Rozprawy doktorskie: „Transmission Power Control”

1

Matthews, S. R. "Harmonic control on power systems". Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295421.

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Kreikebaum, Frank Karl. "Control of transmission system power flows". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50392.

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Power flow (PF) control can increase the utilization of the transmission system and connect lower cost generation with load. While PF controllers have demonstrated the ability to realize dynamic PF control for more than 25 years, PF control has been sparsely implemented. This research re-examines PF control in light of the recent development of fractionally-rated PF controllers and the incremental power flow (IPF) control concept. IPF control is the transfer of an incremental quantity of power from a specified source bus to specified destination bus along a specified path without influencing power flows on circuits outside of the path. The objectives of the research are to develop power system operation and planning methods compatible with IPF control, test the technical viability of IPF control, develop transmission planning frameworks leveraging PF and IPF control, develop power system operation and planning tools compatible with PF control, and quantify the impacts of PF and IPF control on multi-decade transmission planning. The results suggest that planning and operation of the power system are feasible with PF controllers and may lead to cost savings. The proposed planning frameworks may incent transmission investment and be compatible with the existing transmission planning process. If the results of the planning tool demonstration scale to the national level, the annual savings in electricity expenditures would be $13 billion per year (2010$). The proposed incremental packetized energy concept may facilitate a reduction in the environmental impact of energy consumption and lead to additional cost savings.

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Liao, Rui. "Transmission power control in wireless networks". Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/558.

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Ad hoc wireless networks have emerged as a promising communication scheme to meet the ever growing portability and infrastructureless demand of wireless services. The transmission power level affects signal quality and interference which causes congestion and thus impacts the communication performance. Hence, power control has been the focus of extensive research. In this thesis, we examine the problem of power control in wireless networks, specially in ad hoc wireless networks. Two important types of power control, which are power control with fixed SNIR targets and power control with variable SNIR targets, are discussed in the thesis. We first introduce some important techniques and results involved in the development of power control algorithms and give literature review. A PI power control approach from literature is introduced. Due to lack of stability analysis, we show there are problems in the existing algorithm. We then propose a stable Proportional-integral (PI) power control algorithm. A forgetting factor is adopted to improve the transient performance. Distributed power control algorithms for systems with fixed SNIR targets might diverge when the feasibility condition is not satisfied. Multi-objective optimisation (MO) is adopted to deal with power control with variable SNIR targets. After discussing the existing MO algorithm, we propose a quadratic multiobjective-optimisation (QMO) algorithm where a quadratic objective function and the greedy methodology are adopted for the dynamics. Theoretical and simulation results of convergence of the new algorithms are given. We also provide review of some important power control frameworks which can be used to show convergence of power control algorithms. However, the QMO algorithm does not fall into any existing framework. In order to show convergence of the QMO algorithm, we suggest a new generalised framework in this thesis.

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Liu, Haifeng. "Planning reactive power control for transmission enhancement". [Ames, Iowa : Iowa State University], 2007.

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Souccar, Karim. "Transmission power control for wireless sensors networks". [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001664.

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Terra, Luiz Danilo Barbosa. "A global methodology for reactive power management and voltage control in power systems". Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47685.

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Yuan, Yin. "Transmission power control in wireless ad-hoc networks /". View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20YUAN.

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Horner, Jane Louise. "Vibrational power transmission through beam-like structures". Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253408.

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Berggren, Fredrik. "Power control, transmission rate control and scheduling in cellular radio systems". Licentiate thesis, KTH, Signaler, sensorer och system, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1240.

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Gow, John A. "Modelling, simulation and control of photovoltaic converter systems". Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/6871.

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The thesis follows the development of an advanced solar photovoltaic power conversion system from first principles. It is divided into five parts. The first section shows the development of a circuit-based simulation model of a photovoltaic (PV) cell within the 'SABER' simulator environment. Although simulation models for photovoltaic cells are available these are usually application specific, mathematically intensive and not suited to the development of power electronics. The model derived within the thesis is a circuit-based model that makes use of a series of current/voltage data sets taken from an actual cell in order to define the relationships between the cell double-exponential model parameters and the environmental parameters of temperature and irradiance. Resulting expressions define a 'black box' model, and the power electronics designer may simply specify values of temperature and irradiance to the model, and the simulated electrical connections to the cell provide the appropriate I/V characteristic. The second section deals with the development of a simulation model of an advanced PVaware DC-DC converter system. This differs from the conventional in that by using an embedded maximum power tracking system within a conventional linear feedback control arrangement it addresses the problem of loads which may not require the level of power available at the maximum power point, but is also able to drive loads which consistently require a maximum power feed such as a grid-coupled inverter. The third section details a low-power implementation of the above system in hardware. This shows the viability of the new, fast embedded maximum power tracking system and also the advantages of the system in terms of speed and response time over conventional systems. The fourth section builds upon the simulation model developed in the second section by adding an inverter allowing AC loads (including a utility) to be driven. The complete system is simulated and a set of results obtained showing that the system is a usable one. The final section describes the construction and analysis of a complete system in hardware (c. 500W) and identifies the suitability of the system to appropriate applications.

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Gunaratne, Chanaka Sujidhara Rajasinghe. "Traffic-based SIR measurement for power control in W-CDMA". Thesis, University of Surrey, 2002. http://epubs.surrey.ac.uk/844316/.

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Accurate and fast power control is perhaps the most important aspect in W-CDMA, in particular on the uplink. This thesis describes the work earned out to evaluate and enhance the link-level performance of closed-loop power control (CLPC) for the UMTS-FDD uplink. Factors that influence the performance of the CLPC scheme amongst others include the round-trip delay, UE (User Equipment) speed, dynamic range of the handset, the level of diversity available at the receiver and the accuracy of SIR (Signal-to-Interference-plus-Noise Ratio) estimation and channel estimation. The above-mentioned performance improvement is obtained by focussing on the SIR measurement aspect of the power control scheme, and to this end, two new signal quality estimation techniques are proposed and evaluated. Based on the two algorithms, a further comparison is made to investigate the effects of SIR measurement before and after RAKE combining of the signal. Firstly, an improved Eb/N0 estimator is proposed and its performance evaluated both in a stationary (Gaussian) as well as a Rayleigh channel. The improvement in the estimator's performance is obtained by the addition of a smoothing filter to an existing algorithm. The improved algorithm, based on maximum likelihood estimation, is shown to improve the performance of CLPC with an average gain of 0.25 dB (i.e. the average gain for a range of UE speeds) in the power control error (PCE) in a narrowband channel, over the performance without the filter; the algorithm would also offer gains in the wideband channel when the SIR measurement is done before RAKE-combining of the signal. The second algorithm is a traffic-based SIR measurement scheme, so-called because it uses a dedicated traffic channel for the SIR measurement, and hence specific to UMTS-FDD. Again, using the standard deviation of the PCE as the performance metric, it is shown that this scheme achieves gains in the PCE of up to 1.4dB (1.15dB on average) for the 4.75-12.2kbps speech service and up to 2.75dB (2.5dB on average) for 144kbps data, both in UMTS Vehicular environments. The gains achieved are with respect to the performance obtainable with the SIR measurement technique proposed by 3GPP (using dedicated pilot symbols), and they translate to improvements in the CDMA capacity at system-level. Furthermore, the algorithm, which currently assumes perfect blind rate detection, provides a higher improvement in the performance of CLPC for higher data rates (as the figures exemplify), which is an additional advantage since higher data-rate users cause more interference to the network by transmitting higher powers. Results obtained using the PCE performance metric also indicate that the higher path diversity available in W-CDMA (compared to narrowband systems) does not necessarily convert to improved system performance, especially when combining weak taps in the channel, i.e. the performance either stays the same or somewhat degrades. Finally, using the uncoded bit error rate (BER) as the performance metric, two further SIR measurement techniques, both based on variations of the two algorithms discussed earlier, are proposed and compared. The Pre-RAKE scheme, in which the SIR measurement is carried out before RAKE combining of the signal vs. the Post-RAKE scheme where the measurement is carried out after, are compared. The overestimation problem that occurs with the Pre-RAKE scheme is highlighted; hence, it is concluded that Post-RAKE schemes offer superior performance over their Pre-RAKE counterparts. The work has highlighted several issues that need careful consideration as far as SIR measurement is concerned, whether it be for power control or any other radio resource management technique; the overestimation problem which occurs for low SIR values as well as the issue of the number of symbols available for the measurement, can contribute significantly to the SIR measurement error, degrading the performance of CLPC in turn. In addition, it is also useful to have an idea of how much the true SIR can vary within the duration of measurement. Last but not least, the little or no improvement in performance obtained when combining weak taps is attributed to the performance and robustness of the channel estimation algorithms employed; they tend to add more noise than signal power to the RAKE-combined signal when used to combine paths with low Eb/N0 values. The SIR measurement algorithms proposed and discussed in this thesis can be implemented directly in UMTS receivers. On the other hand, the knowledge and information contained herein and the logical approaches considered can lead to the development of new ideas as well as new algorithms.

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Hasanovic, Azra. "Modeling and control of the unified power flow controller (UPFC)". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1633.

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Thesis (M.S.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains viii, 78 p. : ill. Includes abstract. Includes bibliographical references (p. 61-63).

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Mohd, Siam Mohd Fadzil. "The control of a static var compensator and active power filter". Thesis, Heriot-Watt University, 1998. http://hdl.handle.net/10399/1210.

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Abdelaal, Ashraf Khalil Ibrahim. "Expert system applications to electrical power system voltage control and security". Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366882.

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Xiao, Ying. "Operational optimisation of FACTS control for improving transmission services". Thesis, Brunel University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367885.

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Eriksson, Robert. "Coordinated Control of HVDC Links in Transmission Systems". Doctoral thesis, KTH, Elektriska energisystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-30625.

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Dynamic security limits the power transfer capacity between regions and therefore has an economic impact. The power modulation control of high-voltage direct current (HVDC) links can improve the dynamic security of the power system. Having several HVDC links in a system creates the opportunity to coordinate such control, and coordination also ensures that negative interactions do not occur among the controllable devices. This thesis aims to increase dynamic security by coordinating HVDC links, as an alternative to decreasing the transfer capacity. This thesis contributes four control approaches for increasing the dynamic stability, based on feedforward control, adaptive control, optimal control, and exact-feedback linearization control. Depending on the available measurements, dynamic system model, and system topology, one of the developed methods can be applied. The wide-area measurement system provides the central controller with real-time data and sends control signals to the HVDC links. The feedforward controller applies rapid power dispatch, and the strategy used here is to link the N-1 criterion between two systems. The adaptive controller uses the modal analysis approach; based on forecasted load paths, the controller gains are adaptively adjusted to maximize the damping in the system. The optimal controller is designed based on an estimated reduced-order model; system identification develops the model based on the system response. The exact-feedback linearization approach uses a pre-feedback loop to cancel the nonlinearities; a stabilizing controller is designed for the remaining linear system. The conclusion is that coordinating the HVDC links improves the dynamic stability, which makes it possible to increase the transfer capacity. This conclusion is also supported by simulations of each control approach.
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Eriksson, Robert. "Security-centered Coordinated Control in AC/DC Transmission Systems". Licentiate thesis, Stockholm : Royal Institute of Technology, 2008. http://kth.diva-portal.org/smash/record.jsf?searchId=4&pid=diva2:101.

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Elders, Ian Michael. "The use of intelligent systems in control and management of power systems". Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248724.

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Foster, Justin M. "Control systems in power markets: demand response, transmission topology control, and renewable integration". Thesis, Boston University, 2012. https://hdl.handle.net/2144/31554.

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Thesis (Ph.D.)--Boston University
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
National directives emphasizing improved power grid sustainability, reliability, and economic performance motivate innovative research directions in demand response and renewable generation integration. In addition, advances in computing capabilities render feasible new techniques for long standing power market problems. This dissertation proposes and evaluates several novel decision support policies, balanced between improving existing power market operation and preparing for forthcoming technologies and capabilities. In particular, this dissertation considers (i) demand-side decision support and (ii) tractable transmission topology control. The first part of this dissertation uses dynamic programming and duality theory to develop a decision support framework for a load aggregator (LA) managing flexible loads sharing the same short-term capacity constraints -- and in particular -- plug-in electric vehicles (PEVs). The LA submits inflexible and flexible bids to a liberalized hour-ahead power market, while monitoring localized network constraints. Flexible bids are associated with a reservation price and the market clears these bids as a combination of energy demand and capacity reserve, as energy only, or rejects the bid entirely. By allowing the market operator to dispatch PEVs, this strategy provides an effective means for coordination with centralized renewable generation. In addition, the provision of voltage support in the presence of distributed solar arrays is considered. The second part of this dissertation develops sensitivity- or gradient-based algorithms aimed at reducing congestion costs by tractably including topology control in the economic dispatch. Currently, the economic dispatch minimizes generation costs subject to transmission constraints, where the status of each line, i.e., open or closed, is fixed. Recent research shows that by optimally dispatching the network topology along with generation resources, significant congestion costs may be avoided. Optimal transmission topology control requires the solution of a mixed integer program which is computationally intractable for real-sized power networks; however, it appears that much of the cost savings may be attained by changing the status of just a few appropriately selected lines. Therefore, this dissertation proposes tractable transmission topology control policies, which employ sensitivity information readily available from the economic dispatch to select candidate lines to change status.
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Prieto, Araujo Eduardo. "Power converter control for offshore wind energy generation and transmission". Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/396110.

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This thesis discusses the control of different power converters that will have a key role in future offshore wind power systems, enabling the integration of the power generated by the wind turbines into the mainland grid. First, an overview of the evolution of wind turbines is presented, from the first prototypes to the latest topologies in use. Then, a new decentralized control strategy of a triple three-phase permanent magnet synchronous generator, a machine topology specifically designed for offshore wind, is presented. The proposed controller is tested on a wind turbine emulator with a scaled down 30 kW nine-phase generator. It has been suggested that future wind power plants could use medium voltage DC collection networks. These would require DC/DC converters to adapt the voltages between the turbine output and the DC collection grid. Based on this idea, the control design of a DC/DC Dual Bridge Series Resonant Converter (DBSRC) unit is developed and tested in a scaled 50 kW converter prototype. The availability of significant energy resources far from the coast favors the idea of creating offshore wind farms. This poses important technical and economical challenges. To this end, Voltage Source Converter-based High Voltage Direct Current (VSC-HVDC) technology enables high power transmission across distances where High Voltage Alternating Current (HVAC) is impractical. The Modular Multilevel Converter (MMC) is the preferred topology to reach high AC and DC voltages. In this work, the control design of a half-bridge based MMC to enable the converter operation under both normal and unbalanced AC voltage conditions, is addressed. Finally, considering that many offshore wind power plants will be installed in the North Sea in the coming years, a multi-terminal HVDC grid interconnecting several production plants and different points of the mainland grid is envisaged. To deal with DC multi-terminal grid voltage stability, a methodology to address the grid primary voltage control design is proposed based on multivariable frequency methods which are able to evaluate the dynamic behavior of the system.
La present tesi tracta sobre el control dels diferents convertidors que tindran un paper essencial en els futurs sistemes eòlics marins, permetent la integració de la potència generada pels aerogeneradors a la xarxa terrestre. En primer lloc, es presenta un estudi sobre levolució dels aerogeneradors, des dels primers conceptes a les opcions en ús més modernes. A continuació, es detalla una estratègia de control descentralitzada d'una màquina síncrona d'imants permanents de triple estator trifàsic, una topologia específicament dissenyada per eòlica marina. La proposta de control es valida per mitjà d'un emulador de turbina eòlica juntament amb una màquina de nou fases a escala de 30 kW. En els darrers anys s'ha contemplat la possibilitat de que els futurs parcs eòlics emprin corrent continu dins la seva xarxa interna. Per tal de construir aquesta xarxa resulten necessaris convertidors d'adaptació DC/DC entre la sortida de la turbina i la xarxa interna del parc en corrent continu. En base a aquesta proposta, es realitza el disseny del control d'un convertidor DC/DC Dual Bridge Series Resonant Converter (DBSRC). Per validar els resultats obtinguts, es desenvolupa un prototip del convertidor a escala de 50 kW. L'alta disponibilitat de recursos eòlics en indrets allunyats de la costa, afavoreix la creació de nous parcs eòlics marins, fet que presenta reptes econòmics i tècnics importants. Amb aquesta finalitat, la tecnologia Voltage Source Converter High Voltage Direct Current (VSC-HVDC) permet realitzar la transmissió de potència salvant llargues distàncies, on la transmissió High Voltage Alternating Current (HVAC) no és adient. El Modular Multilevel Converter (MMC) és la topologia preferida per assolir altes tensions en AC i DC. En aquest treball, es desenvolupa el disseny del control d'un convertidor MMC amb cel¿les de mig pont per tal d'operar en presència de sots de tensió desequilibrats a la xarxa. Finalment, degut a que en un futur proper s'instal·laran al mar del Nord un gran nombre de parcs eòlics marins, es preveu la creació d'una gran xarxa multiterminal HVDC interconnectant diferents plantes de producció eòlica amb diferents punts de la xarxa terrestre. Per tal d'assegurar l'estabilitat de la xarxa, es proposa una metodologia de disseny del control primari de tensió de la xarxa basada en l'anàlisi freqüencial multivariable, capaç davaluar el comportament dinàmic del sistema.

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Kothandaraman, Arthi Roppel Thaddeus A. "An energy-efficient transmission power control protocol for cooperative robotics". Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/FALL/Electrical_and_Computer_Engineering/Thesis/Kothandaraman_Arthi_45.pdf.

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Guldbrand, Anna. "Analysis of an induction regulator for power flow control in electric power transmission systems". Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-5329.

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Controlling the power flow in transmission systems has recently gained increased interest. The difficulties of building new lines and the pressure of having a high utilization of existing assets, makes the flexibility of grid systems increasingly important.

This master thesis work investigates induction regulators as control devices for active power flow in a transmission system. A small change in angle of the rotor affects both the amplitude and the phase of the voltage. The magnetic coupling in the induction regulator can be controlled by changing the permeability of a thermo magnetic material such as gadolinium and can hence give a second independent controlling parameter. An analytical model and calculations in the

FEM software AceTripleC together with Matlab, is used to simulate the influence of the regulators connected to a simple grid in case1, a 400 kV scenario and case 2, a 45 kV scenario.

The analysis was carried out on a small transmission system consisting of two parallel transmission lines connected to source and load. The induction regulators are connected to one of the parallel transmission lines. The regulators modelled in case 1 must be able to control the active power flow in the regulated line to vary between 50 and 150 % of the original power flow through this line.

This shall be done over a range of 0 to 800 MW transmitted power. The regulators modelled in case 2 must be able to control the active power flow in

the regulated line to vary between 0 and 30 MW, if this does not cause the power flow in the parallel line to exceed 30 MW. This shall be done over a range of 0 to

50 MW transmitted power.

The regulators are designed as small and inexpensive as possible while still fulfilling requirements regarding the active power flow controllability in the grid, current density in windings and maximum flux density in core and gap.

The results indicate that the size of the 400 kV solution has to be reduced to become competitive whereas for the 45 kV solution the relative difference to existing solution is smaller. Advantages with the proposed design over a phase shifting transformer are mainly a simpler winding scheme and the absence of a tap changer.

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Kumbale, Murali. "Bulk transmission system reliability analysis of protection and control groups". Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/13840.

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Sweeney, Dennis G. "Adaptive power control as a fade countermeasure on satellite links". Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/39716.

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Tavakoli-Bina, Mohammad. "The bootstrap variable inductance : a new FACTS controller for AC power systems". Thesis, University of Surrey, 2001. http://epubs.surrey.ac.uk/1043/.

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Kalyani, Radha Padma. "A nonlinear optimization approach for UPFC power flow control and voltage security". Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/Kalyani_completeThesis_09007dcc80438f59.pdf.

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Thesis (Ph. D.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 29, 2007) Includes bibliographical references.

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Törnqvist, David. "Transmission Timing in WCDMA terminals". Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1592.

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Power control is one of the technologies used to utilize the radio resources as efficient as possible in WCDMA. The transmission power is adjusted to transmit with the lowest power level possible while the required received signal quality is maintained. Since there are large variation in channel quality over time, the power has to be adjusted to compensate for these variations. During moments of bad channel conditions a high transmission power has to be used which will to a greater extent interfere with other users in the system.

To solve this problem a concept called transmission timing was proposed. The basic idea is that the transmitter avoids data transmission during the short periods of bad channel conditions caused by fast fading. Higher bit rates can be used to compensate for this when the channel conditions are good.

In this thesis the performance of transmission timing applied to uplink data transmissions is evaluated. This is accomplished through a theoretical analysis as well as simulations of a cellular system using transmission timing. Lowered transmission power is achieved and thus lowered interference is induced. Simulations showed that the transmission power can be lowered by up to 1.6 dB compared to ordinary continuous transmission with equal average data rate. These results are however strongly dependent on the used radio environment. It is also showed that transmission timing provides increased system stability in case of rapid changes in the load situation.

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Babazadeh, Davood. "Distributed Control of HVDC Transmission Grids". Doctoral thesis, KTH, Elkraftteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-202753.

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Recent issues such as priority access of renewable resources recommended by European energy directives and increase the electricity trading among countries lead to new requirements on the operation and expansion of transmission grids. Since AC grid expansions are limited by legislative issues and long distance transmission capacity, there is a considerable attention drawn to application of HVDC transmission grids on top of, or in complement to, existing AC power systems. The secure operation of HVDC grids requires a hierarchical control system. In HVDC grids, the primary control action to deal with power or DC voltage deviations is communication-free and local. In addition to primary control, the higher supervisory control actions are needed to guarantee the optimal operation of HVDC grids. However, the implementation of supervisory control functions is linked to the arrangement of system operators; i.e. an individual HVDC operator (central structure) or sharing tasks among AC system operators (distributed structure). This thesis presents distributed control of an HVDC grid. To this end, three possible supervisory functions are investigated; coordination of power injection set-points, DC slack bus selection and network topology identification. In this thesis, all three functions are first studied for the central structure. For the distributed solution, two algorithms based on Alternating Direction Method of Multipliers (ADMM) and Auxiliary Problem Principle (APP) are adopted to solve the coordination of power injection. For distributed selection of DC slack bus, the choice of parameters for quantitative ranking of converters is important. These parameters should be calculated based on local measurements if distributed decision is desired. To this end, the short circuit capacity of connected AC grid and power margin of converters are considered. To estimate the short circuit capacity as one of the required selection parameters, the result shows that the recursive least square algorithm can be very efficiently used. Besides, it is possible to intelligently use a naturally occurring droop response in HVDC grids as a local measurement for this estimation algorithm. Regarding the network topology, a two-stage distributed algorithm is introduced to use the abstract information about the neighbouring substation topology to determine the grid connectivity.

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Liu, Jun Yong. "Modelling and control of united power flow controller for reinforcement of transmission systems". Thesis, Brunel University, 1997. http://bura.brunel.ac.uk/handle/2438/5225.

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The work involved in the thesis is concentrated on modelling and control of UPFC. The overall objective is to provide effective methods and tools for assessing the impact of UPFC in the reinforcement of transmission systems. The thesis clarifies modelling and control of UPFC into several subproblems, in which the associated models, algorithms and control strategies of UPFC have been systematically reviewed. An electromagnetic transient prototype model of the UPFC has been set up by using its detailed power electronic device as well as its internal closed-loop controller. The problems encountered in the process of building such a model and the way of handling them by EMTP have been discussed. This EMTP-based simulator of SPWM UPFC implemented has provided a useful tool to assist the development and validation of more detailed and practical model of the UPFC for further studies. The steady-state modelling and control for the UPFC has been developed, including: (i) The power injection model of the UPFC suitable for its implementation in an optimal multiplier power flow computation method has been derived in rectangular form. The effectiveness of the proposed algorithm has been compared with the user defined model method. (ii) A systematic method for deriving the control capabilities of the UPFC has been proposed based on predicting the feasibility limit of the system. Using an index derived from optimal multiplier, three dimensional diagrams describing the ranges have been obtained. The results are also verified through the singular value decomposition algorithm. (iii) A power injection model based control method (PIM) has been proposed and implemented to directly derive the UPFC parameters as so to achieve the control objectives. The assumptions, algorithmic process and validation of the PIM have been investigated in detail. Its pros and cons are also discussed. (iv) Five internal limits of the UPFC device have been derived as the constraints to its performance. A complete set of control rules considering these limits as well as their implementation in the PlM have been constructed to form the basis of optimal UPFC control strategies for its steady-state local control. All the above proposed methods are tested and validated on the IEEE 30-bus system, a practical 306-bus system and a meshed network. The thesis concludes by suggesting the future research areas in further UPFC studies.

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Aragüés, Peñalba Mònica. "Operation and control of transmission systems for offshore wind power plants". Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/393893.

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This thesis deals with grid integration of oshore wind power plants through HVDC (High Voltage Direct Current) or HVAC (High Voltage Alternating Current) transmission . The behaviour of wind farms and their transmission systems in normal operation and under faults is analyzed. On the eld of HVDC transmission , a control scheme based on an optimum voltage algorithm is proposed and compared to voltage droop control. The dierences between the proposed scheme and droop control in terms of losses are analyzed, in steady state as well as dynamically. This new control scheme is enhanced, being able to perform secondary and tertiary control strategies simultaneously for DC grids. Concerning HVAC transmission, the operation of AC connected wind power plants equipped with full power converter wind turbines is analyzed under deep voltage sags on the main AC grid. Standard control schemes, based on the strict application of grid codes, can lead to instability problems when this kind of severe disturbances occurs. A coordinated control scheme is proposed to operate the system, ensuring fault ride through capability. An index alerts of instability proximity and allows to actívate active power and reactive power regulation to guarantee safe operation during faults. For enabling the optimal operation of transmission systems, an optimal power flow tool is described for hybrid HVDC-HVAC systems, for different objective functions. This tool is tested in a scaled platform. Finally, the secure and optimal operation of these systems is analysed for a scenario with high penetration of oshore wind, proposing a methodology to evaluate the cost of operation and wind energy curtailed.
La present tesi tracta la integració a xarxa de plantes eòliques marines a través de transmissió en HVDC (Alta Tensió en Corrent Continu) o HVAC (Alta Tensió en Corrent Altern). S'analitza el comportament dels parcs eòlics i del seus sistemes de transmissió en condicions normal i en situacions de pertorbacions elèctriques. En el camp de l'HVDC, es descriu un esquema de control basat en un algorisme de tensions òptimes i es compara amb el control de tensió droop. Les diferències entre l'esquema de control proposat i el droop s'analitzen, des del punt de vista de pèrdues, en estat estacionari i dinàmicament. L'esquema de control proposat es millora, oferint la possibilitat de realitzar estratègies de control secundari i terciari en xarxes DC. Dins de la transmissió en l'HVAC, s'analitza l’operació de parcs eòlics equipats amb convertidors de plena potència quan s'esdevenen sots profunds a la xarxa AC. Els esquemes de control estàndards, basats en l’aplicació estricta dels requisits de connexió, poden comportar problemes d'estabilitat transitòria quan s'esdevenen pertorbacions severes. Es proposa un esquema de control coordinat per operar el sistema, assegurant el fault ride through. Un índex alerta de a de la proximitat d'una inestabilitat i permet activar la regulació de potencia activa i reactiva per assegurar l’operació segura durant la falta. Tenint en compte que l’expansió del sistema de transmissió presenta tant enllaços HVDC com HVAC, es desenvolupa una eina per determinar fluxos de potencia òptims en xarxes híbrides HVDC-HVAC, per diferents funcions objectiu. Es realitzen proves experimentals en una plataforma de baixa tensió per comprovar el funcionament d'aquesta eina. Finalment, s'estudia l’operació òptima i segura d'aquests sistemes, per un escenari amb gran penetració d'energia eòlica, proposant una metodologia per avaluar el cost d’operació i la reducció d'energia eòlica produïda.

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31

Xiao, Shuo Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Transmission power control in body-wearable sensor devices for healthcare monitoring". Publisher:University of New South Wales. Electrical Engineering & Telecommunications, 2008. http://handle.unsw.edu.au/1959.4/41104.

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Emerging body-wearable sensor devices for continuous health monitoring are severely energy constrained and yet required to offer high communication reliability under fluctuating channel conditions. This thesis aims at investigating the opportunities and challenges in the use of dynamic radio transmit power control for prolonging the lifetime of such devices. We first present extensive empirical evidence that the wireless link quality can change rapidly in body area networks, and a fixed transmit power results in either wasted energy (when the link is good) or low reliability (when the link is bad). We then propose a class of schemes feasible for practical implementation that adapt transmit power in real-time based on feedback information from the receiver. We show conservative, balanced, and aggressive adaptations of our scheme that progressively achieve higher energy savings of 14%-30% in exchange for higher potential packet losses (up to 10%). We also provide guidelines on how the parameters can be tuned to achieve the desired trade-off between energy savings and reliability within the chosen operating environment. Finally, we implement and profile our scheme on a MicaZ mote based platform, demonstrating that energy savings are achievable even with imperfect feedback information, and report preliminary results on the ultra-low-power integrated healthcare monitoring platform from our collaborating partner Toumaz Technology. In conclusion, our work shows adaptive radio transmit power control as a low-cost way of extending the battery-life of severely energy constrained body wearable devices, and opens the door to further optimizations customized for specific deployment scenarios.

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32

Koh, Yong-Khiang. "Prediction and control of vibrational power transmission between coupled structural systems". Thesis, University of Southampton, 1992. https://eprints.soton.ac.uk/428197/.

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Nazir, Mohammad Nawaf. "Control of Power Flow in Transmission Lines using Distributed Series Reactors". Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/52978.

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Distributed Series Reactors (DSRs) can be used to control power flow to more fully utilize the capacity of a transmission network, delaying investment in new transmission lines. In this study the IEEE 39 bus standard test system is modified to a 3-phase, unbalanced model consisting of 230 kV, 345 kV and 500 kV lines, where lines of different voltage run in parallel. This model is used to study load growth and the effect of adding DSRs to alleviate resulting overloads, and in particular to alleviate overloads on lines of different voltage running in parallel. The economic benefit of adding DSRs to the network is compared to the addition of new transmission lines in the network. In the second part of the work, the effect of unsymmetrical operation of DSRs on a single transmission line is studied and compared to the symmetrical operation of DSRs. It is found that the unsymmetrical operation of DSRs is more economical. Finally the unsymmetrical operation of DSRs to reduce voltage imbalance in the network is considered.
Master of Science

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34

Fazzini, Enrico. "frequency-diverse arrays design and control for accurate wireless power transmission". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21111/.

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The frequency diversity of the antennas in the radiating system is a powerful strategy, that can lead a big improvement on wireless power transmission applications, but its characterization is merely theoretical in the literature. This work offers a deep and critical numerical analysis of frequency-diverse arrays and shows the advantages of the family with logarithmic distribution of the frequency for radio-frequency energy focusing goals. For the first time, these systems are analyzed through a Harmonic Balance-based simulation combined with the full-wave description of the array made of eight planar monopoles: the rigorous results confirm the potentialities of these complex radiating systems, in particular show how the time-dependency of the radiating mechanism can be favorably deployed. For the first time, an example of practical implementation of an FDA prototype using the SDR technology offered by the Zynq Ultrascale+ RFSoC ZCU111 Evaluation Kit for generation and control of the signals for each radiating element is also given in this work.

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35

Omran, Shaimaa AbdAlla Ezz Ibrahim. "Control Applications and Economic Evaluations of Distributed Series Reactors in Unbalanced Electrical Transmission Systems". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/52240.

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An important issue in today's power system is the need to analyse and determine the adequacy of transmission capacity. There is a need for approaches to increase transmission system capacity without construction of new transmission facilities, all while assuring secure operation of the grid. New technologies can enhance efficiency and reliability, increase capacity utilization, enable more rapid response to contingencies, and increase flexibility in controlling power flows on transmission lines. Distributed Series Reactor (DSR) control is a new smart grid technology that can be applied to control flows in the transmission system. DSRs can be used to balance phase flows in a single line as well as to control the distribution of flow in parallel flow paths. This dissertation investigates the Design of Distributed Series Reactors (DSRs) on transmission lines and provide guidelines and considerations for their implementation in bulk power system transmission networks to control power flow to: increase the exisiting transmission capacity utilization, alleviate overloads due to load growth and contingencies, and mitigate the effects of unbalanced voltages, unbalanced transmission line impedances and unbalanced loads by balancing flows in the phases of an unbalanced line. This dissertation provides several DSR System Design aspects; for a single line by performing an experiment for EHV and high voltage three parallel transmission lines, and for lines within the boundaries of a power system by deployment of DSRs over the IEEE 39 bus system that is modified and modelled as a 3-phase unbalanced transmission model with 345 kV lines that accounts for tower geometry and as a balanced, 3-phase model that is derived from the unbalanced, 3-phase model, and finally for lines within a control area and a set of tie lines among control areas by deployment of DSRs over a real system control area and the tie lines connecting this area to other power pool areas. For all experiments and simulations in this dissertation lines are modelled as 3-phase lines. The DSR system design for Unbalanced vs. Balanced 3-phase systems (Unbalanced immittance, Unbalanced load) are examined. Also the Distributed vs. Lumped models for 3-phase systems are tested. Comparison between DSR system design and transposition for voltage balancing was performed. The effect of bundling the conductors for DSR system design was investiagted. In this dissertation an economic evaluation of DSR System Design for parallel lines and for the IEEE 39 bus three-phase unbalanced line model for N-1 criterion contingency with load growth is performed. The economic evaluation performed for the DSR system design of a power system versus new transmission line construction showed that DSRs can be cost effective in managing load increases from year to a year, and thus avoid larger investments in new line construction until load expectations are proven to be true. Thus, a major value of DSRs is handling load growth in the short term, delaying larger investments. Although many aspects of DSR control implementation have yet to be explored, this work has demonstrated the fundamental concept is sound and the economics are compelling.
Ph. D.

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36

Johal, Harjeet. "Distributed series reactance a new approach to realize grid power flow control /". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26713.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Divan, Deepakraj M.; Committee Member: Begovic, Miroslav M.; Committee Member: Brown, Marilyn; Committee Member: Harley, Ronald G.; Committee Member: Wolf, Wayne H. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Farsangi, Malihe Maghfouri. "Robust control of flexible AC transmission systems for damping power system oscillations". Thesis, Brunel University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269400.

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Saenger, Zetina Siegfried Hans. "Optimal control with Kane mechanics applied to a hybrid power split transmission". Göttingen Sierke, 2009. http://d-nb.info/1000116298/34.

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Mori, Kazuo, Takehiko Kobayashi, Takaya Yamazato i Akira Ogawa. "Transmission Power Control for Downlinks in CDMA/Shared-TDD Cellular Packet Systems". IEEE, 2000. http://hdl.handle.net/2237/7805.

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Akinsolu, Ojuetimi Ifedayo. "A design of variable transmission power control for wireless ad-hoc network". Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/13559.

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Includes bibliography.
Wireless Ad-hoc Network has emanated to be a promising network paradigm that can handle last mile technology due to unprecedented growth of internet users. This network is promising because it extends network to remote areas such as congested environments, rural environments etc. It is known that nodes involved in Wireless Ad-hoc Network rely on battery energy as their source of power. Energy consumption has become one of the major challenges experienced in Wireless Ad-hoc Network, which must be properly tackled. This could be traced to the effect of transmission power on the nodes in the network. Transmission power largely determines the amount of energy consumed by each node in the network. Therefore, a power control technique must be adopted in order to manage and select the optimal transmission power with respect to distance. This transmission power must be sufficient to transfer information from one node to another. Literature have proposed different algorithms for power control technique in Wireless Ad-hoc Network. Some researchers looked at the power control technique in terms of minimising energy consumed from different perspectives, which include power aware routing and power control topology management. However, most of these algorithms were applied at different layers in OSI model such as physical layer, data link layer, network layer and application layer. To achieve a reduced energy consumption at each node in the network, a novel algorithm for transmission power control was designed to select optimal transmission power. The proposed algorithm was designed in such a way that it selects transmission power based on the distance between the nodes without affecting the network throughput. Graph theory is used in this research to model the network topology, and transmission power with respect to the distance.

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Muqattash, Alaa Hilal. "Medium Access Control and Adaptive Transmission Techniques in Wireless Networks". Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1359%5F1%5Fm.pdf&type=application/pdf.

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Mendez, Jose A. (Jose Antonio Mendez Alcazar). "Control signal transmission through power supply cables of a 3-phase PWM motor". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37203.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.
Includes bibliographical references (p. 147-148).
Modem process control systems often employ accurate position or speed controlled PWM motors, which require feedback data for the drive control loop. Current methods require an independently shielded cable for feedback data transmission. This is due to the fact that high-voltage PWM signals could easily interfere with the feedback signals, which are typically one or more orders of magnitude smaller than typical PWM signals. We propose a "zero-wire" solution, in which the additional feedback cable used is eliminated, and the feedback data is sent simultaneously with the PWM signals in the same motor power conductors. In this study, we first analyzed the characteristics of typical feedback and PWM signals. Additionally, a standard representative motor drive cable was carefully measured and analyzed for its wave transport characteristics. The results lead us to select an RF modulation approach in which we modulate the data signals to 900MHz. The data signals are injected and extracted from the power conductors using feed-through capacitors and high-pass filters. To test the performance of our approach, we build a model system in which simulated PWM signals were applied to a 30m motor power cable fitted with data couplers and 900MHz RF RS232 data modems for modulation.
(cont.) Tests with different cables and attenuation were performed and data error rates measured. The error rates for strong RF signals, RSSI (Received Signal Strength Indicator) values higher than -60dBm, were limited by RF modem performance to 0.01%. Error rates did not increase with or without PWM power signals when RSSI values were over -80dBm. A design for transmission of DC power for motor feedback electronics is presented, in which we choose an intermediate frequency carrier at 1MHz to transmit power. The 1MHz signals are injected and extracted through the same feed-through capacitors using band-pass filters. Measurements and simulation have shown that the new feedback data transport system design developed in this project is effective and feasible.
by Jose A. Mendez.
M.Eng.

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43

Ashton, Phillip Michael. "Exploiting phasor measurement units for enhanced transmission network operation and control". Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/9063.

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In order to achieve binding Government targets towards the decarbonisation of the electricity network, the GB power system is undergoing an unprecedented amount of change. A series of new technologies designed to integrate massive volumes of renewable generation, predominantly in the form of offshore wind, asynchronously connecting to the periphery of the transmission system, are transforming the requirements of the network. This displacement of traditional thermal generation is leading to a significant reduction in system inertia, thus making the task of system operation more challenging. It is therefore deemed necessary to develop tools and technologies that provide far greater insight into the state of the power system in real-time and give rise to methods for improving offline modelling practices through an enhanced understanding of the systems performance. To that extent PMUs are seen as one of the key enablers of the Smart Grid, providing accurate time-synchronised measurements on the state of the power system, allowing the true dynamics of the power system to be captured and analysed. This thesis provides an analysis of the existing PMU deployment on the GB transmission system with a view to the future system monitoring requirements. A critical evaluation and comparison is also provided on the suitability of a University based Low Voltage PMU network to further enhance the visibility of the GB system. In addition a novel event detection algorithm based on Detrended Fluctuation Analysis is developed and demonstrated, designed to determine the exact start time of a transmission event, as well as the suitability of such an event for additional transmission system analysis, namely inertia estimation. Finally, a reliable method for the estimation of total system inertia is proposed that includes an estimate of the contribution from residual sources, of which there is currently no visibility. The proposed method identifies the importance of regional inertia and its impact to the operation of the GB transmission system.

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Kirawanich, Phumin. "Fuzzy logic control for an active power line conditioner /". free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060114.

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45

Makido, Satoshi, Takaya Yamazato, Masaaki Katayama i Akira Ogawa. "Hierarchical Transmission of Huffman Code Using Multi-Code/Multi-Rate DS/SS Modulation with Appropriate Power Control". IEICE, 1998. http://hdl.handle.net/2237/7208.

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Kong, Dechao. "Advanced HVDC systems for renewable energy integration and power transmission : modelling and control for power system transient stability". Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4217/.

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The first part is concerned with dynamic aggregated modelling of large offshore wind farms and their integration into power systems via VSC-HVDC links. The dynamic aggregated modelling of offshore wind farms including WT-DFIGs and WT-PMSGs are proposed to achieve effective representations of wind farms in terms of computational time and simulation accuracy for transient stability analysis. Modelling and control of VSC-HVDC systems for integration of offshore wind farms are investigated. Comparisons of two control schemes of rectifier-side converter are carried out to evaluate their dynamic performance for integration of these offshore wind farms in terms of transient stability. The second part is to address the advanced transmission systems with innovative HVDC configurations. Feasibility studies of updated schemes of monoplolar CSC-HVDC link with support of monopolar VSC-HVDC link as the hybrid bipolar CSC/I{VDC system is carried out to deal with two key issues of CSC-HVDC. Small-signal modelling of MTDC grids is investigated and parameter optimisation of PI controller of converters in MTDC grids is carried out using PSO method based on small-signal models of the system at multiple operating points to obtain optimised parameters of PI controllers to improve dynamic performance of MTDC grids at multiple operating points.

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Das, Debrup. "Dynamic control of grid power flow using controllable network transformers". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/43739.

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The objective of the research is to develop a cost-effective, dynamic grid controller called the controllable network transformer (CNT) that can be implemented by augmenting existing load tap changing (LTC) transformers with an AC-AC converter. The concept is based on using a fractionally rated direct AC-AC converter to control the power through an existing passive LTC. By using a modulation strategy based on virtual quadrature sources (VQS), it is possible to control both the magnitude and the phase angle of the output voltage of the CNT without having any inter-phase connections. The CNT architecture has many advantages over existing power flow controllers, like absence of low frequency storage, fractional converter rating, retro-fitting existing assets and independent per-phase operation making it potentially attractive for utility applications. The independent control of the magnitude and the phase angle of the output voltage allow independent real and reactive power flow control through the CNT-controlled line. In a meshed network with asymmetric network stresses this functionality can be used to redirect power from critically loaded assets to other relatively under-utilized parallel paths. The power flow controllability of CNT can thus be used to lower the overall cost of generation of power. The solid state switches in the CNT with fast response capability enable incorporation of various additional critical functionalities like grid fault ride through, bypassing internal faults and dynamic damping. This bouquet of features makes the CNT useful under both steady state and transient conditions without compromising the grid reliability.

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48

Chen, Yaow-Ming. "Active power line conditioner with neural network control /". free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841132.

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Nguyen, Van Liem. "Modeling and control coordination of power systems with FACTS devices in steady-state operating mode". University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0036.

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This thesis is devoted to the development of new models for a recently-implemented FACTS (flexible alternating current transmission system) device, the unified power flow controller (UPFC), and the control coordination of power systems with FACTS devices in steady-state operating mode. The key objectives of the research reported in the thesis are, through online control coordination based on the models of power systems having FACTS devices, those of maximising the network operational benefit and restoring system static security following a disturbance or contingency. Based on the novel concept of interpreting the updated voltage solutions at each iteration in the Newton-Raphson (NR) power-flow analysis as dynamic variables, the thesis first develops a procedure for representing the unified power flow controllers (UPFCs) in the steady-state evaluation. Both the shunt converter and series converter control systems of a UPFC are modeled in their dynamical form with the discrete time variable replaced by the NR iterative step in the power-flow analysis. The key advantage of the model developed is that of facilitating the process of UPFC constraint resolution during the NR solution sequence. Any relative priority in control functions pre-set in the UPFC controllers is automatically represented in the power-flow formulation. Although the developed UPFC model based on the dynamic simulation of series and shunt converter controllers is flexible and general, the number of NR iterations required for convergence can be large. Therefore, the model is suitable mainly for power system planning and design studies. For online control coordination, the thesis develops the second UPFC model based on nodal voltages. The model retains all of the flexibility and generality of the dynamic simulation-based approach while the number of iterations required for solution convergence is independent of the UPFC controller dynamic responses. Drawing on the constrained optimisation based on Newtons method together with the new UPFC model expressed in terms of nodal voltages, a systematic and general method for determining optimal reference inputs to UPFCs in steady-state operation is developed. The method is directly applicable to UPFCs operation with a high-level line optimisation control (LOC) for maximising the network operational benefit. By using a new continuation technique with adaptive parameter, the algorithm for solving the constrained optimisation problem extends substantially the region of convergence achieved with the conventional Newtons method. Having established the foundation provided by the comprehensive models developed for representing power systems with FACTS devices including the UPFC, the research, in the second part, focuses on real-time control coordination of power system controllers, with the main purpose of restoring power system static security following a disturbance or contingency. At present, as the cost of phasor measurement units (PMUs) and wide-area communication network is on the decrease, the research proposes and develops a new secondary voltage control where voltages at all of the load nodes are directly controlled, using measured voltages.

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50

Fabbri, Gabriele. "Control of Five Phase Doubly Fed Induction Machines for Motion and Contactless Power Transmission". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14233/.

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In questa tesi si mostra come un motore a induzione di tipo doubly fed (DFIM) possa assolvere contemporaneamente le funzioni di motore e di trasmissione di potenza In particolare questa peculiarità è particolarmente utile laddove sia necessario alimentare dei dispositivi elettrici a bordo di una macchina automatica a giostra, normalmente alimentati tramite contatti striscianti: da quest’ultimi infatti spesso derivano innumerevoli problematiche di usura e sicurezza. In particolare, in questa tesi verrà trattato un azionamento pentafase: tale scelta è stata dettata dalla possibilità di disaccoppiare la trasmissione di potenza elettrica e quella meccanica. Data la particolarità di tale macchina una lunga sezione è dedicata alla sua descrizione. Si presentano tre diverse metodologie di funzionamento e controllo della macchina doubly fed: in particolare le prime due, che si avvalgono di modulazioni di coppia o di potenza, potrebbero essere implementate anche su un motore trifase qualora risultasse conveniente; al contrario l’ultimo controllo proposto, che si fonda sull’utilizzo indipendente delle frequenze di statore, è applicabile solo a un DFIM pentafase. Dai risultati ottenuti in simulazione, ma comprendenti moltissimi gradi di realismo, appare evidente come quest’ultimo dia i risultati migliori e sfrutti al meglio la macchina pentafase.

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