted using real trace data to compare stochastic learning strategies to the outcomes of several former predictive algorithms. These reveal that SLHA attains better trade-offs than the other studied methods under certain trace data. Advanced characterization of trace sequences, which allows a better performance of SLHA, is a subject of further study.Master of Science
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Esmaili, Gholamreza. "Application of advanced power electronics in renewable energy sourcesand hybrid generating systems." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1141850833.
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Das, Barun Kumar. "Optimisation of stand-alone hybrid energy systems for power and thermal loads." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2018. https://ro.ecu.edu.au/theses/2150.
Full textAbstract:
Stand-alone hybrid energy systems are an attractive option for remote communities without a connection to a main power grid. However, the intermittent nature of solar and other renewable sources adversely affects the reliability with which these systems respond to load demands. Hybridisation, achieved by combining renewables with combustion-based supplementary prime movers, improves the ability to meet electric load requirements. In addition, the waste heat generated from backup Internal Combustion Engines or Micro Gas Turbines can be used to satisfy local heating and cooling loads. As a result, there is an expectation that the overall efficiency and Greenhouse Gas Emissions of stand-alone systems can be significantly improved through waste heat recovery.
The aims of this PhD project are to identify how incremental increases to the hardware complexity of hybridised stand-alone energy systems affect their cost, efficiency, and CO2 footprint. The research analyses a range of systems, from those designed to meet only power requirements to others satisfying power and heating (Combined Heat and Power), or power plus both heating and cooling (Combined Cooling, Heating, and Power). The majority of methods used focus on MATLAB-based Genetic Algorithms (GAs). The modelling deployed finds the optimal selection of hardware configurations which satisfy single- or multi-objective functions (i.e. Cost of Energy, energy efficiency, and exergy efficiency). This is done in the context of highly dynamic meteorological (e.g. solar irradiation) and load data (i.e. electric, heating, and cooling).
Results indicate that the type of supplementary prime movers (ICEs or MGT) and their minimum starting thresholds have insignificant effects on COE but have some effects on Renewable Penetration (RP), Life Cycle Emissions (LCE), CO2 emissions, and waste heat generation when the system is sized meeting electric load only. However, the transient start-up time of supplementary prime movers and temporal resolution have no significant effects on sizing optimisation. The type of Power Management Strategies (Following Electric Load-FEL, and Following Electric and Following Thermal Load- FEL/FTL) affect overall Combined Heating and Power (CHP) efficiency and meeting thermal demand through recovered heat for a system meeting electric and heating load with response to a specific load meeting reliability (Loss of Power Supply Probability-LPSP). However, the PMS has marginal effects on COE. The Electric to Thermal Load Ratio (ETLR) has no effects on COE for PV/Batt/ICE but strongly affects PV/Batt/MGT-based hybridised CHP systems. The higher thermal than the electric loads lead to higher efficiency and better environmental footprint.
Results from this study also indicate that for a stand-alone hybridised system operating under FEL/FTL type PMS, the power only system has lower cost compared to the CHP and the Combined Cooling, Heating, and Power (CCHP) systems. This occurs at the expense of overall energy and exergy efficiencies. Additionally, the relative magnitude of heating and cooling loads have insignificant effects on COE for PV/Batt/ICE-based system configurations, however this substantially affects PV/Batt/MGT-based hybridised CCHP systems. Although there are no significant changes in the overall energy efficiency of CCHP systems in relation to variations to heating and cooling loads, systems with higher heating demand than cooling demand lead to better environmental benefits and renewable penetration at the cost of Duty Factor. Results also reveal that the choice of objective functions do not affect the system optimisation significantly.
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Lao, Keng Weng. "A novel electric traction power supply system using hybrid parallel power quality compensator." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550461.
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Luta, Doudou Nanitamo. "Modelling of hybrid solar wind integrated generation systems in an electrical distribution network." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/1177.
Full textAbstract:
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2014The research in this thesis deals with the application of Model Based Systems Engineering (MBSE) practices in the modelling of power systems. More particularly, we have presented the modelling hybrid photovoltaic wind integrated in an electrical distribution network using SysML (System Modelling Language) which is a modelling language in support of MBSE. MBSE refers to a formalised practice of systems development through the application of modelling principles, methods, languages and tools to the entire lifecycle of a system. Generally speaking, the modelling of power systems is performed using software such as Matlab Simulink, DigSilent, PowerWorld etc. These software programs allow modelling of a system considering only a specific viewpoint, depending on the objective that is to be assessed. The advantage of the SysML over the above mentioned modelling languages lies from the fact that SysML includes different viewpoints of a system. These views are known as the Four Pillars of SysML. Pillar One refers to the requirements of a system and includes all the functional and non-functional requirements. Pillar Two deals with the structure representation of a system by considering all its subsystems and their different connections. Pillar Three considers the behaviour of a system and includes its activities, sequences and different states. The last Pillar includes the detailed characteristics, physical laws and constraints on the system. The main objectives of this research are the development of models which will include: the system’s requirements; the system’s structure representation in term of different entities involved and the relationship between them; the system’s behaviours in terms of activities in different cases considered and transitions from one state to another as well as the interaction between the system and all the stakeholders. Keywords: Model Based Systems Engineering (MBSE), System Modelling Language (SysML), Renewable Energy systems, Hybrid power systems, photovoltaic systems, wind power systems.
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Kreinar, David J. "Energy Management Techniques for Hybrid Electric Unmanned Aircraft Systems." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton159640308960136.
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Weiss, Zachary A. "Analysis and cost optimization of a USCG remote hybrid power system." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FWeiss.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2002.Thesis advisor(s): John Ciezki, Sherif Michael. Includes bibliographical references (p. 101-102). Also available online.
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Odote, Jackson M. "Autonomous photovoltaic and wind hybrid power systems for rural households and communities in Kenya." Thesis, University of Strathclyde, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284826.
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Esmaili, Gholamreza. "Application of advanced power electronics in renewable energy sources and hybrid generating systems." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1141850833.
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Guarracino, Ilaria. "Hybrid photovoltaic and solar thermal (PVT) systems for solar combined heat and power." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58172.
Full textAbstract:
Solar is a particularly promising sustainable energy source in terms of its potential to displace the burning of fossil fuels for heat and power, heating and even cooling, albeit at a cost. The sun load-factor profile has a close and predictable match to the daily varying energy demand for heat and electricity, both thermal and electrical, and thermal storage for periods of low irradiance can be made readily available. In addition, solar thermal technologies can provide a significant fraction of the hot water demand in households, as well as space heating and cooling in residential buildings and for industrial facilities. In fact, solar heating has been proposed as one of the leading solutions in terms of its potential for greenhouse gas abatement [1]. At the small scale, photovoltaic systems presently dominate the domestic solar market with solar to electrical conversion efficiencies of around 15% and at a competitive cost for the building owner. Solar photovoltaic installations were encouraged in Europe at the local level with financial support and now constitute a large and mature market with continuously falling prices. Solar thermal systems are able to make use of a larger proportion of the solar resource as they convert solar energy into heat with a higher efficiency than the PV conversion efficiency. Moreover, the low temperature heat may be used to satisfying the largest portion of the demand for thermal energy that is currently met by fossil fuels. The development of the solar thermal market is strongly dependent on the availability of the local irradiance level and on the cost of the alternative sources of thermal energy. In some countries in Europe the solar thermal market is quite mature (e.g. Austria), whilst in others, such as in the UK, solar thermal energy still contributes marginally to the energy mix and solar thermal systems are not yet cost competitive. Due to the high costs of solar thermal energy systems, these constitute a relatively small market at present with the potential to grow substantially in the near future. A competitive solution for energy (heat and power) provision in buildings is the development of combined solar photovoltaic/thermal (PVT) systems which produce both electricity and heat simultaneously from the same aperture area. This solution is particularly suited to residential applications in urban areas, where the demand for electricity is accompanied by a demand for low temperature heat, and space for solar installations is scarce. Many alternative technologies for PVT integration exist and PVT units can be coupled with various systems for domestic hot water generation and/or space heating. At the design stage of a PVT system, decisions have to be made on the absorber characteristics (consisting of thermal collector and PV laminate), on the thermal to electrical yield ratio and on the application (industrial or residential application, stand alone or grid connected). These design parameters influence the requirements on the fluid temperature and electricity output, and the overall efficiency. In addition, system control can significantly impact the potential of such systems in terms of their performance characteristics in different applications. The aim of this present research effort was to demonstrate the technical and practical feasibility of a novel, high-efficiency hybrid PVT water system, by considering an affordable, small-scale, modular unit that can be scaled easily to cater to varying demand levels. The research investigated the technical issues related to PVT panel technology, by looking in particular at the optical efficiency of the PV cells, at the heat transfer from the PV cells to the fluid, and at the integration of such a unit in a heat and power provision system that attempts to match generation and local demand. A detailed numerical model was developed that constitutes a tool for testing various collector and system designs. The model was validated against experimental data. An experimental apparatus was designed and constructed for the purpose of evaluating the collector model and for collecting a database of performance data on PVT collectors. Collector performance data are scarce at the moment due to the relatively small market size, thus the work constitutes a reference for further development and analysis of this type of collectors. Steady-state tests and dynamic tests were performed on PVT collectors and the results were used to develop a reliable model of collector performance over a wide range of time-varying operating conditions. The model allowed for assessments of various solar PVT system designs under different operating conditions and control strategies. Result showed that such systems may underperform if their operation and design is not designed specifically for the local weather conditions and user-demand specific requirements. It is envisaged that emissivity control applied to the solar cells should be adopted for PVT system application, especially if higher operating temperatures are required (e.g. in combination with thermally driven/heat powered cooling systems). The numerical model confirms that solar cells a with low emissivity coating can maximise the thermal energy output of a PVT system. The potential of improved PVT systems is finally assessed from an economic perspective, in an analysis that considers the potential cost reduction of PVT systems in relation to alternative technologies used as a benchmark.
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Gkiala, Fikari Stamatia. "Modeling and Simulation of an Autonomous Hybrid Power System." Thesis, Uppsala universitet, Fasta tillståndets fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267767.
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In this report, the modeling process and operation of an autonomous hybrid power system is studied. It is built based on a hypothetical case study of electrification of a remote village of 100 inhabitants in Kenya. The power demand is estimated and the costs of equipment components are specified after extensive research, so that the techno-economical design of the system can be carried out. The microgrid consists of photovoltaics, wind turbine, batteries, diesel genset, basic loads and water pumping and purification load. The system is modeled and simulated in terms of power management and its operation as well as the performance of the dispatch strategy is assessed. Problems like the management of extra power or tackling the deficit of power in the system are addressed. The model represents reliably the behavior of the microgrid and several improving actions are suggested.
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Wang, Zhuding. "Distribution system planning a set of new formulations and hybrid algorithms /." online access from Digital Dissertation Consortium access full-text, 2000. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?9994047.
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Amin, Mahmoud. "Efficiency and Power Density Improvement of Grid-Connected Hybrid Renewable Energy Systems utilizing High Frequency-Based Power Converters." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/600.
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High efficiency of power converters placed between renewable energy sources and the utility grid is required to maximize the utilization of these sources. Power quality is another aspect that requires large passive elements (inductors, capacitors) to be placed between these sources and the grid. The main objective is to develop higher-level high frequency-based power converter system (HFPCS) that optimizes the use of hybrid renewable power injected into the power grid. The HFPCS provides high efficiency, reduced size of passive components, higher levels of power density realization, lower harmonic distortion, higher reliability, and lower cost.
The dynamic modeling for each part in this system is developed, simulated and tested. The steady-state performance of the grid-connected hybrid power system with battery storage is analyzed. Various types of simulations were performed and a number of algorithms were developed and tested to verify the effectiveness of the power conversion topologies. A modified hysteresis-control strategy for the rectifier and the battery charging/discharging system was developed and implemented. A voltage oriented control (VOC) scheme was developed to control the energy injected into the grid. The developed HFPCS was compared experimentally with other currently available power converters. The developed HFPCS was employed inside a microgrid system infrastructure, connecting it to the power grid to verify its power transfer capabilities and grid connectivity. Grid connectivity tests verified these power transfer capabilities of the developed converter in addition to its ability of serving the load in a shared manner.
In order to investigate the performance of the developed system, an experimental setup for the HF-based hybrid generation system was constructed. We designed a board containing a digital signal processor chip on which the developed control system was embedded. The board was fabricated and experimentally tested. The system’s high precision requirements were verified. Each component of the system was built and tested separately, and then the whole system was connected and tested. The simulation and experimental results confirm the effectiveness of the developed converter system for grid-connected hybrid renewable energy systems as well as for hybrid electric vehicles and other industrial applications.
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Woo, Wangmyong. "Hybrid Digital/RF Envelope Predistortion Linearization for High Power Amplifiers in Wireless Communication Systems." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6924.
Full textAbstract:
Hybrid Digital/RF Envelope Predistortion Linearization for High Power Amplifiers in Wireless Communication Systems
Wangmyong Woo
151 Pages
Directed by Dr. J. Stevenson Kenney
The objective of this research is to implement a hybrid digital/RF envelope predistortion linearization system for high-power amplifiers used in wireless communication systems. It is well known that RF PAs have AM/AM (amplitude modulation) and AM/PM (phase modulation) nonlinear characteristics. Moreover, the distortion components generated by a PA are not constant, but vary as a function of many input conditions such as amplitude, signal bandwidth, self-heating, aging, etc. Memory effects in response to past inputs cause a hysteresis in the nonlinear transfer characteristics of a PA. This hysteresis, in turn, creates uncertainty in predictive linearization techniques. To cope with these nonlinear characteristics, distortion variability, and uncertainty in linearization, an adaptive digital predistortion technique, a hybrid digital/RF envelope predistortion technique, an analog-based RF envelope predistortion technique, and a combinational digital/analog predistortion technique have been developed.
A digital adaptation technique based on the error vector minimization of received PA output waveforms was developed. Also, an adaptive baseband-to-baseband test system for the characterization of RF PAs and for the validation of linearization algorithms was implemented in conjunction with the adaptation technique. To overcome disadvantages such as limited correction bandwidth and the need for a baseband input signal in digital predistortion, an adaptive, wideband RF envelope predistortion system was developed that incorporates a memoryless predistortion algorithm. This system is digitally controlled by a look-up table (LUT). Compared with conventional baseband digital approaches, this predistortion architecture has a correction bandwidth that is from 20 percent to 33 percent wider at the same clock speeds for third to fifth order IMDs and does not need a digital baseband input signal.
For more accurate predistortion linearization for PAs with memory effects, an RF envelope predistortion system has been developed that uses a combination of analog-based envelope predistortion (APD) working in conjunction with digital LUT-based adaptive envelope predistortion (DPD). The resulting combination considerably decreases the computational complexity of the digital system and significantly improves linearity and efficiency at high power levels.
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Lam, Chi Seng. "An adaptive low dc-voltage controlled LC coupling hybrid active power filter in three-phase four-wire power systems." Thesis, University of Macau, 2012. http://umaclib3.umac.mo/record=b2580608.
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Gallo, Gaetano. "Impact of 48V E/E systems in Hybrid Racing Cars." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Find full textAbstract:
In this work, the possible benefits and drawbacks of 48 Volt E/E systems in MotorSport will be analyzed.
MotorSport has always been a lauchpad for new technologies, and in recent years the necessity to increase the electrical power on cars has become a key study topic.
Increasing the voltage level is one possible solution to mitigate the downsides of increased power.
In this dissertation the technologies currently available on the market will be analyzed, with a focus on 48 Volt systems that are already deployed on hybrid vehicles.
Subsequently, a real racing car E/E architecture will be analyzed and the impact of an installation of a 48 Volt system will be evaluated.
There follows a discussion on vehicle power supply technologies that are already available and the challenges of the supply systems for the future, ending with a set of simulations and considerations about the power supply system of the car under
evaluation.
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Radi, Mohammed A. M. "Power electronics considerations for voltage regulation and VAR control approaches in LV distribution networks-hybrid power electronic modules." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/14697.
Full textAbstract:
The future substation depends on finding a way to mitigate the effects of the drawbacks of the conventional legacy by employing the efficiency of the solid state switches in light of changing the loading features by time such as Electrical Vehicles (EV) and Photo-voltaic (PV) cells. In distribution transformers the ratio between the primary voltage and the secondary voltage cannot be changed, and the use of the on-load taps changers are limited. Poor voltage regulation and reactive power transmission is a direct reason for losses and shortening the life of several devices. This research discusses the considerations of applying Power Electronics (PE) approaches and designs that provide additional functions in regulating the voltage and controlling the reactive power that is injected in the distribution network, using embedded fractional rated converters attached partially with the windings of the LV transformer. These approaches studies the possible considerations that have the potentials to enhance the unit with more flexibility in controlling the voltage and reactive power at the last mile of the network, in order to decrease the losses and meet the future expectations for low voltage networks modifications, and that by using a Power Electronic (PE) approach has less losses and more functionality depending on the reliability of transformer and intelligence of PE solutions. The approach of a hybrid distribution transformer is introduced and its functionality in regulating the voltage and injecting reactive power is illustrated. A back-to-back converter is controlled according to the immediate need for voltage control and reactive power in Low Voltage (LV) networks, and for the purpose of controlling three unbalanced phases using two control strategies; resonant controller and vector control. The overall controller adds or decreases voltage (10%-20%) to/from the total output voltage in order to control the whole output voltage of the transformer. In addition, some loads need high amount of reactive power at last mile of the network, therefore the consideration of using switched capacitors technique is introduced to serve at the end user side whereby its ability to provide automatic variable reactive power compensation in a closed loop system is illustrated. The considerations results indicate significant potentials for deploying PE in the last mile of the network by using innovative designs and suitable control functions with less losses and costs.
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Sharma, Hiteshi. "Stand-alone hybrid energy systems." Thesis, 2018. https://dspace.library.uvic.ca//handle/1828/9206.
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Portugal is highly dependent on imported fuels when it comes to the energy sector. The
government continuously aims at creating a sustainable and competitive renewable energy
system. The need for balancing the supply and load demand in the electrical sector is
a priority. To promote economic development in Portugal, the government always intend
to initiate new projects like the construction of the solar plant. The United Kingdom
(UK) solar company WELink Energy will develop a 220MW solar plant in south Portugal
and have signed an Engineering, Procurement and Construction (EPC) agreement with
China Triumph International Engineering Cooperation (CTIEC). There are 4 ongoing solar
projects in Algarve that will produce enough electricity to ful ll the load demand. The
problem that the government is facing is the expansion of hybrid power system using other
renewable resources in order to overcome climatic changes. In order to design a hybrid
system, it is very important for the government to consider the minimum net present cost
con guration for ful lling the load demand. The standalone hybrid system consists of a
photovoltaic array (PV), a wind turbine (WT), a diesel generator (DG) and a battery.
Di erent scenarios have been considered using HOMER software to obtain the lowest net
present cost of the hybrid system. The results will establish the con guration to eradicate
the problems the villagers are undergoing due to unavailability of electricity. This will lead
to enhanced job opportunities and better living conditions in Algarve.Graduate
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Cheng, Meng-Chia, and 鄭孟佳. "Power Systems Reactive Power Dispatch Using a Hybrid Differential Evolution Method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/41480999861567779020.
Full textAbstract:
碩士崑山科技大學
電機工程研究所
99
This thesis applies a hybrid differential evolution (HDE) method to the optimal reactive power dispatch (ORPD) problem. Based on the minimization of active power transmission losses or the other objectives, the reactive power dispatch is to adjust control variables subjected to some operating constraints. Basically, it is classically a mixed-integer and nonlinear programming problem. Its objectives not only posses nonlinear characteristic, but also exist multiple local optimum. Since HDE is an excellent optimization tool, it is very suitable to deal with the ORPD problem. To verify the effectiveness of the proposed method, comparisons will be made to the basic DE and particle swarm optimization (PSO) methods. Testing on IEEE 30-bus 6-generator and TPC-345 kV simplified systems have indicated that the HDE method is superior to the basic DE and PSO methods in terms of convergence stability and solution quality.
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Yang, Alvin, and 楊國平. "Solar and Wind Hybrid Power Systems and Application." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/15792049283015613188.
Full textAbstract:
碩士中華科技大學
電子工程研究所碩士班
99
After centuries of human development of the industrial revolution,the 21st century, the rise of emerging countries, the demand for energyfaster than the previous human history contained; but in the face of global warming and environmental issues become increasingly strict, clean energyhas become a major issue humanity this century, Although some developedcountries use subsidies to the development of renewable energy use, then still only a minority of its energy needs. According to statistics,between the earth an energy of the sun's bright sunshine 5x1025 kwh, the surface wind can provide 53x1013kwh, 2020 Estimation of human energy needs each year is about 26x1013kwh, only half of the global wind energy can be developed, but only for its solar Hundreds of millions of points of a soabundant and clean energy, if properly increase the use, will significantly reduce the organic pollution of the Earth's environment petrochemicals.February 2005 "Kyoto Protocol" into effect, specific provisions in most countries of carbon dioxide and five other greenhouse gas reduction targets, the human responsible for the global sustainable development as a positive; natural addition to developing clean energy sources, improve energy use Efficiency is also an important issue, open source, cutting two-pronged approach, I believe that the Earth will be in our joint efforts, will be more suitable for continuing evolution of each species, growth. This far as solar energy, wind energy system, Research and Analysis section, and the advantages of combining, the two main activities for the human ― food and shelter, the effect caused by the Research and Analysis to provide information
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Chen, Yi-Huan, and 陳以桓. "MPPT Control for Hybrid Wind Power Generation Systems." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/38903316412187895944.
Full textAbstract:
碩士中原大學
電機工程研究所
101
The purpose of this thesis is to design a maximum power point tracking (MPPT) controller for wind power generation systems in a hybrid energy structure. First, a rotor speed estimation is designed for the wind power generation system for speed sensorless MPPT control. Then, based on the estimated generator speed , a reference current for maximum power point operation is obtained. Accordingly, a boost converter along with sliding mode current controller is used for the MPPT. In detail, the super-twisting sliding mode observer and the second-order sliding mode observer are designed for generator speed estimation. The two observers assure finite-time convergent stability. As a result, the reference current of the maximum power point can be determined on-line. For the MPPT, the sliding mode current controller is developed for the boost converter which is parallel with the other boost converter from battery source. In the hybrid energy structure, the wind power system is always assured in the maximum power operation while the battery source will compensate the lacked power. To verify the validty of the developed system, the simulations and experiments are done by Matlab software and dSPACE DS1103 DSP card. Finally, some comparisons are performed in this thesis.
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Chen, Han-Che, and 陳漢哲. "Development and Optimization of Customized Hybrid Power Systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/13136911373569956114.
Full textAbstract:
碩士國立臺灣大學
機械工程學研究所
103
This thesis develops a hybrid power model that includes PEMFC, secondary battery set, DC/DC converter, PV arrays, chemical hydrogen production system and DC/AC inverter. We can apply the developed hybrid model to estimate the system responses and effectively reduce the cost and time of system development. First, we built an experimental system that includes a 3kW PEMFC, 15Ah Li-Fe battery set, 1.32kW PV arrays and chemical hydrogen production system. The results showed that the hybrid system can provide sustaintable electricity. Second, we develop a hybrid power model by Matlab/SimPowerSystemTM, and tune model parameters based on experimental data. We further conduct several experiments for model verification, and show that the hybrid power model can successfully predict the system responses. Therefore, we can apply the developed power model for customized hybrid power systems for cost analysis and model optimization. The system cost consists of the initial cost of each components and the operating cost during the system operation period. Considering different loading requirements, we can modify the sizes of PV arrays and battery capacities to minimize system cost, and analyze the influence of different power management strategies. In addition, we consider hydrogen price and discuss its impacts on developing hybrid power systems. Because experimental verification of customized power systems can be very costly and time consuming, the developed hybrid system model can be applied to reduce the cost and time of developing customized power systems.
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Hsieh, Yi-Lin, and 謝易霖. "A Remote Anemometer Based on Hybrid Power Systems." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/03806491108611434253.
Full textAbstract:
碩士淡江大學
電機工程學系碩士班
104
At high altitude, many meteorological stations have set, but they still rely on the external electrical power supply, which causes them a construction limitation. To overcome the problem of the power supply and long-range communication, we employ the optical fiber due to its electromagnetic immunity and transmission loss much better than copper wire. Additionally, its raw material is silicon, a significant amount, easily mined, so the price is very low. The design goal is to achieve remote environmental monitoring and green energy supply at a meteorological station. Even though the green energy supply is insufficient to support communication, the proposed scheme based on hybrid power systems will still communicate the monitored information back to central control office. Thus we discuss the remote anemometer based on hybrid power systems, including the wind power and optical power pumping systems. A miniature horizontal axis wind turbine, whose output electrical signal can directly drive the laser diode, generates the wind power and wind speed information. The output light of the laser diode via the optical fiber propagates back to the post-processing unit of central control office so as to measure the monitored wind speed. If the wind power is too low to enable the valid information back, the optical power pumping system at central control office can alternatively activate and bias the laser diode. Therefore, this paper has demonstrated the remote anemometer based on hybrid power systems, whose optical power pumping system can successfully act as an auxiliary power.
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Almeida, Rita. "Large power hybrid PV pumping for irrigation." Doctoral thesis, 2018. http://hdl.handle.net/10451/41762.
Full textAbstract:
The aim of this thesis is to develop technical solutions for the reliable and efficient performance of large-power hybrid photovoltaic (PV) irrigation systems. These solutions have been applied to the design and implementation of two real-scale large-power hybrid PV drip irrigation demonstrators – a 140 kWp hybrid PV-diesel system in Alter do Chão, Portugal, and a 120 kWp hybrid PV-grid system in Tamelalt, Morocco.
Both systems have been working since 2016 and include monitoring systems. In order to do a technical and economic validation of the systems from these monitoring data, it has been necessary to develop new performance indices because, unlike PV grid-connected systems, the operation of this type of systems is affected by factors others than its quality. So, the typical performance ratio (PR) has been factorized in 4 distinct indicators: PRPV (which includes the losses strictly related with the PV system), URIP (which varies with the particular crop and the irrigation period), URPVIS (which is intrinsic to the PVIS design), and UREF (which gives an idea of the use of the system, it is influenced by the monthly irrigation scheduling and the availability of water in the source).
The main technical solutions developed include first, an algorithm that allows the elimination of the problems associated with PV-power intermittences caused, for example, by a passing cloud; second, the match between PV production and irrigation needs through the use of a North-South horizontal axis tracker (N-S); and third the integration of the PV system in the pre-existing irrigation network through solutions which maximize the use of PV energy.
This thesis is structured in 2 different parts. The first one presents the results of the technical and economic validation of the demonstrators. In Portugal, the PV share (PVS) during the irrigation period is 0.49 (in 2017) and 0.36 (in 2018), and the PR is 0.16 (in 2017) and 0.22 (in 2018) extremely influenced by the use of the system (UREF of 0.29 and 0.44 respectively). In Morocco, in 2017 and 2018, the PVS is 0.48 and 0.55, and the PR is 0.24 (with a UREF of 0.32) and 0.29 (UREF of 0.36) respectively. The economic results show an initial investment cost of 1.2 €/Wp, a payback period of 8.8 years in Portugal and 7 in Morocco and, finally, a Levelized Cost of Energy of 0.13 €/kWh in Portugal and 0.07 €/kWh in Morocco, which leads to savings of 61% and 66% in Portugal and Morocco respectively.
In the second part of the thesis, three other novel contributions for the design of large-power PV irrigation systems are made. The first one is a new type of PV generator structure, the Delta structure, which has the objective to achieve constant in-plane irradiance profiles when the end-users do not want to install trackers. It is worth noting that the peak power needed in this structure to achieve the same water volume of the N-S tracker is lower than the one needed with the typical static structure oriented to the Equator.
The second study evaluates the losses in a PV irrigation system depending on the number of PV modules in series of a PV generator. It is possible to conclude that these losses are irrelevant in most situations, casting doubts about the complex designs that are being offered by the market to avoid them. In places with very high mean temperatures, in a stand-alone PV system, these losses can be eliminated with the increase in the number of PV modules in series. On the other hand, in a hybrid PV-grid system it is impossible to eliminate the losses, but they can be minimized.
Finally, a new pump selection method for PV irrigation systems working at a variable frequency is proposed. A simulation exercise carried out for three different places in the Mediterranean zone shows that the water volume pumped by a PV irrigation system with a pump selected with this new method is 7.3 to 20.5% higher than the one pumped with the pump selected with the traditional method.
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Chang, Yu-Ming, and 張育銘. "Planning unit commitment of hybrid power systems in Penghu." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/93394334730237616504.
Full textAbstract:
碩士東南科技大學
電機工程研究所
102
Penghu is one of the mainly Taiwanese outlying island, also the biggest stand-alone power system except Taiwan, it’s mainly powered by twelve diesel engine generators in Chienshan power plant. For efficiently use the wind power in Penghu, it built eight 600kW and six 900kw wind turbines to the system one after another, but because the wind turbines peak load are no output in summer, and off-peak are the biggest output that can’t load in winter, so the plan isn’t considered to integrated into the wind farm in Penghu, and as far as Penghu, every diesel engine generators in Chienshan power plant is large. In particular in off-peak period, it cause the Generator power in total Power generation ratio over loaded, when system happened diesel engine generators trip disturbances, or all wind turbines tripped, it cause the seriously Impact to system frequency. In this paper, we used the power system analyze software PSS/E (Power System Simulator for Engineering) to simulate that use many of the small generators replace the large generators in Chienshan power plant to reduce the Generator power in total Power generation ratio, when system happened trip disturbances, it reduce the effect to the frequency, the simulate result can provide to Taiwan Power Company for reference of upgrade.
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Lai, Chieh-Ting, and 賴玠廷. "A Process Integration Technique for Targeting Hybrid Power Systems." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/93698370525896376588.
Full textAbstract:
博士國立臺灣大學
化學工程學研究所
104
In recent years, renewable energy (RE) has been proposed to address global warming and energy shortage problems. However, to solve the discontinuity and unpredictability of RE, researchers and industries problems have integrated RE with public grid electricity to develop a hybrid power system (HPS). This study applies mathematical programming (MP) to the design of HPS to find the optimal targets and power distribution, which includes the minimum electricity outsourced from the grid and the minimum capacity for electricity storage. Two mathematical models—condensed transshipment model (CTM) and expanded transshipment model (ETM)—are developed to solve HPS optimization problems by making use of the design concept of traditional chemical heat exchanger networks (HEN''s). ETM is divided into two categories: those with single storage equipment (ETM1) and those with multiple equipment (ETM2). Two types of HPS are considered in this study: those involving no electricity loss (the ideal type) and that involving three types of loss (charging/discharging electricity loss, and self-discharging loss). Recently, many researchers use power pinch analysis (PPA) method to solve HPS optimization problems. This method uses a tremendous amount of procedures to calculate physical quantities, which renders this method complicated and time-consuming. To deal with the disadvantages of PPA, this article considers all the supply electricity routes in CTM and ETM, and establishes mathematical models using mathematical programming (MP). With the construction of CTM and ETM models in General Algebraic Modeling System (GAMS), the optimized results of HPS can be obtained nearly instantly, indicating the indispensability of MP. Adjusting the parameters of ETM2, we can consider different types of energy storage devices (e.g.: battery, reservoirs, etc.) and different types of public grids in HPS, in which the costs of energy and equipment can be analyzed for later design. Most parameters in this article—including charging and discharging recovery ratios, and self-discharging recovery ratios—are assumed to be constant. In the future research, these parameters can be thought to be variables to establish a more complete HPS.
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Lin, Po-Yuan, and 林柏元. "Analogical Analysis and Design for Mechanical Hybrid Power Systems." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/19275071409905270776.
Full textAbstract:
碩士臺灣大學
機械工程學研究所
98
The purpose of this research is to develop a method for analyzing and designing mechanical hybrid power systems by the analogism from a mechanical system to an electrical system. At the beginning of the research, two kinds of the mechanical coupling are analyzed and discussed on the characteristics of the system with different couplings. Secondly, there are two reasons to develop a rule which can quickly translate a mechanical system into an electrical system from a viewpoint of a mechanical system. One is to understand the power deployment through the simplification of the system. The other is to apply the methods of analyzing electrical systems to the analysis of the mechanical system. Next, another rule is developed to translate a electrical system back into a mechanical system and the deployment of hybrid power is designed from a viewpoint of electrical systems. Finally, an innovative or improved design of a hybrid system can be developed by translating the designed circuit system back into a mechanical system. The contribution of this research is the development of a method to analyze and design a mechanical hybrid system by applying the analysis methods of electrical system. A multimode hybrid system can be quickly designed and existing hybrid systems can be improved by the application of this method.