A finalidade inicial deste estudo foi desenvolver um modelo computacional multifísico de um acionamento eletrônico, composto por um motor de relutância 4/2 bifásico, um conversor eletrônico de potência, um controlador, os componentes mecânicos estruturais do motor e os acoplamentos entre os diferentes domínios físicos. Para a implementação do modelo proposto, foram utilizados recursos de simulações numéricas e acopladas do MEF (Método dos Elementos Finitos) em uma plataforma de simulação multifísica, de modo a realizar acoplamento entre três áreas do conhecimento: circuitos elétricos, campos eletromagnéticos e componentes mecânicos estruturais e de vibração. Uma vez desenvolvido o modelo multifísico, este foi associado a um procedimento de otimização dos ângulos de disparo que utiliza um modelo de algoritmos genéticos e, como um conjunto, estes foram aplicados na redução da vibração e da ondulação de torque do motor de relutância chaveado, resultando em uma nova metodologia para a abordagem desses problemas. De modo a comprovar os resultados obtidos nas simulações, foram realizados diversos ensaios experimentais para a validação de cada etapa do desenvolvimento, tais como levantamento das formas de onda de tensão e correntes, ensaios de vibração, etc. Os modelos desenvolvidos foram testados em função de modificações realizadas tanto nos parâmetros de controle do acionamento, como também em função de modificações mecânicas estruturais na geometria do rotor. / The initial purpose of this study was developing a multi-physical computational model of a power electronic motor drive, composed to a 2-Phase Switched Reluctance Motor (SRM) 4/2, a power electronic converter, a controller, motor mechanical and structural components and the coupling among different physical domains. For implementing of the proposed model, it was used FEM (Finite Element Method) coupled and numerical simulations resources in a multi-physic simulation platform, in order to accomplish the coupling among the three areas of knowledge: electrical circuits, electromagnetic fields and structural and mechanics components and vibration. Once finished the multi-physical model, it was associated with a optimization procedure of firing angles which uses genetic algorithm model and, as a whole, it was applied on the SRM vibration and torque ripple reduction, resulting in a new methodology to approaching these problems. In order to prove obtained simulation results, it was carried out several experimental tests to validate each development stage, such as the voltage and currents wave forms mapping, vibration tests, etc. The developed models were tested as much function of drive control parameters as the rotor geometry mechanical and structural modifications.

A finalidade inicial deste estudo foi desenvolver um modelo computacional multifísico de um acionamento eletrônico, composto por um motor de relutância 4/2 bifásico, um conversor eletrônico de potência, um controlador, os componentes mecânicos estruturais do motor e os acoplamentos entre os diferentes domínios físicos. Para a implementação do modelo proposto, foram utilizados recursos de simulações numéricas e acopladas do MEF (Método dos Elementos Finitos) em uma plataforma de simulação multifísica, de modo a realizar acoplamento entre três áreas do conhecimento: circuitos elétricos, campos eletromagnéticos e componentes mecânicos estruturais e de vibração. Uma vez desenvolvido o modelo multifísico, este foi associado a um procedimento de otimização dos ângulos de disparo que utiliza um modelo de algoritmos genéticos e, como um conjunto, estes foram aplicados na redução da vibração e da ondulação de torque do motor de relutância chaveado, resultando em uma nova metodologia para a abordagem desses problemas. De modo a comprovar os resultados obtidos nas simulações, foram realizados diversos ensaios experimentais para a validação de cada etapa do desenvolvimento, tais como levantamento das formas de onda de tensão e correntes, ensaios de vibração, etc. Os modelos desenvolvidos foram testados em função de modificações realizadas tanto nos parâmetros de controle do acionamento, como também em função de modificações mecânicas estruturais na geometria do rotor. / The initial purpose of this study was developing a multi-physical computational model of a power electronic motor drive, composed to a 2-Phase Switched Reluctance Motor (SRM) 4/2, a power electronic converter, a controller, motor mechanical and structural components and the coupling among different physical domains. For implementing of the proposed model, it was used FEM (Finite Element Method) coupled and numerical simulations resources in a multi-physic simulation platform, in order to accomplish the coupling among the three areas of knowledge: electrical circuits, electromagnetic fields and structural and mechanics components and vibration. Once finished the multi-physical model, it was associated with a optimization procedure of firing angles which uses genetic algorithm model and, as a whole, it was applied on the SRM vibration and torque ripple reduction, resulting in a new methodology to approaching these problems. In order to prove obtained simulation results, it was carried out several experimental tests to validate each development stage, such as the voltage and currents wave forms mapping, vibration tests, etc. The developed models were tested as much function of drive control parameters as the rotor geometry mechanical and structural modifications.

This thesis presents a new modular structure of the axial flux Switched Reluctance Motor (SRM). The design consists of four stator disks with each adjacent disk rotated 30 degrees apart and four rotor disks connected to a common shaft. The proposed design aims to reduce the unwanted radial force, mitigate the torque ripple, and improve the efficiency. The modular structure distributes the radial force and torque strokes along the axial length of the motor, potentially damping the torque pulsation. In addition, the modular structure would deliver the rating power at a lower current level, reducing the overall ohmic loss. Moreover, if a fault occurs on a motor disk or its control unit, the motor would still operate through other disks, increasing the reliability of the system. To verify the effectiveness of the proposed design, the magneto-static and transient performance of the motor are compared with the conventional single layer structure using 3-D Finite-Element (FE) software tool to see that the proposed motor performs better with lower torque ripple and lower radial force than a conventional single layer structure.

In this study, three different programs are developed for the analysis of the three-phase induction motor, single-phase capacitor type induction motor and switched reluctance motor. The programs are developed by using Pascal and C++ programming languages. In the performance calculations of motors, analytical methods are used and these methods are tested for accuracy. These programs have also capabilities to design an optimum motor, which meets a set of performance, material and manufacturing constraints while minimizing the weight or any other defined objective function. In addition, in this study, an optimization tool is used to obtain an appropriate optimization method for the design of different types of motors. The software is tested over different commercial motors. The results illustrates that the performance calculations and optimization approach of the programs lead to good results.

Since most of the electrical energy is consumed by the electrical motors, it is necessary to use the electrical energy as efficient as possible. Throughout this study four different types of motors (induction motor, permanent magnet radial flux DC motor, permanent magnet axial flux DC motor, switched reluctance motor) are considered and compared based on their torque per unit volume and speed performance comparison. Torque per unit volume equations are obtained for each of the motor, related to quantities such as magnetic flux density and electric loading and the speed performances are compared by using a washing machine application, which has a wide speed range. As a result of this study torque per unit volume and speed performance of each of these four types of motors are obtained and motors of different types are evaluated due to their torque per motor volume, torque per ampere, efficiency and etc. over a wide speed range to have an idea about the applications of these motors.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / O Motor de RelutÃncia VariÃvel (MRV) vem cada vez mais chamando a atenÃÃo da indÃstria e da comunidade acadÃmica. Isso se deve ao crescente desenvolvimento da eletrÃnica de potÃncia e na Ãrea de microprocessadores nos Ãltimos anos, o que permitiu o avanÃo de outros sistemas de acionamentos tais como com MRV. A competitividade do MRV se justifica por seu baixo custo de produÃÃo e manutenÃÃo, uma elevada densidade de potÃncia, robustez e resistÃncia a faltas. O presente trabalho propÃe um esquema de controle robusto baseado em um Controlador Preditivo Generalizado (GPC) pertencente a famÃlia de Controladores Preditivos Baseados em Modelo (MPC) aplicados a malha de corrente e velocidade de um sistema de acionamento com MRV. O controlador proposto, assim como controladores tradicionais aplicados neste tipo de sistema tais como o controlador por Histerese e o controlador PID sÃo tambÃm aplicados com o objetivo de proporcionar meios de comparaÃÃo dos resultados experimentais obtidos. A estrutura do controlador à baseada no projeto de um filtro de modo a permitir uma resposta rÃpida, rejeiÃÃo a distÃrbios, atenuaÃÃo de ruÃdos e robustez com um baixo custo computacional. O controlador proposto foi implementado e os resultados comparados com controladores tradicionais e analisados quantitativamente por meio de Ãndices de desempenho. Para execuÃÃo das rotinas de controle foi utilizado um DSP das Texas Instruments (TMS320F28335), sendo suas caracterÃsticas principais apontadas. O algoritmo do software de controle à esquematizado. O trabalho fez uso da bancada de pesquisa em MRV do laboratÃrio do Grupo de Pesquisa em AutomaÃÃo e RobÃtica (GPAR) da Universidade Federal do Cearà (UFC).

Le domaine de la traction électrique a suscité un très grand intérêt dans les dernières années. La conception optimale de l'ensemble moteur électrique de traction – onduleur doit prendre en compte une variété de critères et contraintes. Étant donnée la liaison entre la géométrie du moteur et la stratégie de commande de l'onduleur, l'optimisation de l'ensemble de traction doit prendre en considération, en même temps, les deux composants.L'objectif de la thèse est la conception d'un outil d'optimisation appliqué à un système de traction électrique légère qu'emploie un moteur à réluctance variable alimenté (MRVCE) par un onduleur triphasé en pont complet. Le MRVCE est modélisé en utilisant la technique par réseau de perméances. En même temps, la technique de commande électronique peut être facilement intégrée dans le modèle pour effectuer l'analyse dynamique du fonctionnement du moteur. L'outil d'optimisation réalisé utilise l'algorithme par essaim de particules, modifié pour résoudre des problèmes multi-objectif. Les objectifs sont liés à la qualité des caractéristiques de fonctionnement du moteur, en temps que les variables d'optimisation concernent la géométrie du moteur aussi que la technique de commande. Les performances de l'algorithme sont comparées avec ceux de l'algorithme génétique (NSGA-II) et d'une implémentation classique de l'algorithme par essaim de particules multi-objectif.Finalement, un prototype de moteur à réluctance variable est construit et le fonctionnement du MRVCE alimenté depuis l'onduleur triphasé en pont complet est implémenté et les outils de modélisation et d'optimisation sont validés / The interest for the electric traction applications has been growing in the last few years. The optimal design of the electric motor and of the inverter that powers it needs to consider a long list of restrictions and criteria. Because of the fact that the geometry of the motor and the switching strategy are closely linked, the optimization of the traction solution needs to consider both, at the same time.The objective of this thesis is the development of an optimization tool applied for the optimization of an electric traction solution that uses the switched reluctance motor (SRM) fed from a three phase full bridge inverter. The SRM is modeled using Permeance Network Analysis (PNA). The switching technique can be easily integrated in the model, which gives the possibility to run a dynamic analysis. The optimization tool created uses the Particle Swarm Optimization (PSO) algorithm, modified for multi-objective problems. The algorithms performances are compared with those of the Genetic Algorithm, using the NSGA-II multi-objective technique and with a classic version of multiple objective particle swarm optimizer (MOPSO).Finally, a SRM prototype is constructed and the drive solution using a full-bridge three phase inverter is implemented. The modeling and optimization tools are thus experimentally validated

Position estimation using only active phase voltage and current is presented to perform high accuracy position sensorless control of a SRM drive. By extracting the amplitude of the first switching harmonic terms of phase voltage and current for a PWM period through Fourier analysis, flux-linkage and position are estimated without external hardware circuitry such as a modulator and demodulator, resulting in increasing cost, as well as large position estimation error produced when the motional back emf is ignored near zero speed. Hence the proposed position estimation scheme covers the entire speed range including the standstill under various loads and it has high resolution information depending on switching frequency. Fourier series and Fast Fourier transform are employed to decompose the phase voltage and current into its first switching harmonic. A two-phase SRM drive system, consisting of an asymmetrical converter and a conventional closed-loop PI current controller, is utilized to validate the performance of the proposed position estimation scheme in comprehensive operating conditions. The estimated values very closely track the actual values in dynamic simulations and experiments. It is shown that the proposed position estimation scheme using Fourier analysis is sufficiently accurate and works satisfactorily at various operating points. This research also proposes an accurate self-inductance measurement method. In general, when applying circulating currents within the body of a ferromagnetic material under conditions of a time varying magnetic flux, the effects of eddy current losses and resistance changes due to heating decrease the magnetic field strength and thereby the reduced magnetic field decreases the magnetic flux-linkage of SRM. These losses make a challenge to the measurement of magnetic characteristics of SRM. These motives lead to propose a measurement methodology based on 60 Hz sinusoidal excitation using a variable AC power supply, which provides an alternative to time domain integration approaches for self-inductance or flux-linkage measurement as well as eliminates error arising from thermal and eddy currents effects. The validation of the proposed method is verified with the correlation between the measurement and FEA results of flux-linkage. Furthermore, this research proposes the solutions for low cost and high efficiency drive systems, consisting of a split AC converter and a two-phase SRM. Its performance is analyzed and verified with experiments at the rated speed under various loads. It is believed that this drive system combined with the proposed position estimation scheme using Fourier analysis is a strong contender to be a low cost motor drive system with single switch per phase having comparable efficiency and acoustic noise level as an asymmetric drive system. / Ph. D.

Linear switched reluctance motor (LSRM) drives are investigated and proved as an alternative actuator for vertical linear transportation applications such as a linear elevator. A one-tenth scaled prototype elevator focused on a home elevator with LSRMs is designed and extensive experimental correlation is presented for the first time. The proposed LSRM has twin stators and a set of translator poles without back-iron. The translators are placed between the two stators. The design procedures and features of the LSRM and the prototype elevator are described. The designed LSRM is validated through a finite element analysis (FEA) and experimental measurements. Furthermore, a control strategy for the prototype elevator is introduced consisting of four control loops, viz., current, force, velocity, and position feedback control loops. For force control, a novel force distribution function (FDF) is proposed and compared with conventional FDFs. A trapezoidal velocity profile is introduced to control vertical travel position smoothly during the elevator's ascent, descent, and halt operations. Conventional proportional plus integral (PI) controller is used for the current and velocity control loops and their designs are described. The proposed control strategy is dynamically simulated and experimentally correlated. Analytical and experimental results of this research prove that LSRMs are one of the strong candidates for ropeless linear elevator applications. However, the proposed FDF is assuming that the feedback current signals are ideal currents indicating actual phase currents without any measurement disturbances mainly arising from sensor noise, DC-link voltage ripple, measurement offset, and variations in the plant model. Meanwhile, real control systems in industry have measurement disturbance problems. Phase current corrupted by measurement disturbances increases torque or force ripple, acoustic noise and EMI. Therefore, this dissertation also presents a novel current control method to suppress measurement disturbances without extra hardware. The controller is based on an extended state observer (ESO) and a nonlinear P controller (NLP). The proposed method does not require an accurate mathematical model of system and can be implemented on a low-cost DSP controller. The proposed ESO is exploited to estimate the measurement disturbances on measured phase currents, and the proposed NLP compensates for the measurement disturbances estimated by the ESO. The performance of the proposed current control is validated through extensive dynamic simulations and experiments. Moreover, this rejection of measurement disturbances results in a reduction of force ripple and acoustic noise. Due to superior and robust current control performance, it is believed that the proposed method can be successfully applied into other motor drive systems to suppress measurement disturbances with the same promising results without extra hardware. / Ph. D.

The development of an add-on sensorless position estimator for a 4.8 m Linear Switched Reluctance Machine (LSRM) with minimal modifications to the transducer-based controller is investigated for the first time in this study. LSRMs require position feedback for closed-loop control but present a low cost, high energy efficiency alternative for linear actuation due to their rugged construction and single-sided excitation. Mechanical position transducers mounted on the vehicle are expensive and can impact reliability. The use of a sensorless position estimator removes all electronics from the passive vehicle, resulting in considerable reductions in cost, maintenance, and mechanical complexity. This study examines the use of an add-on processor and data acquisition system for sensorless position estimation. An approach exploiting the active phase windings is used to preserve the normal operation of the transducer-based DSP controller with the goal of limiting reductions in high performance features such as force ripple reduction and velocity control [3]. The estimator system is retrofit to the transducer-based DSP controller by mimicking the output of a mechanical position sensor by emulating a Quadrature encoder. The feasibility and design issues for an add-on or retrofit position estimator are investigated. Although sensorless schemes for rotary Switched Reluctance Machines (SRMs) have been studied in detail, the problem of sensorless implementations for LSRMs has not been addressed. Experimental validation of the proposed sensorless estimation scheme is attempted, but closed-loop operation is not achieved successfully due to air gap fluctuations. In depth analysis of the sources and propagation of error is presented. / Master of Science