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Sechilariu, Manuela. "Utilisation des réseaux de Petri colorés et temporisés pour la modélisation et la simulation des montages redresseurs et onduleurs." Angers, 1993. http://www.theses.fr/1993ANGE0012.
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Ce mémoire montre la faisabilité d'une technique de commande des convertisseurs statiques, utilisant les réseaux de Petri (RDP). L'originalité de ce travail réside dans l'utilisation de RDP colorés et temporisés pour la modélisation. Deux exemples sont retenus. Le modèle du redresseur triphasé à thyristors est présenté de manière que l'on puisse analyser les valeurs de l'angle de retard d'allumage ; des temporisations de durées variables permettent de simuler la variation de la tension redressée. Le modèle de l'onduleur autonome évolue dynamiquement à la fréquence souhaitée ; le changement de la durée des temporisations associées aux transitions conduit au changement de la fréquence de sortie de l'onduleur. L'étude effectuée sur l'ensemble redresseur-onduleur machine-asynchrone nous permet d'envisager une stratégie de fonctionnement en vitesse de rotation variable, fondée sur une commande algorithmique des temporisations, conformément à l'asservissement donné. Nous avons réalisé une maquette de redresseur à thyristors liée à un ordinateur. La commande est gérée par RDP synchronisé. Elle ouvre des perspectives pour une nouvelle technique de commande des convertisseurs statiques.
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Martincic, Emile. "Étude d'une alimentation alternative pour moteur à réluctance variable à double saillance." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0029.
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Ce mémoire présente l'étude d'une alimentation originale alternative pour moteur à reluctance variable a double saillance. Dans le premier chapitre, un rappel des principes de fonctionnement et d'alimentation des moteurs à reluctance variable à double saillance est rappelé. Différents types d'alimentations faisant appel a des convertisseurs a commutation douce et des ondes sinusoïdales sont présentées. A partir de la constatation que le sens du courant n'est pas impose par principe, un convertisseur rustique est propose. Ce convertisseur direct constitue d'un triac par phase du moteur est utilise pour injecter du courant dans les phases du moteur pendant la croissance de l'inductance. Une commande avec limitation de courant n'est pas nécessaire avec ce type d'alimentation. Les résultats obtenus avec cette alimentation sont étudiés dans le chapitre 3. Le couple moyen en fonction de la vitesse est explicite, ainsi que l'évolution des pertes dans le moteur. Deux modes de fonctionnement en fonction du rapport de la fréquence du réseau a la fréquence électrique du moteur sont distingues. Enfin, le courant absorbe par le moteur est étudié et une méthode de compensation partielle du facteur de puissance est proposée. Dans le chapitre 4, une amélioration permettant de réduire l'ondulation du courant absorbe est étudiée.
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Ковальова, Юлія Вікторівна. "Компенсація реактивної потужності електроприводів з тиристорними перетворювачами напруги." Thesis, Харківський національний університет міського господарства ім. О. М. Бекетова, 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/20765.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.09.03 - електротехнічні комплекси та системи. - Національний технічний університет "Харківський політехнічний інститут" Харків, 2016. Дисертація присвячена компенсації реактивної потужності асинхронних електроприводів та електроприводів постійного струму з тиристорними перетворювачами напруги (ТПН). Розроблені методи для визначення діючого значення реактивного струму асинхронного електропривода з ТПН та електроприводів постійного струму з однофазним та трифазним ТПН з урахуванням кута керування тиристорів. Отримані співвідношення для визначення ємності компенсуючих конденсаторів для заданого кута керування тиристорів, які враховують: для асинхронних електроприводів з ТПН - діюче значення реактивної складової струму холостого ходу; для електроприводів постійного струму з ТПН - діюче значення змінної складової випрямленого струму кола якоря. Удосконалені співвідношення для визначення коефіцієнтів корисної дії двигунів при живленні від ТПН, які враховують: для асинхронних - відношення квадратів діючого значення першої гармоніки струму до діючого значення струму статора; для електроприводів постійного струму - відношення квадратів постійної складової випрямленого струму якоря до діючого значення.The dissertation for the degree of technical sciences candidate, speciality 05.09.03 - electrical complexes and systems. -NTU “KPI”. - Kharkiv, 2016. Dissertation is devoted to compensation reactive power of AC and DC motors with the thyristor voltage convertors. Reactive power produse the losses of the electrical energy on the transmission lines and substation transformers. The methods for determine effective value reactive current stator AC motor and effective value reactive current armature circle DC motor with thyristor voltage convertors are developed. Reactive current of stator AC motor and reactive current of armature circle DC motor as function control angle with the thyristor are derived with the computer models. The results of computer simulation were approximated with known methods and analytical formulas are developed. The correlations for determination of capacity compensating condensers for the set control angle with the thyristors are obtained. They take into account: for AC motor - effective value of reactive component of stator current; for DC motor - effective value of variable component of the rectifiered current of armature circle. The formulas for the calculation of capacity condensers for compensation reactive power of the thyristor electric drive are based on equality effective value nonsine energy of the magnetic field of the motor winding and energy of the electric field of condenser. The efficiency factor are determined for AC and DC motors.
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Ковальова, Юлія Вікторівна. "Компенсація реактивної потужності електроприводів з тиристорними перетворювачами напруги." Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/20760.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.09.03 - електротехнічні комплекси та системи. - Національний технічний університет "Харківський політехнічний інститут" Харків, 2016.
Дисертація присвячена компенсації реактивної потужності асинхронних електроприводів та електроприводів постійного струму з тиристорними перетворювачами напруги (ТПН). Розроблені методи для визначення діючого значення реактивного струму асинхронного електропривода з ТПН та електроприводів постійного струму з однофазним та трифазним ТПН з урахуванням кута керування тиристорів. Отримані співвідношення для визначення ємності компенсуючих конденсаторів для заданого кута керування тиристорів, які враховують: для асинхронних електроприводів з ТПН - діюче значення реактивної складової струму холостого ходу; для електроприводів постійного струму з ТПН - діюче значення змінної складової випрямленого струму кола якоря. Удосконалені співвідношення для визначення коефіцієнтів корисної дії двигунів при живленні від ТПН, які враховують: для асинхронних - відношення квадратів діючого значення першої гармоніки струму до діючого значення струму статора; для електроприводів постійного струму - відношення квадратів постійної складової випрямленого струму якоря до діючого значення.The dissertation for the degree of technical sciences candidate, speciality 05.09.03 - electrical complexes and systems. -NTU “KPI”. - Kharkiv, 2016. Dissertation is devoted to compensation reactive power of AC and DC motors with the thyristor voltage convertors. Reactive power produse the losses of the electrical energy on the transmission lines and substation transformers. The methods for determine effective value reactive current stator AC motor and effective value reactive current armature circle DC motor with thyristor voltage convertors are developed. Reactive current of stator AC motor and reactive current of armature circle DC motor as function control angle with the thyristor are derived with the computer models. The results of computer simulation were approximated with known methods and analytical formulas are developed. The correlations for determination of capacity compensating condensers for the set control angle with the thyristors are obtained. They take into account: for AC motor - effective value of reactive component of stator current; for DC motor - effective value of variable component of the rectifiered current of armature circle. The formulas for the calculation of capacity condensers for compensation reactive power of the thyristor electric drive are based on equality effective value nonsine energy of the magnetic field of the motor winding and energy of the electric field of condenser. The efficiency factor are determined for AC and DC motors.
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Pascal, Jean-Pierre. "Etude de circuits d'aide à la commutation de thyristors GTO montés en série pour des applications à la traction ferroviaire." Paris 6, 1986. http://www.theses.fr/1986PA066273.
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Revue des propriétés des thyristors interrupteurs. Aptitude à l'utilisation en grande traction. Etude du rétablissement de la tension aux bornes. Soufflage et mise en série des thyristors interrupteurs. Caractérisation des GTO de grande puissance.
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張華 and Hua Zhang. "Digital vector control of forced-commutated cycloconverter drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31234574.
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Zhang, Hua. "Digital vector control of forced-commutated cycloconverter drives /." [Hong Kong] : University of Hong Kong, 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1594847X.
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Resende, Jose Wilson. "Interaction between controlled reactors and converters : a harmonic analysis." Thesis, University of Aberdeen, 1986. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU367868.
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This thesis presents the development of a generalised computer program to calculate harmonic currents and voltages in six and twelve-pulse thyristor controlled reactors under non-ideal conditions. Thyristor controlled reactors are a relatively new source of harmonic distortion in power systems. The steady state characteristic harmonics are well known. Other non-characteristic harmonics can, however, be generated. A detailed representation is therefore necessary. Apart from the most common non-ideal conditions, such as voltage, impedance and firing pulse unbalances, this work allows voltage harmonic distortions, two firing pulse control methods, the effect of the feedback control in the equally spaced firing pulse control and the effect of the step-down transformer saturation. The effect of the a.c. system impedance, filters and capacitor banks is also included. Four different models of filters were implemented. With non-infinite a.c. systems, the harmonic currents generated are not totally absorbed by the filters. The remaining distortion may affect the main busbar voltages. Therefore, an iterative method was adopted in which the distorted voltages calculated at the end of one iteration are used to calculate the new currents and voltages. The process is repeated until convergence is reached. Several cases were then studied using this program which was then joined to an existing steady-state converter harmonic program. For instance, the need for a more complete representation of controlled reactors, converters and a.c. system network is illustrated. This study begins considering an hvdc station under ideal conditions which are then gradually moved towards more real conditions. The influence of the a.c. system representation in harmonic studies is also discussed. This analysis also compares the performance of two filter designs, namely the tuned and the damped filters. A study of harmonic magnification in the presence of a.c. and d.c. resonances is also included. The harmonic calculations program presented in this thesis is able to study so many conditions of operation of converters and/or thyristor controlled reactors that it is impractical to show all the possible cases. For instance, filters and capacitor banks can be installed at the converter busbar or at any controlled reactor busbar. Furthermore, the three-phase calculation approach allows studies in which some abnormal operation, such as the absence of a filter branch or capacitor bank at one phase, can be observed.
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Chikwanda, Herbert Simbarashe. "The naturally commutated, converter-fed, variable speed induction machine drive." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/47805.
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Zhang, Bin. "Development of the Advanced Emitter Turn-Off (ETO) Thyristor." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/26095.
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Advancements in the power electronics systems have been directly related to the availability of improved power semiconductor devices. The device performance greatly determines the efficiency, reliability, volume, and cost of the power electronics system. This dissertation is dedicated to develop an advanced high power semiconductor device, the emitter turn-off (ETO) thyristor, which is targeted to improve the limitations of the present high power devices.
Major improvements in electrical and mechanical designs of the ETO for high power and high frequency operation are proposed which result in improved snubberless turn-off capability, low conduction loss, and low gate drive power consumption of the new generation ETO.
A revolutionary self-power generation method of the ETO is proposed. Different from the conventional high power devices which require the external power input for their gate drivers, ETO achieves complete optically controlled turn-on and turn-off and all the internal power required is self-generated. This advancement will have a major impact to high power converter designs.
A novel integrated method to eliminate the dead-time requirement is proposed for ETO. This method not only improves the output waveform quality but also increases the reliability and reduces the cost of the high power PWM voltage source converters. With this unique function, the upper and the lower ETO's within a converter phase leg can receive the ideal complementary (without dead-time) PWM signals and solve shoot-through problems.
Method to measure the ETO current and transfer the current information to a PWM signal is proposed. Based on the ETO's built-in current sensor, the over-current protection function of the ETO is designed as well. The experimental results show that the built-in current sensor has a very high precision, and the over-current protection function can effectively protect the ETO during the short circuit faults.
In order to improve ETO's turn-off capability, a comprehensive investigation of the turn-off failure mechanism of the ETO was performed. A series of simulations and experiments are carried out to study the ETO turn-off operation. The detail turn-off failure mechanisms are presented. The conditions to cause the ETO failure are addressed. The approaches to improve the ETO's turn-off capability are discussed.Ph. D.
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Babayan-Aghan, Vahik. "Investigation into different types of single-phase AC/DC convertors." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/7063.
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The work detailed in the thesis compares the performance of single-phase thyristor bridge converters under different control strategies; considering in particular the efficiency, ac side power factor and harmonic content of the current and voltage waveforms. Extensive practical investigations were performed, in which, analogue and digital control circuits were developed to provide the drive signals necessary for a converter to operate in the different control modes for: a) A series -connected fully-controlled double thyristor bridge (used mainly in traction applications) operating under sequence control and; b) A fully controlled single-bridge operating under sequence and conventional control. A novel pulse-width modulation control strategy was developed for the single-bridge converter, using gate turn-off thyristors as the switching elements, whereby output voltage control is obtained by variation of the modulation index. Turn-on and turn-off signals for the power devices were obtained using an analogue control circuit. The advantages and disadvantages of this switching strategy compared with conventional and sequence control were studied, and results clearly showed that an improved input power factor and lower supply current and load voltage harmonics were all obtained. Mathematical models for single and double bridge converters operating under sequence and conventional control were developed using tensor techniques. Using these models, computer programmes were written in Fortran 77 on the University mainframe computer, to assemble automatically and solve the network equations as the converter topology changes. In addition, analytical models were also developed on the assumption that the load current is completely smooth. However, such an assumption is not justifiable with ac-to-dc converters and consequently a novel technique was developed to include the load current ripple in calculating the supply current harmonics. The results obtained are compared with both the computed and experimental ones.
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Motto, Kevin. "Application of High-Power Snubberless Semiconductor Switches in High-Frequency PWM Converters." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/35778.
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For many years, power electronics in the high-power area was performed with extremely slow semiconductor switches. These switches, including the thyristor and the Gate Turn-Off (GTO) thyristor, had the capacity to handle very high voltages and currents but lacked the ability to perform high frequency switching. Low-power converters, such as computer power supplies and low horsepower motor drives, have employed high-frequency switching for years and have benefited from very nice output waveforms, good control dynamic performance, and many other advantages compared to low frequency switching. Recent improvements in high-power semiconductor technology has brought switching performance similar to that of the low-power MOSFETs and IGBTs to the high-power area through the advancement of the IGBT's ratings to create the High Voltage IGBT (HVIGBT) and the development of new GTO-derived devices including the Integrated Gate Commutated Thyristor (IGCT) and the Emitter Turn-Off (ETO) thyristor. These new devices all feature high switching speed and the capability to turn off without the requirement for a turn-off snubber. With these new device technologies the high-power field of power electronics can realize dramatic improvements in the performance of systems for utility applications and motor drives.
However, with these high-speed switches come new issues relating to noise, protection, performance of diodes, and thermal management in high-frequency applications. This thesis addresses the application of these new devices, especially the ETO and the IGCT.
Examples of each device technology (IGBT, IGCT, and ETO) have been characterized in both their switching performance and conduction loss. The tests performed show how these new devices may be applied to various applications. The switching loss, especially related to turn-off, is the dominant factor in the power dissipation of the high-power switches, so knowledge of these characteristics are very important in the system design.
To demonstrate the operation of the ETO, two power converters were constructed. The first was a 100 kW DC/DC converter, which demonstrated the operation of the ETO in a typical building block configuration, the half-bridge. The second system, a 1 MegaVolt-Amp (MVA) three-phase inverter, demonstrated the ETO in an application where the switching frequency and power level were both high. The test results demonstrate the expected characteristics of the high-frequency converters. The development of the ETO's gate driver is described.
During the inverter testing, a new failure mode was found involving a parasitic diode within the ETO. This failure mode was analyzed and solutions were proposed. One of the proposed solutions was implemented and there were no more failures of this type. Another possible failure mode regarding a circulating current in an IGCT-based system is also analyzed.
Soft-switching techniques can help reduce the switching loss in power semiconductor switches. Several topologies were considered for application in the high-power area, and one was selected for further investigation. A prototype Zero Current Transition (ZCT) circuit was developed using an IGCT as the main switch. The turn-off loss was reduced dramatically through the tested ZCT circuit, and the diode recovery was also alleviated.Master of Science
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Boutry, Arthur. "Theoretical and experimental evaluation of the Integrated gate-commutated thyristor (IGCT) as a switch for Modular Multi Level Converters (MMC)." Thesis, Lyon, 2021. http://www.theses.fr/2021LYSEI095.
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Une étude sur la réduction/suppression de l'inductance de limitation di/dt pour IGCTs et du clamp RCD en utilisant des diodes rapides en silicium (Si) et des diodes en carbure de silicium (SiC) dans les convertisseurs multiniveaux modulaires (MMC). Cette thèse contient :- Analyse des sous-modules de MMC HVDC existants.- Évaluation de l'intérêt des IGCTs dans les sous-modules MMC HVDC et comparaison des pertes avec les IGBT, en utilisant des facteurs de mérite spécifiques aux MMC créés dans cette thèse.- Test de double pulse avec diode à récupération rapide dans un module plastique pour tenter de réduire et supprimer l'inductance limitant le di/dt.- Packaging de puces de diodes SiC PiN à haute tension et courant élevé, test avec IGCT dans le même montage, pour tenter de réduire et supprimer l'inductance limite di/dt, et analyser les spécificités de la diode SiC dans ce montageA study on Integrated gate-commutated thyristors (IGCT) di/dt limiting inductance and RCD-clamp reduction/suppression using plastic module silicon (Si) fast recovery diodes and silicon carbide (SiC) diodes, in Modular Multilevel Converters (MMC). This PhD contains:- Analysis of existing HVDC MMC Submodules.- Assessment of the interest of the IGCT in HVDC MMC Submodules and losses comparison with IGBTs, using MMC-specific figures-of-merit created in this thesis.- Double pulse test with fast recovery diode in plastic module to attempt to reduce and suppress the limiting di/dt inductor.- Packaging of High-Voltage High-Current SiC PiN diode dies, test with IGCT in the same setup to attempt to reduce and suppress the limiting di/dt inductor and analyze the specificities of the SiC diode in this setup
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Leisten, Joseph Michael. "Application of a new high speed gate turn off thyristor in single ended resonant converter topologies." Thesis, University of Brighton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239723.
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Xu, Zhenxue. "Advanced Semiconductor Device and Topology for High Power Current Source Converter." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11068.
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This dissertation presents the analysis and development of an innovative semiconductor device and topology for the high power current source converter (CSC).
The CSC is very attractive in high power applications due to its lower output dv/dt, easy regeneration capability and implicit short-circuit protection. Traditionally, either a symmetrical gate turn-off (GTO) thyritor or an asymmetrical GTO in series with a diode is used as the power switch in the CSC. Since the GTO has a lower switching speed and requires a complicated gate driver, the symmetrical GTO based CSC usually has low dynamic response speed and low efficiency. To achieve high power rating, fast dynamic response speed and low harmonics, an advanced semiconductor device and topology are needed for the CSC.
Based on symmetrical GTO and power MOSFET technologies, a symmetrical emitter turn-off (ETO) thyristor is developed that shows superior switching performance, high power rating and reverse voltage blocking capability. The on-state characteristics, forced turn-on characteristics, forced turn-off characteristics and the load-commutated characteristics are studied. Test results show that although the load-commutation loss is high, the developed symmetrical ETO is suitable for use in high power CSC due to its low conduction loss, fast switching speed and reverse voltage blocking capability.
The snubberless turn-on capability is preferred for a semiconductor device in a power conversion system, and can be achieved for devices with forward biased safe operation area (FBSOA). The FBSOA of the ETO is investigated and experimentally demonstrated. The ETO device has excellent FBSOA due to the negative feedback provided by the emitter switch. However, the FBSOA for a large area ETO is poor. A new ETO concept is therefore proposed for future development in order to demonstrate the FBSOA over a large area device.
To improve the turn-on performance of the large area ETO, a novel concept, named the transistor-mode turn-on, is proposed and studied. During the transistor-mode turn-on process, the ETO behaves like a transistor instead of a thyristor. Without a snubber, the transistor-mode turn-on for the ETO is hard to achieve. Through the selection of a proper gate drive and di/dt snubber, the transistor-mode turn-on can be implemented, and the turn-on performance for the ETO can be dramatically improved.
To increase the power rating of the CSC without degrading the utilization of power semiconductor devices, a novel multilevel CSC, named the parallel-cell multilevel CSC, is proposed. Based on a six-switch CSC cell, the parallel-cell multilevel CSC has the advantages of high power rating, low harmonics, fast dynamic response and modularity. Therefore, it is very suitable for high power applications. The power stage design, modeling, control and switching modulation scheme for a parallel-cell multilevel CSC based static var compensator (STATCOM) are analyzed and verified through simulation.Ph. D.
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Modeer, Tomas. "Cascaded Converters with Gate-Commutated Thyristors : Experimental Verification and Auxiliary Power Supply." Doctoral thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166666.
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This thesis describes an effort to investigate the use of gate-commutated thyristors(GCTs) in cascaded converters. Cascaded converters, such as modularmultilevel converters (M2Cs) and cascaded H-bridge converters (CHBs), haveproved to be especially suitable in high-voltage, high-power applications. Allof the most important advantages of cascaded converters, e.g. redundancy andscalability, can be attributed to the modular structure. Of special interestregarding the choice of semiconductor power devices is the reduced requirementon the switching frequency of individual devices. This brings a shift in thetrade-off between switching and conduction losses, where the latter has moreimportance in cascaded converters than in other topologies. This shift favorsthyristor-type devices like the GCT, which can achieve very low conductionlosses.To quantify the potential gain in the application of GCTs in cascadedconverters the losses have been calculated and a comparison between differentsubmodule implementations has been presented. The comparison has shownthat GCTs can provide 20-30% lower losses compared to insulated-gate bipolartransistors (IGBTs) in a typical HVDC application. In order to verify the lowlosses of GCT-based submodules, extensive work has been put into buildingand testing full-scale submodules employing GCTs. A resonant test circuithas been developed in which the submodules can be tested in steady-stateoperation which allows calorimetric measurements of the losses. The calorimetricmeasurements have verified that the loss calculation was reasonableand not lacking any important components.A drawback of GCTs is that the gate-drive units require much more powerthan gate-drive units for comparable IGBTs. In order to employ GCTs inhigh-voltage cascaded converters some means of supplying this power in thesubmodule must be provided. One option is to take this power from thesubmodule dc-link, but this requires a dc-dc converter capable of high inputvoltages. A tapped-inductor buck converter with a novel, autonomous highsidevalve was developed for this application. The autonomous operation of thehigh-side valve allows reliable operation without galvanic isolation components.A converter with a high-side valve with series-connected MOSFETs capable ofan input voltage of 3 kV has been presented.QC 20150521
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Perera, Lasantha Bernard. "Multi Level Reinjection ac/dc Converters for HVDC." Thesis, University of Canterbury. Electrical and Computer Engineering, 2006. http://hdl.handle.net/10092/1085.
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A new concept, the multi level voltage/current reinjection ac/dc conversion, is described in this thesis. Novel voltage and current source converter configurations, based on voltage and current reinjection concepts are proposed. These converter configurations are thoroughly analyzed in their ac and dc system sides. The fundamentals of the reinjection concept is discussed briefly, which lead to the derivation of the ideal reinjection waveform for complete harmonic cancellation and approximations for practical implementation. The concept of multi level voltage reinjection VSC is demonstrated through two types of configurations, based on standard 12-pulse parallel and series connected VSC modified with reinjection bridges and transformers. Firing control strategies and steady state waveform analysis are presented and verified by EMTDC simulations. The multi level current reinjection CSC is also described using two configurations based on standard 12-pulse parallel and series connected CSC modified with associated reinjection circuitry. Firing control strategies and steady state waveform analysis are presented and verified by EMTDC simulations. Taking the advantage of zero current switching in the main bridge valves, achieved through multi level current reinjection, an advanced multi level current reinjection scheme, consisting thyristor main bridges and self-commutated reinjection circuitry is proposed. This hybrid scheme effectively incorporates self-commutated capability into a conventional thyristor converter. The ability of the main bridge valves to commutate without the assistance of a turn-off pulse or line commutating voltage under the zero current condition is explained and verified by EMTDC simulations. Finally, the applications of the MLCR-CSC are discussed in terms of a back to back HVDC link and a long distance HVDC transmission system. The power and control structures and closed loop control strategies are presented. Dynamic simulation is carried out on PSCAD/EMTDC to demonstrate the two systems ability to respond to varying active and reactive power operating conditions.
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Poyiadjis, Soteris. "A New Cell Bypass Arrangement and Control for Modular Multilevel Converters based on Thyristor Forced Commutation Circuit." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-201660.
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HVDC transmission lines are a competitive and in some cases are proven to bea superior choice compared to AC transmission applications. Suitable convertershave been developed for that matter where Modulär Multilevel Converters (MMC)are highly preferred due to their low losses, no filtering requirementsand direct andfast control of AC and DC side. However, the overall eciency of the converteris higher than of a six pulse voltage source converter, it is still lower than the linecommutated converter type.In this master thesis an attempt to decrease the conduction losses of the MMC isinvestigated. A new cell structure design used in MMC is proposed along with itsassociated control strategy. The main idea is to divert the current at steady stateoperation through thyristors, which have lower conduction resistance than IGBTsthat are used in MMC topologies, at time intervals where the capacitor is bypassedfrom the cell. This new cell commutation is tested initially in the lab and thenthe whole structure operation is validated on a 3 phase MMC PSCAD model. Theresults from the lab confirmed the commutation of the new cell and the results fromthe 3 phase model showed that the new cell structure does not disturb the normaloperation of the MMC. A rough loss comparison that have been conducted betweenthe new cell structure and a half bridge that is used in a typical MMC, showed thatthe first one was less efficient. For that reason a generalized concept is introducedwhich promise higher efficiency than of the proposed concept.HVDC transmission är ett fördelaktigt sätt att överföra eekt i jämförelse med ACtransmission. Omriktare har utvecklats för att passa applikationen, där ModularMultilevel Converters (MMC) har visat sig passa bra för HVDC på grund av de lågaförlusterna och dess obentliga krav på lter. Dessutom har de en direkt och snabbkontrollteori på både AC och DC sidan. Även om dess totala verkningsgrad är högreän hos six-pulse voltage source converter (VSC) men lägre än Line CommutatedConverter (LCC).Detta exjobb innefattar att minska ledningsförlusterna i MMCn. En ny designav cell strukturen föreslås, tillsammans med en passande kontrollteori. Idén äratt, på grund av dess lägre ledningsresistans använda tyristorer snarare än IGBTervilka annars är vanliga i MMCer, detta då kondensatorn är förbikopplad.. Dennya cellstrukturen testas initialt experimentellt i laboratorium och hela systemetvalideras genom simulering av en 3-fas MMC modell i PSCAD. De experimentellaresultaten bekräftade att den nya modellen fungerar och de simulerade resultatenvisar att den föreslagna topologin inte stör funktionen hos MMCn. En jämförelsemellan den nya topologin och den konventionella halvbridge strukturen har gjorts,där den föreslagna topologin hade lägre verkningsgrad. Istället har en generelltkoncept introducerats för att utlova en högre verkningsgrad än den först föreslagnatopologin.
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Fellah, Mohamed-Karim. "Commande numérique industrielle des convertisseurs à thyristors d'une machine synchrone autopilotée." Vandoeuvre-les-Nancy, INPL, 1991. http://docnum.univ-lorraine.fr/public/INPL_T_1991_FELLAH_M_K.pdf.
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Un des points importants de cette étude, qui s'inscrit dans le cadre d'une collaboration de recherche EDF-CEGELEC-CRAN, est la réalisation complète d'une commande numérique industrielle d'une machine synchrone autopilotée sur la base d'un cahier des charges présentant des contraintes en précision pour les angles de retard à l'amorçage et en dynamique de suivi fréquentiel. Une première partie de cette thèse contribue d'une manière importante à l'étude des phénomènes liés aux imperfections du réseau électrique d'alimentation, en particulier à l'extraction de la composante fondamentale d'un réseau perturbé à fréquences variables. Ceci représente une recherche spécifique sur le problème de synchronisation. Une seconde partie s'intéresse aux allumeurs numériques et aux méthodes de génération des impulsions de gâchettes. Une description et une étude comparative de plusieurs allumeurs déjà existants (allumeur à coïncidence, à retard, incrémental) est faite, ensuite, un allumeur (allumeur multi-stratégies) est proposé. Une dernière partie présente, enfin, l'étude complète (du cahier des charges à la réalisation pratique) de la commande de portes d'une machine synchrone autopilotée. Par ailleurs, la rapidité des processus, la complexité des interactions entre les différentes fonctions ont conduit à concevoir cette commande en se basant sur le formalisme de la méthode MAREL (Méthode de conception d'Applications temps Réel pour la commande de processus Électromécaniques) développée au CRANOne of the important points of this study, which has been carried out in cooperation with EDF-CEGELEC-CRAN, is the complete realization of an industrial digital control of a self-controlled synchronous machine. This realization is based 0!l a given operation requirements specification especially for firing angle accuracy and variable-frequency following. In the first part of the thesis, phenomena related to the imperfections of power supply network are studied in a certain depth, especially the extraction of the fundamental of a noisy variable-frequency network. This is a specific research on the synchronizing problem. In the second part, we discuss digital firing circuits for thyristors and gate pulse production algorithms. We will give a description and a comparaison of several existing firing algorithms (reference crossing, time delayed, incremental) and then, propose a firing algorithm said hybrid algorithm. Finally, a complete study is made on firing control (from operation requirements specification to its hardware and software realization) of thyristor bridges for a self-controlled synchronous machine. Note that the rapidity of process, the complexity of the interaction between different functions make us, during the realizing procedure, to' follow the design method MAREL (Méthode de conception d'Applications temps Réel pour la commande de processus ELectromécaniques : design method for real time applications in electromechanical process control) developed in CRAN
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Mazari, Benyounès. "Étude et réalisation de la commande numérique d'un cycloconvertisseur à trente six thyristors." Vandoeuvre-les-Nancy, INPL, 1992. http://www.theses.fr/1992INPL135N.
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La thèse porte sur l'étude et la réalisation d'un cycloconvertisseur à commande entièrement numérique destine à la commande vectorielle d'une machine synchrone. Dans la première partie, après avoir brièvement rappelé les différentes structures des changeurs de fréquence, nous décrivons le cycloconvertisseur étudié et présentons les principes généraux relatifs au système de commande. La seconde partie est consacrée à la modélisation et a la simulation numérique de l'ensemble cycloconvertisseur-machine synchrone. Nous présentons les principes généraux d'une nouvelle méthodologie de modélisation des ensembles comprenant des convertisseurs à liaison directe. Par la suite, nous appliquons la méthodologie de simulation développée au système étudié. La dernière partie s'intéresse à la réalisation du système de puissance et en particulier a la formalisation et a la mise en œuvre de la commande numérique du cycloconvertisseur. Nous utilisons une méthode de conception permettant une approche globale des problèmes à résoudre, basée sur le concept de réseaux de pétri interprétés. A partir de la formalisation du cahier des charges, nous obtenons un bilan de toutes les fonctions à accomplir. Pour cela, le système est découpé en blocs fonctionnels regroupant un certain nombre de fonctions bien identifiées. Les taches élémentaires ainsi obtenues sont ensuite reparties entre diverses technologies afin d'aboutir à une solution hybride dans laquelle le microcalculateur tient un rôle dominant pour les calculs et les traitements d'algorithmes nécessaires au contrôle du système
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Andler, Daniel [Verfasser]. "Experimental Investigation of Three-Level Active Neutral Point Clamped Voltage Source Converters using Integrated Gate-Commutated Thyristors / Daniel Andler." München : Verlag Dr. Hut, 2014. http://d-nb.info/1051550092/34.
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Andler, Osorio Daniel Andrés [Verfasser]. "Experimental Investigation of Three-Level Active Neutral Point Clamped Voltage Source Converters using Integrated Gate-Commutated Thyristors / Daniel Andler." München : Verlag Dr. Hut, 2014. http://d-nb.info/1051550092/34.
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Murray, Nicholas John. "Flexible Power control in Large Power Current Source Conversion." Thesis, University of Canterbury. Electrical and Computer Engineering, 2008. http://hdl.handle.net/10092/2610.
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This thesis describes a new concept, applicable to high-power current-sourced conversion (CSC), where a controllable firing-angle shift is introduced between series and parallel converters to enable independent active and reactive power control. The firing-shift concept solves a difficult problem, by giving thyristor based CSCs the control flexibility of pulse-width modulated (PWM) converters, but without a loss in efficiency or rating. Several configurations are developed, based on the firing-shift concept, and provide flexible, efficient solutions for both very high power HVDC transmission, and very high current industrial processes.
HVDC transmission configurations are first developed for 4-quadrant high-pulse operation, based on the series connected multi-level current reinjection (MLCR) topology. Independent reactive power control between two ends of an HVDC link are proven under firing-shift control, with high-pulse operation, and without on-load tap changing (OLTC) transformers. This is followed by application of firing-shift control to a bi-directional back-to-back HVDC link connecting two weak systems to highlight the added dc voltage control flexibility of the concept.
The fault recovery capability of an MLCR based ultra-HVDC (UHVDC) long distance transmis-sion scheme is also proven under firing-shift control. The scheme responds favourably to both ac disturbances and hard dc faults, without the risk of commutation failures and instability experienced during fault recovery of line-commutated conversion.
The two-quadrant capability of very high current rectification is also proven with configurations based on phase-shifted 12-pulse and MLCR parallel CSCs. The elimination of the electro-mechanical OLTC/satruable reactor voltage control, the high-current CSC’s biggest shortcoming, greatly improves controllability and with firing-shift control, ensures high power-factor for all load conditions. This reduces the reactive power demands on the transmission system, which results in more efficient power delivery
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LIMA, Nelio Neves. "Operação do gerador de indução em conexão assíncrona com a rede monofásica." Universidade Federal de Goiás, 2010. http://repositorio.bc.ufg.br/tede/handle/tde/999.
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Previous issue date: 2010-03-26This text reports the effort to present a proposal of a power generation system based on cage rotor Induction Electrical Machine associated to a sinusoidally-switched PWM (Pulse Width Modulation) frequency converter responsible for maintaining constant 60 Hz frequency at the generator leads. DC side at the PWM converter is nonsynchronously connected to a single-phase utility line by means of a full-bridge current-fed thyristor inverter, employing a step-down DC-DC converter in order to turn the grid injected current into a sinusoidal waveform. The proposed system allows for the operation as cogenerator in sites fed by single-phase utility net where there is availability of energetic resources. The DC capacitor voltage (Vdc) is controlled through the DC side energy balance adjusting the amplitude of the active current sent to the utility grid. The control strategy employed was the analogic proportional-integral (PI) error compensation. The system is also able to act as reactive power compensator to the AC loads as the Cdc capacitor represents a voltage source to the inverter and the three-phase diode bridge allows for bidirectional power flow between AC and DC sides. Simulation and experimental results has corroborated system viability to provide three-phase balanced regulated voltages complying with ANEEL 505/2001 Resolution and with IEEE Std 519-1992.
Este trabalho apresenta a proposta de um sistema para geração de energia elétrica baseado na Máquina de Indução Trifásica (MIT) com rotor tipo gaiola de esquilo associada a um conversor de freqüência chaveado no modo PWM (modulação por largura de pulsos na sigla em inglês) senoidal. O lado CC do conversor de frequência é conectado assincronamente à rede monofásica da concessionária através de um inversor monofásico em ponte completa a tiristores, alimentado em corrente, e de um conversor CC-CC abaixador de tensão, utilizado para modular senoidalmente a corrente injetada na rede via inversor. Este sistema permite a operação como co-gerador em localidades alimentadas por linhas monofásicas e com disponibilidade de recursos energéticos. O conversor de freqüência é responsável por manter a freqüência fundamental nos terminais do gerador de indução fixa em 60 Hz. A tensão no capacitor Ccc (Vcc) é controlada através da manutenção do balanço energético no lado CC do conversor PWM, ajustando a amplitude da corrente ativa injetada na rede monofásica em um valor adequado. A estratégia empregada para implementação do controle foi a compensação analógica tipo proporcional-integral (PI) do erro de Vcc. O sistema é ainda capaz de atuar como compensador de potência reativa para as cargas CA, já que o capacitor Ccc representa uma fonte de tensão contínua para o inversor e a ponte trifásica a diodos permite o fluxo bidiredional de energia entre os lados CA e CC do sistema. Os resultados de simulação e experimentais sustentam a viabilidade do sistema para prover tensões trifásicas equilibradas e reguladas, satisfazendo os requisitos da resolução 505/2001 da ANEEL e da norma IEEE Std 519-1992 do IEEE/ANSI.
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Luz, Alessandro Lucindo da. "Operação flexível de conversores trifásicos conectados à rede elétrica." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152449.
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Este trabalho de mestrado descreve uma estratégia de operação multifuncional e flexível aplicado a conversores trifásicos CC-CA (inversores) conectados à rede de distribuição de energia elétrica. A estratégia proposta é capaz de injetar potência ativa na rede e compensar correntes de distúrbios (reativos, desbalanço e harmônicos) simultaneamente. O maior objetivo desta operação flexível é de melhorar a Qualidade de Energia Elétrica em um ponto de acoplamento comum (PAC) permitindo a compensação total ou parcial destes distúrbios ou fatores que degradam a Qualidade de Energia Elétrica. O fator de potência é o principal fator de qualidade a ser observado e ele é calculado através da Teoria da Potência Conservativa – CPT. Entretanto, com base no fator de potência medido pelo lado da rede de distribuição e o fator de potência desejado, um coeficiente de compensação – k é calculado para o ajuste das correntes de compensação dos distúrbios que geram a potência não ativa.
This paper depicts a multifunctional and flexible control strategy applied in three-phase inverters, which are connected to the distribution network. The proposed strategy is able to inject active power into the electrical grid and compensate current disturbances (reactive, harmonics and unbalance) simultaneously. The main goal of this flexible strategy is to improve the Power Quality at the point of common coupling (PCC) allowing full or partial compensation of disturbances. Power factor is the main quality index observed and it is calculated according to Conservative Power Theory - CPT. Therefore, based on the power factor measured in the grid side and the desired value for the power factor, a compensation coefficient - k is calculated continuously adjusting the amplitude of the compensation current.
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Bonnin, Xavier. "Alimentation électrique des dispositifs de décharge à barrière diélectrique." Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/13645/1/bonnin.pdf.
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Les dispositifs DBD se répandent dans un grand nombre d’applications industrielles. Utilisés depuis plus de 150 ans pour la production d’ozone afin de décontaminer l’eau à grande échelle, ils ont depuis la fin du XXème siècle investi les domaines du traitement de surface polymère, du dépôt de couche mince sur substrat et de l’émission lumineuse pour la décontamination ainsi que la médecine. Ces dispositifs sont mis en oeuvre avec un générateur électrique dont les caractéristiques impactent fortement la qualité de la décharge. Ce travail s’inscrit en partie dans le cadre du développement d’une application de traitement de surface à pression atmosphérique. Il aborde la problématique de l’augmentation de la vitesse de dépôt de couche mince au travers des paramètres de l’alimentation électrique. Plus précisément, ce travail s’intéresse aux apports d’une alimentation en courant rectangulaire et aborde également les problématiques liées à la conception et à la fabrication de ce convertisseur. En particulier, une grande attention est portée sur l’étude du transformateur élévateur, car au travers de ses éléments parasites capacitifs, ce dernier peut limiter le transfert de puissance entre la source électrique et le dispositif DBD. Un deuxième aspect de cette étude consiste à entrevoir l’intérêt que revêtent deux convertisseurs statiques dédiés à l’alimentation de dispositifs DBD. Le premier consiste en une alimentation résonante en régime de conduction discontinue dont la particularité est de posséder trois degrés de liberté (fréquence, tension d’entrée et largeur d’impulsion), ce qui lui confère un intérêt exploratoire. Le second convertisseur consiste en une alimentation résonante haute tension et haute fréquence permettant l’éviction du transformateur élévateur, et mettant en oeuvre des interrupteurs au nitrure de gallium (GaN) afin d’atteindre une fréquence de fonctionnement supérieure au mega-Hertz avec un faible niveau de pertes.
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Xie, Hailian. "On Power-system Benefits, Main-circuit Design, and Control of StatComs with Energy Storage." Doctoral thesis, Stockholm : Skolan för elektro- och systemteknik, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10302.
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Hadjikypris, Melios. "Supervisory control scheme for FACTS and HVDC based damping of inter-area power oscillations in hybrid AC-DC power systems." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/supervisory-control-scheme-for-facts-and-hvdc-based-damping-of-interarea-power-oscillations-in-hybrid-acdc-power-systems(cc03b44a-97f9-44ec-839f-5dcbcf2801f1).html.
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Modern interconnected power systems are becoming highly complex and sophisticated, while increasing energy penetrations through congested inter-tie lines causing the operating point approaching stability margins. This as a result, exposes the overall system to potential low frequency power oscillation phenomena following disturbances. This in turn can lead to cascading events and blackouts. Recent approaches to counteract this phenomenon are based on utilization of wide area monitoring systems (WAMS) and power electronics based devices, such as flexible AC transmission systems (FACTS) and HVDC links for advanced power oscillation damping provision. The rise of hybrid AC-DC power systems is therefore sought as a viable solution in overcoming this challenge and securing wide-area stability. If multiple FACTS devices and HVDC links are integrated in a scheme with no supervising control actions considered amongst them, the overall system response might not be optimal. Each device might attempt to individually damp power oscillations ignoring the control status of the rest. This introduces an increasing chance of destabilizing interactions taking place between them, leading to under-utilized performance, increased costs and system wide-area stability deterioration. This research investigates the development of a novel supervisory control scheme that optimally coordinates a parallel operation of multiple FACTS devices and an HVDC link distributed across a power system. The control system is based on Linear Quadratic Gaussian (LQG) modern optimal control theory. The proposed new control scheme provides coordinating control signals to WAMS based FACTS devices and HVDC link, to optimally and coherently counteract inter-area modes of low frequency power oscillations inherent in the system. The thesis makes a thorough review of the existing and well-established improved stability practises a power system benefits from through the implementation of a single FACTS device or HVDC link, and compares the case –and hence raises the issue–when all active components are integrated simultaneously and uncoordinatedly. System identification approaches are also in the core of this research, serving as means of reaching a linear state space model representative of the non-linear power system, which is a pre-requisite for LQG control design methodology.
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Lorenz, Tomáš. "Regulace příkonu přečerpávacích vodních elektráren v čerpadlovém provozu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217583.
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This paper focuses on the Double Fed Induction Machine in the Pumped Storage Power Plants. It includes listing of this plants in the world, where such a technology is used; principle of Double Fed Induction Machine, its usage with variable speed, advantages and disadvantages and also experience of its usage.
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Reymond, Cédric. "Conception d'une structure innovante de convertisseur AC-DC de type Totem-pole avec correction du facteur de puissance : application aux chargeurs de batteries des véhicules électriques." Thesis, Tours, 2019. http://www.theses.fr/2019TOUR4015.
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Les gouvernements responsabilisent les états sur l’environnement avec la mise en œuvre de solution pour décarboner la production de l’électricité. En 2020, 20 % de l’énergie produite sera générée par les énergies renouvelables. Cependant ces énergies vertes sont intermittentes et nécessitent une capacité de stockage importante pour la gestion locale des « smart grids ». Cette solution pose deux nouvelles problématiques : la nécessité d’un convertisseur bidirectionnel et la gestion des courants d’appel. Pour faciliter l’étude de ces problématiques, la thèse propose de lier au travers d’un bilan de puissance, les performances des différents limiteurs de courant sur une topologie de convertisseur innovante. Cette analyse permet de mettre en exergue une solution alternative de limitation des courants d’appel dans la conversion de l’énergie. Enfin, un circuit novateur sur le contrôle des composants de puissance de type thyristors/Triacs sera proposé et caractérisé pour palier une des contraintes liées à la réversibilité du convertisseurGovernments empower states over the environment with implementation of solution to clean up the electricity production sources. In 2020, 20% of the produced energy will be generated by renewable energies. However, theses green energies are occasional and require a huge storage capacitance for the local smart grids management. This solution puts two new issues: the necessity of having a bidirectional converter and the inrush currents management. To facilitate the study of these problems, the thesis suggests binding through a power balance, the performances of the current limiter on an innovative topology converter. This analysis highlight an alternative solution of inrush current strategy in energy conversion. Finally, a novel control circuit for SCRs/Triacs components will be proposed and characterized for landing one of the constraints linked to the converter reversibility
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Гаврилюк, Ігор Миколайович, and Havryliuk Ihor. "Розробка проекту лінії електропередачі з вставкою постій¬ного струму." Master's thesis, ТНТУ імені Івана Пулюя, 2019. http://elartu.tntu.edu.ua/handle/lib/29562.
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В дипломній роботі виконано дослідження можливих варіантів об’єднання несинхронних електроенергетичних систем та систем з різними стандартами регулювання частоти.
Метою роботи є розробка лінії електропередачі «Ковель – Хелм» з вставкою постійного струму для продажу електроенергії з України у Польщу.
Об’єкти, аналогічні спроектованому у даному проекті, можна впровад¬жувати і в інших елек-тричних мережах, що дозволить значно зменшити розміри синхронних мереж змінного струму, запобігти або обмежити каскадні відключення, підвищити коефіцієнт корисної дії електромереж і надійність електроенергетичних систем.In the diploma paper deals with the possibility of combining non-synchronous power systems and systems with different frequency control standards. The purpose of the work is to develop a Kovel-Helm transmission line with a DC insert for the sale of electricity from Ukraine to Poland. Objects similar to those projected in this project can be implemented in other power grids, which will significantly reduce the size of AC synchronous networks, prevent or limit cascade outages, increase the efficiency of grids and the reliability of power systems.
ПЕРЕЛІК УМОВНИХ СКОРОЧЕНЬ.................................................................... 7 ВСТУП .................................................................................................................…8 1 АНАЛІТИЧНА ЧАСТИНА ...............................................................................13 1.1 Призначення вставок постійного струму......................................................13 1.2 ВВППС – основні характеристики системи .................................................15 1.3 Варіанти застосування ВВППС .....................................................................16 1.4 Керування потужністю ...................................................................................17 1.5 Поведінка ВВППС в умовах виходу з ладу системи змінного струму......18 1.6 Вплив підключеної мережі змінного струму на ВПС .................................19 1.7 Споживання реактивної потужності .............................................................21 1.8 Висновки до розділу .......................................................................................23 2 НАУКОВО-ДОСЛІДНА ЧАСТИНА................................................................24 2.1 Пріоритетні напрями діяльності магістрального електромережевого комплексу.........................................................................................................24 2.2 Заходи шодо зниження комерційних втрат електроенергії ........................28 2.3 Перспективи передачі електроенергії за допомогою постійного струму .30 2.4 Основні причини використання ППС в ОЕС України ................................32 2.5 Висновки до розділу .......................................................................................35 3 ТЕХНОЛОГІЧНА ЧАСТИНА ..........................................................................36 3.1 Вибір напруги ліній електропередач постійного струму............................36 3.2 Вибір схеми вставки постійного струму.......................................................40 3.3 Перетворення й регулювання струму конверторами ..................................41 3.4 Вибір тиристорів .............................................................................................44 3.5 Система захисту тиристорів від перенапруг та перевантажень .................48 3.6 Система охолодження тиристорних модулів ...............................................50 3.7 Визначення кількості тиристорів у вентильних групах перетворювача ...52 3.8 Висновки до розділу .......................................................................................54 4 ПРОЕКТНО-КОНСТРУКТОРСЬКА ЧАСТИНА ...........................................55 4.1 Вибір раціонального січення проводів .........................................................55 6 4.2 Розрахунок споживання реактивної енергії перетворювачами..................56 4.3 Усунення впливу вищих гармонік напруги й струму у схемі ВПС...........60 4.4 Розрахунок фільтрокомпенсуючого пристрою............................................65 4.5 Активні фільтри...............................................................................................71 4.6 Висновки до розділу .......................................................................................74 5 СПЕЦІАЛЬНА ЧАСТИНА................................................................................75 5.1 Вибір трансформатора ....................................................................................75 5.2 Компенсація реактивної потужності.............................................................78 5.3 Вибір місця під’єднання компенсаційних пристроїв ..................................81 5.4 Розрахунок потужності компенсаційних пристроїв ....................................81 5.5 Зменшення струму несиметрії у вставках постійного струму ...................84 5.6 Струм к.з. на шинах високої напруги трансформаторів .............................86 5.7 Вибір обладнання ............................................................................................87 5.8 Висновки до розділу .......................................................................................92 6 ОБГРУНТУВАННЯ ЕКОНОМІЧНОЇ ЕФЕКТИВНОСТІ..............................93 6.1 Критерії економічної ефективності енергетичного виробництва..............93 6.2 Визначення капітальних затрат .....................................................................94 6.3 Вартість електроенергії ..................................................................................95 6.4 Розрахунок економічної ефективності..........................................................98 7 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ...100 7.1 Заходи безпеки при обслуговуванні електроустановок ............................100 7.2 Захист персоналу від впливу електричних і електромагнітних полів .....103 7.3 Захист персоналу підстанції від наведених напруг ...................................106 8 ЕКОЛОГІЯ........................................................................................................108 8.1 Актуальність охорони навколишнього середовища..................................108 8.2 Вплив на людину електромагнітного забруднення довкілля ...................108 8.3 Вплив магнітного поля повітряних ліній постійного струму високої і надвисокої напруги на навколишнє середовище.......................................110 ЗАГАЛЬНІ ВИСНОВКИ ДО ДИПЛОМНОЇ РОБОТИ ...................................112 ПЕРЕЛІК ПОСИЛАНЬ .......................................................................................113
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Laamiri, Saber. "Commande des systèmes électriques : machines synchrones et convertisseurs multi-niveaux." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0031/document.
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Ce travail de thèse a pour objectifs l'observation et la commande des convertisseurs multi-niveaux et la commande des machines synchrones. Pour satisfaire le besoin des clients de l’entreprise GS Maintenance et pour des raisons de maintenance, une commande en courant de la machine synchrone est implémentée expérimentalement. L'accent est mis sur le démarrage de ce type de machines car durant ces phases de fonctionnement (basses vitesses), les forces électromotrices sont faibles pour assurer la commutation des thyristors de l'onduleur. Ensuite, l'entreprise a proposé à ses clients un convertisseur statique en moyenne tension afin de garder sa place dans la variation de vitesse. Dans ce cadre, une commande en tension moderne de la machine synchrone alimentée par un onduleur de tension est proposée et validée par des résultats de simulation. Compte tenu du fonctionnement en moyenne tension, les convertisseurs multi-niveaux ont été retenus par l’entreprise. Dans ce cadre, le convertisseur multicellulaire série est proposé dans ce travail et une commande directe basée sur la théorie des modes glissants et le principe de priorité est conçue pour assurer l'équilibrage des tensions flottantes du convertisseur. Cette commande a été généralisée pour un nombre quelconque de cellules du convertisseur et validée par des résultats de simulation pour un nombre de cellules égal à 7. Pour réduire le coût et l'encombrement du convertisseur, un observateur adaptatif des tensions flottantes est proposé en prenant en compte les états de commutation du convertisseur. Cet observateur est ensuite associé à la commande directe en boucle fermée. Un banc d'essai du convertisseur à 3 cellules est réalisé au sein de l’entreprise et l’ensemble « observateur + commande directe » est testé expérimentalement sur ce bancThis PhD thesis aims to the observation and control of multilevel converters and the synchronous machines control. To satisfy the needs of GS Maintenance's customers and for maintenance reasons, a control strategy for a current fed self controlled synchronous machine is validated by experiments tests. The proposed strategy focus on a very low speed because the machine counter electromotive force is insufficient for inverter thyristors switching. Recently, the company proposed for its customers a power converter with medium voltage to keep its place in the speed variation. So, a modern voltage control of the synchronous machine fed by a voltage inverter is proposed and validated by simulation results. Medium voltage operation encouraged the company to choose the multi-level converter. Then, the flying capacitor converter is proposed in this work and a direct control based on the sliding mode theory and the priority principle is designed to guarantee the voltage balance. This control strategy has been generalized for any number of cells of the converter and validated by simulation results for a 7 cells converter. To reduce the cost and complexity of the converter, an adaptive observer floating voltages is proposed by taking into account the switching states of the converter. This observer is then associated with the direct control in closed loop. A test bench of a 3 cells converter is set up in the company. Experimental tests of « observer based direct control » are then conducted on this test bench
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Bendjoua, Jamel. "Contribution à l'étude de l'alimentation des machines électriques de fortes puissances : minimisation des ondulations de couple lors de l'alimentation par cycloconvertisseur." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL119N.
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Ce travail porte sur la modélisation, la simulation, la commande du système cycloconvertisseur-machine synchrone et asynchrone et de la comparaison de leurs performances en terme d'ondulation de couple électromagnétique. On montre que la machine synchrone permet, en statique, d'avoir un couple moins ondulé. Par contre, la machine asynchrone présente un meilleur comportement dynamique lors du démarrage. Afin de limiter les harmoniques provoqués par le temps mort de sécurité, une deuxième horloge permettant d'imposer la durée du palier nul à une valeur fixe est proposée. Enfin, dans le but de réduire les ondulations du couple, une modification de la structure du cycloconvertisseur en ajoutant six thyristors de roue libre est étudiée. Cette modification a permis de réduire, d'une façon importante, les ondulations du couple de la machine synchrone fonctionnant à facteur de puissance unitaire
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Anele, Amos Onyedikachi. "Nonlinear modelling and control of a thyristor-controlled series capacitor for power flow enhancement." 2012. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000968.
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M. Tech. Electrical Engineering.Discusses energy as the basic necessity for the economic development of a country. Many functions necessary to present-day living grind to halt when the supply of energy stops. Energy exists in different forms in nature but the most important form is the electrical energy. Therefore, enhancing power flow in transmission systems is important for efficient power supply because a modern-day society requires a large amount of electrical energy for domestic, commercial and industrial purposes. Among the various means of enhancing power flow in transmission systems with the help of FACTS devices, this research work focussed on the aspect of improving the power system stability. Therefore, efficient supply of electric power to various customer load demands can be achieved when the future power system engineers and researchers carry out nonlinear modelling, bifurcation analysis and control of their system with FACTS devices such as TCSC for power system stability enhancement.
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Venkatesha, M. K. "Study and design of new inverter/converter thyristor circuits for various purposes." Thesis, 1997. http://hdl.handle.net/2009/2632.
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Murray, Nick. "Flexible power control in large power current source conversion : a thesis presented for the degree of Doctor of Philosophy in Electrical and Computer Engineering at the University of Canterbury, Christchurch, New Zealand /." 2008. http://hdl.handle.net/10092/2610.
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Yeh, Chen-wei, and 葉辰威. "A DC side injection strategy for improving AC line condition applied in an 18-pulse thyristor converter system." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/k7jvc4.
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碩士國立臺灣科技大學
電機工程系
99
In this thesis, the thyristor rectifiers are applied to the 18-pulse converter system and a DC side injection strategy is proposed to directly inject the compensation currents at the DC side of the 18-pulse converter for improving the overall AC line condition with various delay angles. The digital signal processor (TMS320F2812) is applied as the core of control in this thesis for feeding back the parameters in system, calculating the compensation commands, and generating the triggering signals for thyristor rectifiers and three-phase inverter. In the proposed scheme, the delta/delta/double polygon phase-shifting transformer is deployed to offer three three-phase voltage sources with ±20° phase-shift to the three thyristor rectifiers and their outputs are connected to the inter-phase transformer for generating the 18-pulse DC output voltage. A three-phase current-controlled inverter directly injects compensation currents into these outputs for improving AC line condition. Besides the advantage of the low kVA rating [2.409%Po (pu)], the three-phase inverter used in the proposed DC side injection strategy connects to the 18-pulse converter system in parallel. Therefore, when the inverter malfunctions, the system can still work with the traditional 18-pulse converter. In this thesis, a DC side injection strategy is proposed for 18-pulse converter systems and modified with the constraints of the latching current and the holding current when applying thyristors. The two modified compensation strategies are compared in simulation. The proposed compensation strategy is highly proper for preexisting 18-pulse converter systems to operate on the occasions demanding lower harmonics or to apply thyristors for controlling output voltage. The compensation strategy can compensate with various delay angles. A 3kW prototype is built for test. Both simulation and experimental results demonstrate the validity of the proposed scheme.
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Tewari, Karan. "Investigation of high temperature operation emitter turn off thyristor (ETO) and electro thermal design of heatpipe based high power voltage source converter using ETO." 2006. http://www.lib.ncsu.edu/theses/available/etd-08142006-235205/unrestricted/etd.pdf.
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Кбайдат, Імад. "Дослідження та розробка системи керування електричним приводом." Магістерська робота, 2020. https://dspace.znu.edu.ua/jspui/handle/12345/4863.
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Кбайдат Імад. Дослідження та розробка системи керування електричним приводом : кваліфікаційна робота магістра спеціальності 153 "Мікро- та наносистемна техніка" / наук. керівник З. А. Ніконова. Запоріжжя : ЗНУ, 2020. 105 с.UA : Розроблено привід подачі робочого інструмента металообро-бних верстатів, який має повністю цифрове рішення системи авто-матичного регулювання і системи імпульсно-фазового керування, що дозволило збільшити функціональність.
EN : The drive of giving of the working tool of metalworking machines which has completely digital decision of system of automatic control and system of pulse-phase control that allowed to increase functionality is developed.