Pour voir les autres types de publications sur ce sujet consultez le lien suivant : Three-phase current inverter.
Thèses sur le sujet « Three-phase current inverter »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 34 meilleures thèses pour votre recherche sur le sujet « Three-phase current inverter ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les thèses sur diverses disciplines et organisez correctement votre bibliographie.
1
White, Terence H. « A three-phase hybrid dc-ac inverter system utilizing hysteresis control ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FWhite%5FTerence.pdf.
Texte intégral
2
Hussien, Zahrul Faizi. « Current control of three-phase PWM Inverter for flywheel energy storage system ». Thesis, University of Southampton, 2000. https://eprints.soton.ac.uk/47946/.
Texte intégralRésumé :
The thesis is concerned with the use of flywheel energy storage system (FESS) in utility load levelling application. The work presented consists of two parts, first, an evaluation of utility load levelling schemes with FESS as the energy storage medium, and second, the development of power electronic interface of FESS to the utility. The thesis presents a study to evaluate FESS load levelling schemes in a UK electricity supply and distribution company. It identifies and quantifies the costs and benefits of the schemes, and carries out a financial appraisal based on Net Present Value (NPV) and Internal Rate of Return (IRR) methods. The results indicate that the DSM schemes utilising FESS can be financially viable for a UK electricity supply and distribution business in a mass-produced (low-cost) FESS scenario, and provide FESS manufacturers and developers with cost goals for such applications. The conclusions drawn provide the motivation for further technical research undertaken within the programme of work. The main work presented is in the area of power electronic interface between FESS, as well as other energy storage devices or energy sources, and the utility for embedded generation. The thesis particularly focuses on the design of current controllers for an interface in the form of three-phase voltage-source pulsewidth modulated (VS-PWM) inverter connected to the utility via LCL filter. Two different current controller structures based on suboscillation current control method have been analysed and designed, aided by computer simulation studies carried out using a general purpose dynamic system simulation software, Matlab Simulink. General properties of a three-phase VS-PWM inverter have been investigated to establish a basic understanding of its operation. The phenomenon of phase interaction in a system with no neutral connection has been examined and the effect of practical inverter nonlinearities caused by interlock time delay (dead time) and on-state voltage drops of the semiconductor devices has been discussed. Various PWM current control techniques have been investigated, including the three-independent hysteresis current control, advanced hysteresis current control, suboscillation current control and space vector current control. The suboscillation current control method has been chosen as produces a well defined harmonic spectrum in the output current without the need for complicated computations and extensive hardware, and can be easily implemented in analogue to avoid problems •sampling and computation time delay generally associated with digital controllers. Fundamental appreciation of the suboscillation PWM technique has been established from analytical synthesis of the modulation process, providing a rational basis for the current controller and computer simulation model validation. An inherent disadvantage of the suboscillation control method has been found to be its limited controller gain, causing a steady-state error to and the effect of inverter nonlinearities to be quite significant. In the first current controller structure, a simple compensation has been utilised to enable the gain to be increased beyond the conventional limit. Simulation results show that the steady-state error the current waveform has been improved and the effect of inverter nonlinearities has been It also makes the current controller less susceptible to the inherently noisy environment, current controller has been experimentally built and tested to validate the simulation results and to validate the practical aspects of its implementation. In the second current controller structure, a cyclic feedback system based on Iterative Control (ILC) has been utilised to eliminate the periodic error in the current waveform. The structure is more complicated and the cyclic feedback system requires digital implementation. Simulation results indicate that the cyclic feedback system is effective in eliminating periodic error in the current waveform. Due to time constraints and hardware limitations, ital implementation of the system has not been possible but is recommended for future research.
3
Cho, Younghoon. « Multi-Branch Current Sensing Based Single Current Sensor Technique for Power Electronic Converters ». Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/39793.
Texte intégralRésumé :
A new concept of current sensor reduction technique called multi-branch current sensing technique (MCST) is proposed in this dissertation. In the proposed current sensing method, one more branch currents are simultaneously measured several times in a single switching cycle by using a single current sensor. After that, the current reconstruction algorithm is applied to obtain all phase currents information. Compared to traditional single current sensor techniques (SCSTs), the proposed method samples the output of the current sensor regularly, and the current sensing dead-zone is dramatically reduced. Since the current sampling is performed periodically, its implementation using a digital controller is extremely simple. Moreover, the periodical dead-zone and the dead-zone near the origin of the voltage vector space which have been a big problem in the existing methods can be completely eliminated. Accordingly, there is no need to have a complicated vector reconfiguration or current estimation algorithm. The proposed MCST also takes the advantages of a SCST such as reduced cost and elimination of the sensor gain discrepancy problem in the multiple current sensor method. The fundamental concept, implementation issues, and limitation of the proposed MCST are described based on three-phase systems first. After that, the proposed MCST is adopted to two-phase inverters and multi-phase dc-dc converters with little modifications.
Computer simulations and hardware experiments have been conducted for a three-phase boost converter, a three-phase motor drive system, a two-phase two-leg inverter, a two-phase four-leg inverter with bipolar modulation, a two-phase four-leg inverter with unipolar modulation, and a four-phase dc-dc converter applications. From the simulations and the experimental results, the feasibilities of the proposed method mentioned above are fully verified.Ph. D.
4
Jacobs, D. M. (Danver Maxwill). « Voltage control of medium to high power three-phase inverter supply systems ». Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52608.
Texte intégralRésumé :
Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: In this thesis a new voltage control method is developed for a three-phase inverter supply system. The inverter supply system consist of a Permanent Magnet Generator, a three-phase rectifier, a three-phase inverter plus LC-filter and a three-phase transformer in series. This system supplies power to a network or to a stand-alone load. The main focus of this thesis is on the control aspects of the inverter and the LC-filter. Different voltage control systems are investigated and compared to each other. From these methods the proposed voltage control method is developed where only the output voltages are measured to establish good voltage control. All these voltage control methods are also simulated with a software package. The proposed voltage control method compares very well with other voltage control methods. The results that are obtained in the simulations are satisfactory. The proposed voltage control method is also implemented in an 8 kW laboratory scale model and, again, very good practical results are obtained. A TMS320F240 nsp controller is used to implement the proposed voltage control method. The controller compensates well for load steps, and these results compare well to an alternative voltage control method, which was also evaluated practically.
AFRIKAANSE OPSOMMING: In hierdie tesis IS 'n nuwe spanningsbeheermetode ontwikkel VIr 'n drie-fase wisselrigter kragtoevoerstelsel. Die wisselrigter kragtoevoerstelsel bestaan uit 'n Permanent Magneet Generator, 'n drie-fase gelykrigter, 'n drie-fase wisselrigter plus Le-filter, en 'n drie-fase transformator in serie. Hierdie stelsel voorsien krag aan 'n netwerk sowel as aan 'n alleenstaande las. Die hooffokus van hierdie tesis is op die beheeraspekte van die wisselrigter en Le-filter. Verskillende spanningsbeheermetodes is deeglik ondersoek en vergelyk met mekaar. Uit hierdie metodes is dan die voorgestelde beheermetode ontwikkel waar slegs die uittreespanning gemeet word om goeie spanningsbeheer te kan doen. Al hierdie spanningsbeheermetodes is dan gesimuleer met 'n sagteware pakket. Die voorgestelde spanningsbeheermetode vergelyk baie goed met die ander spanningsbeheermetodes. Die resultate verky in die simulasies is ook baie bevredigend. Die voorgestelde beheermetode is ook geïmplementeer op 'n 8 kW laboratorium skaalmodel en weereens is baie goeie praktiese resultate verky. 'n TMS320F240 DSP-beheerder is gebruik om die voorgestelde beheermetode mee te implementeer. Die beheerder kompenseer baie goed vir lastrappe en vergelyk ook goed met 'n ander spanningsbeheermetode wat prakties ge-evalueer is.
5
Ayhan, Ufuk. « Investigation Of Dc Bus Current Harmonics In Two And Three Level Three-phase Inverters ». Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614182/index.pdf.
Texte intégralRésumé :
Within scope of this work, double-fourier analysis method of rapid calculation and
detailed simulation method, which are used to investigate DC bus current harmonics
in two level and three level three-phase inverters systematically, will be emphasized
and two methods will be compared via applying different modulation techniques. In
addition, DC bus currents will be investigated visually for various working
conditions and modulation methods. After that, analysis methods will be applied
and harmonic spectrums will be determined. After all, it will be showed that
calculated harmonic spectrums could be treated as unified harmonics around certain
frequencies and these unified harmonics could be reached easily via looking at
predetermined table. Moreover, it will also be showed that unified harmonic values
could be used to determine harmonic current components that are necessary for
sizing DC bus capacitor and could be used in various inverter analysis.
6
Un, Emre. « Common Mode Voltage And Current Reduction In Voltage Source Inverter Driven Three Phase Ac Motors ». Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609062/index.pdf.
Texte intégralRésumé :
In this thesis various reduced common mode voltage (RCMV) pulse width modulation (PWM) techniques and active/passive common mode voltage (CMV) reduction methods for voltage source inverter driven three-phase AC motors are theoretically and practically investigated. A novel RCMV-PWM method, the near state PWM (NSPWM) method is proposed for operation at high modulation index. At low modulation index, a modified version of an existing RCMV-PWM method, AZSPWM1, termed as MAZSPWM, is proposed to mitigate the voltage reflection problem of the method. An optimum modulation algorithm combining NSPWM and MAZSPWM with seamless transition is proposed. The proposed RCMV-PWM methods significantly reduce CMV but they suppress common mode current (CMC) partially. Utilization of a common mode inductor together with RCMV-PWM methods is effective in suppressing the CMC. In the study, in addition to the CMV characteristics, various practical performance characteristics such as voltage linearity, inverter output current ripple, inverter DC-link current ripple, and output line-to-line voltage pulse pattern are also analyzed. The study involves analysis, computer simulations, and detailed laboratory experiments.
7
Alves, rodrigues Luis Gabriel. « Design and characterization of a three-phase current source inverter using 1.7kV SiC power devices for photovoltaic applications ». Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT030.
Texte intégralRésumé :
Classiquement, la chaîne de conversion de l’énergie électrique des centrales photovoltaïques comporte un champ photovoltaïque (PV) délivrant une tension maximale de 1kV suivi d’un hacheur élévateur connecté à un onduleur de tension triphasé. Cette chaîne de conversion à deux étages (DC/DC + DC/AC) est ensuite raccordée sur le réseau moyenne tension au travers d’un transformateur BT/HTA. Dans l’objectif de simplifier les systèmes de conversion PV, ce travail de recherche s’intéresse à l’étude et la mise en œuvre d’une topologie DC/AC n’employant qu’un seul étage de conversion : l’Onduleur de Courant triphasé. Bien que relativement simple, l’Onduleur de Courant présente comme inconvénient majeur les pertes par conduction. Pour pallier ce problème, des interrupteurs à grand-gap au Carbure de Silicium (SiC) sont employés, ce qui permet de convertir de l’énergie de façon performante (η>98.5%) tout en gardant une fréquence de commutation élevée (plusieurs dizaines de kHz). Les modules à semi-conducteurs de puissance du marché n’étant pas compatibles avec ce type de convertisseur, des modules particuliers en SiC ont été développés dans le cadre de la thèse. La caractérisation dynamique de ces nouveaux modules est réalisée dans le but de servir de base à la conception d’un démonstrateur de l’Onduleur de Courant d’une puissance nominale de 60kW. Enfin, le rendement de la partie semi-conducteur de puissance est évalué par une méthode calorimétrique confirmant l’aptitude de la topologie à fonctionner à des fréquences de commutation supérieures. L’originalité de ces travaux réside principalement dans la conception, caractérisation et mise en œuvre de ce nouveau module de puissance adapté à cette topologie connue, mais peu étudiée à l’heure actuelle avec des interrupteurs au SiCClassically, the energy conversion architecture found in photovoltaic (PV) power plants comprises a multitude of solar arrays delivering a maximum voltage of 1kV followed by a step-up chopper connected to a three-phase voltage source inverter. This two-stage conversion system (DC/DC + DC/AC) is then connected to the MV grid through a LV/MV transformer. In order to simplify the PV systems, this research work focuses on the study and implementation of a DC/AC topology employing a single conversion stage: the three-phase current source inverter (CSI). Although relatively simple, the CSI presents as major drawback the conduction losses. To deal with this problem, wide-bandgap silicon carbide (SiC) semiconductors are used, which allows to efficiently convert energy (η> 98.5%) while keeping a relatively high switching frequency (several tens of kHz). Nonetheless, since the available power semiconductor modules on the market are not compatible with the CSI, a novel 1.7kV SiC-based module is developed in the context of the thesis. Thus, the dynamic characterization of the new SiC device is carried out and serves as a basis for the design of a 60kW Current Source Inverter prototype. Finally, the inverter’s semiconductor efficiency is evaluated through a calorimetric method, confirming the ability of the topology to operate at higher switching frequencies. At the present time, little research has been conducted on the CSI implementation with SiC devices. The originality of this work lies mainly in the design, characterization and implementation of the new SiC power module adapted to this well-known inverter topology
8
Titiz, Furkan Kaan Verfasser], Doncker Rik W. [Akademischer Betreuer] [De et Sibylle [Akademischer Betreuer] Dieckerhoff. « A three-phase low-voltage grid-connected current source inverter / Furkan Kaan Titiz ; Rik W. de Doncker, Sibylle Dieckerhoff ». Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1216040907/34.
Texte intégral
9
Titiz, Furkan Kaan [Verfasser], Doncker Rik W. [Akademischer Betreuer] De et Sibylle [Akademischer Betreuer] Dieckerhoff. « A three-phase low-voltage grid-connected current source inverter / Furkan Kaan Titiz ; Rik W. de Doncker, Sibylle Dieckerhoff ». Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1216040907/34.
Texte intégral
10
Ingram, David. « An Evaluation of Harmonic Isolation Techniques for Three Phase Active Filtering ». Thesis, University of Canterbury. Electrical and Computer Engineering, 1998. http://hdl.handle.net/10092/1260.
Texte intégralRésumé :
Recent advances in power electronics have lead to the wide spread adoption of advanced power supplies and energy efficient devices. This has lead to increased levels of harmonic currents in power systems, degrading the performance of electrical machinery and interfering with telecommunication services. Active filters provide a solution to these problems by compensating for the distorted currents drawn by non-linear loads. Optimal methods for controlling these active filters have been determined by computer simulation and experimental implementation. Methods used for isolating the harmonic content of an unbalanced three phase load current were compared by computer simulations. A technique based on the Fast Fourier Transform (FFT) was developed as part of this work and shown to perform favourably. Notch Filtering, Sinusoidal Subtraction, Instantaneous Reactive Power Theory, Synchronous Reference Frame and Fast Fourier Transform methods were simulated. The methods shown to be suitable for compensation of three phase unbalanced loads were implemented in a Digital Signal Processor to evaluate true performance. These methods were Notch Filtering, Sinusoidal Subtraction, Fast Fourier Transform, and a High Pass Filter based method. A completely digital hysteresis current controller for a three phase active filter inverter has been developed and implemented with a Field Programmable Gate Array. This controller interfaces directly to a digital signal processor and is resistant to electromagnetic interference. Results from the experimental hardware verified that the active filter model used for simulation is accurate, and may be used for further development of harmonic isolation methods. A technique using notch filtering gives the best performance for steady loads, with the FFT based technique giving the most flexible operation for a range of load current characteristics. Novel use of the FFT based harmonic isolation technique allows selective cancellation of individual harmonics, with particular application to multiple shunt filters connected in parallel.
11
Silva, Carlos Elmano de Alencar e. « Estudo e desenvolvimento experimental de um sistema eÃlico interligado a rede elÃtrica ». Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7458.
Texte intégralRésumé :
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorFundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico
Este trabalho apresenta o estudo e desenvolvimento de um sistema eletrÃnico de aproveitamento de energia eÃlica a partir de um gerador sÃncrono de Ãmà permanente conectado a uma turbina de vento. O sistema opera com velocidade variÃvel, permitindo o mÃximo aproveitamento da energia cinÃtica incidente na turbina de vento. Essa energia cinÃtica à convertida em energia elÃtrica pelo gerador sÃncrono de Ãmà permanente e depois de totalmente condicionada, injetada na rede elÃtrica convencional. Esse condicionamento à feito por um sistema eletrÃnico objeto de estudo e desenvolvimento deste trabalho, o qual consiste em um retificador trifÃsico interligado a um inversor monofÃsico em ponte completa com saÃda em corrente. SÃo apresentadas a revisÃo bibliogrÃfica de sistemas de aproveitamento de energia eÃlica para geraÃÃo de energia elÃtrica pertinentes ao escopo do trabalho, a anÃlise do estÃgio retificador (potÃncia e controle), a anÃlise do estÃgio inversor (potÃncia e controle), uma comparaÃÃo teÃrica de rendimento entre o retificador trifÃsico proposto neste trabalho (bridgeless trifÃsico) e o retificador trifÃsico dois nÃveis, e os resultados experimentais de um protÃtipo de validaÃÃo de 5kW do sistema proposto.
This work presents the study and development of an electronic system for wind energy exploitation from a permanent magnet synchronous generator connected to a wind turbine. The system operates with variable speed, allowing maximum use of the kinetic energy incident on the wind turbine. This kinetic energy is converted into electrical energy by the permanent magnet synchronous generator and, after being fully conditioned, injected into the conventional power grid. This conditioning is done by an electronic system object of study and development of this work, which consists of a rectifier connected to a single-phase full-bridge inverter with current output. Are presented the literature review of the relevant wind energy conversion systems to the scope of work, the analysis of the rectifier stage (power and control), the analysis of the inverter stage (power and control), a efficiency theoretical comparison between the proposed rectifier (three-phase bridgeless) and the three-phase fullbridge rectifier, and the experimental results of an 5kW validation prototype of the proposed system.
12
Chen, Hanling. « AVERAGE-VALUE MODELING OF HYSTERESIS CURRENT CONTROL IN POWER ELECTRONICS ». UKnowledge, 2015. http://uknowledge.uky.edu/ece_etds/78.
Texte intégralRésumé :
Hysteresis current control has been widely used in power electronics with the advantages of fast dynamic response under parameter, line and load variation and ensured stability. However, a main disadvantage of hysteresis current control is the uncertain and varying switching frequency which makes it difficult to form an average-value model. The changing switching frequency and unspecified switching duty cycle make conventional average-value models based on PWM control difficult to apply directly to converters that are controlled by hysteresis current control.
In this work, a new method for average-value modeling of hysteresis current control in boost converters, three-phase inverters, and brushless dc motor drives is proposed. It incorporates a slew-rate limitation on the inductor current that occurs naturally in the circuit during large system transients. This new method is compared with existing methods in terms of simulation run time and rms error. The performance is evaluated based on a variety of scenarios, and the simulation results are compared with the results of detailed models. The simulation results show that the proposed model represents the detailed model well and is faster and more accurate than existing methods. The slew-rate limitation model of hysteresis current control accurately captures the salient detail of converter performance while maintaining the computational efficiency of average-value models. Validations in hardware are also presented.
13
Rutkovskiy, Yaroslav. « A Novel Control Method for Grid Side Inverters Under Generalized Unbalanced Operating Conditions ». Cleveland State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=csu1610646102417883.
Texte intégral
14
Morávek, Lukáš. « Řídicí modul BLDC motoru ». Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242079.
Texte intégralRésumé :
Diploma thesis describes design and realization of hardware and software for controlling and regulation of the high-speed drive with BLDC motor, which will serve as a spindle for CNC milling machine. The thesis described in detail the schematic design and the design of printed circuit board of the power part, control part and power supply part of the three-phase transistor inverter controlled by DSP processor. It is also described in detail program of DSP processor for controlling and regulation of the BLDC motors, which the function is verified by the final measurements. The result of Diploma thesis is functional high-speed drive with BLDC motor.
15
Li, Yong. « Unified zero-current-transition techniques for high-power three-phase PWM inverters ». Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/26843.
Texte intégralRésumé :
This dissertation is devoted to a unified and comprehensive study of zero-current-transition (ZCT) soft-switching techniques for high-power three-phase PWM inverter applications. Major efforts in this study are as follows: 1) Conception of one new ZCT scheme and one new ZCT topology; 2) Systematic comparison of a family of ZCT inverters; 3) Design, implementation and experimental evaluation of two 55-kW prototype inverters for electric vehicle (EV) motor drives that are developed based on the proposed ZCT concepts; and 4) Investigation of the ZCT concepts in megawatts high-frequency power conversions. The proposed ZCT techniques are also applicable to three-phase power-factor-correction (PFC) rectifiers.
In order to minimize switching losses, this work first proposes a new control scheme for an existing three-phase ZCT inverter circuit that uses six auxiliary switches. The proposed scheme, called the six-switch ZV/ZCT, enables all main switches, diodes and auxiliary switches to be turned off under zero-current conditions, and in the meantime provides an opportunity to achieve zero-voltage turn-on for the main switches. Meanwhile, it requires no modification to normal PWM algorithms. Compared with existing ZCT schemes, the diode reverse-recovery current is reduced significantly, the switching turn-on loss is reduced by 50%, the resonant capacitor voltage stress is reduced by 30%, and the current and thermal stresses in the auxiliary switches are evenly distributed.
However, a big drawback of the six-switch ZV/ZCT topology, as well as of other types of soft-switching topologies using six auxiliary switches, is the high cost and large space associated with the auxiliary switches. To overcome this drawback, this work further proposes a new three-phase ZCT inverter topology that uses only three auxiliary switches-- the three-switch ZCT. The significance of the proposed three-switch ZCT topology is that, among three-phase soft-switching inverters developed so far, this is the only one that uses fewer than six auxiliary switches and still has the following three features: 1) soft commutation for all main switches, diodes and auxiliary switches in all operation modes; 2) no modification to normal PWM algorithms; and 3) in practical implementations, no need for extra resonant current sensing, saturable cores, or snubbers to protect the auxiliary switches.
The proposed six-switch ZV/ZCT and three-switch ZCT inverters, together with existing ZCT inverters, constitute a family of three-phase ZCT inverters. To explore the fundamental properties of these inverters, a systematic comparative study is conducted. A simplified equivalent circuit is developed to unify common traits of ZCT commutations. With the visual aid of state planes, the evolution of the family of ZCT inverters is examined, and their differences and connections are identified. Behaviors of individual inverters, including switching conditions, circulating energy, and device/component stresses, are compared.
Based on the proposed six-switch ZV/ZCT and three-switch ZCT techniques, two 55-kW prototype inverters for EV traction motor drives have been built and tested to the full-power level with a closed-loop controlled induction motor dynamometer. The desired ZCT soft-switching features are realized together with motor drive functions. A research effort is carried out to develop a systematic and practical design methodology for the ZCT inverters, and an experimental evaluation of the ZCT techniques in the EV motor drive application is conducted. The design approach integrates system optimization with characterizations of the main IGBT device under the ZCT conditions, selection, testing and characterization of the auxiliary devices, design and selection of the resonant inductors and capacitors, inverter loss modeling and numerical analysis, system-level operation aspects, and layout and parasitic considerations. Different design aspects between these two ZCT inverters are compared and elaborated. The complexity of the 55-kW prototype implementations is compared as well. Efficiencies are measured and compared under a group of torque/speed points for typical EV drive cycles.
Megawatts high-frequency power conversion is another potential application of the ZCT techniques. The integrated gate commutated thyristor (IGCT) device is tested and characterized under the proposed six-switch ZV/ZCT condition, and the test shows promising results in reducing switching losses and stresses. Improvements in the IGCT switching frequency and simplification of the cooling requirements under ZCT operations are discussed. In addition, a generalized ZCT cell concept is developed based on the proposed three-switch ZCT topology. This concept leads to the discovery of a family of simplified multilevel soft-switching inverters that reduce the number of auxiliary switches by half, and still maintain desirable features.Ph. D.
16
Kumar, Rajiv. « Programmed harmonic reduction in single phase and three phase voltage-source inverters ». Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1178302407.
Texte intégral
17
Jung, Jin Woo. « Modeling and control of fuel cell based distributed generation systems ». Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1116451881.
Texte intégralRésumé :
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvi, 209 p.; also includes graphics. Includes bibliographical references (p. 202-209). Available online via OhioLINK's ETD Center
18
Kwak, Sangshin. « Design and analysis of modern three-phase AC/AC power converters for AC drives and utility interface ». Texas A&M University, 2005. http://hdl.handle.net/1969.1/2336.
Texte intégralRésumé :
Significant advances in modern ac/ac power converter technologies and demands
of industries have reached beyond standard ac/ac power converters with voltage-source
inverters fed from diode rectifiers. Power electronics converters have been matured to
stages toward compact realization, increased high-power handling capability, and
improving utility interface. Modern ac/ac power converter topologies with various
control strategies have been introduced for the further improvements, such as matrix
converters, current-fed converters, PWM rectifiers, and active power filters. In this
dissertation, several new converter topologies are proposed in conjunction with
developed control schemes based on the modern ac/ac converters which enhance
performance and solve the drawbacks of conventional converters.
In this study, a new fault-tolerant PWM strategy is first proposed for matrix
converters. The added fault-tolerant scheme would strengthen the matrix converter
technology for aerospace and military applications. A modulation strategy is developed
to reshape output currents for continuous operation, against fault occurrence in matrix
converter drives.
This study designs a hybrid, high-performance ac/ac power converter for high
power applications, based on a high-power load commutated inverter and a mediumpower
voltage source inverter. Natural commutation of the load commutated inverter is
actively controlled by the voltage source inverter. In addition, the developed hybrid
system ensures sinusoidal output current/voltage waveforms and fast dynamic response
in high power areas.
A new topology and control scheme for a six-step current source inverter is
proposed. The proposed topology utilizes a small voltage source inverter, to turn off
main thyristor switches, transfer reactive load energy, and limit peak voltages across
loads. The proposed topology maximizes benefits of the constituent converters: highpower
handling capability of large thyristor-based current source inverters as well as fast
and easy control of small voltage source inverters.
This study analyzes, compares, and evaluates two topologies for unity power
factor and multiple ac/ac power conversions. Theoretical analyses and comparisons of
the two topologies, grounded on mathematical approaches, are presented from the
standpoint of converter kVA ratings, dc-link voltage requirements, switch ratings,
semiconductor losses, and reactive component sizes. Analysis, simulation, and
experimental results are detailed for each proposed topology.
19
Aboelhassan, Mustafa Osman Elrayah. « Robustní řízení synchronního stroje s permanentními magnety a spínaným tokem ». Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-233605.
Texte intégralRésumé :
Je jasné, že nejúspěšnější konstrukce zahrnuje postup vícefázového řízení, ve kterém každá fáze může být považována za samostatný modul. Provoz kterékoliv z jednotek musí mít minimální vliv na ostatní, a to tak, že v případě selhání jedné jednotky ostatní mohou být v provozu neovlivněny. Modulární řešení vyžaduje minimální elektrické, magnetické a tepelné ovlivnění mezi fázemi řízení (měniče). Synchronní stroje s pulzním tokem a permanentními magnety se jeví jako atraktivní typ stroje, jejíž přednostmi jsou vysoký kroutící moment, jednoduchá a robustní konstrukce rotoru a skutečnost, že permanentní magnety i cívky jsou umístěny společně na statoru. FS-PMSM jsou poměrně nové typy střídavého stroje stator-permanentní magnet, které představují významné přednosti na rozdíl od konvenčních rotorů - velký kroutící moment, vysoký točivý moment, v podstatě sinusové zpětné EMF křivky, zároveň kompaktní a robustní konstrukce díky umístění magnetů a vinutí kotvy na statoru. Srovnání výsledků mezi FS-PMSM a klasickými motory na povrchu upevněnými PM (SPM) se stejnými parametry ukazuje, že FS-PMSM vykazuje větší vzduchové mezery hustoty toku, vyšší točivý moment na ztráty v mědi, ale také vyšší pulzaci díky reluktančnímu momentu. Pro stroje buzené permanentními magnety se jedná o tradiční rozpor mezi požadavkem na vysoký kroutící moment pod základní rychlostí (oblast konstantního momentu) a provozem nad základní rychlostí (oblast konstantního výkonu), zejména pro aplikace v hybridních vozidlech. Je předložena nová topologie synchronního stroje s permanentními magnety a spínaným tokem odolného proti poruchám, která je schopná provozu během vinutí naprázdno a zkratovaného vinutí i poruchách měniče. Schéma je založeno na dvojitě vinutém motoru napájeném ze dvou oddělených vektorově řízených napěťových zdrojů. Vinutí jsou uspořádána takovým způsobem, aby tvořila dvě nezávislé a oddělené sady. Simulace a experimentální výzkum zpřesní výkon během obou scénářů jak za normálního provozu, tak za poruch včetně zkratových závad a ukáží robustnost pohonu za těchto podmínek. Tato práce byla publikována v deseti konferenčních příspěvcích, dvou časopisech a knižní kapitole, kde byly představeny jak topologie pohonu a aplikovaná řídící schémata, tak analýzy jeho schopnosti odolávat poruchám.
20
Bhasagare, Mayuresh. « Three-phase multilevel solar inverter for motor drive system ». Thesis, 2015. http://hdl.handle.net/1805/7929.
Texte intégralRésumé :
Indiana University-Purdue University Indianapolis (IUPUI)This thesis deals with three phase inverters and the different control strategies that can be associated with an inverter being used together. The first part of this thesis discusses the present research in the fields of PV panels, motor drive systems and three phase inverters along with their control. This control includes various strategies like MPPT, Volts-Hertz and modulation index compensation. Incorporating these techniques together is the goal of this thesis. A new topology for operating an open end motor drive system has also been discusses, where a boost converter and a flyback converter have been used in cascade to run a three phase motor. The main advantage of this is increasing the number of levels and improving the quality of the output voltage, not to mention a few other benefits of having the proposed circuit. A new algorithm has also been designed for starting and stopping the motor, which controls the current drawn from the power source during starting.
21
Lee, Ming-Hsueh, et 李明學. « Design and Implementation of a Three-Phase Inverter with Hysteresis Current Control ». Thesis, 2015. http://ndltd.ncl.edu.tw/handle/51417642632607481801.
Texte intégralRésumé :
碩士國立臺灣大學
電機工程學研究所
103
A three-phase four-wire inverter with hysteresis current control for the photovoltaic (PV) system application is proposed in this thesis. There are usually two series-connected dc-link capacitors in the input side of a three-phase four-wire inverter. Unstable operation may result if the two capacitor voltages are different. In this thesis, a control method is developed according to the relationship between the dc-link capacitor voltage and the neutral wire current. By detecting the dc-link capacitor voltage, the neutral wire reference current signal can be generated to adjust the offset of hysteresis current band, so the capacitor voltage shifting and unstable operation can be avoided. On the other hand, there are many switches in the three-phase four-wire inverter and their switching losses dominate the inverter’s efficiency. In this thesis, the zero voltage switching operation is achieved by producing the bi-directional inductor current so that the switching loss can be reduced. Finally, simulation and hardware implementation results verify the feasibility and performance of the proposed three-phase four-wire inverter with hysteresis current control.
22
Chen, Chia Chi, et 陳家齊. « Design of a Three Phase Current-Sourced Inverter for Photovoltaic Energy Conversion Systems ». Thesis, 2011. http://ndltd.ncl.edu.tw/handle/05461257110017924376.
Texte intégralRésumé :
碩士長庚大學
電機工程學系
99
Abstract Photovoltaic (PV) cell is a solid-state device which can generate electricity from solar irradiation where the physics was portrayed from an illumination current source in parallel to a junction diode and an internal resistance. When the PV is loading, the portion of the illumination current will enter the shunt branch according to the current-division principle. It means that if the output current of the PV cell is well regulated, the maximum power output will be achievable. This thesis presents a more direct method to regulate PV cell current by using a current-sourced inverter (CSI). The proposed CSI is a tandem structure that can convert the output power of the PV cells to the load for multiple purposes. In addition, a voltage observer based controller controls the line current so as to provide power to the grid with a unity power factor. To evaluate the performance of the proposed photovoltaic energy conversion system (PECS), a computer simulation is performed in the MATLAB/SIMULINK environment using the Power System Blockset (PSB). Furthermore, a laboratory prototype of a fully digital-controlled 1.5kVA PECS is implemented. The fully-digital controller based on the TMS320F28335 DSP hosts the sampling, A/D conversion and the control purposes. Computer simulation and experimental results demonstrate the effectiveness of the proposed system.
23
(11198991), Harshita Singh. « Passive Mitigation of Common-Mode Current in Three-Phase Two-Level Inverter-Based Systems ». Thesis, 2021.
Trouver le texte intégralRésumé :
Power electronic converters are being used in a variety of applications, from electric vehicles to the utility grid. These converters are designed to offer high efficiency, which is achieved by switching semiconductor devices between on or off states at a high frequency. Associated with this switching is a common-mode voltage. The high-frequency components in this voltage excite the parasitic capacitances in the system, resulting in the flow of common-mode current. Since this current completes its path through an unintended path, it can interfere with the functioning of other devices or equipment. One way to reduce the CM current in a system is through the use of passive components. These include strategically placed capacitors and common-mode inductors to limit the impact of the common-mode quantities.
While the design of common-mode inductors has been set forth in the literature, the effect of magnetic hysteresis in the core has been inappropriately ignored. This phenomenon becomes increasingly important when the allowable common-mode current is significantly smaller than the differential-mode current, such as in high-power converters.
In this work, passive mitigation of common-mode current in three-phase two-level voltage-source-inverter based systems is considered. A mitigation strategy is proposed and described. The components used in this strategy, namely a common-mode inductor and a proposed common-mode shorting network, are introduced. This is followed by a discussion on the time domain hysteresis modeling that facilitates the magnetic design of a common-mode inductor. The issue of self-capacitance of a common-mode inductor is then addressed. Then, a rigorous multi-objective optimization-based design methodology for a common-mode inductor which addresses magnetic hysteresis at a fundamental level is set forth.
This is followed by a discussion of a new tool in common-mode current mitigation, a proposed common-mode shorting network. A design strategy for this component is also set forth. The dissertation concludes with two experimental system demonstrations of the proposed strategy and components on laboratory test systems.
24
Dash, Prajna Paramita. « A High-Performance Three-Phase Grid-Connected PV System Based On Multilevel Current Source Inverter ». Thesis, 2013. http://hdl.handle.net/10012/7356.
Texte intégralRésumé :
Current Source Inverter (CSI) topology is gaining acceptance as a competitive alternative for grid interface of renewable energy systems due to its unique and advantageous features. Merits of CSI over the more popular Voltage Source Inverter (VSI) topology have been elaborated on by a number of researchers. However, there is a dearth of quality work in modeling and control of CSI topology interfacing renewable energy resources to the grid. To enrich the study focussing on application of CSI for renewable energy interface, this thesis develops a multilevel structure based on CSI for three-phase grid-connected Photovoltaic (PV) application. In the first part of research, a single-stage CSI interfacing to PV array is developed. The CSI-based PV system is equipped with Maximum Power Point Tracker (MPPT), DC-link current controller, and AC-side current controller. To eliminate the nonlinearity introduced by the PV array, a feed-forward control is introduced in the DC-link current controller. The AC-side current controller is responsible for maintaining unity power factor at the Point of Common Coupling (PCC). To verify the performance of the developed CSI-based PV system, a number of simulation studies are carried out in PSCAD/EMTDC environment. To illustrate the performance of the CSI-based PV system during transients on the grid side, simulation studies are carried out for four kinds of faults. Results obtained from fault studies are highly in favor of CSI topology and provide illustrative evidence for short-circuit current protection capability of the CSI. On the other hand, the VSI-based PV system performs poorly when subjected to similar grid transients.
To extend the research on CSI-based PV system further, a multilevel structure based on CSI is developed. The multilevel structure is a parallel combination of $n$ CSI units and capable of producing $2n+1$ levels of current at the terminal of the inverter. Each unit in the multilevel structure has its own MPPT, DC-link current controller. However, on the AC-side a combined current controller is proposed. The design results in a high power rating with reduced number of filters, sensors and controllers. The developed multilevel structure can operate with PV arrays exposed to equal and unequal insolation level. However, when the PV arrays are operating under unequal insolation level, low order harmonics are generated in the sinusoidal current that is injected into the grid. Elimination of these harmonics is performed by implementing a modified control strategy in stationary reference frame that corresponds to the harmonic component that needs to be minimized. The modified control strategy operates in coordination with the existing DC-side and AC-side current controllers, and MPPTs. Therefore, real-time suppression of current harmonics can be ensured. Performance of the multilevel structure is verified by different transient studies.
25
Chen, Yan-ning, et 陳彥寧. « Implementation of a Three-Phase Multi-Level Current Source Inverter Based on Selective Harmonic Elimination ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/87114734188344256900.
Texte intégralRésumé :
碩士國立臺灣科技大學
電機工程系
98
This thesis proposes a multi-level current source inverter based on selective harmonic elimination technique. The required notch angles are solved from a set of non-linear simultaneous equations which is established by quarter-waveform symmetric assumption. Newton- Raphson method is used to solve the non-linear simultaneous equations through off-line calculation in a personal computer . Then, the solved notch angles are stored in a digital controller which employs a digital signal processor (TMS320F2812) and a complex programmable logic device (ispMACH 4256V). The multi-level current source inverter is consist of two stages: the dc current source stage and the inverter stage. The digital controller provides switching pattern for the switches in the two stages. In addition to the digital controller, a three-phase five-level current source inverter with output filter is built for test and measurement. Moreover, a simulation program is built to confirm the correction of the notch angles solved by off-line calculation through the harmonic analysis. Both the simulation and experimental results shows the validity of the proposed multi-level current source inverter.
26
Wei, Hsiao-Tse, et 魏孝哲. « Current Harmonics Mitigation Control Strategy for Six-arm Inverter with Three-phase Permanent-magnet Synchronous Motor Drives ». Thesis, 2015. http://ndltd.ncl.edu.tw/handle/7mu3nm.
Texte intégralRésumé :
博士國立臺灣科技大學
電機工程系
103
This dissertation focuses on development of low-torque ripple and high stability with a six-arm inverter for three-phase permanent-magnet synchronous motor (PMSM) drives. In this structure, the power circuit uses six-arm three-phase inverter. Each phase of the PMSM is operating independently to raise the utilization factor of dc-link voltage. By using zero-sequence current estimator, it calculates the content of third-harmonic in current. These calculated results can be used to eliminate the third-harmonic of current. When a winding of three-phase PMSM breaks down, the other two winding currents will be corrected to result in a 60-degree angle difference. The component which can suppress the third-harmonic of current was injected into healthy phases to eliminate currents harmonics, thereby reducing torque ripple. In this dissertation, Matlab/Simulink is used to simulate the proposed PMSM system. Performances with different current control and current harmonics mitigation control strategies for PMSM operated under normal and post-fault conditions are compared. This control method could be used to implementation of system. A prototype PMSM system was built with TMS302F28335 digital signal processor. And the program was completed by C language. Under the normal operation of the system, the third-harmonic of current decreases from 28.71% to 3.05%. The peak current required for system falls from 1.212 pu to approximately 1.017 pu. The current of zero-axis decreases from 0.256 pu to 0.021 pu. When the phase a open-circuit is in fault condition, the third-harmonic of current in phase b decreases from 7.00% to 1.36%. The third-harmonic of current in phase c decreases from 9.91% to 3.06%. The third-harmonic of current in zero-axis falls from 25.19 pu to 2.19 pu. The electromagnetic torque ripple decreases from 85.57% to 2.85%.The proposed system performance is thus verified experimentally.
27
Hu, Jyun-Wei, et 胡峻瑋. « Design and Implementation of Novel Predictive Current Controllers for a Three-Phase Two-Level Voltage Source Inverter ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/81365713523009274314.
Texte intégralRésumé :
碩士國立臺灣海洋大學
電機工程學系
104
This thesis proposes a novel model-free predictive current control for a three-phase two-level voltage source inverter. Unlike the predictive current control using seven voltage vectors, the proposed method uses 19 resultant voltage vectors, each of the vectors consisted of two voltage vectors. Since the numbers of available voltage vectors are increased from eight to nineteen, the predictive error can be effectively reduced. In addition, the proposed method does not require load parameters, back electromotive force, and system models. To compare to the model-based predictive current control, the proposed one belongs to a model-free approach because it is based on loading current detection, implying that the method is in sensitive to parameter variations. Finally, a TMS320F28335 digital signal controller, made by Texas Instruments Company, is used to validate the feasibility of the proposed method. From simulation and experimental results, there are better current-tracking performance in steady-state and transient responses than the existed predictive current control.
28
Chiu, Chi-Lun, et 邱啟倫. « Design and Implementation of Model-Free Predictive Current Controller for Four-Switch Three-Phase Inverter-Fed Synchronous Reluctance Motors ». Thesis, 2015. http://ndltd.ncl.edu.tw/handle/45034255736362108121.
Texte intégralRésumé :
碩士國立臺灣海洋大學
電機工程學系
103
This thesis presents a novel predictive current control for four-switch three-phase inverter-fed synchronous reluctance motor drive systems. We not only develop a new strategy for four-switch three-phase inverter-fed synchronous reluctance motor drive systems, but also discuss the feasibility and correctness of this method so as to improve the ability of the current control of the motor drive system. Furthermore, we expect to meet the industrial requirements of low-cost drive system equipped with high-performance current control. Compared to the six-switch drive system, the four-switch three-phase drive system can effectively reduce the development costs in both hardware and software. For a four-switch three-phase synchronous reluctance motor drive system, its switch strategies that we can choose are few. Generally speaking, the drawback of hysteresis current control is that it has large ripples in the output currents of the inverter. In order to improve the current-tracking performance, the development of the new switching strategy for low-cost drive system is urgently needed. As a result, the proposed method is based on the stator current measurement and the current variation so as to predict the future stator current. A digital signal processor, TMS320F2809, made by Texas Instruments Company, is used to execute the algorithms of the proposed predictive current control and hysteresis current control. Experimental results can be used as a reference for developing a new switching strategy of a four-switch three-phase drive system in the future.
29
Chen, Chih-Wei, et 陳志偉. « New Hybrid Pulse-Width Modulation Technique to Reduce Current Distortion and Extend Current Reconstruction Range for Three-Phase Inverter using only DC-link Sensor ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/4jj6ej.
Texte intégralRésumé :
碩士國立臺北科技大學
電機工程系研究所
100
The objective of this thesis is to develop a new modulation technique which can reduce the current distortion and extend the current reconstruction range for three-phase inverter using only DC-link sensor. The PWM technique is a hybrid method which consists of space vector modulation method and the PWM method without using null switching states. The former provides low current distortion, however it is with narrower current reconstruction range. In contrast, the later extends the current reconstruction range at the cost of higher current distortion. The proposed method, in the measurable region of space vector modulation method, space vector modulation is used to reduce the current distortion. Moreover, as the modulation range is out of that measurable region, the PWM method without using null switching states is applied to extend the current reconstruction range, and achieve the current reconstruction of the three-phase inverter. In this thesis, an ALTERA produced Field Programmable Gate Array (FPGA) EPF10K70RC240-3 is used as the control platform. This proposed method for current reconstruction is realized using induction motor (IM). An induction motor with specifications of rated power 750 W, rated speed 1680 RPM, no. of poles 4, rated frequency 60 Hz, rated voltage 220/380 V(ê/Y), rated current 3.1/1.8 A. Finally, the experimental results will confirm the effectiveness of the proposed method, where the current can be reconstructed even under very low modulation index with low harmonics distortion of inverter output current.
30
Peng, Chih-I., et 彭智義. « Design and Implementation of An Improved Predictive Current Controller for Four-Switch Three-Phase Inverter-Fed Synchronous Reluctance Motor Drive systems ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/d859f9.
Texte intégral
31
Wu, Dong-Yue, et 吳東岳. « Design and Implementation of Two-Vector-Based Predictive Current Controllers for a Voltage Source Inverter with a Three Phase Passive Filter ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/33122464866377213803.
Texte intégralRésumé :
碩士國立臺灣海洋大學
電機工程學系
104
This thesis proposes a two-vector-based model-free predictive current control for a six-switch three-phase voltage source inverter with a three-phase passive filter. Generally, the existing predictive current control only consider the operations of eight switching modes, whereas the proposed method simulates the operations of fourteen ones, each of which is based on a combination of two voltage vectors. This implies that the accuracy of current prediction can be effectively improved by using the proposed strategy. In additional, the proposed method is based on the load current measurements and the current difference calculations together with the addition operation to predict the future load currents. Therefore, the proposed method does not depend on any system parameters, such as resistance, inductance, and back-EMF. Simulations are completed using MATLAB® software, whereas experiments are implemented via a 32-bit digital signal processor, TMS320F28335, made by Texas Instruments Company. Both simulation and experimental results show that the current-tracking performance of the proposed method is superior to that of the existing ones.
32
WU, YI-CHI, et 吳怡錡. « Design and Implementation of Three phase Inverters in Parallel with Current Sharing Control ». Thesis, 2019. http://ndltd.ncl.edu.tw/handle/976w3s.
Texte intégralRésumé :
碩士國立臺北科技大學
電機工程系電力電子產業碩士專班
107
Title：Design and Implementation of Three-phase Inverters in Parallel with Current Sharing Control Pages：88 School：National Taipei University of Technology Department：Electrical Engineering, Time：July, 2019 Degree：Master Researcher：Yi-Chi Wu Advisor：Yen-Shin Lai Ph.D. Keywords：Current Sharing, Parallel System, Three-phase Inverter in Parallel, Differential Mode Circulating Current The objective of this thesis is to design and implement a three-phase inverters in parallel with current sharing control. The system consists of two DC/AC inverters, with interleaved NSVM as switching method to reduce total harmonic distortion and common mode voltage. Both current and circulating current controllers are used to suppress the differentia mode circulating current and thereby reducing the current imbalance between two inverters and increase the system reliability. Moreover, the coupled inductor is used to improve the circulating current. The specifications of experimental platform include input DC voltage of 148 V, switching frequency 15 kHz, the three-phase star connection R-L loads of 36 Ω/5 mH and permanent-magnet synchronous motor. The Renesas Micro Controller Unit (MCU) 32-bit SH7137 is used as the control platform to verify current sharing control implementation and analysis. Experimental results show the current sharing control can be achieved with the presented control.
33
Li, Nong-Yi, et 李穠義. « Design and Implementation of Modulated Predictive Current Controllers for Three-Phase Four-Leg Two-Level Inverters ». Thesis, 2019. http://ndltd.ncl.edu.tw/handle/j4uksd.
Texte intégralRésumé :
碩士國立臺灣海洋大學
電機工程學系
107
This thesis proposes a novel type of modulated model-free predictive current control for three-phase four-arm two-level inverters. Compared to traditional techniques, the proposed method effectively improves current response at high frequencies by incorporating the optimal selection of two switching states based on simple calculation and then combines to the next switching state. This selection method effectively detects the optimal two modulated switching states in each sampling period. In addition, the improved control response at high frequency effect is introduced using an enhanced updating mechanism of the current difference. This is to enable the switching states of alike phase voltage to update current difference amount at the same time. In order to verify the proposed method, the simulation is conducted using MATLAB/Simulink software, and implemented using the TMS320F28379D dual-core digital signal controller by Texas Instruments. The simulation and experimental results show that the proposed method can significantly improve the current tracking performance compared with the existing methods.
34
Huynh, Phuoc-Sang, et 黃福尚. « Design and Implementation of an FPGA-Based Digital Current Controller in Applications to Three-Phase PWM Inverters ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/31321744764925582271.
Texte intégralRésumé :
碩士國立交通大學
電機工程學系
102
This thesis presents the design and implementation of an FPGA-based digital current controller, providing a fully integrated solution for high-performance three-phase inverters. The synchronous coordinate current control algorithm is realized with dead-time compensation and one-shunt current sampling by using the introduced controller. First of all, DPWMMIN strategy is employed in the controller under considerations of linear range modulation and switching losses, based on the evaluation of three typical PWM methods, SPWM, SVPWM and DPWMMIN. In the DPWMMIN scheme, the linear modulation range is allowed a 15.5-percent increase in comparison with SPWM. Moreover, on/off switching occurs in only two phase legs each switching cycle, thus the DPWMMIN method introduces less switching losses. Secondly, dead time is required in the standard PWM inverter control to prevent dc-link short circuit. However, this blanking time also results in distortion in output voltage and it becomes quite significant for inverters under low modulation index. A dead-time compensation technique is developed for DPWMMIN. By using the compensation scheme, the width of output voltage pulses is corrected in every switching cycle without position shift. Thirdly, one-shunt current sampling imposes practical implementation challenges for reliable current sensing and low current distortion over wide load variation ranges. Boundary conditions for phase current reconstruction with one-shunt current sensing have been derived from small time intervals of effective voltage vectors. A simple sampling technique is introduced to achieve correct three-phase current information from dc-link current for the DPWMMIN strategy with a minimum of undesirable side effects. Finally, the core of the synchronous coordinate current control algorithm is the coordinate transformation, which needs several multiplications for realization. However, if a dedicated multiplier is used for each multiplication, the cheaper and smaller FPGAs cannot meet the logic resource requirement. To overcome this limitation, a multiplier-sharing strategy is used, which can reduce the number of dedicated multipliers in the FPGA. Experimental verification has been given to illustrate the performance of the proposed controller by using ARM-based mixed-signal FPGA PSOC board, SmartFusion A2F500M3F.