The switched reluctance motor has the advantages of the low production cost, high operating efficiency, high stability, and high start torque. It can deliver a wide speed range, and therefore make it very attractive to the engineers and researchers. The double salient structure of SRM result in a non-linear stator inductance, so the output reluctance torque has a highly non-linear behavior. A digital signal processor based drive system for SRM is developed and implemented in this thesis using the TI TMS320F240 DSP system which is with universal peripheral interface circuits. The built-in pulse width modulation(PWM) module of the DSP system can auto-generate PWM output signal by setting the relative registers to simplify the hardware design. This research built a complete drive system for SRM, both the closed-loop velocity controller and current compensator were designed according to the proportional-integral(PI) control mechanism, and all schemes were coded in the DSP program. Simulation and experiment results demonstrate that the proposed drive system makes reluctance torque output very smoothly with a preferable velocity response.

In this thesis, the design of a Switching Power Supply for switched-reluctance motor drive system power factor correction is presented. Switching power technology for the power supply is now widely used, which has the main advantages of high efficiency and small size. However, the traditional type of Switching Power Supply will reduce the impact on electricity usage and quality, and produce electricity pollution and waste, for example low power factor, and high harmonic distortion. In order to improve the power factor, this paper used the traditional method of multiplier power factor correction circuit, and the use of state-space averaging method to analysis Buck Derived Converters to implement the Switching ¡@ Reluctance Motor Drive circuit design; In addition, this thesis used the Average Current Control method to cause the inductor current to follow a sinusoidal signal, achieving the purpose of¡@power factor correction.The design of Buck Converters is based on switching theory. With this method, the electricity pollution problems introduced by switching reluctance motor drives is solved by the Averagingmethod derived form the converters. The mathematical Buck Converter model is brought into a block diagram, based on the design of Buck¡@Converters, and then simulated with PsPICE software. Finally the design of the output voltage control, compensation and current control loop is performed.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 55-56). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 55-56). Also available on the Internet.

This research focuses on the creation of a thermal estimator to be used in an integrated electromagnetic, thermo-mechanical design tool for the rapid optimal initial sizing of switched reluctance and induction machines. The switched reluctance model includes heat generation in the rotor due to core losses, heat transfer across the air gap through convection, and a heat transfer path through the shaft to ambient. Empirical Nusselt correlations for laminar shear flow, laminar flow with vortices and turbulent flow are used to estimate the convective heat transfer coefficient in the air gap. The induction model adds ohmic heat generation within the rotor bars of the machine as an additional rotor heat source. A parametric, self-segmenting mesh generation tool was created to capture the complex rotor geometries found within switched reluctance or induction machines. Modeling the rotor slot geometries in the R-θ polar coordinate system proved to be a key challenge in the work. Segmentation algorithms were established to model standard slot geometries including radial, rectangular (parallel-sided), circular and kite-shaped features in the polar coordinate system used in the R-θ solution plane. The center-node mesh generation tool was able optimize the size and number of nodes to accurately capture the cross sectional area of the feature, in the solution plane. The algorithms pursue a tradeoff between computational accuracy and computational speed by adopting a hybrid approach to estimate three dimensional effects. A thermal circuits approach links the R-θ finite difference solution to the three dimensional boundary conditions. The thermal estimator was able to accurately capture the temperature distribution in switched reluctance and induction machines as verified with experimental results.

This thesis intends to examine the principles of operation for switched reluctance machines (SRM) and examine the power electronic drive circuits that control them, in order provide a basis of understanding for evaluating total drive efficiency and responsiveness potential. This document specifically examines the characteristics of a motor drive circuit which affect motor and converter efficiency and driving performance. A drive topology suited for efficient operation and excellent responsiveness is proposed. Finally, a SRM drive system model for evaluating these systems in simulation is described as a tool for comparative evaluations in future work. The end goal of this work is to provide a foundation of knowledge for future work, developing in-wheel, SRM-based, high performance hybrid electric drivetrains in future ground combat vehicles which are modular, possess an open architecture for upgrades, and operate with high efficiency and improved mobility. / text

This thesis presents the development of an in-wheel drive system consisting of an axial-flux switched-reluctance motor and a hub suspension. The motor is designed using Maxwell's stress tensor and numerical analysis techniques, including FEA and transient numerical simulations. A new integral inductance function is introduced that improves the accuracy of the motor model, and a new in-phase current-shaping technique is implemented using a fuzzy controller to extend the constant-power region of the motor. The hub suspension system is simulated using a half-car model with 6 degrees of freedom, and the overall torque, power, and efficiency of the drive system is calculated. A peak torque of 500[Nm] is developed at the high end of the drive system's speed range, and the hub suspension system is shown to eliminate the impact of the motor's increased unsprung mass on vehicle handling.

Pages 6-12 missing. / Thesis (MScEng)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: The transverse flux machine (TFM) offers the opportunity of high torque to volume ratios which makes it an excellent candidate for direct wheel drives and low speed generator applications. TFMs have a three dimensional flux path which eliminates iron laminates as a viable core material. Soft magnetic composites have been adopted in these machines due to their isotropic nature. There are three main variants of TFMs, namely, active rotor (with magnets on the rotor), passive rotor (with magnets on the stator), and reluctance (with no magnets). As a relatively recent development in electrical machines, the TFM still has many hurdles facing its adoption in industry. Some of these hurdles are high cogging torque, a difficult construction, and expensive materials. This thesis focuses on the design of a three phase 50 kW passive rotor machine. Finite element simulation is used to determine the optimal configuration, and the final machine is analysed in detail. The construction process and associated problems are also detailed. The completed machine did not perform to the desired specification, but much knowledge was gleaned about the TFM, the construction caveats, and future potential directions. / AFRIKAANSE OPSOMMING: Die transversale-vloed masjien (TFM) met sy hoe draaimoment tot volume verhouding, is 'n uitstekende kandidaat vir direkte wiel aandrywing en lae spoed generator toepassings. Die vioed pad van die masjiene is drie-dimensioneel, wat yster laminasies as kern materiaal elimineer. "Soft magnetic composites" kan gebruik word vir hierdie masjiene as gevolg van hulle isotropiese eienskappe. Daar bestaan drie hoof variante van die TFM, naamlik, die aktiewe rotor (met magnete op die rotor), passiewe rotor (met magnete op to stator), en reluktansie (sonder magnete). Die TFM is 'n redelike nuwe tipe masjien en daar is nog probleme wat opgelos moet word voordat die industrie sal begin om dit te gebruik. Van hierdie probleme is "cogging" draaimoment, 'n moeilike konstruksie en duur materiale. Die fokus van hierie tesis is op die ontwerp van 'n 50 kW drie-fase passiewe rotor masjien. Eindige element simulasie is gebruik om die optimale konfigurasie te kry, en 'n analise is gedoen op die finale masjien. Die konstruksie proses en die probleme wat daarmeer saam gaan is ook beskryf. Die prototipe masjien wat gebou is het nie aan sy oorspronklike spesifikasie voldoen nie, maar baie kennis is opgedoen oor die TFM, die konstruksie proses, en potensiele toekomende toepassings.

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

Thesis (MScEng)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: Two distinct simulation methods have been developed to simulate the single and the multi-phase excited current waveforms of the switched reluctance machine (SRM) under single pulse mode operation. These simulation methods are explained and evaluated in this thesis. A non-commercial finite element package that takes the SRM's nonlinear magnetic property into account is used in this regard. The simulation program uses the finite element solution directly during the simulation. Both simulation methods have been investigated in terms of result and total simulation time. In this investigation it is shown how feasible the simulation methods will be with the next generation of fast computers. The factors affecting the simulated current waveforms of the SRM under single pulse mode operation are investigated in detail in this thesis. With these factors taken into account, the measured and simulated multi-phase current waveforms are compared with each other and discussed. / AFRIKAANSE OPSOMMING: Twee verskillende simulasie metodes is ontwikkel om die enkel- en multi-fase stroomgolfvorms van die geskakelde reluktansiemasjien (GRM) onder enkelpulsmodus-werking te simuleer. In hierdie tesis word hierdie simulasie metodes verduidelik en geëvalueer. 'n Nie-kommersiële eindige element pakket wat die nielinieêre magnetiese eienskap van die GRM in ag neem is in hierdie verband gebruik. Die simulasie program gebruik die eindige-element oplossing direk gedurende die simulasie. Beide simulasie metodes is ondersoek in terme van resultaat en simulasietyd. In hierdie ondersoek word getoon hoe uitvoerbaar hierdie tipe simulasie metodes gaan wees met die volgende hoë spoed generasie rekenaars. Die faktore wat die gesimuleerde stroomgolfvorms van die GRM onder enkelpulsmodus-werking beïnvloed word deeglik in hierdie tesis ondersoek. Met hierdie faktore in ag geneem word die gemete en gesimuleerde multi-fase stroomgolfvorms met mekaar vergelyk en bespreek.