Dissertations / Theses on the topic 'Synchronous PWM'

Sensorless-controlled drives represent a solution drawing an increasinglyimportant attention for the benefits they entail. At the cost ofa slightly lower dynamics compared with the traditional drives, theyinvolve a reduction of the system costs and complexity and improvednoise immunity and reliability. Besides the traditional signal injectionmethods, involving a limitation of the machine voltage margin, higheriron losses, torque ripple and acoustic noise, a new method has beenproposed in 2010 by professors Bolognani, Faggion and Sgarbossa.This algorithm, which has been defined "intrinsic injection" method,makes used of the harmonic content deriving from the PWM modulation.In this work, the intrinsic injection sensorless algorithm and its implementationin a MATLAB=Simulink environment is the object of study.Its theoretical foundation is deeply analysed together with the phenomenaand the operating conditions that might affect its performance.The drive model is described and three different alternatives for the estimatorhave been proposed. Simulations have been run with the estimatoroperating both in open-loop and in closed-loop. The influencesof the sampling frequency, of the motor speed, of the load torque, ofthe implemented modulation strategy and of the DC-link voltage amplitudehave been analysed. Lastly, the drive has been simulated withregard to a fan or pump application case.
Sensorlösa drivsystem är en lösning som nuförtiden drar en utökad uppmärksamhet för de fördelar som de medför. Även om de uppvi- sar en sämre dynamik jämfört med de traditionella drivsystemen, det finns vissa fördelar som minskning av systemkostnader och komplex- itet, samt förbättrad ljudimmunitet och tillförlitlighet. Förutom de tra- ditionella metoderna baserad på en signalinjektion, som leder till an begränsad spänningsmarginal samt högre järnförluster, vridmoment rippel och akustiskt brus, i året 2010 har en ny metod föreslagits av Prof. Bolognani, Dr. Faggion och Dr. Sgarbossa. Denna algoritm defi- nierades "inre injektion-metoden, eftersom den utnyttjar strömöverto- ner som framkallas från pulsbreddmodulering. I detta arbete är analysen av ?inre injektion-metoden och dess imple- mentering i en MATLAB/Simulink-miljö ett föremål. Den teoretiska grunden analyseras i detaljer tillsammans med fenomenet och drifts- förhållandena som kan påverka prestanda. Drivsystemsmodellen be- skrivs och tre olika alternativ föreslås. Simuleringar körs med en algo- ritm som arbetar både i öppen slinga och i sluten slinga. Påverkan av samplingsfrekvensen, motorhastighet, lastmoment, pulsbreddmodu- lering strategi och spänning i DC-mellanleden analyseras och simuleras med avseende på ett fläkt- eller pumpapplikationsfodral.

DC power systems have a constant DC-link voltage, as well as the advantages such as high stability, high efficiency, small size and light weight; therefore, they are widely used in stand-alone power systems, e.g. the power systems in aircrafts and automobiles, isolated wind power generation systems, etc. Permanent-Magnet Synchronous Generators (PMSGs) possess the advantages including high power density, high efficiency, and high control precision, and have obtained great attention and have been widely used in military, inductry, and daily life. Pulse Width Modulation (PWM) rectifier has been one of the main power conversion topologies thanks to its full controllability. The key point in the dissertation is to study the DC power system consisting of a PMSG to be the main power input device and a PWM rectifier to be the main power conversion topology. The objective of control is to output a constant DC-link voltage in a wide PMSG speed range. Since the PM-excited flux linkage is constant, when the PMSG is working at a high speed, field-weakening is needed to stabilize the stator voltage, further to stabilize the DC-link voltage. Hybrid excitation may be used to realize the field-weakening, but it has complex structure; no auxiliary devices are needed in the field regulation with the armature current, and can be easily realized with the PWM recifier and field-regulation control strategies. In this dissertation, the typical applications of the DC power systems are first introduced, with a comprehensive analysis and elaboration on the relevant research throughout the world. The research work is focused on the DC power system and its stabilization control, which is composed of a PMSG and a PWM rectifier. The involved research content in this dissertation includes the following aspects: 1. DC power system design with a wide-speed-range PMSGAs for the common DC power systems, PMSG with high power density, high efficiency is selected to the system power input device, usually with a variable-speed prime mover. The PWM rectifier with fully controlled switches is chosen to be the power conversion topology, which converts the AC power generated by PMSG into DC power, and supplies the DC load after the DC filter. The matching between the system requirements and the generator parameters are determined. Through finite-element analysis (FEA), a PMSG with strong field-weakening ability and suitable for wide-speed-range operation has been designed and manufactured, and the system test bench has been built based on dSPACE. 2. Study, analysis, optimization and experimental verification of the traditional control strategiesAccording to the PMSG designed in part 1, the DC-link model has been built, as well as the control model of the traditional control strategies, e.g. field-oriented control (FOC), direct torque control (DTC), and the effectiveness of the DC-link voltage stabilization control has been verified in a wide speed range. The theory of active damping has been proposed and analyzed, and has been utilized in the DC-link voltage control. When the load on the DC-link changes, the dynamic response of the DC-link voltage has been greatly accelerated, and it recovers quickly to its reference value. In the meantime, the performance influence of the prime mover speed on the actual system test bench should be considered. Finally, the performance of FOC and DTC has been compared and analyzed. 3. Analysis and experimental verification of the direct voltage control (DVC), and the comparative study of all the studied control strategiesThe derivation process of DVC has been theoretically analyzed: the inner current loops in FOC have been eliminated to obtain the direct voltage field-oriented control (DVFOC); the reference value of d-axis voltage in DVFOC has been replaced by the product of the stator voltage calculated by the speed and the load condition, and the sine value of load angle generated by the DC-link voltage PI controller, in order to form the DVC-1. Further, the DC-link voltage PI controller directly outputs the reference value of load angle and it becomes DVC-2. Finally, the comparative study has been carried out among all the studied control strategies.
Doctorat en Sciences de l'ingénieur et technologie
info:eu-repo/semantics/nonPublished

A servo system intended to steer antennas on board ships is designed, built and tested. It uses a Brushless Direct Current (BLDC) motor with an encoder to keep track of its position, and Field Oriented Control (FOC) implemented on Toshibas microprocessor TMPM373 in order to control the current flowing to the motor. The servo system will be connected in cascade to another already existing servo system and controlled with two input signals. The first signal determines if the antenna axis should rotate clockwise or counter clockwise. The second signal is a stream of pulses, where each pulse means that the motor should move one encoder point. A printed circuit board is designed and built to complete these tasks. A proportional-integral regulator is used to control the position of the motor, using the position error as the controller input. The servo system is tested. The performance of the resulting servo system is sufficient to satisfy the required position error limit of 0.5 degrees. In order to reduce the periodic disturbances presented in the system in experiments, Iterative Learning Control (ILC) is implemented. It is shown that using ILC further decreases the position error.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This dissertation addresses the analysis and control of permanent magnet synchronous generators (PMSG) found in wind energy conversion system. The operation modes of the wind turbine the current and voltage constraints of a PWM rectifier are defined and a methodology to determine the generator current is presented. The generator currents obtained guarantee the maximization of wind energy extraction as well as the minimization of the PMSG and rectifier losses. In addition, a space-vector modulation technique in overmodulation region is reviewed in detail and applied aiming: (i) to maximize the generator power; (ii) to utilize the entire PWM rectifier DC link voltage resource, and (iii) to obtain a smooth transition to six-step operation. Furthermore, a single current controller is designed for all operating modes being capable to avoid the controller states overload as well as the undesired effects due to the operation in the overmodulation region. The stability analysis of the closed loop system is investigated by means of linear matrix inequality conditions to estimate a region of operation with guaranteed stability. Simulation results are presented to demonstrate the performance of the proposed system.
Esta dissertação trata da análise e do controle de geradores sincronos a íımã permanente usados em sistema de conversão de energia eólica. Os modos de operação da turbina eólica sob restrição de tensão e corrente são definidos e uma metodologia para determinar as correntes do gerador ´e apresentada. As correntes obtidas do gerador garantem a maximização da potência extraída do vento bem como a minimização das perdas do conjunto gerador e retificador PWM. Além disso, a técnica de modulação vetorial na região de sobremodulação é revisada em detalhes e aplicada com objetivo de: (i) maximizar a potência do gerador, (ii) utilizar todo o recurso do barramento CC disponível pelo retificador PWM e (iii) obter uma transição suave para operação do retificador para o modo de seis-pulsos. Uma técnica de controle vetorial é apresentada e comparada. Um único controlador de corrente é projetado para todos os modos operacionais, sendo capaz de evitar tanto sobrecarga dos estados do controlador quanto os efeitos indesejáveis provenientes da operação na região de sobremodulação. A análise da estabilidade do sistema em malha fechada é investigada por meio de desigualdades matriciais lineares para determinar uma região de estabilidade garantida. Por fim, resultados de simulação são apresentados para demonstrar o bom desempenho do sistema proposto.

Malgré les améliorations de topologies des convertisseurs DC/AC, l'onduleur à deux niveaux reste le "gold standard" dans l'industrie ceci pour de multiples raisons : simplicité, fiabilité, etc. Dans le cadre de cette thèse entre Centrale Nantes et Renault, de nouvelles commandes d'onduleur ont été développées afin d'améliorer les performances sans modifier la topologie du convertisseur. Pour cela, deux approches basées sur des commandes hors-ligne synchrones ont été proposées. Premièrement, celles qui relaxent la contrainte de symétrie angulaire entre phases, usuellement imposée au convertisseur. Deuxièmement, celles qui sont à porteuse triangulaire consistant à injecter une séquence homopolaire de fréquence triple dans la modulante. La conséquence de cette approche est une généralisation de l’injection d'harmonique classique de rang trois. Un calcul aux limites a permis de montrer l'existence d'une méthodologie facilement implantable, qui prend la forme d'une injection d’une dent de scie. Les deux approches revisitent les stratégies de commande par modulation de largeur d'impulsion (MLI) de la littérature grâce à des considérations simples à base de relaxation et d'extension de propriétés existantes. L'ensemble de ces stratégies améliorent significativement le taux de distorsion harmonique des tensions ou courants fournis par l'onduleur pour des fréquences de commutations synchrones faibles. Ces observations ont été réalisées en simulation et validées sur un banc expérimental de faible puissance
Despite improvements in DC/AC converter topologies, the two-level inverter remains the "gold standard" in the industry for many reasons: simplicity, reliability, etc. In this thesis between Ecole Centrale and Renault, new inverter controls have been developed to improve the performance without modifying the converter topology. For this purpose, two approaches based on synchronous off-line controls have been proposed. Firstly, an angular symmetry relaxation between phases usually imposed on the converter. Secondly triangular carrier based strategies, meaning injecting a triple frequency homopolar sequence into the modulating signal. The consequence of this approach has given rise to a generalization of the classical third harmonic injection. A calculation extension has shown the existence of an easily implementable methodology, which takes the form of a sawtooth injection. Both approaches revisit the pulse width modulation (PWM) control strategies of the literature with simple considerations based on relaxation and extension of existing properties. The advantage of all these strategies is that they improve significantly the harmonic distortion rate of the voltages or currents supplied by the inverter for low synchronous switching frequencies. These observations have been done in simulation and validated on a low power experimental bench

The study designs and constructs a three-phase to three-phase direct AC&ndash
AC matrix converter based surface mounted permanent magnet synchronous motor (PMSM) drive system. First, the matrix converter topologies are analyzed and the state-space equations describing the system have been derived in terms of the input and output variables. After that, matrix converter commutation and modulation methods are investigated. A four-step commutation technique based on output current direction provides safe commutation between the matrix converter switches. Then, the matrix converter is simulated for both the open-loop and the closed-loop control. For the closed-loop control, a current regulator (PI controller) controls the output currents and their phase angles. Advanced pulse width modulation and control techniques, such as space vector pulse width modulation and field oriented control, have been used for the closed-loop control of the system. Next, a model of diode-rectified two-level voltage source inverter is developed for simulations. A comparative study of indirect space vector modulated direct matrix converter and space vector modulated diode-rectified two-level voltage source inverter is given in terms of input/output waveforms to verify that the matrix converter fulfills the two-level voltage source inverter operation. Following the verification of matrix converter operation comparing with the diode-rectified two-level voltage source inverter, the simulation model of permanent magnet motor drive system is implemented. Also, a direct matrix converter prototype is constructed for experimental verifications of the results. As a first step in experimental works, filter types are investigated and a three-phase input filter is constructed to reduce the harmonic pollution. Then, direct matrix converter power circuitry and gate-driver circuitry are designed and constructed. To control the matrix switches, the control algorithm is implemented using a DSP and a FPGA. This digital control system measures the output currents and the input voltages with the aid of sensors and controls the matrix converter switches to produce the required PWM pattern to synthesize the reference input current and output voltage vectors, as well. Finally, the simulation results are tested and supported by laboratory experiments involving both an R-L load and a permanent magnet synchronous motor load. During the tests, the line-to-line supply voltage is set to 26 V peak value and a 400 V/3.5 kW surface mounted permanent magnet motor is used.

With rising fuel prices, increasing electrification, and imminent fines on CO2 emission within the EU, the requirement for energy and cost efficient supply concepts is becomingmore and more important in the automotive industry. This thesis presents an assessmentof, and improvement for energy and cost efficient power supply concepts for low-end automotiveand light e-mobility electronic control units, containing small µCs, and analogand logic components. Specifically, linear regulators, synchronous and non-synchronous buck converters, andswitched capacitor converters are investigated and assessed theoretically. The mostpromising concept, namely a discrete buck converter, is further studied using theoreticalassessment, experiment, and simulations. The key result of this work is a concept for replacing commonly used linear regulatorsin small electronic control units (ECUs) by a more efficient supply with only a smallcost adder. Specifically, since no low-end switched converter ICs are available today, wedeveloped a buck converter with discrete control circuit. This concept provides a cheap,yet efficient alternative to linear regulators for a wide range of applications. In addition,the application of this concept is supported by component selection criteria, and also bythe developed simulation models.

This work discusses about nowadays problematic of the electronic comutation motors.This work also describes the opportunity of electronic control of these motors. The result of this work is realization of electronic control circuit from discreet components. There also are mentioned is proposal of electronic control board from SMD components. This control board include temperature control with ventilator switching , commutation logic, PWM speed control. In the last part of this paper are results of evaluation measurements of EC motor.

O objetivo principal deste trabalho é o desenvolvimento de controladores robustos baseados no princípio do modelo interno, em referenciais síncrono e estacionário, para aplicação ao estágio de saída de uma fonte ininterrupta de energia (UPS) a fim de minimizar a distorção na tensão de saída causada pela conexão de cargas não lineares balanceadas e desbalanceadas. A formulação em referencial estacionário (abc) é realizada através da aplicação de controladores com múltiplos modos ressonantes, a fim de se estabelecer erro nulo ao seguimento de referência senoidal e rejeição de distúrbios na tensão de saída devido às correntes com elevado conteúdo harmônico drenadas pelas cargas. Além disso, o controle é formulado em referencial síncrono (dq0) utilizando controladores Proporcional-Integral (PI) convencionais muito difundidos na maioria das aplicações comerciais de UPS. O projeto de ambos controladores é realizado utilizando uma metodologia de controle robusto com realimentação de estados, onde os parâmetros dos controladores são determinados através da resolução de um problema de otimização convexa sujeito a um conjunto de restrições na forma de desigualdades matriciais lineares (LMI). Uma análise comparativa de desempenho é realizada entre controladores com um modo ressonante (sintonizado na fundamental) e o PI em dq0, pois apresentam estruturas funcionalmente equivalentes sob a ótica do princípio do modelo interno aplicada a seus respectivos referenciais. Além do mais, demonstra-se a melhoria no desempenho com o uso dos controladores múltiplo ressonantes em referencial estacionário onde escolhe-se as frequências de ressonância de cada modo de maneira a suprimir os efeitos de harmônicas específicas na tensão de saída da UPS. A análise comparativa entre os controladores propostos é realizada através de simulações numéricas, utilizando os procedimentos de ensaio dinâmico e estático e as exigências estabelecidas pela norma internacional IEC 62040-3.
The main objective of this work is the development of robust controllers based on the internalmodel principle, in synchronous and stationary frames, applied to the output stage of an uninterruptible power supply (UPS), in order to minimize the output voltage distortion caused by the connection of balanced and unbalanced nonlinear loads. The formulation in stationary abc-frame is accomplished through the aplication of a multiple resonant controller, so that, it is possible to achieve zero-error tracking of the sinusoidal reference and disturbances rejection on the output voltage due to the high amount of harmonic currents drained by the loads. Moreover, a controller in synchronous reference frame (dq0 axis) is formulated through the application of conventional Proportional-Integral (PI) controllers which are widely used in comercial UPS applications. The design of both controllers is formulated using a state-feedback robust controlmethod, in which the controller parameters are determined by solving a convex optimization problem subject to a set of LMI constraints. A comparative analysis on the performance of the single-mode resonant controller (tuned at the fundamental frequency) and the PI controller is performed, because these controllers are functionally equivalent in the sense of the internal model principle applied to their respective frames. Furthermore, the improvement in performance is demostrated with the use of multiple resonant controllers in stationary abc-frame where the resonance frequencies are chosen to suppress the effects of a specific harmonic in the UPS output voltage. The comparative analysis of the proposed controllers is performed through numerical simulations, making use of the dynamical and steady-state test methods and performance requirements defined by the IEC 62040-3 international stardard.

This work is focused on innovative construction of the industrial radial sealless pump and mainly on construction of the three phase DC/AC converter based on new semiconductor technology SiC. These new semiconductor devices allow move switching frequency up to 100 kHz. For such high switching frequency new non-conventional topology of the output filter was designed. This high frequency is currently unusual in three-phase application with output voltage 400V. High switching frequency reduces size of wound components of the output filter and its presence is accepted in terms of total weight and price of the whole system. Clear sinus waveform of the output converter voltage reduces torque ripple, EMC and extend the lifetime and reliability of mechanical parts and the whole pump drive. Three phase synchronous motor is directly placed into the pump body and is designed as slotless motor. In the inlet area is the classical bearing replaced by active magnetic bearing. It is used due to possibility to pump aggressive liquids or substances where high level of cleanness has to be guaranteed.

Product Lifecycle Management (PLM) systems are used by thousands of engineering companies world wide. Improving these systems will have a drastic and global effect. One possible improvement is to integrate synchronous collaborative applications with PLM systems. These applications allow multiple people to work on a single digital object simultaneously. They have already been shown to reduce the time a task requires. Using these applications to complete a project will reduce the project time. However, simply including synchronous collaborative applications within a PLM system ignores powerful benefits that could provide further time-saving benefits. The integration must allow improved awareness at the project level, so that users can mediate their own actions.This thesis presents a method for such an integration. It also presents a prototype which implements that method. Testing was carried out using this prototype. As hypothesized, including synchronous collaborative applications shortened the overall project time. In addition, providing awareness information and allowing users to mediate themselves further shortened project times and reduced variation in those times. Proper integration should therefore provide awareness at the project level and allow users to mediate themselves to some extent.

This thesis is a study on an unconventional slow speed direct drive permanent magnet (PM) generator. Unlike a standard permanent magnet synchronous generator (PMSG) which has the copper coils wound around iron teeth, the work in this thesis will present a generator where the copper coils are directly mounted on the stator which eliminates the slots and teeth in the generator. By having a slotless design it is possible to eliminate cogging torque, iron losses in teeth and achieve a lightweight design. These characteristics can prove useful when developing generators for an application such as wind turbines, or more specifically vertical axis wind turbines (VAWTs) in remote areas where weight and serviceability is of concern. This thesis consists of two main parts where the main focus was on the design and simulation of slotless generators. The second part of the thesis was to investigate an available slotless axial flux machine. For the simulations, three different models were created in 2D using CAD software. Two of the models were double-rotor slotless generators and one was a single rotor variant. The electromagnetic properties of these models were analysed using FEMM and COMSOL. The results showed that the double rotor variant with the smaller magnets were more favourable considering the price of magnets and no iron core losses. The experimental results of the axial flux machine gave insight into the construction of commercially available axial slotless generators which could be used to further analyse these types of machines.

Superconductors are known for carrying very high current density without any loss of energy. This characteristic helps to achieve very high power capacity with compact size of machine. In application of superconductors, the main obstacle has been the cooling of the conductors since it operates at very low temperatures below ambient. After the discovery of high temperature superconductor (HTS) in 1986, several prototype machines have been built using in DC field winding. The application of superconductor in AC armature winding has not been feasible due to excessive AC losses. These losses are caused due to penetration of time varying magnetic field. This thesis concerns the possibility of the application of superconductor in armature windings of permanent magnet synchronous generator. A 10 MW wind power generator with copper winding has been taken as reference machine and the machine has been redesigned with several pole-slot combinations using superconductor. Permanent magnet has been used as the source of field. Three alternatives have been designed with superconductor in armature winding and the machine with 176 poles, 192 slots has been selected as the best among them based upon the active weight of the generator, outer volume, utilization factor, power factor, full load losses, and total harmonic distortion and cogging torque. The selected machine has been found to be 62 ton in weight where as that of reference machine is 90 ton. Moreover, the outer volume of the superconducting machine is about 2.5 times lesser than that of the copper winding reference machine. The reduction in volume of generator will consequently reduce the volume of nacelle and the reduction in weight will reduce the transportation cost. The major reference of comparison has been the utilization factor of the machines which is 110 kN•m/m3 for the proposed superconducting machine whereas that for reference machine has been 44.6 kN•m/m3. The total loss in superconducting machine has not been calculated due to unavailability of actual AC losses in superconductors. Therefore, a tolerable limit of AC losses has been calculated using the losses incurred by the reference machine which is 0.82 mW/A•m at 20 K when a perpendicular AC field of 0.39 T is applied. Normalized AC losses lower than this value will make the superconducting machine to possess lower loss in comparison to reference machine. Some measures to improve the power factor of superconducting machine by increasing the thickness of magnet have also been studied. It has been found that an increase by 20 mm of additional layer of magnet makes the proposed superconducting machine to have better power factor than the reference machine. Hence, the SC machine consumes less reactive power from the grid and needs a smaller power electronic converter in the system. In this work, it has been put forth that permanent magnet synchronous generators with AC superconductors will make a system compact in size and weight provided AC superconductors with lower losses than aforementioned value are manufactured.

Thesis (MScEng)--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: The thesis describes the optimum rotor design and performance of a 110kW Permanent-Magnet assisted (PM-assisted) Reluctance Synchronous traction Machine (RSM) using bonded permanent magnet sheets. Particular attention is given to the performance of the machine drive in the flux-weakening speed region. A detail explanation is given of the finite-element design optimisation, the basic principles of operation and the control-design of the PM-assisted RSM drive. A theoretical torque comparison of the PM-assisted RSM, the standard RSM and the induction machine is also done. The measured and calculated results of the different drives are presented and analysed in detail. It is concluded that the performance of the PM-assisted RSM in terms of torque, voltage and power factor compares favourably well with that of the induction machine in both the constant torque and flux-weakening speed regions. Furthermore, it is shown that the temperature rise of the stator winding of the PMassisted RSM is lower than that of the RSM with both machines at the same load.
AFRIKAANSE OPSOMMING: Die tesis beskryf die optimum rotor ontwerp en vermoë van 'n 110 kW Permanent- Pagnet-ondersteunde (PM-ondersteunde) Reluktansie Sinchroon Masjien (RSM) trekkrag aandryfstelsel. Spesifieke aandag word gegee aan die vermoë van die aandryfstelsel in die vloedverswakking spoedgebied. 'n Volledige verduideliking word gegee van die eindige-element ontwerp optimering, die basiese beginses van werking en die beheer-ontwerp van die PM-ondersteunde RSM aandryfstelsel. 'n Teoretiese vergelyking van die draaiumoment-vergelyking van die PM-ondersteunde RSM, die standard RSM en die induksmasjien word gedoen. Die berekende en gemete resultate van die verskillende aandryfstelsels word in detail aangebied en ge-analiseer. Dit is gevind dat die vermoë van die PM-ondersteunde RSM in terne van draairnoment, spanning en arbeidsfaktor gunstig vergelyk met dit van die induksiemasjien in beide die konstante draairnoment en vloedverswakking spoedgebiede. Verder word getoon dat die temperatuur-styging van die statorwinding van die PM-ondersteunde RSM laer is as die van die RSM, met deide masjiene by die selfde las

Everyone is noting that Permanent Magnet Synchronous Machines (PMSMs) are more and more invading home, commercial and industrial applications thanks to their superior performance and efficiency, high torque and power density. Due to these features, this kind of machines is widely employed in several fields of technology. In the transportation branch, electric traction based on PMSM is becoming a strong competitor with conventional propulsion systems based on either combustion engines or induction machines. Clear examples are pure and hybrid electric vehicles, trains etc... Due to the always more pressing energy label constraints, PMSM are conquering the market of large home appliances, e.g. washing machines and dryers, refrigerators and air conditioner. Finally, robotics and high precision systems, machine tool and industrial applications are always more employing PMSM for high performance and efficiency devices. In recent years there has been a growing interest in Synchronous Reluctance Machines (SyRMs) since they feature superior reliability and are cost effective due to the absence of permanent magnets in the rotor. Due to these relevant characteristics, the possibility of replacing PMSM with SyRMs in existing applications is very attractive for people working in all the aforementioned fields. The motivations of this thesis are driven by industrial needs. In particular, the topics of this research have been developed according to specific requirements provided by E.E.I. S.p.a. (Equipaggiamenti Elettronici Industriali - Vicenza, Italy), the industrial partner that has been supporting the scholarship of my PhD. Two main research themes have been determined regarding the control of synchronous machines, in particular IPMSMs and SyRMs. First, the possibility to develop a control algorithm able to exploit the wide speed range operation capability of the machine. This is a crucial aspect in the design of an electric drive that allows avoiding the oversizing of both the power converter and the motor, which in turn brings to space and money savings. The second topic consists in the analysis of open research topics regarding the sensorless control of PMSM. Position estimation algorithms allow avoiding the use of position sensors leading to advantages in term of cost and reliability of the drive. For these reasons sensorless applications are very attractive from an industrial point of view. However, the performances of conventional algorithms for the position estimation at zero or low speed degrade in case of heavy saturation condition and they could be prone to instability.
Le macchine sincrone a magneti permanenti (PMSM) sono sempre più utilizzate in applicazioni domestiche, commerciali e industriali per via della loro superiore efficienza, coppia elevata e alta densità di potenza. Grazie a queste caratteristiche, questo tipo di macchine viene ampiamente utilizzato in diversi campi. Nel settore dei trasporti, la trazione elettrica basata su PMSM sta diventando un forte concorrente dei sistemi di propulsione convenzionali basati su motori a combustione o macchine a induzione. Chiari esempi sono i veicoli elettrici puri e ibridi, i treni, ecc. A causa dei vincoli sempre più stringenti delle classi energetiche, le macchine PMSM stanno conquistando il mercato dei grandi elettrodomestici, ad es. lavatrici e asciugatrici, frigoriferi e condizionatori. Infine, la robotica e i sistemi di alta precisione, le macchine utensili e le applicazioni industriali impiegano sempre più macchine a magneti permanenti per dispositivi ad alte prestazioni ed efficienza. Negli ultimi anni c'è stato un crescente interesse per le macchine a riluttanza sincrona (SyRMs) poiché presentano una superiore affidabilità e sono economicamente vantaggiose a causa dell'assenza di magneti permanenti nel rotore. Per questo la possibilità di sostituire i motori a magneti permanenti presenti nelle esistenti applicazioni con macchine sincrone a riluttanza è di grande interesse per chi lavora nei campi precedentemente citati. Esigenze industriali hanno determinato le attività descritta in questa tesi. In particolare, gli argomenti di ricerca sono stati scelti e sviluppati in base alle specifiche esigenze di E.E.I. S.p.a. (Equipaggiamenti Elettronici Industriali - Vicenza, Italia), il partner industriale che ha finanziato la mia borsa di studio. Due principali temi di ricerca riguardanti il controllo delle macchine sincrone, in particolare IPMSM e SyRM, sono stati individuati. Innanzitutto, la possibilità di sviluppare un algoritmo di controllo in grado di sfruttare la capacità di questi motori di lavorare in un ampio intervallo di velocità. Questo è un aspetto cruciale nella progettazione di un azionamento elettrico poichè consente di evitare il sovradimensionamento del convertitore di potenza e del motore, che a sua volta porta a risparmi di spazio e denaro. Il secondo argomento riguarda l'analisi del controllo sensorless dei motori sincroni. Gli algoritmi di stima della posizione consentono di evitare l'uso di sensori che portando vantaggi in termini di costi e affidabilità dell'azionamento. Per queste ragioni le applicazioni sensorless sono molto interessanti da un punto di vista industriale. Tuttavia, le prestazioni degli algoritmi convenzionali per la stima della posizione a velocità bassa o nulla peggiorano in caso di condizioni di forte saturazione e potrebbero portare perfino all’instabilità dell’algoritmo.

Automatic voltage regulation is necessary for all power producing synchronous generators to ensure that the produced power have a constant and stable voltage level and to sustain grid stability. The aim of this thesis is to design and build an automatic voltage regulator for a synchronous generator. A six-phase permanent magnet alternator will be used to excite the rotor with solid-state relay controlled rotating bridge rectifier. The field current is regulated by a closed loop control system that is based on a programmable logic controller, PLC. Programing of the PLC is executed in the developing environment CoDeSys, IEC 61131-3, which is the international standard for programing PLC applications. Simulations for predicting the system behavior is done with a web based in-browser tool, circuitlab.com. The results show a good performance of the regulator and the closed loop system although there is room for improvement of the solid-state controlled rectifier system.

Permanent magnet (PM) machines offer several advantages in traction applications such as high efficiencyand high torque per volume ratio. The iron losses in these machines are estimated mostly with empiricallaws taken from other types of machines or with finite element simulations (FEM). In the first part of thisthesis the objective is to define an accurate analytical model for the stator yoke, teeth and rotor of a PMmotor which should work well enough for all operating point (different loads and frequency).This analytical model is found using an iterative process. After building a loss matrix and flux matrix basedon FEM simulations, it is possible to curve fit each of the lines or the rows of the matrix in order to achievethe best fitting for every operating point. This is a very new approach; it was shown that it gives thepossibility, even with a very limited number of FEM simulations, to achieve an accurate estimation of thelosses.The second part of this report focuses on optimizing this analytical method, comparing it with otherpossibilities, analyzing limits and advantages. Special attention is also given to the effects of the losses onthe temperatures in different parts of the machine. In the last part of the thesis, the analytical model isused to test a new control strategy. Its goal is to reduce the total losses of the motor and optimize the ratiobetween torque and total losses for a given driving cycle.

This thesis deals with the estimation algorithms, reassuming in detail the principles commons techniques and testing them in simulation and by experimentation. The following estimator typologies are discussed: MRAS estimator in the high speed region, estimator based on the high frequency injection signals in the low and zero speed region. As regards the MRAS estimator, after its description, a particular application that exploits this estimation solution is presented. Then, a sensorless control of a Permanent Magnet synchronous motor drive for a hybrid electric catamaran is reported. A Surface mounted Permanent Magnet motor has been chosen and a distinctive sensorless control of this machine is deeply described. Control performance is validated by simulation and experimental results. Start–up mode, reversal of speed and synchronization lost occurrence will be specifically treated. Moreover the estimator sensitivity is studied. The dependence on the stator inductance and the independence of the resistance of the estimation error is demonstrated and verified by means of experimental tests. After that, a high frequency injected voltage for estimating the electrical angular position of the rotor is used for the sensorless control of salient–pole Permanent Magnet (PM) synchronous motor drives. A high frequency speed–dependent ellipse rotating voltage vector is injected to the motor. It generates a high frequency current vector in the estimated synchronous reference frame, that contains information on actual rotor position. This type of estimation technique exploits the anisotropy of the rotor and gives an estimation that is not affected by rotor speed. A recent aspect of the topic intensively investigated is the behaviour of different rotor geometries when subjected to high frequency rotor position estimations and, consequently, the design of sensorless oriented configurations. The reasons of these studies arise from the iron saturation which occurs in the rotor and that modifies and can even cancel rotor saliency and introduces a cross coupling (cross-aturation) between d– and q–axis. This paper experiments the behaviour of two of the principal sensorless oriented rotor configurations (IPM and Inset) and compare the experimental results with those predicted by the finite element simulations carried out during the motor design, in order to validate prediction tools and find out new design hints. In addition, the estimation error dependence on the mutual inductance is demonstrated. Estimation error quantities calculated by means of FEM simulations and measured with experimental tests are compared for both the machines. Main contribution of this thesis consists in introducing a new configuration of SPM motor, in which a turn has been wound around each pole in order to modify the direct axes flux linkage dynamics while preserving the quadrature axis one, thus creating a rotor dynamic anisotropy (ringed–pole rotor). Consequently, the motor can be used in a position sensorless control which exploits the anisotropic rotor features by high frequency injected signals. The model of the machine is described in the paper, and the main equations describing the motor dynamics are reported. Simulations, design hints and experimental results are reported so as to validate the proposed new rotor structure. With this solution, the novel machine can be used in a position sensorless control drive which exploits the anisotropic rotor features by high frequency injected signals. A Ringed-pole motor has been tested with two different estimator: a two states observer and a three states observer. Expected drive performance is validated by simulation and experimental results. Finally the thesis investigates successfully the possibility of extract rotor position information of Interior Permanent Magnet Motors from PWM current harmonic contents. To this aim, a general description of PWM voltage harmonics is at first given. Current harmonics are then derived assuming an anisotropic rotor. It is proved that rotor position information can be derived if single edge PWM is adopted. A speed and position estimation scheme is illustrated and the new rotor position estimation technique is then validated by simulations.
I convenzionali azionamenti elettrici per il controllo dei motori a Magneti Permanenti (PM) richiedo la conoscenza della posizione rotorica per poter applicare le trasformazioni dal sistema di riferimento stazionario a quello rotorico e viceversa. La posizione viene di norma determinata con un trasduttore di posizione che può essere un resolver, sonde ad effetto Hall o encoder. La presenza di questo trasduttore aumenta i costi, la grandezza e la complessità circuitale degli azionamenti e dei motori. Inoltre la loro manutenzione o sostituzione diventa difficoltosa in particolari applicazione, per es. pompe sommerse, macchine per l’eolico, ecc. L’eliminazione di questi trasduttori, quindi, risulta essere un gran vantaggio in termini di costi, affidabilità e riduzione della grandezza fisica del motore o anche dello stesso azionamento. E’ chiaro che questa eliminazione comporta che l’azionamento includa una tecnica alternativa in grado di stimare la posizione e la velocità rotoriche: questi azionamenti vengono definiti azionamenti sensorless. Negli ultimi anni la ricerca ha proposto diverse soluzioni di tipo sensorless che permettono la stima della posizione, diversificando per`o le tecniche per la regione di funzionamento in alta velocità da quelle in bassa velocità o a rotore fermo. Al giorno d’oggi, stimatori basati sulla ricostruzione del vettore di flusso o della fem (stimatori MRAS) vengono utilizzati per il primo caso, mentre nel secondo caso vengono utilizzati stimatori basati sulla iniezione di tensione ad alta frequenza. Mentre nel primo caso la tipologia di stimatore può essere applicata sia ai motori di tipo isotropi che con quelli anisotropi, la seconda tipologia di stimatore può essere applicata solo a motori anisotropi, visto che sfrutta la salienza magnetica per estrarre la posizione elettrica. Questa tesi verte appunto su queste due tipologie di stimatori, riassumendo in dettaglio i principali algoritmi utilizzati oggigiorno e implementandoli sia a livello simulativo che a livello sperimentale. Per una trattazione completa di questo argomento, vengono anche studiate le tre più comuni configurazioni rotoriche (a PM Interni, a PM a montaggio Superficiale ed Inset (incassati)) con una particolare attenzione verso quello che è il comportamento anisotropo o isotropo della macchina stessa e la possibilità di applicare uno o l’altro degli algoritmi sensorless descritti. Entrando in maggior dettaglio, per quanto riguarda lo stimatore MRAS, dopo una sua descrizione, viene presentato in una particolare applicazione che si riferisce ad un catamarano ibrido. Vengono quindi affrontate e discusse le problematiche legate alla strategia di partenza del motore tramite rampa di velocità, dell’aggancio sulla posizione stimata, dell’inversione di marcia. Inoltre viene studiata la sensitività dello stimatore che si dimostra dipendere dall’induttanza di statore e non dalla resistenza. Invece per quanto riguarda lo stimatore basato sull’iniezione di segnali ad alta frequenza è stato per prima cosa descritto sia nel caso con iniezione nel sistema di riferimento statorico sia in quello rotorico. Lo studio è stato effettuato con una formulazione di tipo generale, adattata poi per il tipo di iniezione di segnale effettuata. La trattazione tiene conto anche della induttanza differenziale mutua e questo ha permesso di ricavare un legame tra l’errore di stima la induttanza mutua stessa. Vengono presentati inoltre tre diversi schemi per l’estrazione della posizione elettrica: mediante regolatore PI, osservatore a due stati ed osservatore a tre stati. Dopo di che, lo stimatore con iniezione nel sistema di riferimento rotorico è stato testato sia in simulazione che su banco prova. La bontà dell’algoritmo di stima è stata provata su motori con due diverse configurazioni rotoriche: a PM Interni e di tipo Inset. L’induttanze diretta, in quadratura e mutua sono state studiate in dettaglio con il supporto di simulazioni agli elementi finiti (FEM). Grazie a questo studio è possibile prevedere l’errore di stima che verrà poi confrontato con quello ottenuto dalle prove sperimentali. Come detto in precedenza lo stimatore ad iniezione di segnale può essere utilizzato solo con quei motori che presentano una salienza magnetica. Da questa categoria quindi sono esclusi i motori SPM che, salvo alcune eccezioni come l’Inset, sono isotropi. Si è quindi pensato a come indurre in questi motori un comportamento anisotropo solo alle alte frequenze, cioè alle frequenze del segnale iniettato per la stima. In questa tesi viene presentata questa nuova configurazione rotorica definita "Ringed-pole". Questa consiste nella realizzazione di una gabbia di rotore inserendo degli anelli di rame cortocircuitato attorno a ciascun magnete permanente. La soluzione permette di andare a modificare alle alte frequenze il comportamento magnetico dell'asse diretto, mantenendo invariato quello di quadratura. In questo modo si viene a creare un comportamento anisotropo appunto alle alte frequenze, mantenendo però il comportamento isotropo della macchina per le basse frequenze. Questa caratteristica permette quindi di sfruttare lo stimatore basato sull'iniezione di tensioni alle alte frequenze, per la stima di posizione anche nel caso di motori SPM isotropi. Sono state eseguite simulazioni FEM e prove sperimentali per validare l’idea di base e provare l'effettiva possibilità della stima di posizione. Un secondo contributo riguarda la presentazione di un nuovo stimatore basato sulle armoniche di corrente causate dalla modulazione PWM. L'idea di base consiste nel pensare che la modulazione PWM effettui una intrinseca iniezione di tensione ad alta frequenza, più precisamente alla frequenza di switching. Queste tensioni inducono delle armoniche di corrente alla stessa frequenza che contiene l'informazione sulla posizione elettrica. L'informazione può essere estratta mediante uno schema di stima simile a quello che viene utilizzato nella normale iniezione di tensione. E' stata quindi effettuata una trattazione matematica per ricavare le espressioni delle componenti di tensione e di correnti alla frequenza di switching. Sono state eseguite delle simulazioni preliminari per confermare la correttezza dell’idea di base.

This master’s thesis goes into design of particular circuits for three phase inverter. Inverter’s control is ensured by digital signal controller MC56F8013 with his program. Principle of control is suggested for individual motors. Inverter design considerate universal use and capability for any three phase motor. Particular blocks are compatible each other.

This thesis is a detailed study of how two error correction schemes affect the precision of shaft position estimation in state-observer techniques for sensorless control surface-mounted Permanent Magnet Synchronous Motors (PMSM), variance correction and variable PI regulation. A novel sensorless estimation technique based on Linear Kalman Filter (LKF) through constant variance correction is proposed and compared with the conventional Flux Linkage Observer (FLO) method and other state-estimation sensorless control techniques namely, Extended Kalman Filter (EKF), variable variance correction, Single Dimension Luenberger (SDL) observer and Full-Order Luenberger (FOLU) observer both through variable PI regulation. These five sensorless control techniques for PMSM are successfully implemented in the same lab-based hardware platform, i.e. full digital float-point-type DSP control inverter-fed PMSM system. Experiments are reported on each sensorless method covering position estimation, speed response, self-startup and load behaviour. Intensive analysis has also been carried out on the impact of error correction of estimated position on the steady/dynamic PMSM characteristics with different sensorless approaches. The experiment demonstrates that the novel Linear Kalman Filter can achieve the minimum average position estimation error throughout the electrical cycle of the five sensorless estimation techniques during no load operation at rated speed and also makes PMSM capable of self-startup for any initial rotor position except the dead area. A speed response experiment for LKF shows that individual speed estimation can be extracted directly from LKF state estimation for sensorless control PMSM. Experiments on the five sensorless methods proves that position error correction scheme is the dominating factor for state estimation sensorless control PMSM and better dynamic/steady control performance can be achieved using a variance correction scheme applied in EKF/LKF than with variable PI regulation applied in SDL/FOLU. The thesis also concludes that the novel Linear Kalman Filter is an optimised cost-effective sensorless estimation method for the PMSM drive industry compared with classic and Flux Linkage observers/Extended Kalman Filters.

A stator turn fault in a safety-critical drive application must be detected at its initial stage and imperatively requires an evasive action to prevent a serious accident caused by an abrupt interruption in the drive s operation. However, this is much challenging for the case of an interior permanent magnet synchronous motor (IPMSM) drives because of the presence of the permanent magnets that cannot be turned off at will. This work tackles the problem of increase the stator turn fault tolerance of IPMSM drives in safety-critical applications. This objective is achieved by an on-line turn fault detection method and a simple turn fault-tolerant operating strategy. In this work, it is shown that a stator turn fault in a current-controlled voltage source inverter-driven machine leads to a reduced fundamental positive sequence component of the voltage references as compared to the machine without a turn fault for a given torque reference and rotating speed. Based on this finding, a voltage reference-based turn fault detection method is proposed. In addition, it is also revealed that an adjustment to the level of the rotating magnetic flux in an appropriate manner can yield a significant reduction in the propagation speed of the fault and possibly prevention of the fault from spreading to the entire winding. This would be accomplished without any hardware modification. Based on this principle, a stator turn fault-tolerant operating strategy for IPMSM drives maintaining drive s availability is proposed. To evaluate these turn fault detection method and fault-tolerant operating strategy, an electrical model and a thermal model of an IPMSM with stator turn faults are derived. All the proposed models and methods are validated through simulations and experiments on a 10kW IPMSM drive.

Cette thèse de doctorat s'inscrit dans un projet pour le développement du transport ferroviaire piloté par la société ALSTOM Transport. Il répond aux prévisions de quadruplement des déplacements interurbains et régionaux en France à l'horizon 2020 en respectant les contraintes environnementales très sévères, dont les normes restrictives du niveau de bruit émis par les trains. Une réduction importante du bruit émis par le moteur est donc nécessaire. Notre mission dans ce projet a été de développer un outil capable de prédire le bruit d'origine électromagnétique produit par les moteurs synchrones à aimants permanents, équipés d'un bobinage distribué ou concentré, et alimentés par des tensions MLI. Pour cela, un modèle multi-physique a été développé.Un couplage numérique - analytique a été mis en place pour calculer les forces magnétiques dans l'entrefer. La perméance globale d'entrefer et les inductances synchrones sont ainsi calculées grâce à des simulations éléments finis en statique, et très rapides. Un niveau de précision et de rapidité de résolution inégalé est obtenu pour le calcul des forces magnétiques. L'alimentation MLI, la perméabilité des clavettes, la saillance du rotor et l'asymétrie des dents du stator sont pris en compte. La rapidité de l'outil permet un couplage avec un superviseur d'optimisation. Deux prototypes ont été dimensionnés et fabriqués dans le but de valider le modèle multi-physique
This thesis is part of a project for the development of rail transportation piloted by ALSTOM TRANSPORT. It meets the forecasts of fourfold increase of the interurban and regional travels in France before 2020, by respecting very severe environmental requirements, among which the restrictive standards of noise level emitted by trains. An important reduction of the noise radiated by motors is required. Our mission in this project was to develop a tool capable of predicting the electromagnetic noise produced by permanent magnet synchronous motors equipped with distributed or concentrated windings, and fed by a PWM converter. For that purpose, a multi-physics model was developed.A numerical - analytical coupling was set up to calculate the airgap magnetic pressures. Global airgap permeance and synchronous inductances are thus calculated thanks to statics finite element simulations. An unequalled level of precision and speed of resolution is obtained for the computation of airgap magnetic pressures. The PWM supply, the wedge permeability, the rotor shape and the asymmetry of stator teeth are taken into account. The quickness of the resolution allows coupling our tool with an optimization supervisor. Two prototypes were designed and built in order to validate the multi-physics model

This text focuses on advanced torque control of permanent magnet synchronous motor drives. A novel modular structure is introduced to simplify the design and implementation of Model Predictive Control (MPC). The layout consists of the control and the control framework. The dynamic control is the novel virtual flux controller, which is used to reach desired reference values, and the state observer, which is used to reduce effects of non-modeled system properties. The control framework consists of static mappings to simplify the control problem. Besides the alpha-beta and d-q transformations, a reference generation procedure is used to generate state references based on optimality criteria. Also, the actuation scheme is part of the control framework and defines the available input set and the resulting control properties. The first method actuates directly switch states, i.e. voltage vectors, which yield an integer set named Finite Control Set (FCS). The other method actuates duty cycles via modulation, which yield the Convex Control Set (CCS). A stability analysis is carried out for both, CCS-MPC and FCS-MPC. MPC is called stable, if it is feasible and convergent, which can be ensured using the main MPC stability theorem. However, stringent computation requirements make it difficult to apply the theorem in practice. Thus, the Lyapunov based MPC approach is applied to the motor drive, which provides stability guarantees independent of the prediction horizon. A stability constraint based on control Lyapunov functions (CLF) ensures convergence to the origin and the resulting optimal control problem is shown to be feasible for all time. In other words, a control input can be found at each sampling instant, which satisfies all constraints and yields a stable closed-loop system. The properties of CCS-MPC are derived using a nonlinear controller and the constrained closed-loop system is shown to be stable in the sense of Lyapunov. The stability properties of FCS-MPC are more complex due to the integer input set. Using set-theoretical methods, it is shown that a sufficiently large control error can be steered towards the origin. In other words, the proposed FCS-MPC is shown to be set stable, i.e. the control error is guaranteed to converge to a well-defined neighborhood of the origin. MPC requires that a Constrained Finite Time Optimal Control (CFTOC) problem is solved at each sampling time. Small sampling periods and limited computation capabilities of embedded hardware require the CFTOC to be sufficiently simple, which is achieved using the virtual flux model in the static reference frame. The problem size is contained using a sufficiently small prediction horizon and efficient algorithms are necessary to provide a result within a sampling period. The CFTOC of the proposed CCS-MPC is a (convex) linear or quadratic programming problem, which can be solved using existing efficient algorithms. To provide a minimal approach, an efficient algorithm is introduced to solve the one-step-ahead prediction CFTOC analytically. FCS-MPC results in a mixed integer programming problem and is therefore more difficult to solve with standard numerical methods. In practice, the CFTOC is solved by enumeration, which is combined with branch-and-bound, i.e. branch-and-cut, techniques to improve the computational efficiency. The control algorithms have been developed on a Software-in-the-Loop (SiL) platform based on Matlab/Simulink and the code is implemented without modification on an experimental test-bench. The evaluation confirms the design and implementation of CCS-MPC and FCS-MPC and shows good results in dynamic and steady-state operation. The two MPC approaches have complimentary properties, which can be used to target different applications. CCS-MPC achieves a constant switching frequency and is a promising alternative to proportional-integral (PI) vector control. The concept can be combined with different modulation schemes, e.g. the Symmetric Space Vector Modulation (SSVM) and the Discontinuous Space Vector Modulation (DSVM) are used in this text. FCS-MPC takes the inverter switching into account and achieves an approximately constant switching ripple but a variable switching frequency. The concept is most profitably applied to systems where a high sampling frequency compared to the switching frequency is desired, e.g. high power or servo drives. Moreover, FCS-MPC lacks Pulse Width Modulation (PWM) harmonics in its current spectrum. Consequently, it is advantageous in terms of acoustic noise since emphasized tones are missing. However, the distinguished PWM harmonics of CCS-MPC are simpler to filter. In summary, it can be said that the work on advanced torque control of permanent magnet synchronous motor drives has produced an innovative strategy. The introduction of a new structure has significantly simplified the model predictive control problem, the concept of stability in particular. Moreover, this structure results in the implementation of simple algorithms, which can be computed efficiently.
Il soggetto affrontato dal presente lavoro sono i controlli avanzati di coppia per azionamenti con un motore sincrono a magneti permanenti. A questo scopo, è stata introdotta una struttura modulare che semplifica la progettazione e l’implementazione del controllo predittivo basato su un modello (model predictive control, MPC): lo schema è costituito dal controllo dinamico e dal quadro di controllo. Il controllo dinamico è un regolatore di flusso virtuale, utilizzato per raggiungere un valore di riferimento voluto e un osservatore di stato che serve a ridurre gli effetti delle proprietà non modellizzate del sistema. Il problema del controllo è stato semplificato tramite l’utilizzo di trasformate statiche chiamate quadro di controllo. Accanto alle trasformate alpha-beta e d-q viene usata una procedura per la generazione di riferimenti di stato, basati su un criterio ottimale. Il quadro di controllo contiene anche lo schema di attuazione, che serve per definire l’insieme di ingressi disponibili. Da un lato, il controllore comanda in modo diretto l’accensione e lo spegnimento dei semiconduttori, ovvero i vettori di tensione, ottenendo un insieme finito d’ingressi (Finite Control Set, FCS). Dall’altro lato vengono attuati cicli di accensione (duty-cycles) attraverso una modulazione (pulse width modulation, PWM): ciò risulta in un insieme convesso d’ingressi (convex control set, CCS). È stata eseguita un’analisi di stabilità sia per CCS-MPC sia per FCS-MPC. MPC è stabile, se il problema di controllo ottimale ad esso associato è risolvibile e l’errore di stato converge all’origine. Tale stabilità può essere garantita attraverso il principale teorema di stabilità di MPC. Tuttavia, i requisiti di calcolo restrittivi rendono il teorema difficilmente applicabile nella pratica. Di conseguenza, viene introdotto l’approccio MPC basato su Lyapunov (Lyapunov-based MPC) per gli azionamenti, il quale fornisce garanzie sulla stabilità indipendentemente dall’orizzonte di predizione. Un vincolo di stabilità basato sulle funzioni di controllo di Lyapunov (control Lyapunov function, CLF) assicura la convergenza all’origine ed è stato provato che il problema ottimale di controllo risultante è sempre risolvibile. In altre parole, ad ogni istante di campionamento si può trovare un ingresso che soddisfi tutti i vincoli del sistema e renda stabile il sistema a circuito chiuso. Le proprietà di CCS-MPC vengono ottenute utilizzando un controllo non lineare ed è dimostrato che il sistema vincolato ad anello chiuso è stabile secondo Lyapunov. Le proprietà di stabilità di FCS-MPC sono più complesse a causa dell’insieme non continuo d’ingressi. Utilizzando metodi della teoria degli insiemi si dimostra che un errore di controllo sufficientemente ampio può essere diretto verso l’origine e tenuto in un dintorno dell’origine ben definito. MPC richiede che in ogni istante di campionamento si risolva un problema di ottimizzazione (constrained finite time optimal control, CFTOC). La limitata potenza di calcolo dei microcontrollori e la brevità dei periodi di campionamento richiedono un CFTOC relativamente semplice, che si può ottenere utilizzando un modello di flusso virtuale nel sistema statico di riferimento. Scegliendo piccoli orizzonti di predizione si limita la dimensione del CFTOC, la cui risoluzione necessità di algoritmi efficienti, che permettano di ottenere un risultato all’interno di un periodo di campionamento. Il CFTOC di CCS-MPC è un programma (convesso) lineare o quadratico (linear program, lp; quadratic program, qp) che può essere risolto tramite algoritmi efficienti e noti. Al fine di elaborare una strategia di tipo minimalista, viene introdotto un algoritmo efficiente che risolve analiticamente il problema con un orizzonte di predizione di un passo. Il CFTOC di FCS-MPC è un problema di programmazione lineare o quadratico a numeri misti interi (mixed-integer) ed è quindi più difficile da risolvere con metodi numerici standard. In pratica si calcolano tutte le soluzioni possibili, tra le quali viene scelta la soluzione ottimale. Per migliorare l’efficienza di calcolo si combina quest’approccio con tecniche branch-and-bound e branch-and-cut. Gli algoritmi di controllo sono stati sviluppati su una piattaforma software-in-the-loop (SiL) basata su Matlab/Simulink e il codice di programmazione è stato implementato su un banco di prova sperimentale, senza modifiche. La valutazione approva la progettazione e la realizzazione di CCS-MPC e FCS-MPC e indica buoni risultati sia nell’operazione dinamica che in quella stazionaria. I due approcci MPC hanno proprietà diverse che risultano vantaggiose per applicazioni differenti. CCS-MPC ha una frequenza di commutazione costante ed è un’alternativa promettente al controllo vettoriale proporzionale-integrale (PI). Il concetto può essere combinato con diversi schemi di modulazione, nella fattispecie si usa la modulazione simmetrica di vettori spaziali (symmetric space vector modulation, SSVM) e la modulazione discontinua di vettori spaziali (discontinuous space vector modulation, DSVM). FCS-MPC tiene conto della commutazione dell’inverter e raggiunge all’incirca un ripple di commutazione costante, ma ottiene una frequenza di commutazione variabile. Il concetto è vantaggioso per sistemi dove è richiesta un frequenza di campionamento alta rispetto alla frequenza di commutazione, per esempio azionamenti ad alta potenza o servoazionamenti. Inoltre, lo spettro della corrente di FCS-MPC non contiene armoniche PWM e di conseguenza è vantaggioso in termini di rumore acustico, data la mancanza di toni distinti. Tuttavia, le armoniche PWM distinte di CCS-MPC sono più semplici da filtrare. Si può concludere affermando che lo studio del problema dei controlli avanzati di coppia per azionamenti con un motore sincrono a magneti permanenti, ha portato all’individuazione di una strategia innovativa. L’introduzione di una nuova struttura di controllo ha semplificato notevolmente il problema di controllo predittivo, con particolare attenzione al concetto di stabilità. Inoltre, le implementazioni di tale struttura si sono rivelate particolarmente efficaci su piano computazionale.

Táto práca pojednáva o problematike vytvárania a simulácie reluktančnej sieti synchrónneho stroja s V tvarovanými permanentnými magnetmi v programe PSpice. Na začiatku sa oboznámime s konštrukciou a parametrami stroja a potom vyvodíme základné rovnice na výpočet každého prvku siete. Vypočítame každý prvok tohto stroja a potom vytvoríme túto sieť v PSpice. Na začiatku je simulovaná sieť statická a všetky magnetické odpory sú lineárne. Neskôr nahradíme lineárne odpory reprezentujúce plechy nelineárnymi a počítame s precovnou teplotou permanentných magnetov. Potom porovnáme naše výsledky s FEM metódou počítanými hodnotami a vypočítame indukované napätie v jednej cievke stroja. Na záver vypočítame výkonovú a momentovú charakteristiku stroja.

Tato práce se zabývá synchronním motorem s permanentními magnety na rotoru (PMSM), jeho modelováním a návrhu regulační struktury. V práci jsou uvedeny způsoby a výhody použití permanentních magnetů v elektrických motorech. Dále se práce zabývá transformací třífázové soustavy do dq0. Pomocí Parkovy transformace jsou v práci odvozeny rovnice stroje v dq0 souřadnicovém systému a vytvořeny náhradní schémata stroje v dq osách. Rovnice i schémata zahrnují jak ztráty v mědi, tak ztráty v železe. Náhradní schémata jsou popsány elektrickými a mechanickými rovnicemi a následně překresleny do grafické podoby v programu Matlab Simulink. Vytvořeny jsou dva modely PMSM, jeden s uvažováním ztrát v železe a druhý bez těchto ztrát. Pro oba dva modely je zde popsán postup návrhu regulátorů proudu a otáček. Pro model, u kterého jsou uvažovány ztráty v železe je navíc použito více druhů řídicích strategií a tyto strategie jsou mezi sebou navzájem porovnány.

La révolution technologique majeure des nouveaux aéronefs repose sur une électrification intensive de nombreux constituants de l'appareil et le fait que la vitesse des génératrices électriques n'est plus fixe mais variable. Cette nouvelle manière de générer la puissance électrique engendre des variations de tension sur les réseaux DC. De plus, pour accroître la compacité des Machines Synchrones à Aimants Permanents (MSAP) à puissance donnée, on augmente autant que possible leur vitesse d'entrainement, en les associant pour certaines applications à des réducteurs mécaniques. La variation du niveau de tension du bus DC alimentant une MSAP haute vitesse implique son dimensionnement afin d'assurer sa contrôlabilité sur toute la plage de vitesse reportant d'importantes contraintes sur l'onduleur de tension. Pour pallier ce problème, une solution consiste à intercaler un convertisseur DC/DC entre le filtre d'entrée et l'onduleur de tension pour maintenir la tension DC d'entrée de l'onduleur à une valeur adaptée au fonctionnement de la MSAP et optimiser son dimensionnement. Cependant, cette solution augmente l'ordre du système, ce qui accroît la complexité de son contrôle, accentuée par les contraintes liées à la nature haute-fréquence des MSAP considérées.Les travaux menés dans cette thèse concernent l'étude, l'optimisation et le contrôle des structures d'alimentation des actionneurs haute vitesse connectés aux réseaux DC avioniques à tension variable. Il en résulte que pour les applications avioniques considérées, ces architectures d'alimentation intégrant un convertisseur DC/DC supplémentaire permettent de réduire sa masse et son volume sans dégrader le rendement global de la chaîne de conversion notamment avec les convertisseurs à source impédante qui permettent de supprimer structurellement les ondulations de courant en entrée du convertisseur. De plus, des stratégies de commande Pulse Amplitude Modulation employées avec des architectures de contrôle non-linéaires (platitude, passivité) permettent d'assurer le contrôle de ces MSAP haute-vitesse tout en assurant leur stabilité sur toute la plage de fonctionnement
The main technological revolution of the new aircrafts is based on intensive electrification of many components of the aircraft. Moreover, the speed of electrical generators is no longer fixed but variable. This new way of generating electrical power generates voltage variations on DC networks. Besides, to increase the compactness of the Permanent Magnet Synchronous Machines (PMSM) at a given power, their mechanical speed is increased as much as possible by combining them with mechanical reducers for certain applications. The variation of the voltage level of the DC bus supplying a high-speed PMSM implies its sizing in order to ensure its controllability over the entire speed range which carries significant stresses on the Voltage Source Inverter (VSI). To solve this problem, one solution consists in adding an extra DC / DC converter between the input filter and the VSI to maintain the inverter input voltage at a value adapted to the operating point of the PMSM and to optimize its dimensioning. However, this solution increases the order of the system, which increases the complexity of its control, accentuated by the constraints related to the high-frequency nature of the PMSMs considered. The work carried out in this thesis concerns the study, the optimization and the control of the power supply architecture of the high-speed actuators connected to variable-voltage avionic DC networks. As a result, for the avionics applications considered, these power supply architectures integrating an additional DC / DC converter make it possible to reduce the mass and the volume of the power supply structure without degrading the overall efficiency of the conversion chain, in particular by using the impedance-source converters which allow to cancel the DC input current ripples. In addition, Pulse Amplitude Modulation (PAM) control strategies used with non-linear control architectures (flatness, passivity) make it possible to control these high-speed PMSMs while ensuring their stability over the entire operating range

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California
Although PCM/TDM framed data is one of the most prevalent formats handled by flight test ranges, it is often required to acquire and process other types. Examples of such non-standard data types are radar position information and meteorological data from both ground based and radiosonde systems. To facilitate the process and management of such non-standard data types, a micro-processor based system was developed to acquire and transform them into a standard PCM/TDM data frame. This obviated the expense of developing additional special software and hardware to handle such non-standard data types.

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.

碩士
國立臺灣科技大學
電子工程系
93
This thesis presents a synchronous PWM controller for self-oscillation Royer inverter. The dead-time-modulated PWM (DTM-PWM) controller is composed of a monostable circuit and a constant-current charger (CCC). The controller use the primary-side feedback control strategy to eliminate the thermometer effect occurring in the cold-cathode fluorescent lamp (CCFL).The referred sawtooth is composed with a constant-period charge time and a variable dead-time. The synchronizing strategy is conducted by modulating the dead-time according to the resonant frequency of the Royer inverter. The design strategy for building the design example is proposed. A DTM-PWM controlled dimmable Royer inverter with two-CCFL by primary-side control is realized and experimented. The results of analysis and theoretical prediction are verified with experiments.

碩士
國立成功大學
工程科學系碩博士班
93
This thesis presents a new direct torque control (DTC) system to control the permanent magnet synchronous motor (PMSM) based on a TMS320F2812 digital signal processor (DSP) experiment board. The digitalized PMSM control system was implemented by using DSP experiment board with advantages such as high precision and reliability and the controlling error caused by the variance of temperature or the interference of noise can be banished. 　The proposed DTC scheme in this thesis uses a flux compensator to eliminate the error in stator flux estimation at low speed operating region of the conventional DTC. Furthermore, to improve the flux linkage tracking, two PI controllers used to be the torque controller and the flux controller. The outputs magnitude of the flux regulator, , is controlled by the outputs of the torque controller and flux controller. The voltage command of the output of the flux regulator will be used to decide the space voltage vector PWM and determine the magnitude of the stator flux linkage. 　The simulation and experimental results for the proposed DTC were compared with a conventional DTC. These show that the proposed DTC has a high control performance than the conventional DTC.

碩士
國立成功大學
工程科學系碩博士班
94
Based on the Diagonal Half-Bridge Forward (DHBF) DC/DC converter and soft switching technique, a novel Zero-Voltage-Transition Pulse-Width Modulation (ZVT-PWM) DHBF DC/DC converter is proposed in this thesis. It has high power conversion efficiency. 　　The diagonal switches of the conventional DHBF converter exhibits hard switching. To achieve soft-switching operation, the voltages of the diagonal switches must resonate down to zero before switching. 　　The proposed converter is developed by paralleling an auxiliary circuit at primary side of the transformer of the DHBF converter. The auxiliary circuit comprises a resonant inductor, a resonant capacitor and an auxiliary switch, which is used to control resonant occurrence. The diagonal switches of the proposed converter can operate under zero-voltage switching (ZVS) and the auxiliary switch can also operate under zero-current switching (ZCS). It is effective to increase the efficiency of the converter. Moreover, the synchronous rectification technique is also employed to reduce the conduction losses of the output rectifier. As a result, the proposed converter still exhibits high efficiency at heavy load. 　　The operation principle and theoretical analysis of the proposed converter are presented herein. They are validated by IsSpice simulations and experimental results. A prototype of ZVT-PWM DHBF converter for input and / output is finally implemented. The overall efficiency of the proposed converter achieves at full load. The efficiency of the soft switching technique and the synchronous rectification technique is demonstrated by the proposed ZVT-PWM DHBF DC/DC converter.

博士
國立中山大學
電機工程學系研究所
100
This thesis presented a sensor-less permanent magnet synchronous motor (PMSM) driver for controlling air-conditioner rotary compressor speed. In this thesis, a quasi-sine pulse-width modulation (PWM) driving method was proposed. Furthermore, the current feedback control scheme and rotor magnet pole position detection were included. The system structure was implemented by using a digital signal processing (DSP) platform. The proposed driving scheme was compared with the square-wave driving without current feedback and six-step square-wave driving method with current feedback. Moreover, the passive and shunt semi-active power factor correction (PFC) technique were researched for the air-conditioner application. Experimental results demonstrated that the system power factor could be improved by the proposed shunt semi-active PFC method. Besides, the proposed sensor-less quasi-sine PWM driving method implemented in an air-conditioner compressor driver was capable of reducing the magnitude of rotational speed ripples, compressor vibration, and system power consumption.

碩士
國立中山大學
電機工程學系研究所
88
Because of several advantages, e.g. compact structure, high air-gap flux density, and high torque capability, the PM synchronous motor plays an important role in recent years. The basic principle of controlling a PMSM is based on vector control. The control performance is influenced by factors as the plant parameter variations, the external load disturbances, and the unmodeled or nonlinear dynamics. In the thesis, we apply a recently proposed robust 2DOF configuration to designing controllers for PMSM to achieve the robust asymptotical tracking under perturbations in both the motor and the controllers. Two design methods are adopted to implement the desired controllers, i.e. the linear algebraic method and the design method. The effect of the well-known internal model principle is addressed in the former design method. The merit of the latter design method is that both time and frequency domain design specifications can be easily included in the design procedure. Computer simulation results are displayed to illustrate the advantages of our designs.

碩士
國立成功大學
電機工程學系碩博士班
90
This thesis presents the results of a study on integration of a permanent magnet generator (PMG)/a synchronous generator (SG) and a PV System. A PMG and a SG are respectively utilized as a wind generator. To improve variable frequency, variable voltage, and loading effects of both generators under random wind speeds, a rectifier module and a battery system are employed to combine both PV and wind systems. The stored energy in the battery system is converted into constant voltage and constant frequency by means of an inverter module to supply isolated loads or connect to a utility grid. A d-q axis equivalent-circuit machine model is employed to establish the PMG, SG, rectifier, inverter, PV, and battery models in order to derive the complete dynamic equations of the studied system under three-phase balanced loading conditions. The derived system model is also employed to obtain system eigenvalues to determine dynamic stability. Experimental results obtained from a laboratory 500 W PMG, a 300 W SG, a 1.5 kW PV system, a 24 V battery system, and a 4.5 kW inverter module are compared with the simulated results to validate feasibility of the proposed models.

Η παρούσα διπλωματική πραγματεύεται τη μελέτη και κατασκευή ενός κυκλώματος οδήγησης ενός Σύγχρονου Κινητήρα Μαγνητικής Αντίδρασης. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Σκοπός είναι η μελέτη και κατασκευή ενός κυκλώματος Τριφασικού Αντιστροφέα Πηγής Τάσης, ο οποίος θα επιτρέπει την υλοποίηση βαθμωτού και διανυσματικού ελέγχου της λειτουργίας του Σύγχρονου Κινητήρα Μαγνητικής Αντίδρασης. Στην παρούσα διπλωματική εργασία υλοποιήθηκε βαθμωτός έλεγχος της γωνιακής ταχύτητας περιστροφής του δρομέα (με σταθερό λόγο V/f), ανοιχτού και κλειστού βρόχου. Όσον αφορά το Σύγχρονο Κινητήρα Μαγνητικής Αντίδρασης, τα τελευταία χρόνια έχει αναπτυχθεί έντονο επιστημονικό ενδιαφέρον σχετικά με τη βελτιστοποίηση της κατασκευής του, καθώς και του ελέγχου της λειτουργίας του μέσω διαφόρων μεθόδων ελέγχου. Το κυριότερο χαρακτηριστικό του συγκεκριμένου κινητήρα αποτελεί η έλλειψη οποιασδήποτε μορφής διέγερσης στον δρομέα. Επομένως, η δημιουργούμενη ροπή οφείλεται αποκλειστικά στη λεγόμενη ροπή μαγνητικής αντίδρασης, από την οποία προέρχεται και η ονομασία του κινητήρα. Στην παρούσα διπλωματική εργασία, γίνεται μια εισαγωγή στους κινητήρες εναλλασσόμενου ρεύματος, ενώ η ανάλυση επικεντρώνεται στον προαναφερθέντα κινητήρα, προσεγγίζοντάς τον από διάφορες πλευρές (κατασκευαστικά χαρακτηριστικά, μαθηματικό μοντέλο, σύγκριση με άλλους τύπους κινητήρων). Επιπλέον γίνεται μια θεωρητική ανάλυση του Τριφασικού Αντιστροφέα Πηγής Τάσης, ο οποίος χρησιμοποιείται για την οδήγηση του κινητήρα, καθώς και της τεχνικής Διαμόρφωσης Εύρους Παλμών, η οποία χρησιμοποιείται για την παλμοδότηση των ημιαγωγικών στοιχείων ισχύος. Η προσομοίωση του κινητήρα ήταν το επόμενο βήμα για την καλύτερη κατανόηση της δυναμικής απόκρισης του κινητήρα. Η παρούσα διπλωματική εργασία συνεχίζεται με την αναφορά στο σχεδιασμό και την κατασκευή των απαραίτητων κυκλωμάτων, ενώ ιδιαίτερη αναφορά γίνεται στο μικροελεγκτή που χρησιμοποιήθηκε στην υπάρχουσα εργασία, καθώς και στο πρόγραμμα που δημιουργήθηκε για τις λειτουργίες ανοιχτού και κλειστού βρόχου. Τέλος, η ολοκλήρωση της διπλωματικής εργασίας έρχεται μέσω της παρουσίασης των πειραματικών αποτελεσμάτων, στα οποία έγινε χρήση των κατασκευασθέντων κυκλωμάτων.
This Thesis is focused on the study and development of a Drive System for the Synchronous Reluctance Motor. This work was conducted in the laboratory of Electromechanical Energy Conversion, at the department of Electrical and Computer Engineering, in the University of Patras, Greece. The main purpose of this project was the study and construction of a three Phase Voltage Source Inverter for the control of the performance of a Synchronous Reluctance Motor by the implementation of Scalar and Vector control. In this thesis, a scalar V/f control scheme was applied, both open and closed loop, for the control of the rotational speed of the rotor. As far as the Synchronous Reluctance Motor is concerned, in the latest years a great interest has emerged around this motor, which mainly focuses in the optimization of its construction and control. The main feature of this motor is that the rotor does not have any field winding. By this way, the output torque is produced only by the so called reluctance torque. In this work, an introduction on the AC motor is done, while the main interest is focused on the already mentioned motors. The analysis of this motor covers many aspects, such as the construction characteristics, the mathematical model of the motor, as well as a comparison with other popular motors. Moreover, the three Phase Inverter is studied, since it is used for the control of the motor. Also, there is an extended reference on the Pulse Width Modulation technique, which is used for the control of power devices. In the next chapters, the simulation of this motor is presented, since it is necessary fot the understanding of its dynamic behavior. In the following, an analysis on the design and construction of the required printed circuit boards is done, while the microcontroller which was used is presented in a more detailed way. The flowacharts of the open and closed loop control methods of the rotational speed are also given. Finally, the experimental results for both cases are presented and analysed.

碩士
逢甲大學
電機工程所
96
The main purpose of this thesis is to design and implement a Permanent Magnet Synchronous Motor (PMSM) drive by using the Digital Signal Processor (DSP) controller. The Direct Torque Control (DTC) is a method to control the torque by calculating the magnetic flux and torque based on the measured voltage and current of the motor. Because of the fast response characteristics for torque and flux changes, if has widely adopted to the AC inductor motors drive. In order to obtain the same results as in the inductor motors drive, the DTC algorithm will be applied to the PMSM drive in this thesis. Due to the fast and quick switching of the motor drive, large amount of the harmonics are generated in the supply terminal and then result in the low power factor for the drive. This thesis will design and implement an active power factor corrector to improve this drawback. Also, for real time monitoring the dynamic behavior of motor drive, a serial communication via the USB controller interface will be designed to communicate between the DSP and PC. Finally, a prototype PMSM drive will be implemented and the experimental results will also be demonstrated.

碩士
逢甲大學
電機工程所
98
The purpose of this thesis is to design a direct-drive wind permanent magnet synchronous generator for use in small-scale wind energy applications. First, based on the proposed design procedure, a suitable slot and pole number combination and winding layout are selected. Then a prototype generator that meets the required output power is designed. In order to reduce the cogging torque and increase the efficiency, the shapes of slot in the stator and the size of the magnets in the rotor are optimized using the Taguchi method coupled with the finite element analysis firstly. A technique is used to improve the generator efficiency. The optimized result achieves the demand of output power. The cogging torque and efficiency match the goal.

碩士
國立臺灣科技大學
電機工程系
97
This thesis applies the cell-based IC design flow procedure to develop a vector control chip for a speed sensorless interior permanent magnet (IPM) synchronous motor. First, the speed sensorless vector control system for an IPM is established. The system is per unitized so that it can be applicable to different motor specifications. Next, the computer-aided design tool, MATLAB/Simulink, is used to build the floating-point based numerical model, which is then used to design fixed-point Q-value based 32-bit and 16-bit numerical models for the IPM control system. Based on the numerical simulation results, the thesis develops the Verilog HDL programming codes for the IPM vector control system on the Xilink ISE platform. The numerical results are verified and the initial IC design phase is achieved. The second phase of IC design follows the routing and placement procedure: The register transfer level produced by the programming codes is logically synthesized and the netlist is generated. Through automatic placement and routing, the final placement for the sensorless IPM vector control chip is obtained.

The growth of embedded generation and portable electrical installations has led to an increased demand for low cost, flexible and reliable generator systems for military and commercial applications. An interior permanent magnet (IPM) machine has high power density due to its reluctance torque and magnetic torque components so it can produce a large constant power-speed range. However, an IPM machine needs demagnetizing current at high-speed during the flux-weakening region and thus develops an inverter shutdown problem in an uncontrolled generator mode operation. In order to overcome the disadvantages of the IPM machine, the permanent magnet assisted synchronous reluctance generator (PMa-SynRG) can be a good solution for low cost, high efficiency reliable generator systems. A PMa-SynRG can produce a high efficiency drive by utilizing the proper amount of magnet and reluctance torque. This work proposes a PMa-SynRG with two flux barriers and permanent magnets embedded in the second layer of the rotor. A neodymium magnet (NdFeB) was used as permanent magnets in the rotor to prevent demagnetization. Finding the minimum amount of magnet is one of the goals of the optimization process. The objectives of this work are to build an optimal design for the 3kW generator and an advanced power electronics converter for the PMa-SynRG drive system. In order to find the optimized 3kW machine, a Lumped Parameter Model (LPM) was used to achieve fast computation, and Differential Evolution Strategy (DES) was used to embed the LPM in an efficient numerical optimization routine to identify optimum designs. Finite Element Analysis (FEA) was used for test performance of optimum designs. On the basis of differences between LPM and FEA, model predictions were used to fine tune the LPM model. For new optimum design converges, numerical optimizations and iterations were performed to produce LPM and FEA predictions. For the drive system, the thyristor based, current-fed drive is much simpler and has lower power losses compared to the pulse width modulation (PWM) drive. Eliminating the requirement for self-controlled switches is a distinct advantage for lower cost. Another feature of the developed current-fed drive is its inherent capability to provide generating action by making the PMa-SynRG operates as a generator, rectifying the phase voltages by means of the three-phase rectifier and feeding the power into the load. These features make the current-fed drive a good candidate for driving any type of synchronous generators including the proposed PMa-SynRG.

碩士
國立聯合大學
電機工程學系碩士班
95
In this paper, we try to apply a fuzzy variable structure controller in the speed control of permanent magnet synchronous motor. Since the variable structure controller is extremely robust, it can be used to eliminate the variance of motor parameters as well as the impact of external load on the system response. However, the introduction of high speed and discontinuous switching action cause the so-called chattering phenomenon, which is highly undesirable because it may excite high frequency unmodeled plant dynamics and may lead to unforeseen instability. To overcome the drawback, we replace the discontinuous term of the variable structure system with a fuzzy logic controllers, and turn them into control variables with fuzzy properties. As a result, the chattering of the variable structure controller and the control performance of the system are improved. Both simulation and experiments studies on the design of a speed servo controller for a PM synchronous motor are presented to demonstrate its effectiveness. The experimental results also demonstrate that the proposed method provides better performance than the variable structure control with a smooth function.

博士
國立成功大學
電機工程學系
102
Generally, in order to implement the drive control of the PM synchronous motor, the rotor position information is essential. However, position sensors may increase the cost and volume of the motor system due to the extra components and wiring. Moreover, most position sensors are sensitive to change in ambient temperature. As a result, the reliability of the position sensor based approach is far from satisfactory in some specific applications. In order to alleviate the above problem, this dissertation develops a general purpose position sensorless method for PM synchronous motor drives. This dissertation proposes a sliding-mode current observer based on a general purpose equivalent back-EMF model. By using the back-EMF estimated from the sliding-mode current observer, one can indirectly obtain the information of the angular position and velocity of the rotor. The estimated rotor position is accurate, and fast convergence of the observer is guaranteed over a wide speed range. Moreover, only stator resistance and stator inductances in the q-axis are essential to the calculation of the general purpose equivalent back-EMF, which is easy to implement in low-cost microcontrollers. In addition, the drives of PM synchronous motors capable of electric braking not only allow the motors to smoothly decelerate to a soft stop, but also can recover kinetic energy so as to improve the efficiency of energy consumption. In order to conduct an in-depth study on this topic, this dissertation analyzes and implements three possible position sensorless electric braking commutation strategies based on a general full-bridge motor drive without any additional power switches and bulky passive components. For the position sensorless electric braking commutation strategies, theoretical analysis on different performance indices such as maximum voltage conversion ratio, braking torque, energy recovery ratio, etc., are carried out and compared among each commutation strategy. Finally, theoretical analysis, several experiments and various applications are performed to verify the effectiveness of the proposed methods. Experimental results indicate that the proposed position sensorless FOC and electric braking commutation methods are suitable for various speed regulation applications.