Diplomová práce se zabývá topologickou optimalizací elektrických strojů a reluktančními synchronními stroji spouštěnými za sítě. Práce obsahuje literární rešerši na téma topologické optimalizace elektrických strojů a na téma synchronní reluktanční stroj spouštěný ze sítě. Jsou zde popsány možné způsoby charakterizace optimalizovaného prostoru. Především je rozebrán vliv rozmístění Gaussových funkcí na finální Gaussovu síť. V této práci je vytvořen vyhodnocovací algoritmus pro jednotlivé jedince, který zajišťuje komunikaci mezi Ansys Maxwell a optimalizačním softwarem SyMSpace. Navíc tento algoritmus vede ke zkrácení výpočetní doby počáteční selekcí nevyhovujících jedinců. Dále je provedena topologická optimalizace LSSynRM s využitím normalizované Gaussovy sítě a zhodnocení výsledků.

Master thesis deals with analysis of the definite synchronous reluctance motor with salient poles and design of synchronous reluctance motor with barriers for magnetic flux. The work is divided into five parts. In the first part there is a brief overview of realized synchronous reluctance motor designs and also operating principle of motor of this type is described. The next part contains the basic parameters of the synchronous reluctance motor with salient poles; the parameters were found with analytical calculation. The third part demonstrates verified by means of FEMM results of analytical calculations for linear and nonlinear states and with transient analysis of motor using Ansys Maxwell environment. In the following part results of testing of the synchronous reluctance motor with salient poles are presented as well as the comparation of these results with calculated values and the results of simulations. The closing part of the thesis shows the design of synchronous reluctance motor with barriers for magnetic flux. All obtained parameters were examined using FEMM and Ansys Maxwell. The final version of the proposed motor was analysed when supplied directly by mains and through the converter by Maxwell- Simplorer co-simulation.

This Master thesis focuses on the design of a high efficiency Permanent-Magnet-Assisted Synchronous Reluctance Motor (PMASynRM) intended for pump applications. The new motor is designed to replace an existing Induction Motor (IM) in a pump product. The basic principles of SynRM, and PMASynRM Motors and a good analytical model were introduced. Due to the complexity and high non-linearity of this specific electrical machine, Finite Element Method (FEM) and an analytical model were combined. First, a parameter sensitivity analysis was carried out with the software SPEED. However, SPEED does not give appropriate results for the sensitivity analysis of the distance from the shaft to the first barrier, and in this case, the FEM software FLUX was used instead. Using FEM as well, the risk of demagnetization of the magnets was controlled for the nominal current and for overload conditions. Furthermore, some conclusions were drawn in terms of the losses, and efficiency for the selected design. The design fulfills the required efficiency placing either ferrite or neodymium iron bore magnets in the rotor barriers. However, if ferrite magnets are employed, the maximum current should be controlled to avoid demagnetization. Finally, a ferrite PMASynRM prototype was built and tested in the lab. The simulation results as well as the measurement of other possible technologies including IM and Line Start Permanent Magnets (LSPM) machine were compared with the measurements of the prototype in terms of efficiency, power factor and cost. It is concluded that the designed PMASynRM is a good alternative as it surpassed the required efficiency and the results from the simulation were close to the test measurements. / Detta examensarbete fokuserar på konstruktion av en högverkningsgradmotor av typen Permanent-Magnet-Assisterad Synkronreluktansmotor (PMASynRM) avsedd för pumpapplikationer. Syftet är att asynkronmotorn i befintliga pumpar ska bytas ut mot den nya konstruktionen. På grund av maskinens komplexitet och dess höga olinjäritet kombinerades Finite Element Modelling metoden (FEM) och en analytisk metod. Till en början genomfördes en parameterberoende analys med SPEED för att komma fram till hur modellens olika parametrar påverkar maskinens prestanda. FEM beräkning gav mer pålitligt resultat för parameterstudie när det gällde avståndet från axeln till den första barriären (jämför med SPEED). Detta val hade fördelen att man även kunde studera avmagnetiseringsrisken vid märkström samt undersöka vid vilken ström magneterna faktiskt avmagnetiserades. Därutöver drogs slutsatser om verkningsgrad, prestanda och förluster. PMASynRM uppfyller önskad verkningsgrad med ferrit eller neodymmagneter. Om ferritmagneter används bör den maximala strömmen kontrolleras för att undvika avmagnetisering. Till slut byggdes och testades en PMASynRM prototyp. Resultaten från simulationen samt mätningarna av andra möjliga teknologier, som asynkronmotor och nätstartande permanentmagnetiserad motor (LSPM), jämfördes med mätningarna av prototypen med avseende på verkningsgrad, effektfaktor och kostnad. Slutsatsen är att PMASynRM är ett bra alternativ eftersom den överträffade den önskade verkningsgraden och eftersom resultaten från simulationen låg mycket nära testmätningarna.

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

Este trabalho se insere num contexto de desenvolvimento da capacitação para aplicações de motores de relutância chaveados, com ênfase aos aspectos eletromagnéticos do acionamento. Inicialmente, são apresentados os principais aspectos construtivos do motor e de funcionamento do seu conversor. São discutidos os fluxos de energia do acionamento e sao apresentadas as suas características operacionais, bem como as possibilidades para o seu controle. Foi desenvolvida uma metodologia de projeto embasada numa formulação empírica e no método dos elementos finitos, implementado através do programa flux2d. Desta forma, foi projetado um protótipo para desenvolver meio newton-metro a três mil rotações por minuto. A formulação empírica baseia-se na adoção de diversas hipóteses simplificadoras do circuito ferromagnético. O método dos elementos finitos foi empregado com a finalidade da obtenção de um refinamento do dimensionamento do motor. O protótipo projetado foi fabricado e testado. Os objetivos dos ensaios foram a confrontação com os diversos valores calculados no projeto e a verificação do seu desempenho em diversas condições de carga. Finalizando o trabalho, os resultados obtidos são analisados, ressaltando-se os aspectos relevantes ocorridos durante o seu desenvolvimento. São também apresentadas, as atividades subsequêntes previstas. / This work is related to the development activities of switched reluctance motors, mainly on their electromagnetic characteristics. The motor\'s basic construction features and the converter\'s operation characteristics are showed, as well as, the energy flows, performance aspects and the effects of the control parameters. The principal elements of motor desigm are discussed. A method of design is developed based on empirical formulas and on finite elements method (using the software FLUX2D). Thus, a prototype was designed with ratings of 0,5 Nm at 3000 rpm. The empirical formulas are developed on a simplified model of the motor and taking into account the referred author\'s experience. The finite elements method was used with the aim of getting a design refinement, as well as, the static torque characteristics, inductances and flux as a function of rotor position and current. The prototype was built and tested. The tests were conducted to compare the actual with the designed parameters and to evaluate the performance characteristics. Finally, the results are analysed and the main facts observed during the development of the work are reported. The next planned activities are also showed.

Este trabalho se insere num contexto de desenvolvimento da capacitação para aplicações de motores de relutância chaveados, com ênfase aos aspectos eletromagnéticos do acionamento. Inicialmente, são apresentados os principais aspectos construtivos do motor e de funcionamento do seu conversor. São discutidos os fluxos de energia do acionamento e sao apresentadas as suas características operacionais, bem como as possibilidades para o seu controle. Foi desenvolvida uma metodologia de projeto embasada numa formulação empírica e no método dos elementos finitos, implementado através do programa flux2d. Desta forma, foi projetado um protótipo para desenvolver meio newton-metro a três mil rotações por minuto. A formulação empírica baseia-se na adoção de diversas hipóteses simplificadoras do circuito ferromagnético. O método dos elementos finitos foi empregado com a finalidade da obtenção de um refinamento do dimensionamento do motor. O protótipo projetado foi fabricado e testado. Os objetivos dos ensaios foram a confrontação com os diversos valores calculados no projeto e a verificação do seu desempenho em diversas condições de carga. Finalizando o trabalho, os resultados obtidos são analisados, ressaltando-se os aspectos relevantes ocorridos durante o seu desenvolvimento. São também apresentadas, as atividades subsequêntes previstas. / This work is related to the development activities of switched reluctance motors, mainly on their electromagnetic characteristics. The motor\'s basic construction features and the converter\'s operation characteristics are showed, as well as, the energy flows, performance aspects and the effects of the control parameters. The principal elements of motor desigm are discussed. A method of design is developed based on empirical formulas and on finite elements method (using the software FLUX2D). Thus, a prototype was designed with ratings of 0,5 Nm at 3000 rpm. The empirical formulas are developed on a simplified model of the motor and taking into account the referred author\'s experience. The finite elements method was used with the aim of getting a design refinement, as well as, the static torque characteristics, inductances and flux as a function of rotor position and current. The prototype was built and tested. The tests were conducted to compare the actual with the designed parameters and to evaluate the performance characteristics. Finally, the results are analysed and the main facts observed during the development of the work are reported. The next planned activities are also showed.

The interest in breaking the historical dependence on fossil energy and begin moving towards more renewable energy sources is rising worldwide. This is largely due to uncertainties in the future supply of fossil fuels and the rising concerns about humanity’s role in the currently ongoing climate changes. One renewable energy source is ocean waves and Uppsala University has since the early 2000s been performing active research in this area. The Uppsala wave energy concept is centered on developing linear generators coupled to point absorbing buoys, with the generator situated on the seabed and connected to the buoy on the sea surface via a steel wire. The motion of the buoy then transfers energy to the generator, where it is converted into electricity and sent to shore for delivery into the electrical grid. This thesis will mainly focus on the development and evaluation of technologies used to automate the manufacturing of the translator, a central part of the linear generator, using industrial robotics. The translator is a 3 m high and 0.8 m wide three sided structure with an aluminum pipe at its center. The structure consists of alternating layers of steel plates (pole-shoes) and ferrite magnets, with a total of 72 layers per side. To perform experiments on translator assembly and production, a robot cell (centered on an IRB6650S industrial robot) complimented with relevant tools, equipment and security measures, has been designed and constructed. The mounting of the pole-shoes on the central pipe, using the industrial robot, proved to be the most challenging task to solve. However, by implementing a precise work-piece orientation calibration system, combined with selective compliance robot tools, the task could be performed with mounting speeds of up to 50 mm/s. Although progress has been made, much work still remains before fully automated translator assembly is a reality. A secondary topic of this thesis is the development of stand-alone measurement systems to be used in the linear generator, once it has been deployed on the seabed. The main requirements of such a measurement system is robustness, resistance to electrical noise, and power efficiency. If possible the system should also be portable and easy to use. This was solved by developing a custom measurement circuit, based on industry standard 4–20 mA current signals, combined with a portable submersible logging unit. The latest iteration of the system is small enough to be deployed and retrieved by one person, and can collect data for 10 weeks before running out of batteries. Future work in this area should focus on increasing the usability of the system. The third and final topic of this thesis is a short discussion of an engineering approach to kinetic energy storage, in the form of high-speed composite flywheels, and the design of two different prototypes of such flywheels. Both designs gave important insights to the research group, but a few crucial design faults unfortunately made it impossible to evaluate the full potential of the two designs.

Spårledningar används inom tunnelbanan för att visa tågets position samt bestämma tågets hastighet genom att bryta spänningsamplituden i signalen vid olika frekvenser. Frekvensen till spårledningen fås från en roterande frekvensomformare. I dagens anläggning används roterande frekvensomformare med borstar. Dessa avger i relärum mycket värme och ger miljöproblem i form av koldamm från borstarna. Det befintliga systemet är gammal och har funnits i drift över 30 år, därför håller reservdelar på att ta slut samt service till systemet svårtillgängligt. Detta examensarbete har undersökt möjligheten att uppgradera till nyare system som bygger på en lösning med roterande borstlös frekvensomformare där reservdelarna och service är tillgängliga i minst 25 år. Undersökningen jämför olika roterande borstlösa frekvensomformare från olika leverantörer för att hitta en frekvensomformare där kraven från Trafikförvaltningen uppfylls. Studien har haft fokus på problemområdet med borstade frekvensomformaren som producerar skadliga ämnen såsom koldamm och värmen i relärum. Diskussioner med tillverkningsföretag av roterande borstlös frekvensomformaren har skett under denna studies gång där möjliga alternativ för vidare utveckling av systemet i relärum analyseras. I projektet har även diskuterat möjligheten att använda det nya systemet av frekvensomformare med borstlösa motor och generator istället för den nuvarande borstade frekvensomformaren som finns i anläggningen. Resultatet har även visat att den roterande borstlösa frekvensomformaren kan omvandla frekvensen till 75 Hz. Det nya systemet uppfyller kraven från Trafikförvaltningen samt att systemet håller i minst 25 år till. Att systemet håller minst i 25 år till var ett stort krav av Trafikförvaltningen som uppfylldes under denna studie. / Track lines are used in subway stations to show the train locations and determine the speed of the train by chopping the frequency. The frequency of the track lines is obtained from a rotary frequency converter. In today's stations, rotary frequency converters with brushes are commonly used. These emit a great deal of heat in some relays and produce environmental problems in the form of carbon dust from the brushes. The existing systems have been used for over 30 years and obtaining spare parts and conducting maintenance on the systems can be difficult. This degree project examines the possibility of newer systems being built on a rotating brushless frequency converter, where the spare parts and servicing would be available for at least the next 25 years. The project surveys and compares different rotating brushless frequency converters from different suppliers to find an identical frequency converter to meet the requirements of the Traffic Administration. The result of this study has had a lot of focus on the problem area with the brushed frequency converter that produces harmful substances such as carbon dust and the heat in the relay room. Discussions with manufacturing companies of rotating brushless frequency converters have been made during this study where possible options were discussed for further development of the system in relay rooms. The result has also discussed the possibilities of using the new system of frequency converters with brushless motor and generator instead of the current brushed frequency converter available in the facility. The result has also shown that the rotating brushless frequency converter can convert the frequency to 75 Hz. The new system meets RAMS requirements of the Trafikförvaltning, and the system lasts for at least 25 years. This was a major requirement of the Trafikförvaltning, which was fulfilled during this study.