In this study, development of software, which can analyze and optimize an SRM by accurately calculating its performance, is aimed. Existing methods in the literature are investigated. Some studies for the calculation of performance use 2D field solutions and are known to be accurate / however, using field solutions is not feasible for the optimization purpose. So, a method based on a set of normalized permeance and force data are chosen for prediction of magnetizing characteristics. Selected methods are programmed into the software with a user friendly interface. The results from the software are compared with test results from an existing motor. It is found that the accuracy of the predictions is not acceptable if the effect of end winding leakage flux is not accounted for. An approach is proposed for accounting the end winding leakage. The software is modified accordingly. In this case, the results obtained are found to have good accuracy, compared with measurements. The SR motor design optimization problem is treated as a constrained wieght optimization problem. This problem is converted to an unconstrained optimization problem, by using the Augmented Lagrangian method. To decrease the computation time of some of the performance calculation algorithms, some modifications are made. These are described in the related sections. The derivatives for the optimization process are numerically calculated. The accuracy of the performance calculation is once again verified against test results at this stage. The optimization software is then used to optimize the design of an SR motor for a washing machine application. The results obtained are discussed.

Background: People are living longer with chronic life-limiting illnesses such as cancer. Much is expected of lay cancer carers with the shift of complex non-acute care to the community and the pressures this can place on family relationships. The lay caregiving role does not appeal to all, yet willingness to care is often expected by others including health professionals. Carers who feel reluctant but committed to the role may experience adverse consequences. Reluctance to care is under-investigated, particularly in the cancer context, and its indicators may include a poor carer-patient relationship, perceived lack of choice and lifestyle disruption. Existing theories of caregiving do not adequately explain reluctance to care, and the concept remains under-developed. The assumptions underpinning this study are that: some cancer carers are reluctant to care, some carers may be reluctant toward specific aspects of the caregiving role or at different times during the cancer trajectory, and some reluctant carers will not want to reveal or discuss their unwillingness. Aim: The aim of the study was to gain a clearer understanding of lay carers’ reluctance to care for patients with recurrent cancer. Methods: A mixed methods design was used. In Phase I, data provided by a consecutive sample of carers (N = 98) of cancer patients corresponding to the patients’ final year were analysed to explore the context in which reluctance to care might exist or develop, and focusing on differences by spousal relationship and by gender in anxiety and depression, awareness of the stage of cancer, perceived social support, and perceived burden. In Phase II, a purposive sample of carers of patients with recurrent cancer (N = 16) were interviewed in-depth, using open-ended questions to generate qualitative data regarding their perceptions and experiences of caregiving and reluctance to care. Complementary data were obtained from a purposive sample of health professionals who interact with cancer carers (N = 13). The interview transcripts were analysed qualitatively to identify patterns and themes which would provide insights into the dimensions of reluctance to care. Results: In Phase I, spouses perceived greater family support but caregiving had a greater negative impact on their daily activities and social interaction. Non-spouses were more anxious than spouses, but reported greater social support, and less negative impact on their finances, daily schedule and health. Female carers were more anxious and depressed than males, who reported less burden and greater social support. Awareness of the stage of cancer was positively but weakly correlated with anxiety and depression. In Phase II, reluctance to care was experienced by both spouses and non-spouses and was not gender specific. Carers and health professionals held diverging perceptions and expectations of the lay caregiving role. Caregiving was an obligatory but invisible role and for some carers it led to exhaustion due to a lack of role boundaries. Carers were faced with forced choices. The lay caregiving role seemed to come as a non-negotiable package of expectations which gave carers the autonomy to accept their role rather than the choice to refuse it. Contextual factors which seem conducive to reluctance were overshadowed by carers’ commitment to the role, which suggests that their preferences were a lower priority despite the personal cost. There was indirect evidence of reluctance in others: family members distanced themselves from the caregiving situation, and health professionals were distanced from carers by their patient-centredness. Conclusions: This study has identified three fundamental dimensions of reluctance to care: the invisibility of the caregiving role, its lack of boundaries and its forced choices. Caregiving is often a sacrificial rather than reciprocal role, but reluctance is seen as an abnormal rather than realistic response to abnormal role expectations. The findings were limited by the extent to which carers disclosed reluctance and the extent to which reluctant carers remained in the role. As a result, reluctance to care may have been underestimated. Measuring this latent and taboo topic is likely to remain a challenge as the concept of reluctance to care continues to evolve. This study has established the importance of ongoing work on a topic which cannot remain hidden as the need for lay cancer care continues to expand.

Thesis (Ph.D.)--University of Western Sydney, Nepean, 1995. / Includes bibliography.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: This thesis deals with different design aspects of the multi-flux barrier rotor of the reluctance synchronous machine (RSM). The effect of the different designs on the performance of the RSM is investigated by means of two-dimensional finite element analysis. The finite element analysis is also directly used in the optimum design of the rotor of the RSM. The importance of the use of the finite element analysis in the design and performance calculations of the RSM is illustrated in this thesis. The design aspects of the RSM which are focussed on in this thesis are, amongst other things, the chording of the stator winding, the skewing of the rotor and the ratio of the number of rotor flux barriers to the number of stator slots of the RSM. The effects of these design aspects on the average torque and torque ripple of the RSM are investigated and general design directives are given. The occurrence of flux pulsations in the stator teeth and rotor iron segments of the RSM are also studied to some extent. The finite element optimum design of a4-pole RSM-rotor with a high number of flux barriers is described in the thesis. This optimum designed rotor is built and the RSM with this rotor is tested in the laboratory. Its calculated and measured performances are studied and compared with a conventional, low number rotor flux barrier RSM. It is found, amongst other things, that the RSM with the high number of rotor flux barriers has a slightly higher average torque with a significantly lower torque ripple. / AFRIKAANSE OPSOMMING: Hierdie tesis handeloor verskillende ontwerp-aspekte van die reluktansie sinchroonmasjien (RSM) met 'n multi-vloedversperringsrotor. Die effek van die verskillende ontwerpe op die vermoë van die RSM is met behulp van twee-dimensionele eindige element analise ondersoek. Die eindige element analise is ook direk in die optimum ontwerp van die rotor van die RSM gebruik. Die belangrikheid van die gebruik van die eindige element analise in die ontwerp en vermoë-berekening van die RSM word in die tesis geïllustreer. Die ontwerp-aspekte van die RSM waarop in hierdie tesis gefokus word, is onder andere die spoelsteekverkorting van die statorwikkeling, die skuinsing van die rotor en die verhouding van die getal rotor-vloedverperrings tot die getal statorgIeuwe van die RSM. Die effek van hierdie ontwerpaspekte op die gemiddelde draaimoment en draaimoment-rimpel van die RSM word ondersoek en algemene riglyne vir die ontwerp van die RSM word gegee. Die voorkoms van vloedpulsasies in die statortande en rotor yster segmente van die RSM word ook deels ondersoek. Die eindige element optimum ontwerp van 'n 4-pool RSM-rotor met 'n hoe getal vloedversperrings word in die tesis beskryf. Hierdie optimum ontwerpte rotor is gebou en die RSM met hierdie rotor is in die laboratorium getoets. Die berekende en gemete vermoë is bestudeer en vergelyk met die vermoë van 'n RSM met 'n konvensionele, lae getal vloedversperrings rotor. Dit is onder andere gevind dat die RSM met die hoë getal rotor-vloedversperrings 'n effens hoër gemiddelde draaimoment het met 'n behuidende laer draaimoment-rimpel.

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The aim of this study is to critically evaluate the voltage injection position sensorless control technique as applied to the reluctance synchronous machine (RSM) drive and to implement the technique on a 5.5 kW RSM and a 110 kW RSM. The technique is evaluated by using an accurate mathematical model of the RSM in a simulation package, called Simuwin. The negative effects that cross-magnetisation and the slotted air-gap have on the technique are intensively investigated. It was showed that these effects can cause an error in the position estimation of up to 30°. The TMS320F240 DSP was used as the controller for the RSM drives to implement the position sensorless control technique. Measurements on both RSM drives confirm the simulated results. / AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om die spannings-injeksie posisie sensorlose beheer tegniek soos toegepas op die reluktansie sinchroon masjien (RSM) aandryfstelsel, krities te evalueer en te implementeer op 'n 5.5 kW RSM en op 'n 110 kW RSM. Die tegniek is geevalueer deur 'n akkurate wiskundige model van die RSM saam te stel en die model te gebruik in 'n simulasie pakket, genaamd Simuwin. Daar is veral klem gele op die negatiewe invloed wat kruis-magnetisering en 'n gegleufde lug-spleet op die tegniek het. Dit is bewys dat hierdie eienskappe van die RSM 'n fout in die posisie afskatting van tot 30° kan veroorsaak. Die TMS320F240 DSP is gebruik as beheerder vir die RSM aandryfstelsels om sodoende posisie sensorlose beheer op altwee masjiene toe te pas. Metings op albei stelsels bevestig die simulasies.

Made available in DSpace on 2014-07-29T15:08:20Z (GMT). No. of bitstreams: 1 anexo dissertacao weldon.pdf: 502529 bytes, checksum: e010c8b9335a273bd3a0c2fd72779737 (MD5) Previous issue date: 2009-06-30 / This work presents a proposal for testing Switched Reluctance Motors, which is feasible by the design and construction of an automated test bench. The test proposal intends to measure phase s resistance; to compute copper loss; to obtain the magnetizing curves for aligned and unaligned rotor and a performance test, which is based on fixing the under test motor rotor speed by a drive machine that is drove by a frequency inverter. The computational automation is restricted in changing the d.c. voltage applied to the under test switched reluctance motor by a programmable sinusoidal voltage source; changing and/or fixing the under test rotation speed of the switched reluctance; changing the semiconductor-switch switching angle; acquisition and processing of the data obtained in the tests. Computational simulations were performed for validating tests results made in an available switched reluctance motor / Este trabalho apresenta uma proposta de ensaios de Motores a Relutância Chaveados, a qual se viabiliza através do projeto e construção de uma bancada automatizada. A proposta de ensaios compreende, entre outros procedimentos, em medir as resistências das fases; calcular a perda ôhmica; determinação das curvas de magnetização nas posições de pólos, do estator e rotor, alinhados e desalinhados e o desempenho, o qual se fundamenta na fixação da velocidade de rotação dos motores sob teste através de uma máquina de indução trifásica de grande potência comparada à potência do motor sob teste, cujo acionamento é realizado por meio de um conversor de freqüência. A automação realizada via computacional está circunscrita aos seguintes aspectos: variação da tensão de corrente contínua aplicada ao motor a relutância; variação e fixação da velocidade de ensaio do motor a relutância; variação do ângulo de disparo das chaves semicondutoras do conversor de potência; aquisição e processamento dos dados obtidos nos ensaios e determinação da velocidade do motor. Através do método dos elementos finitos foram realizadas simulações computacionais pertinentes para confrontar com os ensaios realizados em um motor a relutância chaveado disponível.

Orientadores: Ernesto Ruppert Filho, Alfeu Joãozinho Sguarezi Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T10:59:20Z (GMT). No. of bitstreams: 1 Barros_TarcioAndredosSantos_M.pdf: 8048124 bytes, checksum: 1b2ffa1afb318d0a5c4d249edbb6a773 (MD5) Previous issue date: 2012 / Resumo: O objetivo deste trabalho é o de propor técnicas de controle de potências ativa e reativa de geradores de relutância variável (GRV) aplicados 'a geração eólica de energia eólica. Desenvolveu-se uma técnica de controle direto de potência ativa utilizando um controlador proporcional-integral e outra técnica utilizando um controlador de modos deslizantes. Inicialmente, realizou-se uma revisão bibliográfica e um estudo sobre a máquina de relutância variável a fim de compreender o seu funcionamento e o seu modelo matemático dinâmico. Neste trabalho são apresentados resultados de simulações para estudar a operação do GRV com os controladores propostos num sistema ideal de geração conectado com a rede elétrica. Um modelo matemático dinâmico não linear que leva em conta as curvas de magnetização do gerador em função da posição do rotor foi utilizado nas simulações desenvolvidas. O conversor responsável por magnetizar o GRV e captar a energia gerada e o conversor que envia a energia gerada para a rede elétrica foram modelados matematicamente utilizando o aplicativo computacional SimpowerSystems do Matlab R, que apresenta uma biblioteca de componentes e de ferramentas de análise para modelagem e simulação de sistemas de energia elétrica com eletrônica de potência. Os resultados das simulações são apresentados e os desempenhos dos controles propostos durante o funcionamento do GRV em velocidade variável com diferentes referências de potências ativa e reativa são comparados / Abstract: The objective of this thesis is to propose techniques for active and reactive power for switched reluctance generators (SRG) applied to wind generation. A direct for active power control using the proportional and integral controller and another technique using the sliding mode controller were developed. Initially a literature review and a study of the switched reluctance machine in order to understand its operation and its dynamic mathematical model were done. This thesis presents results of simulations to study the SRG operation with the controllers proposed in an ideal generation system connected to the grid. A non-linear dynamic mathematical model which takes into account the magnetization curves of the generator as a function of rotor position was used in the simulations carried out. The converter responsible for the SRG magnetization and for the capture of generated energy and the converter that sends the generated energy to the grid were mathematically modeled using the software SimpowerSystems Matlab R, which has a library of components and analysis tools for modeling and simulation of electric power systems and power electronics. The simulation results are shows and the proposed controllers performance during the operation of the SRG variable speed references with different active and reactive power are compared / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

This thesis presents the design and analysis of specialised control systems for switched reluctance (SR) and permanent magnet (PM) machines in vehicular electric applications. Control systems for operation in motoring and power generation are considered for both the types of machines. The SR machine operation considered in this thesis is mainly focused towards the application of aero-engine starter/generators. The control designs for PM machines are formulated considering general fault-tolerant and isolated multiphase PM machines which can be applied in the majority of safety-critical vehicular power and propulsion applications. The SR motoring mode presented in this thesis considers the control design for operation from zero speed to a high speed range, while SR generation mode is confined to the high speed range, such as for the requirements of aero-engine starter/generator operation. This thesis investigates applied control methods for both single-pulse and chopping modes of operation. Classical excitation control versus peak current control and the introduction of a zero-voltage interval are compared for SR motor operation. Optimized excitation control versus two classical forms of excitation control are developed and compared for SR generator operation. Studies include simulation of a 12/8 250kW machine and experimental work on a 6/4 300W machine. The PM motoring and power generation considered in this thesis focuses on a special class of PM machines and drives which are specifically designed for fault-tolerant operation. Optimized control strategies for the operation of PM machines with the parallel H-bridge per-phase converter architecture are investigated. Mathematical modelling of the machine and drive with a consideration of harmonics is presented. The developed control methods are then evaluated by means of finite-element model based simulations of a 125kW five phase surface PM rotor machine and an interior PM rotor machine.

No description available.

This diploma thesis deals with design of rotor of synchronous reluctance machines. There is a theoretical description of rotor geometry of synchronous reluctance machine that respects natural flow of magnetic flux inside complete rotor. The parametric model of rotor is made with usage of ANSYS Maxwell and Matlab software. Furthermore, the parameters of the machines are confirmed using the same program. Finally, changes of motor parameters are observed in connection with different rotor geometries.