Dissertations / Theses on the topic 'Synchronous Reluctance Motor'

This thesis investigates the development of a machine which is termed as singly salient reluctance (SSR) motor and its drive system. The stator of SSR motor is identical to that of a conventional induction motor or any other ac machine. Its rotor has salient poles with internal flux barriers or flux guides. This research covers the detailed designs of the SSR motors and their magnetic circuit analysis using finite element method (FEM). The parameters which are important for designing the SSR motor are investigated. This investigation resulted in designs which have low manufacturing cost as well as high torque per ampere, efficiency and power factors. This thesis also researches the different drive system for the SSR motor. The SSR motor is tested as a variable speed drive with closed loop control and supplied with dc source. Therefore for this purpose a controller system is designed and built. In addition, the SSR motor supplied by ac source using open loop control is also tested for synchronous operation. Some of the proposed designs are built and their performance compared with their predicted analysis. The SSR motors showed a competitive performance compared with equivalent induction motor in both efficiency and power factor. However the validity of the theoretical designs is assessed by comparing them with experimental results. Quite good agreement between experimental and theoretical evaluations has been achieved. In addition, suggested further improvements for SSR motors and drive systems are discussed.
Doctor of Philosophy (PhD)

This thesis investigates the development of a machine which is termed as singly salient reluctance (SSR) motor and its drive system. The stator of SSR motor is identical to that of a conventional induction motor or any other ac machine. Its rotor has salient poles with internal flux barriers or flux guides. This research covers the detailed designs of the SSR motors and their magnetic circuit analysis using finite element method (FEM). The parameters which are important for designing the SSR motor are investigated. This investigation resulted in designs which have low manufacturing cost as well as high torque per ampere, efficiency and power factors. This thesis also researches the different drive system for the SSR motor. The SSR motor is tested as a variable speed drive with closed loop control and supplied with dc source. Therefore for this purpose a controller system is designed and built. In addition, the SSR motor supplied by ac source using open loop control is also tested for synchronous operation. Some of the proposed designs are built and their performance compared with their predicted analysis. The SSR motors showed a competitive performance compared with equivalent induction motor in both efficiency and power factor. However the validity of the theoretical designs is assessed by comparing them with experimental results. Quite good agreement between experimental and theoretical evaluations has been achieved. In addition, suggested further improvements for SSR motors and drive systems are discussed.

Recently, permanent magnet assisted (PMa)-synchronous reluctance motors (SynRM) have been considered as a possible alternative motor drive for high performance applications. In order to have an efficient motor drive, performing of three steps in design of the overall drive is not avoidable. These steps are design optimization of the motor, identification of the motor parameter and implementation of an advanced control system to ensure optimum operation. Therefore, this dissertation first deals with the design optimization of the Permanent Magnet Assisted Synchronous Reluctance Motor (PMa-SynRM). Various key points in the rotor design of a low cost PMa-SynRM are introduced and their effects are studied. Finite element approach has been utilized to show the effects of these parameters on the developed average electromagnetic torque and the total d-q inductances. As it can be inferred from the name of the motor, there are some permanent magnets mounted in the rotor core. One of the features considered in the design of this motor is the magnetization of the permanent magnets mounted in the rotor core using the stator windings to reduce the manufacturing cost. At the next step, identification of the motor parameters is discussed. Variation of motor parameters due to temperature and airgap flux has been reported in the literatures. Use of off-line models for estimating the motor parameters is known as a computationally intensive method, especially when the models include the effect of cross saturation. Therefore in practical applications, on-line parameter estimation is favored to achieve a high performance control system. In this dissertation, a simple practical method for parameter estimation of the PMa-SynRM is introduced. Last part of the dissertation presents one advanced control strategy which utilized the introduced parameter estimator. A practical Maximum Torque Per Ampere (MTPA) control scheme along with a simple parameter estimator for PMa-SynRM is introduced. This method is capable of maintaining the MTPA condition and stays robust against the variations of motor parameters. Effectiveness of the motor design procedure and the control strategy is validated by presenting simulation and experimental results of a 1.5 kW prototype PMa-SynRM, designed and manufactured through the introduced design method.

The Synchronous Reluctance Motor (SynRM) has been studied. A suitable machine vector modelhas been derived. The influence of the major parameters on the motor performance has beentheoretically determined.Due to the complex rotor geometry in the SynRM, a suitable and simple combined theoretical(analytical) and finite element method has been developed to overcome the high number ofinvolved parameters by identifying some classified, meaningful, macroscopic parameters.Reducing the number of parameters effectively was one of the main goals. For this purpose,attempt has been made to find and classify different parameters and variables, based on availableliteratures and studies. Thus a literature study has been conducted to find all useful ideas andconcepts regarding the SynRM. The findings have been used to develop a simple, general, finiteelement aided and fast rotor design procedure. By this method rotor design can be suitablyachieved by related and simplified finite element sensitivity analysis.The procedure have been tested and confirmed. Then it is used to optimize a special rotor for aparticular induction machine (IM) stator. This optimization is mainly focused on the torquemaximization for a certain current. Torque ripple is also minimized to a practically acceptablevalue. The procedure can also be used to optimize the rotor geometry by considering the othermachine performance parameters as constrains.Finally full geometrical parameter sensitivity analysis is also done to investigate the influence ofthe main involved design parameters on the machine performance.Some main characteristics like magnetization inductances, power factor, efficiency, overloadcapacity, iron losses, torque and torque ripple are calculated for the final designs and in differentmachine load conditions.Effects of ribs, air gap length and number of barriers have been investigated by means of suitableFEM based method sensitivity analysis.

A microprocessor control scheme for variable speed switched reluctance motor(SRM) drives is discussed. A particular implementation derived from first principles of the SRM is presented. The Intel 8088 microprocessor is used for the design implementation. It is shown that given the control requirements of the SRM like firing different phases according to rotor position and phase currents, a microprocessor controller is a good choice. The controller is economical since it uses standard TTL chips. The slow response at low speeds is also discussed. Experimental results performed on a static inductive load using a simulated position feedback are presented, showing how the current control available at lower speeds is lost at higher speeds, due to limited dc bus voltage. A listing of the controller software with adequate comments and the circuit diagrams are appended.
Master of Science

In this thesis different methods of optimizing line start permanent magnet motor (LSPM) for magnet cost reduction is studied. Influence of different parameters has been studied by simulating magneto-static and transient FEM models of the machine. Finally a motor design of a LSPM with high rotor saliency has been proposed. The first method investigated is the use of flux barriers in LSPM and its effect on the magnetic flux leakage. The flux barriers reduce the flux leakage and hence help in reducing magnet volume. The second method studied is the use of two different grades of magnets. Using low price magnets help in reducing the total magnet cost without reducing the air gap flux density. The reduction in NdFeB magnet volume is not substantial by using both the methods mentioned above. The third method investigated is increasing the saliency of the rotor by introducing flux barriers and reducing the corresponding magnet volume. Both the magneto static and transient models are used to study the effect of different parameters of the motor. The placement and volume of magnet plays a critical role in motor performance. At first, the developed reluctance torque of the motor is maximized by doing parametric study and then magnets are placed in slots to achieve the required efficiency and power factor. The motor is simulated with NdFeB magnets and with Ferrite magnets. It has been found that using high saliency LSPM motor the NdFeB magnet volume can be reduced significantly. It is also shown that the same performance of motor (as compared to the motor with NdFeB magnets) can be achieved by using Ferrite magnets. The volume of Ferrite magnet required will be larger but still cost-wise using Ferrite is an attractive choice. Therefore, a design of motor is proposed using both NdFeB magnets and Ferrite magnets. Finally, the performance of proposed LSPM motor with high saliency is compared with that of an induction motor.

Sensorless control of the synchronous reluctance motor has been a topic of research for more than a decade, producing several successful methods to accomplish this goal. However, a technique that has been overlooked is the full-order nonlinear observer, which is essentially a software model of the motor driven by measurements from the actual motor. Presented in this thesis is the design, implementation, and experimental testing of a full-order observer-based sensorless control technique which requires only the phase current and voltage measurements that are typically available in standard three-phase inverters. A technique is also presented for calculating a table of observer feedback gains parameterized only by the steady-state motor speed. This allows a gain-scheduling observer to be implemented which, as shown using experiments, improves the transient response of the observer over a wide speed range. The sensorless controller consists of a full-order nonlinear observer coupled with an input-output linearization speed controller. The resulting controller was implemented in Simulink and executed on a dSPACE DS1103 real-time DSP board using the Real-Time Workshop extension to Simulink. A custom built three-phase IGBT inverter was used to interface the DSP to a 100 watt synchronous reluctance motor for laboratory testing. The resulting sensorless controller was able to successfully track a varying speed reference from 150 rpm to 1800 rpm with a tracking error under 5% for most of the speed range. At the lowest speeds, the tracking error begins to increase but the observer remains stable down to 150 rpm.

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.

In the last decades, the development trends of high efficiency and compact electric drives on the motor side focused on Permanent Magnet Synchronous Machines (PMSMs) equipped with magnets based on the rare-earth elements. The permanent magnet components, however, dramatically impact the overall bill of materials of motor construction. This aspect has become even more critical due to the price instability of the rare-earth elements. This is why the Permanent Magnet Assisted Synchronous Reluctance Motor (PMaSynRM) concept was brought to the spotlight as it gives comparable torque density and similar efficiencies as PMSM although at a lower price accredited for the use of magnets built with ferrite composites. Despite these advantages, PMaSynRM drive design is much more challenging because of nonlinear inductances resulting from deep cross saturation effects. It is also true for multi-phase PMSM motors that have gained a lot of attention as they proportionally split power by the increased number of phases. Furthermore, they offer fault-tolerant operation while one or more phases are down due to machine, inverter, or sensor fault. The number of phases further increases the overall complexity for modeling and control design. It is clear then that a combination of multi-phase with PMaSynRM concept brings potential benefits but confronts standard modeling methods and drive development techniques. This Thesis consists of detailed modeling, control design, and implementation of a five-phase PMaSynRM drive for normal healthy and open phase fault-tolerant applications. Special emphasis is put on motor modeling that comprises saturation and space harmonics together with axial asymmetry introduced by rotor skewing. Control strategies focused on high efficiency are developed and the position estimation based on the observer technique is derived. The proposed models are validated through Finite Element Analysis (FEA) and experimental campaign. The results show the effectiveness of the elaborated algorithms and methods that are viable for further industrialization in PMaSynRM drives with fault-tolerant capabilities.
En últimas décadas, las tendencias de desarrollo de accionamientos eléctricos compactos y de alta eficiencia en el lado del motor se centraron en las maquinas síncronas de imanes permanentes (PMSM) equipadas con imanes basados en elementos de tierras raras. Sin embargo, los componentes de imán permanente impactan dramáticamente en el coste de construcción del motor. Este aspecto se ha vuelto aún más crítico debido a la inestabilidad de precios de los elementos de tierras raras. Esta es la razón por la que el concepto de motor de reluctancia síncrona asistido por imán permanente (PMaSynRM) se ha tomado en consideración, ya que ofrece una densidad de par comparable y eficiencias similares a las de PMSM, aunque a un precio más bajo acreditado para el uso de imanes construidos con compuestos de ferritas. A pesar de drive PMaSynRM resulta muy complejo debido a las inductancias no lineales que resultan de los efectos de saturación cruzada profunda. Esto también es cierto para los motores PMSM polifásicos que han ganado mucha atención en los últimos años, en los que se divide proporcionalmente la potencia por el mayor número de fases. Además, ofrecen operación tolerante a fallas mientras una o más fases están inactivas debido a fallas en la máquina, el inversor o el sensor. Sin embargo, el número de fases aumenta aún más la complejidad general del diseño de modelado y control. Está claro entonces que una combinación de multifase con el concepto PMaSynRM tiene beneficios potenciales, pero dificulta los métodos de modelado estándar y las técnicas de desarrollo del sistema de accionamiento. Esta tesis consiste en el modelado detallado, el diseño de control y la implementación de un drive PMaSynRM de cinco fases para aplicaciones normales en buen estado y tolerantes a fallas de fase abierta. Se pone especial énfasis en el modelado del motor que comprende la saturación y los armónicos espaciales junto con la asimetría axial introducida por la inclinación del rotor. Se desarrollan estrategias de control enfocadas a la alta eficiencia y se deriva la estimación de posición basada en la técnica del observador. Los modelos propuestos se validan mediante Análisis de Elementos Finitos (FEA) y resultados experimentales. Los resultados muestran la efectividad de los algoritmos y métodos elaborados, que resultan viables para la industrialización de unidades PMaSynRM con capacidades tolerantes a fallas.
Engineria electrònica

Nowadays, the interest in the synchronous reluctance machines is growing up due to their several merits in comparison to other machine types. These machines offer high torque density with respect to the induction machines. Their torque density is slightly lower than permanent magnet synchronous machines even though the lower performance is compensated by a much cheaper rotor. Since synchronous reluctance machines do not induce voltage when the stator is not supplied, there are not short circuit currents and braking torques due to the electrical faults, e.g. they have high fault tolerant capability. In addition, synchronous reluctance machine has a robust structure, and a wide constant power speed range. For these aforementioned reasons, these machines are employed in several applications. However, there is a prominent defect of this kind of machines which is the low power factor. This defect is addressed by assisting the motor by permanent magnets within the flux barriers of the rotor leading to the permanent magnet assisted synchronous reluctance motor. In addition, these kinds of machines has high torque ripple. This is due to the high harmonic content in the magneto motive force which interacts with the rotor anisotropy. Several approaches are proposed to reduce the torque ripple, such as: (a) using skewed rotor, (b) adopting two different flux-barrier geometries in the same lamination, i.e., asymmetric rotor, (c) using equally spaced the flux-barrier ends along the rotor periphery, and (d) optimization approaches were applied to smooth the torque. The synchronous reluctance machine is becoming of great interest in the last years, due to two key reasons: (i) the increase of rare earth permanent magnet cost and (ii) the increasing request of high-efficiency machines. Therefore, the reluctance motor and the ferrite permanent assisted reluctance motor are becoming competitors of both surface-mounted permanent magnet machines and induction machines in many applications. Such motors are also becoming particularly interesting when the control is based on the sensor-less rotor position detection. Even if there is a great interest in this kind of machines, there is a few work about the analytical design of their rotor, e.g. about how to select the end barrier angles, designing the iron ribs, and designing the permanent magnet robust towards the demagnetization. In the majority of the cases the reluctance machine is analyzed by using finite element analysis. The results are precise and useful for achieving a specific geometry to be prototyped, but they refer to that particular solution and they lose generality. In other words, it is difficult to find general rules to design reluctance machines, since the analysis approach is focused on a single objective. During the manufacturing process, there are some manufacturing imprecision, such as mass unbalance, bearing tolerance, shaft bow, and etc., cause eccentricity fault. Eccentricity may cause magnetic and dynamic problems with additional vibrations, noises, and torque pulsations. Although the eccentricity faults in induction and permanent magnet motors are extensively investigated, there are a few publications on synchronous reluctance machines with eccentricity. It is important to study the effect of rotor eccentricity on these machines because of their high anisotropy and critical iron parts in the rotor (iron ribs). For the aim of designing the iron ribs thicknesses, the unbalanced magnetic force acting on theses ribs should be accurately estimated. Main contribution of the thesis This thesis aims to give an useful analytical approach for reaching a preliminary geometry of both synchronous reluctance and permanent magnet assisted synchronous reluctance motors, as starting point for a successive optimization. For more accurate design of the rotor iron ribs, the electro-magnetic force acting on the rotor, in different rotor eccentricity cases, are analytically computed. In addition, a comparative studies (analytically and FE) between the synchronous reluctance, permanent magnet assisted, and surface mounted permanent magnet machines, in different eccentricity cases, is carried out. Therefore, this thesis is divided into four main parts. At the first part, an analytical model based on the magnetic equivalent lumped network of the reluctance motor is discussed. This model studies the magnetic performance of the concentric synchronous reluctance motor. Then, this analytical model is adopted in order to study the impact of different eccentricity scenarios (static and dynamic eccentricity) on the reluctance motor. Different stator windings configurations (distributed and concentrated windings) and different rotor geometries (symmetric and asymmetric rotor) are considered. After that, the eccentric synchronous reluctance machine is compared with the eccentric permanent magnet assisted synchronous reluctance machine. The impact of the barrier dimensions, the rotor geometry, and the permanent magnet type is highlighted in this comparison. Furthermore, an analytical comparison between the reluctance motor and the surface mounted permanent magnet motor is carried out in different cases of eccentricity. The axial non uniform displacement of the rotor axis from the stator axis, at one end and both ends of the axis, are involved in this analytical comparison. The second part aims to achieve more realistic estimation of the electromagnetic forces acting on the rotor by considering the effect of stator slots and the magnetic voltage drop due to the actual B-H curve of the motor iron. The analytical model is developed for both eccentric and concentric synchronous reluctance motor. Then, an experimental validation of the analytical and FE analysis is carried out. At the third part, an analytical approach for designing the permanent magnet of the permanent magnet assisted reluctance motor is proposed. The width and the thickness are selected so as to achieve the desired no-load air-gap flux density and resist the demagnetization under the desired loading conditions, respectively. Both complete and simplified analytical analyses are discussed. In addition, the analytical approach is presented in both cases of neglecting and considering the rotor iron ribs. Then, from the previously mentioned three parts of this thesis, a rapid multi-objectives analytical approach is proposed to achieve the initial design of the synchronous reluctance and permanent magnet assisted synchronous reluctance motors. Finally, at the fourth part, a graphical user interface application for concentric and eccentric synchronous reluctance motor is developed. This application estimates stator and rotor scalar magnetic potential, air-gap flux density, electromagnetic torque, magnetic force acting on the rotor. The input parameters of this application are - the geometrical data of the stator and rotor, - the electric loading (kA/m), the electric load angle in (electric degree), - the rotor geometry type, e.g., symmetric or asymmetric rotor geometry, - number of flux-barriers per rotor pole, - eccentricity type or no eccentricity, e.g., healthy case, - the eccentricity value. Then, the user can run the application to estimate the magnetic performance of both concentric and eccentric synchronous reluctance motor.
Negli ultimi vent'anni l'interesse per le macchine sincrone a riluttanza è notevolmente cresciuto. Lo sviluppo e la ricerca dedicata a questi motori, supportata dai diversi vantaggi che presentano rispetto ad altri tipi di macchine, ha permesso a questa tipologia di macchina di guadagnarsi uno quota di mercato in diverse applicazioni industriali. I motori a riluttanza offrono una piu alta densità di coppia rispetto ai motori asincroni. Tuttavia, se confrontati con i motori sincroni a magneti permanenti, essi presentano una densità di coppia ed una efficenza minori. Tale decremento delle prestazioni rispetto alle macchine a magneti permanenti è tuttavia compensato dalla complessiva riduzione del costo di costruzione del rotore. In aggiunta, essi presentano una struttura rotorica piu robusta delle macchine sincrone a magneti superficiali e consentono di ottenere un piu ampio range di funzionamento a potenza costante. I principali svantaggi delle macchine sincrone a riluttanza sono il basso fattore di potenza e le elevate oscillazioni di coppia. Il primo svantaggio, correlato alla assenza di alcun sistema di eccitazione sul rotore, viene normalmente mitigato attraverso l'introduzione di magneti permanenti all'interno delle barriere di flusso. Questo tipo di configurazione prende il nome di motore a riluttanza assistita da magnete permanente. Il secondo svantaggio, ossia l'eccessivo torque ripple, è dovuto all'elevato contenuto armonico della forza magnetomotrice che interagisce con l'anisotropia rotorica. Diversi approcci sono stati proposti in letteratura allo scopo di ridurre tali oscillazioni, tra i quali: (a) lo skewing del rotore, (b) barriere rotoriche geometricamente asimmetriche rispetto all'asse interpolare, (c) barriere rotoriche asimmetriche rispetto all'asse polare, (d) equa distribuzione delle barriere lungo la periferia del rotore, e (e) l'ottimizzazione della intera geometria delle barriere. Il grande interesse suscitato negli ultimi anni è dovuto principalmente a due motivi: (i) l'aumento di costo delle terre rare, utilizzate in magneti ad elevato contenuto energetico (NdFeB e SmCo); (ii) la crescente richiesta di macchine ad alta efficienza. Pertanto, il motore a riluttanza e il motore a riluttanza assistito da magneti permanenti stanno diventando concorrenti di entrambe le macchine a magneti permanenti e macchine a asincrone in molte applicazioni. Un altro vantaggio intrinseco delle macchine sincrone a riluttanza è che non inducono tensione a vuoto, quando il rotore è fermo, conseguentemente le correnti di corto circuito e coppie frenanti che si possono creare a causa dei guasti elettrici, sono trascurabili. Per quanto concerne l'aspetto controllistico è doveroso sottolineare il crescente interesse verso le le macchine sicrone a riluttanza. Tale interesse è sostanzialmente giustificato dalla naturale propensione della stessa macchina ad essere controllata senza alcun sensore di velocità. Sebbene vi sia un grande interesse per questo tipo di macchine, ci sono pochi lavori sulla progettazione analitica del loro rotore, ad esempio su come selezionare gli angoli di fine barriera, il dimensionamento dei ponticelli di ferro ed dettagli sulla progettazione robusta nei confronti della smagnetizzazione dei magneti permanenti. Nella maggior parte dei casi la macchina riluttanza viene analizzata mediante analisi agli elementi finiti. I risultati sono precisi e utili per realizzare una geometria specifica, ma si riferiscono ad una particolare soluzione perdendo generalità. In altre parole, è difficile trovare regole generali per progettare macchine a riluttanza. Per colmare questa lacuna, questa tesi si propone di fornire un approccio analitico utile alla determinazione di una geometria preliminare del motore, come punto di partenza per un'ottimizzazione successiva. La progettazione accurata dei ponticelli di ferro del rotore e gli effetti sulla forza elettromagnetica che agisce sul rotore con diversi gradi di eccentricità sono considerati. Questo lavoro di tesi è suddiviso in quattro parti principali. Un modello analitico basato sul circuito magnetico equivalente a parametri concentrati del motore a riluttanza viene presentato e discusso nella prima parte. Questo modello studia il rendimento magnetico del motore sincrono a riluttanza concentrica. Lo stesso modello analitico è utilizzato per lo studio di differenti casi di eccentricità ed il loro impatto sulle prestazioni del motore a riluttanza. Motori a riluttanza con diversi tipi di avvolgimenti statici e diverse geometrie di rotore, simmetriche ed asimmetriche, vengono considerate. Lo stesso metodo viene applicato a motori a riluttanza con magneti permanenti e confrontata con il motore a riluttanza eccentrico. I risultati prodotti dai modelli utilizzati vensono confrontati tramie simulazioni agli elementi finiti. Inoltre, un confronto analitico tra il motore a riluttanza e motore a magneti permanenti superficiali viene condotta in diversi casi di eccentricità. La seconda parte si propone di stimare in modo più accurato le forze elettromagnetiche agenti sul rotore, considerando l'effetto delle cave di statore e la caduta di tensione magnetica dovuta alla effettiva curva B-H del lamierino ferromagnetico. Il modello analitico è indicato per macchine con e senza presenza di eccentricità. Infine, misure sperimentali vengono condotte per validare la bonta' dei modelli analitici ed agli elementi finiti. Nella terza parte, si propone un approccio analitico per la progettazione del motore a riluttanza assistito da magneti permanenti. La larghezza e lo spessore dei magneti sono scelti in modo da realizzare la densità di flusso a vuoto al trafetto desiderata e resistere alla smagnetizzazione che si possono presentare in condizioni di sovraccarico. Infine, un rapido approccio analitico e multi-obiettivo è proposto per la progettazione preliminare di motori a riluttanza e motori a riluttanza assistiti. Nella quarta parte è stata sviluppata un'interfaccia utente grafica per l'analisi del motore a riluttanza. Questa applicazione stima i potenziali scalari magnetici di statore e rotore, la densità di flusso al traferro, la coppia elettromagnetica, la forza magnetica che agisce sul rotore. I parametri di ingresso di questa applicazione sono: - dati geometrici dello statore e del rotore, - carico elettrico (kA / m), e la sua fase (grado elettrico), - il tipo di geometria del rotore, ad esempio, simmetrico o asimmetrico (Macaone), - Numero di barriere di flusso per polo del rotore, - il tipo di eccentricità o nessuna eccentricità, per esempio, il caso con rotore concentrico, - il valore di eccentricità. Perciò, l'utente può usare l'applicazione per stimare le prestazioni della macchina.

This thesis aims to design and develop LSPM motors capable of operating in two distant synchronous speeds with good starting torque and steady state characteristics for variety of industrial applications, in particular offshore and maritime applications. The proposed designs are based on variable pole numbers for the stator and the rotor. The stator winding consist of two independent windings with different pole numbers to switch the winding and change the operating pole count for low and high speed applications. For the motor to operate in these two distinct operating speeds, the rotor must be capable of creating two different magnetic polarities (pole numbers) to adapt itself to the stator operating pole number. For this purpose, two different schemes for the rotor structure are proposed. In scheme I two-speed operation is realized by the combination of electromagnetic torque and reluctance torque which enables the motor to operate as a synchronous PM motor at high speed and synchronous reluctance motor at low speed. In scheme II, rotor with dual PM polarity is proposed which enables the motor to operate as a PM motor at both low and high speed regions.

The Switched Reluctance Motors(SRM) have gained considerable attention in the variable speed drive market mainly due to the simple construction of the motor and the possibility of developing low cost converters and controllers. As these machines are under development, a considerable amount of research effort is directed to the experimental performance evaluation of the SRM drives. System efficiency, electromagnetic torque, torque ripple, output and losses are some of the required measurements.
Master of Science

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.

This dissertation focus on a Maximum Torque per Ampere (MTPA) control scheme for a non-linear synchronous reluctance motor (Sync-Rel). Due to the absence of permanent magnets, Sync-Rel motors have poor torque production capability and relatively low power factor. Therefore, it is important to maximize the torque given the maximum current of the power inverter. In the classical solution to the MTPA control problem, the d-q current components are considered equal. This solution assumes a linear magnetic circuit for the Sync-Rel motor. In practical applications, the Sync-Rel motor has a non-linear magnetic core. As a consequence, the linear solution to the MTPA problem is not the best one anymore. In this dissertation, we model a non-linear Sync-Rel motor using a simplified magnetic model, taking into account the magnetic saturation. Then, we design a non-linear MTPA controller. The Sync-Rel motor drive is simulated, and the performance of both linear and non-linear controller are compared.

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.

The electrification of automobiles has emerged as the sustainable powertrain solutionto meet United Nations sustainable development goals of sustainable cities andcommunities, affordable and clean energy, and climate action. The success of theelectrification depends on the efficiency of traction motors. Hence, the automobileindustry is dedicated to improving the performance of electrical traction machinesfor high performance and sustainability. The thesis aims to build various electricalmachine’s concept designs and quantify their behaviour on sustainability andperformance. The thesis objective is to design Permanent Magnet Synchronous Motor (PMSM),Synchronous Reluctance Motor (SynRM), and Permanent Magnet SynchronousReluctance Motor (PM­SynRM). The thesis work comprises of accurate performanceestimation and optimisation of these electrical machines through a finite element based method. The in­house scripts are developed to estimate the performance, electrical losses, and efficiency of these electrical machines through flexible open-source tools. The performance of PMSM with rare-­earth magnet Neodymium Ferrite Boron(NdFeB) and without rare­-earth magnet (ferrite) is done to evaluate the role of bothmagnets in producing torque density. The SynRM is evaluated and optimized usinggenetic algorithms in the thesis. The electrical machines are designed without the useof rare-­earth magnets to eliminate the degradation of the environment and reduce thecost and weight of the motor.
The electrification of automobiles has emerged as the sustainable powertrain solutionto meet United Nations sustainable development goals of sustainable cities andcommunities, affordable and clean energy, and climate action. The success of theelectrification depends on the efficiency of traction motors. Hence, the automobileindustry is dedicated to improving the performance of electrical traction machinesfor high performance and sustainability. The thesis aims to build various electricalmachine’s concept designs and quantify their behaviour on sustainability andperformance. The thesis objective is to design Permanent Magnet Synchronous Motor (PMSM),Synchronous Reluctance Motor (SynRM), and Permanent Magnet SynchronousReluctance Motor (PM­SynRM). The thesis work comprises of accurate performanceestimation and optimisation of these electrical machines through a finite element based method. The in­house scripts are developed to estimate the performance, electrical losses, and efficiency of these electrical machines through flexible open-source tools. The performance of PMSM with rare-­earth magnet Neodymium Ferrite Boron(NdFeB) and without rare­-earth magnet (ferrite) is done to evaluate the role of bothmagnets in producing torque density. The SynRM is evaluated and optimized usinggenetic algorithms in the thesis. The electrical machines are designed without the useof rare-­earth magnets to eliminate the degradation of the environment and reduce thecost and weight of the motor.   Sammanfattning på svenska / Abstract in Swedish Elektrifieringen av bilar har framstått som en hållbar drivlinelösning för att mötaFörenade Nationernas hållbara utvecklingsmål för hållbara städer och samhällen, medprisvärda och rena energi och klimatåtgärder. Framgången med elektrifieringen berorpå effektivitet på motorer för framdrivningen. Därför är bilindustrin dedikerad tillatt förbättra prestanda för elmotorer för hållbarhet och hög prestanda. Avhandlingensyftar till att bygga olika konceptdesign för elmotorer för framdrivning och kvantifieraderas beteende på hållbarhet och prestanda. Uppsatsmålet är att utforma Permanent Magnet Synchronous Motor (PMSM),Synchronous Reluktance Motor (SynRM) och permanent magnetassisterad SynRM(PM­SynRM). Examensarbetet består av noggrann prestationsuppskattning ochoptimering av dessa elektriska maskiner genom finit element metod (FEM). Deskripten för att hantera FEM för elektormagnetisk design är in­house utveckladeför att uppskatta flexibelt prestanda, elektriska förluster och effektiviteten hos dessaelektriska maskiner genom att använda öppen källkod. Prestanda för PMSM med en sällsynta jordartsmagnet (NdFeB) och PMSM utansällsynta jordartsmagnet (ferrit) räknades fram för att utvärdera båda magneternasroll för att producera vridmomentdensitet. SynRM och PM­SynRM maskinernautvärderas och optimeras med hjälp av genetiska algoritmer i avhandlingen.De studerade elektriska maskinerna är designad utan användning av sällsyntajordartsmagneter för att eliminera miljöförstöring och minska motorns kostnad ochvikt.

Alcune aree definite dall'Unione Europea nel contesto delle smart cities and communities si fondono pienamente con i motori elettrici come, per esempio, l'efficienza energetica, le tecnologie a basse emissioni di carbonio e la mobilità. I motori elettrici sono utilizzati in molteplici applicazioni industriali e non, consumando tra il 43% e il 46% dell'energia elettrica prodotta su scala mondiale.Nonostante alcune applicazioni siano contraddistinte da dinamiche elevate, come manipolatori o macchine utensili, la maggior parte di esse sono caratterizzate da basse dinamiche in quanto facenti parte di processi industriali, per esempio pompe, compressori, ventilatori o nastri trasportatori. Si è stimato che il costo dell'intero ciclo di vita di un motore elettrico è ascrivibile per il 92% - 95% all'energia consumata, il che indurrebbe un tempo di ritorno dall'investimento per installazione di un azionamento elettrico minore di due anni. Nonostante il notevole risparmio economico e ambientale ottenibile, è piuttosto sorprendente apprendere che solo il 10% - 15% di tutti i motori industriali siano controllati da azionamenti elettrici. Per quanto riguarda le diverse tecnologie di motori elettrici, i motori sincroni a riluttanza stanno ricevendo una notevole attenzione sia da ricercatori industriali che accademici. Il crescente interesse è principalmente motivato dalle loro intrinseche caratteristiche quali l'alta efficienza, il basso costo e il basso impatto ambientale dovuto alla mancanza di magneti permanenti. Per di più, le loro caratteristiche soddisfano appieno i requisiti imposti dalle smart cities and communities e sono adatti per tutte le applicazione, caratterizzate da una bassa dinamica, viste sopra. Per questi motivi, questa tecnologia di motori può essere posta al centro dei processi di rinnovamento di quelle applicazioni. Vi è ampio consenso sul potenziale incremento delle vendite sia di azionamenti elettrici che di motori sincroni a riluttanza. I motori sincroni a riluttanza sono soggetti a una marcata saturazione magnetica, rendendo i classici modelli a parametri concentrati poco adatti. La prima parte di questa tesi riguarda lo sviluppo di un innovativo modello magnetico per motori anisotropi. Si basa su una rete neurale non tradizionale, chiamata Radial Basis Function. La sua proprietà locale rende questo tipo di rete neurale particolarmente adatta ad un addestramento durante il normale funzionamento del motore. Si propone una completa procedura di design e addestramento della stessa. In particolare vengono fatte alcune considerazione le quali permettono di definire a priori alcuni parametri della rete neurale rendendo il problema di addestramento lineare. Si descrivono due algoritmi di addestramento, il primo veloce ma computazionalmente dispendioso perciò adatto per un'implementazione offline mentre il secondo idoneo ad un addestramento online. Infine, per concludere l'identificazione parametrica del motore, si propone uno schema basato sull'iniezione di una corrente continua il quale permette di stimare la resistenza di statore indipendentemente da tutti gli altri parametri della macchina. L'indipendenza parametrica permette un notevolmente miglioramento nell'accuratezza di stima del modello magnetico ottenuto con la rete neurale. La seconda parte di questa tesi, invece, tratta il controllo del motore e come sia possibile migliorarne le performance utilizzando il modello identificato. Innanzitutto, per incrementarne l'efficienza si presenta un innovativo metodo per trovare la curva a massima coppia per corrente. La tecnica proposta lavora in stretta simbiosi con l'identificazione del modello magnetico in quanto è in grado di capire dove si trova la curva cercata rispetto all'attuale punto di lavoro sfruttando la stima locale dei flussi magnetici. Identificata la direzione di movimento, l'azionamento continuamente muove il punto di lavoro coerentemente. Infine, si propongono tre diversi controlli di corrente pensati per gestire un motore fortemente non lineare, tutti basati sul modello stimato. Il primo è un controllore proporzionale-integrale nel quale i parametri vengono modificati al variare del punto di lavoro con lo scopo di mantenere la dinamica della corrente di motore costante. Il secondo è anch'esso basato su un controllore proporzionale-integrale ma a guadagni costanti accoppiato ad un'azione di feed--forward la quale compensa tutte le non linearità presenti nella mappa magnetica. Infine, il terzo è un controllo predittivo il quale determina direttamente la posizione degli switch tali per cui la funzione di costo è minimizzata. All'interno del controllo, è inserito un vincolo sulla corrente massima e si utilizza un particolare algoritmo per ottenere un lungo orizzonte di predizione. Tutti i metodi presentati nella tesi sono stata verificati attraverso dettagliate simulazioni e prove sperimentali, eccezione fatta per il controllo predittivo il quale è stato testato attraverso simulazioni.
Smart cities and communities are conjugated by European Union in different areas, including energy efficiency, low carbon technologies and mobility which are deeply merged with electric motors. Electric machines are ubiquitous in industry for a wide range of applications, consuming between 43% and 46% of all electricity that is generated in the world. Although some machines are used for high-performance applications, such as robots and machine tools, the majority are used in industrial processes for pumps, compressors, fans, conveyors, and other slower-dynamic applications. It is estimated that 92% - 95% of the life cycle costs of electric motors are associated with the energy they consume, leading to typical payback periods of < 2 years for the installation of an adjustable-speed drive. It is rather surprising to learn that, despite overwhelming evidence of the attainable savings, only 10% - 15% of all industrial motors presently use electronic adjustable speed drives. On the motor side, Synchronous Reluctance (SynR) motors are gaining lots of attention from industrial researchers and academics, due to their inherent characteristics like the high efficiency, the low cost and the low environmental footprint. Their characteristics fully meet the requirements imposed by smart cities and communities and the aforementioned low-dynamics applications, so they could be the heart of the revamping of those plants. There is wide agreement that the potential for future growth in the sales of industrial drives and SynR motors is still very substantial. SynR motors are prone to magnetic saturation, making the classic model with lumped parameters unsuitable. The main part of this thesis concerns the development of a new magnetic model for anisotropic motors, especially for SynR motors. It is based on a special kind of neural network (NN), called Radial Bases Function (RBF) NN, which is particularly advisable for an online updating due to its local property. A complete training procedure is proposed in which some considerations are done to define several NN parameters and to convert the nonlinear training problem into a linear one. Two different training algorithms are presented, the former one is fast but computationally cumbersome then suitable for an offline training while the latter one is lighter then proper for an online training. In order to complete the online parameters identification, a scheme based on a DC current injection is developed to estimate the stator resistance. An exhaustive analysis is carried out to disclose that the proposed method is independent from other motor parameters which is a strength asset in a saturable motor. An accurate stator resistance value improves in turn of the magnetic model. The second part of this dissertation deals with how to exploit an accurate magnetic model to enhance the motor control. In order to improve the efficiency of the motor, exploiting the RBF NN model and the online training algorithm, the Maximum Torque per Ampere (MTPA) curve is found. Starting from a blank NN, it is continuously online trained and a proper algorithm understands where the MTPA curve is respect to the current working point. Afterwards, the drive moves itself towards the actual MTPA. Finally, three different current control schemes tailored for anisotropic motors are presented, all based on the available NN-based magnetic model. The first one is a gain-scheduling PI control where the control gains are accordingly tuned to the working point to keep constant the control bandwidth. The second one is based on a classical PI regulator with a FF action to compensate for all the nonlinearity of magnetic maps. The third one is a constrained direct Model Predictive Control (MPC) where a long prediction horizon is achieved. In order to accomplish a long prediction horizon, the Sphere Decoding Algorithm is properly modified to make it suitable for a nonlinear system. The whole thesis was fully validated through an intensive simulation and experimental stage, except the long--horizon MPC which was tested only by simulation.

Du fait de sa robustesse et de son faible coût, la machine synchro-réluctante (MSR) constitue une alternative intéressante à la machine asynchrone. A pertes égales, une MSR bien optimisée offre un couple et par suite un rendement plus élevés. Ainsi, la MSR est très compétitive pour les applications à haute vitesse, à forte puissance ou à haute température. Cette thèse se propose d’optimiser les machines synchro-réluctantes à rotor massif et avec barrières de flux pour produire le maximum de couple avec un facteur de puissance le plus élevé possible. Pour cela, une modélisation originale utilisant des réseaux de perméances non linéaires a été mise au point pour les deux types de MSR. Les modèles proposés sont significativement plus rapides et aussi précis que les modèles par éléments finis. De plus, la réalisation d’un prototype à barrières de flux a permis de les valider expérimentalement
Because of its robustness and its low cost, the synchronous reluctance motor (SynRM) is an interesting alternative to the induction motor. At equal losses, a correctly optimized SynRM offers a higher torque and then a higher efficiency. Thus, the SynRM is very comptetitive for high speed, high power or high temperature applications. This thesis intends to optimize massive rotor and flux barrier rotor SynRM to produce the maximum torque with the highest possible power factor. For this purpose, an original non linear reluctance network modeling of synchronous reluctance motors with a massive or a flux barrier rotor was developed. The proposed models are significantly faster than the finite element ones and take accurately into account the saturation of all ferromagnetic parts of the motor. The construction of a flux barrier rotor prototype allowed an experimental validation of the modeling approach

This theses is related to design of synchronous reluctance motors of the transverse-laminated type. The first part describes synchronous reluctance machine via space-vector theory. Furthermore this part briefly discuss the main design aspects of synchronous reluctance machines. The main part of this thesis is related to practical electromagnetic rotor design for synchronous reluctance machine by means of finite element method. On this base the rotor has been fabricated and placed inside of induction motor instead of his original rotor. On this prototype was made several measurements which were compared with results from finite element method analysis. The last part of this theses is related to short study of synchronous reluctance machine dynamical behaviour under scalar and vector control.

This thesis deals with the analysis, design and test of three-phase high efficiency electrical motors, with particular reference to motors with a rotor winding. At first, the background and the motivations of this work are described. The bibliography on the subjects is deeply examined and a selection of the most relevant papers can be found in the reference. In this scenario, the main objective of this thesis are illustrated. The Line-Start (LS) Synchronous Machine (SyM) design is a subject under investigation since the beginning of the last century, when solid state power converters was not available to drive SyMs. The LS SyM diffusion was limited by the intrinsic difficulties in its design and by the availability of the cheaper and more robust Induction Machine (IM). The working principle of IM and LS SyM are briefly described, as well as the state of the art of the techniques of analysis. Recently, there is a renewed interest on LS SyMs due to the new efficiency requirements and fast analysis techniques are required for the LS SyM design. A Finite-Element (FE) aided analytical model is developed to simulate the LS SyM dynamic. The aim is to develop a model that gives reliable solutions with limited computational efforts compared with other analysis techniques. With this procedure, the LS SyM rotor parameters can be quickly calibrated to fulfill the dynamic load requirements. An innovative analysis technique of LS SyM steady state condition is described. Such an analysis is carried out in the same reference frame used for classical SyMs. It is shown that the analysis can be used to optimize some machine parameters. The issues in LS SyM manufacturing are introduced, with particular reference to the die casting process. The possibility to apply the recent improvements in the SRM design to LS SyM is discussed from the manufacturing point of view. Stochastic optimization has been adopted for the design of electrical motors to reduce the torque ripple, increase the average torque and reduce the losses. The LS SyM torque ripple reduction, achieving at the same time a high average torque, is an important issue even though this topic is not treated extensively in the literature for LS SyM. For this reason, a stochastic optimization is considered in this thesis for the design of a new LS SyM lamination. The analysis is applied on a small size, 2-pole, three-phase LS SyM as this category is still not found in the motor market. The optimization is carried out considering the necessity to achieve a robust design, suitable for the industrial production, as such a LS SyM must be competitive with the workhorse of electrical motors, the IM. One of the most promising design is prototyped. Its performance are compared with the corresponding IM. To demonstrate the feasibility in adopting LS SyM in the large-scale production, an innovative LS SyM design is proposed. The main aim is to use the same lamination for motors of different number of poles so as to reduce the manufacturing cost. A tradeoff between contrasting aspects is necessary in the design step. The performance achievable by these rotor structures are quantified. An analytical model that describes the mutual interaction between coupled electrical circuits in machines with complex rotor structure is developed. Such a model is useful to analyze the parasitic torques in the torque characteristic of motors with rotor cage such as IM and LS SyM. The literature reveals that this topic has been discussed extensively for IM. As regards LS SyM, there is a lack of theoretical studies regarding harmonic phenomena due to the complex machine structure. This part of the thesis aims to fill this gap. The high and unstable cost of rare-earth PMs, together with the advances in solid-state control technology, leads designers to reconsider IM for variable speed drive (VSD) applications. To the aim of making the IM suitable for the full-speed sensorless control, a particular cage design is considered. An intentionally created saliency is introduced in the rotor so as to allow the rotor position to be estimated by means of a high frequency (HF) injected signal in the stator winding also at zero-speed. Different experimental tests are carried out on IMs with asymmetrical rotor cage to validate the analysis techniques and quantify the achievable performance. As far as the HF signal injection sensorless technique is concerned, the cross-saturation differential inductance of SyMs represents an issue. It causes a rotor position estimation error, reducing the region in which such technique is effective. The proper-ties of the cross-saturation inductance are deeply discussed. It is originally shown that the cross-saturation inductance depends from certain machine parameters. With such an analysis, a designer can consider the effect of the cross-saturation inductance in any model-based control algorithm. A rotor winding is added in Surface-mounted permanent-magnet machine (SPM) to create a HF anisotropy that is useful to detect the rotor position by means of a HF signal injection. Such a configuration is called ”ringed-pole”. In literature, this technique has been used on small-size machines. In certain configuration, the presence of the additional rotor winding causes significant rotor losses. This part of the thesis studies the rotor losses in ringed pole machines by means of FE analysis and analytical models. The aim is to investigate if the ringed-pole technique can be adopted also for large machines from the point of view of additional losses. With few exceptions, the work described in this thesis is always supported by means of experimental measurements. Dedicated experiments has been designed. Their results are compared with those achieved with analytical models or FE analysis.
Questo lavoro di tesi è incentrato sull’analisi, la progettazione e la prototipazione di macchine elettriche trifase ad alto rendimento, con particolare riferimento a motori dotati di avvolgimenti rotorici. Inizialmente si descrivono le motivazioni di questo lavori di tesi e il contesto in cui essa si inserisce, illustrandone i principali obiettivi. Una dettagliata analisi bibliografica è alla base del lavoro svolto. Una selezione di questi lavori si trova nelle referenze. I motori sincroni autoavvianti (LS SyM) sono stati introdotti nella prima metà del novecento e la loro progettazione è soggetto di ricerca sin da allora. Essi non si sono mai affermati a causa della loro difficile progettazione e per la disponibilità del più robusto ed economico motore ad induzione (IM). Dopo aver descritto il principio di funzionamento di IM e LS SyM, se ne illustrano le tecniche di analisi sviluppate fino al giorno d’oggi. Negli ultimi anni vi è un rinnovato interesse verso i LS SyM grazie agli stringenti requisiti di rendimento. Vi è quindi la necessità di tecniche di progettazione veloci ed affidabili per LS SyM. I risultati di simulazioni agli elementi finiti sono stati combinati a modelli analitici per descrivere la complessa dinamica di LS SyM. L’obiettivo è quello di ottenere una risposta sufficientemente precisa in tempi molto più brevi rispetto ad altre tecniche di analisi. In questo modo si rende possibile una rapida e precisa calibrazione dei parametri rotorici necessari per soddisfare determinati requisiti di carico dinamico. Parte di questa tesi è dedicata allo sviluppo di una tecnica di analisi per LS SyM in condizioni di regime. Tale analisi `e condotta nello stesso sistema di riferimento usato nei classici modelli per macchine sincrone non autoavvianti. Si mostra che l’analisi proposta permette anche di ottimizzare alcuni parametri di macchina. Negli ultimi anni vi sono stati numerosi sviluppi nella progettazione di macchine sincrone a riluttanza, con o senza l’assistenza di magneti permanenti. In questa tesi si è voluto investigare sulla possibilità di applicare tali sviluppi ai LS SyM, tenendo in considerazione i vincoli costruttivi legati alla presenza della gabbia rotorica. Lo scopo è quello di ridurre il volume di magneti permanenti utilizzati per contenere i costi di produzione. Si è affrontato il problema dell’industrializzazione dei LS SyM, con particolare riferimento al processo di pressofusione del rotore. Nell’intento di ridurre il ripple di coppia, incrementare la coppia media e ridurre le perdite dei motori elettrici, recenti lavori propongono l’utilizzo di algoritmi di ottimizzazione stocastica nella fase di progettazione. I suddetti obiettivi sono basilari anche per LS SyM, anche se per questo tipo di motori la letteratura è meno fornita. Per questo motivo si è voluto utilizzare un algoritmo di ottimizzazione nella fase di progettazione della lamiera di un LS SyM. L’analisi è applicata ad un LS SyM trifase a 2 poli di piccola taglia, dato che ancora non si trovano nei cataloghi dei principali costruttori. L’ottimizzazione è sviluppata considerando la necessità di ottenere un progetto robusto e comunque adatto alla produzione industriale, dato che tale LS SyM deve essere competitivo con l’ormai consolidato IM. Una promettente struttura rotorica è stata prototipata. Le prestazioni ottenute sono confrontate con quelle del corrispondente IM. Si è proposta un innovativa configurazione di LS SyM per dimostrare la fattibilità del loro utilizzo su scala industriale. Lo scopo è quello di utilizzare la stessa lamiera per motori con un diverso numero di poli, riducendo di conseguenza il costo di produzione. Per fare ciò è necessario un compromesso tra aspetti contrastanti nel progetto. In questa parte di tesi, si è voluto quantificare le prestazioni ottenibili da tali geometrie nelle diverse configurazioni. In questa tesi si è sviluppato un modello analitico per caratterizzare l’interazione di circuiti elettrici accoppiati in strutture complesse quali quelle dei LS SyM. Questa analisi mira ad essere uno strumento per la determinazione analitica delle coppie parassite in motori dotati di gabbia rotorica come LS SyM e IM. La letteratura riporta un gran numero di lavori riguardanti la descrizione di coppie parassite nella caratteristica di coppia di motori IM. In LS SyM, l’analisi delle coppie parassite è molto più complessa a causa della struttura di macchina. In letteratura, gli studi analitici riguardanti gli effetti di armoniche di MMF in motori LS SyM sono pochi ed incompleti. L’elevato ed instabile prezzo dei magneti permanenti, assieme allo straordinario sviluppo dell’elettronica allo stato solido, ha spinto a riconsiderare il motore ad induzione per applicazioni a velocità variabile. In questo scenario, si è considerato un avvolgimento rotorico a gabbia di scoiattolo in cui i conduttori sono asimmetrici. Tale asimmetria permette il riconoscimento sensorless della posizione rotorica tramite iniezione di segnali ad alta frequenza negli avvolgimenti di statore anche a velocità molto basse. Sono stati condotti test sperimentali su prototipi di IM con gabbia asimmetrica allo scopo di verificare le tecniche di analisi e di quantificare le prestazioni ottenibili da tali geometrie. Proseguendo l’analisi delle problematiche riscontrate in controlli di tipo sensorless con iniezione di segnale, si sono approfondite le proprietà della mutua induttanza differenziale causata dal fenomeno della saturazione incrociata tra asse d e q in macchine sincrone. Essa causa un errore nella stima della posizione rotorica, riducendo di fatto l’applicabilità del controllo sensorless con iniezione di segnale. Dopo aver discusso in dettaglio le propriet`a di tale induttanza, si `e dimostrato che essa dipende da alcuni parametri di macchina. Con i risultati ottenuti, può essere intrapresa una serie di accorgimenti nel controllo della macchina volta a mitigare l’effetto negativo dell’induttanza mutua dovuta alla saturazione incrociata. Uno o più avvolgimenti rotorici possono essere introdotti anche in motori sincroni a magneti permanenti superficiali, allo scopo di estendere l’applicabilità del controllo sensorless con iniezione di segnale anche a questo tipo di motori. In questo tipo di macchine, denominate ”ringed-pole”, tali avvolgimenti rotorici possono essere sede di perdite importanti nel funzionamento a regime. In letteratura, questa tecnologia è stata applicata a motori di piccola taglia. In questo contesto, si sono studiate le perdite rotoriche di macchine ”ringed-pole” tramite analisi agli elementi finiti e modelli analitici. Lo scopo è quello di verificare se l’uso di tale tecnologia può essere esteso a macchine di taglia superiore dal punto di vista delle perdite rotoriche. Con poche eccezioni, gli argomenti di questa tesi sono validati tramite misure sperimentali. I risultati delle prove sperimentali sono confrontati con quelli provenienti da modelli analitici o da analisi agli elementi finiti.

The stacked polyphase bridges (SPB) converter topology is investigated in the presentthesis as a fault-tolerant choice for permanent-magnet synchronous reluctance (PMSyn-Rel) motor control. Integrated motor drive systems are studied as they offer great benefitsfor propulsion applications. Moreover, the importance of a modular topology, like theSPB, for an electric powertrain is discussed. The latter consists of a number of seriesconnected, 3-phase 2-level inverter submodules that supply separate sets of windings ina multi-star motor. The specifications of building a four-board SPB setup are examined,while the challenges of an active voltage balancing controller are analyzed. The designprocess is explained step-by-step and the final printed circuit boards (PCBs) are presented.Furthermore, the significance of low electromagnetic interference design for a converterthat requires high speed communication is highlighted. Finally, the prototype is testedthoroughly and the expected fault-tolerant capabilities are validated on a PMSynRel motor.
I detta examensarbete unders¨ok SPB-omriktartopologin (stacked polyphase bridges converter)i termer av ett feltolerant elektriskt drivsystem f¨or en permamentmagnetassisteradsynkron reluktansmaskin (PMSynRel). SPB-omriktaren best°ar av ett antal seriekoppladetrefasomriktare av tv°aniv°atyp som, var och en, f¨orser effekt till en trefaslindningtillh¨orande en modul¨ar elmaskin av multifastyp. Specifikation, design och konstruktion aven SPB-omriktare med fyra seriekopplade moduler studeras. Designproceduren presenterasi en steg-f¨or-steg-process och de tillverkade kretskorten presenteras utf¨orligt. Kommunikationenmellan de olika kretskorten unders¨oks med s¨arskild tonvikt p°a l°ag elektromagnetiskinterferens vilket ¨ar n¨odv¨andigt om h¨og kommunikationshastighet skall kunnauppn°as. Den f¨ardigst¨allda prototypen har utv¨arderats experimentellt och kapaciteten f¨orfeltolerans har demonstrerats vid drift av en PMSynRel-maskin utrustad med en multifaslindning.

Automotive applications focus to develop drive-train technologies with higher energy efficiency and lower environmental impact. Electric and hybrid vehicles are gaining popularity since they fulfill these requirements . The aim of optimal motor design is to achieve high torque and power densities, wider speed range and high efficiency within the area defining the most frequent operating points. This work presents a methodology to optimize electric motors for traction applications considering a multi-physics approach. The magnetic behavior is evaluated using a complex reluctance networks capable to compute the cross-coupling. The results of the magnetic model are the inductances, iron losses, and magnet flux linkage. The thermal behavior is evaluated using a thermal network and it is coupled with the magnetic model. The electric model is feed with the solution of the thermal and magnetic model. The electric model aims to calculate the whole operating area of the motor to allow optimizing the machine considering the most frequent operating zone. Therefore, a fast tool to evaluate different variables within the torque-speed map is convenient for this purpose. In this context, starting from a preliminary motor design, and taking into account motor cross-coupling effects and power losses, this thesis presents a new methodology for optimizing and evaluating the behavior of permanent magnet machines, such as synchronous reluctance machines, and permanent magnet assisted synchronous reluctance machines, in all operational points. Apart from the torque and efficiency, many other electrical variables can be obtained, such as the current space vector angle, power factor or electrical power among others. The proposed methodology also allows optimizing the design of the machine under a pre­established control law; thus obtaining the current set point trajectory in the dq frame and allowing a fast and accurate evaluation of motor performance.The results obtained by means of the proposed simulation tool are compared against finite element analysis simulations and experimental data, thus validating the usefulness and accuracy of the proposed methodology.
El sector de la automoción se está centrando en las tecnologías con alta eficiencia y un bajo impacto medioambiental. En este sentido el desarrollo de vehiculos eléctricos o hibridos está ganando importancia en este sector. Por lo tanto, el diseño de motores eléctricos que cumplan las especificaciones necesarias para aplicaciones de tracción eléctrica es un punto de especial interés . El principal objetivo en la optimización de motores eléctricos es conseguir altas densidades de par o potencia, alta eficiencia y un buen factor de potencia, teniendo en cuenta la zona de trabajo más común. Este trabajo presenta una metodologia para optimización de motores eléctricos, concretamente motores de reluctancia síncrona, para aplicaciones de tracción eléctrica. Para ello es necesario crear diferentes modelos para evaluar el comportamiento eléctrico, térmico y magnético del motor así como calcular los diferentes puntos de trabajo. El modelo magnético, que está basado en redes de reluctancia, permite calcular las inductancias, el flujo magnético del imán y las pérdidas en el hierro teniendo en cuenta la saturación cruzada. El modelo térmico estará basado en redes térmicas y permite evaluar la temperatura de diferentes partes del motor (dientes, bobinado, cabezas de bobina o imanes) para evaluar la viabilidad de estos motores y definir bien el valor de algunos parámetros como la resistencia del bobinado y las propiedades magnéticas del imán. El modelo eléctrico está basado en la resolución de las ecuaciones completas del motor en los ejes dq, los parámetros necesarios (inductancias, resistencia, perdidas en el hierro, flujo del imán) serán obtenidos en los modelos magnético y térmico. En este punto, la metodología propuesta es capaz de calcular todos los puntos de operación de la máquina. Hay que remarcar que en este punto se puede calcular la eficiencia, factor de potencia, ángulo de corriente. La tesis propuesta empezará el proceso diseño optimizado del motor calculando un pre-diseño para introducirlo en un optimizador que usará los mapas calculados para evaluar su función de coste teniendo en cuenta que estos mapas estarán obtenidos considerando saturación cruzada, perdidas en el hierro y variaciones de temperatura, se puede afirmar que el motor resultante está evaluado en todos sus dominios exceptuando el mecánico. Para el análisis mecánico se propone un estudio en elementos finitos posterior a la optimización. En este análisis se podrán introducir estructuras que mejoren la resistencia mecánica del motor y que serán restricciones para una nueva optimización. Una vez cerrado el proceso iterativo entre optimización y análisis mecánico se tendria el motor final. En la tesis propuesta se usa esta metodologia para diseñar varios motores, con lo cual se permite la validación de la misma.

碩士
明志科技大學
電機工程研究所
101
This paper discusses the control of synchronous reluctance motor. This paper first introduces synchronous reluctance motor structure, characteristics and mathematical models. An optimum excited angle of the stator phase current is found. Using LabVIEW software package, a synchronous reluctance motor drive system is controlled. For synchronous reluctance motor operating environment, use the fuzzy speed control to three-phase current commands to adjust the relevant parameters of the controller in real-time, the speed response of the controlled drive system can be effectively improved. This control method can be successfully applied to the speed control system. In addition to verify the feasibility of the control method in this article, the implementation of a synchronous reluctance motor speed control system was accomplished. The system uses a 64-bit digital signal processor NI SBRIO-9631 as the core to control of three-phase current and torque angle and fuzzy speed control. Experimental results show that the proposed method is feasible.

碩士
國立臺北科技大學
電機工程系電力電子產業研發碩士專班
103
ABSTRACT Title: Anaiysis and Control of Synchronous Reluctance Motor School: National Taipei University of Technology Page :63 Department: Electrical Engineering Time: 2015 Degree : Master Researcher: Yi-Xiang Lin Advisor : Ming-Shi Huang Keywords: Synchronous reluctance motor, Torque ripple, Maximal torque per ampere In order to improve the efficiency of electric motors, the EU has asked motors to comply with IE3 standard in recent year. Since the Synchronous Reluctance Motor (SynRM) which has several merits such as low-cost, witnout current and magnet in rotor, high output torque in low speed and efficiency already met the standards IE3 and IE4, SynRM have been gradually accepted by markets. Due to both the output torque influenced by magnetic saturation and some limitations caused by position sensorless control, the SynRM is still limited to use in slow load variation filed, such as fan and pump. The disadvantages of position sensorless control may include weak standstill torque, poor low speed operation, and insufficient speed bandwidth. In recent years, the falleiy sharply price of rotor position sensor, integrated motor and drive design encourage SynRM to expand the application fields The main purpose of this research is to develop the control strategies which may provide fast response and stable speed control for the SynRM using encoder. To accomplish this objective, the governed equations are derived and parameters measured method is proposed for SynRM Finally, a DSP-based (TI TMS320F28035) motor drive is built to implement the proposed control strategies and validate the functions.Finally, the electric parameters, steady and transient characteristics of a SynRM and its drives made by ABB are tested for future research reference.

碩士
國立中央大學
電機工程學系
86
In this paper, A high sensitivity torque control method is proposed. The new method can produce maximum rotating magnetic field in the space every time and possesses fastest torque response ability. It is suitable for large-speed-varied field.In order to prove that the new torque control method has quick torque response ability, we compare it with the other two used torque control methods ( Maximum Torque Control, Field Oriented Control ). The PI controller is adopted as speed controller. The theory is proposed first, then the simulation is given. The experimental results confirm the validity of the proposed new torque control technique the last.

碩士
國立雲林科技大學
電機工程技術研究所
87
The synchronous reluctance motor has the simple structure, easy controllability, no slip and rotor without permanent magnets which has the advantages both of induction motor and brushless motor. Under the rising growth of power electron and powerful calculation of microprocessors, the AC motors have increasingly disentangled from the conventional analog controller, and develop toward the half-digital or full-digital controller. The high performance rotor oriented vector control of the synchronous machine requires an accurate knowledge of rotor position to convert the measurable stator quantities into their rotating frame equivalents. The position information is traditionally optical encoders or magnetic resolvers. It makes the synchronous machines more expensive and less mechanically robust. In this thesis a DSP based sensorless closed-loop speed control for the synchronous reluctance motor is presented. The space vector pulse width modulation method is applied. The system is based on a TMS320C31 DSP for control calculator unit and a TMS320P14 DSP for space vector pulse width modulation calculator unit. For improving the synchronous reluctance motor low torque flaw, we adopt the maximum torque strategy. For sensorless control, a base speed range of 90-200 rad/sec has been achieved.

碩士
國立成功大學
電機工程研究所
83
Under the guidance of developing technology of , the control method of AC motors has gradually discarded the drawbacks of conventional analog controller, and developes toward half- digital or full-digital controller. Due to the special characteristics of its simple and sturdy structure, needlessness of permanent magnents, high efficiency, and easy controllability, the synchronous reluctance motors possess the potential to become a new actuator. Thus, this dissertation investigates a DSP-Based full-digital speed regulated system of synchronous reluctance motors. First, the operation principles, structures, and applied occasions of reluctance motors are introduced. Secondly, the control methods of the constant current angle and constant current in inductive axis are deduced by means of mathematic models. And then, the dissertation analyzes the differences between the above two control methods, and employs H-infinity control theorem to design the speed controller. Finally, it proposes a principle of the digitalized PWM generation and the developed VSI to achieve the purpose of full-digital speed control.

碩士
國立雲林科技大學
電機工程系
103
This thesis presented a Complementary Sliding Mode Control (CSMC) on Synchronous Reluctance Motor (SynRM), which is implemented on two different process structures, the DS114 control board and MCU PIC30F4011. Traditional sliding mode control (SMC) is robust for parameters variations and external disturbance. SMC could have different responses if we choose different sliding surfaces. Two different sliding surfaces are chosen as the path of tracking error in CSMC. This method has excellent robustness and fast responses. This theory was proved by the experimental results. Many control theories were implemented on a high cost controller like DS1104 control board that caused those theories couldn’t be popularized. In this thesis, we implemented the ac motor control and complementary sliding mode control by a low cost PIC30F4011 microchip. In addition, this thesis was implemented the IGBT module’s driver circuit and the intelligent power module circuit for motor control.

碩士
國立成功大學
電機工程學系
104
The Bureau of Energy, Ministry of Economic Affairs indicated that industrial electricity reached 55% of the overall electricity consumption, and motors used 70% of industrial electricity. Moreover, it’s about 48.8% of low voltage motors been used in fans and pumps. Most of pumps use single phase induction motors (IM); however, in the trend of pursuing higher efficiency motors and energy standards, single phase IMs with the second side copper loss have lower efficiency compared with other kinds of motors. Hence, a single-phase IM with synchronous reluctance motor’s (SynRM) flux barriers structure is proposed in this study, namely the line start synchronous reluctance motors (LSSynRM), which is capable to overcome speed reduction while load is added. The proposed design isn’t only able to maintain high synchronous speed with high flow for pumps, but also can reduce the second side copper loss. Further, LSSynRM maintains the capability in high efficiency range. A prototype of LSSynRM has been constructed, and the experimental result is compared to FEM simulation to verify the line-start ability and fix-speed ability.

碩士
國立宜蘭大學
機械與機電工程學系碩士班
100
The squirrel-cage induction motor (IM) accompanied with a general-purpose variable-voltage variable-frequency (VVVF) inverter has been widely used for various variable speed applications. The popular IM is knows as rugged, cost-effective, and easy to obtain; however, the efficiency of an IM is decreased when it is driven by a general purpose inverter. Besides, the rated torque is not easy to maintain especially in low speed operation. In order to improve the efficiency, output power, and low speed performance of widely used inverter-driven IMs, this paper presents a comparative study between the squirrel-cage IM and reluctance synchronous motor (RSM) applied to an one-horsepower variable-speed blower. The experimental results reveal that the power density and efficiency of the RSM is clearly higher than the squirrel-cage IM based on the same stator. Furthermore, the cost-effective sinusoidal commutation accompanied with low resolution Hall effect sensors can provide satisfactory performance to drive the potential RSMs. From the points of view of cost, efficiency and power density, the emerging RSM can be very competitive for general-purpose variable speed applications compared with other AC machines if the cost of rare-earth materials remains high and sources are unreliable.

碩士
明新科技大學
電機工程系碩士班
107
Synchronous reluctance motor is the main axis of this thesis. Using Synchronous Reluctance Motor (Synchronous Reluctance Motor, SynRM) vector control, SynRM can get faster response and reduce system response time, optimize its performance and improve energy efficiency. Firstly, the mathematical model of SynRM and each control module is constructed in PSIM, and the mathematical model is used to simulate and verify the feasibility and correctness. And in line with the needs of the hardware, the idea of the implementation can be presented in reality to prove the correctness of the system design. The motor control can be divided into current control of the inner loop and speed/position control of the outer loop. The current control is to set the stator current to the q-axis position, and the rotor magnetic field direction is set to the d-axis position. The speed/position control is to drive the encoder of the permanent magnet synchronous motor by the synchronous reluctance motor to obtain the motor. The rotor position is controlled by the rotor magnetic field, which is the design of the vector controller. The system control core of the vector controller of this paper is designed with the digital signal processor eZdsp TMS320F28335. The designed system includes coordinate transformation, d, q two-axis current control and outer loop rotation/position control of the inner loop. The method proposed in this paper is simple and suitable for practical drive control design.

博士
國立中央大學
電機工程研究所
89
This dissertation analyzes the torque sensitivity and proposes high performance position and speed control methods of synchronous reluctance motors (SynRM). Four torque control methods, based on different objects such as maximizing the torque/ampere ratio and the power factor, are generally used for a cageless SynRM. However, the torque production of a SynRM with cage rotor is not the same as that of a cageless SynRM. The difference between them is the transient torque, which exists in the cage rotor when it is not synchronous with the stator flux. This dissertation firstly analyzes the transient torque through the sensitivity function. Secondly, a new totally invariant state feedback controller is proposed to enhance the robustness of SynRM drive systems by combining the classical state feedback controller and the variable structure control (VSC). The combination of these two different control methods has both their merits: a) the easy design of the state feedback and b) the strong robustness of the VSC. In other words, the system performance can be directly designed for the nominal system by using the well-known classical state feedback, such as the pole placement or the linear quadratic method. Then, VSC is used to ensure the control effect. To demonstrate the effectiveness of totally invariant state feedback controller, it is applied to the position control of a SynRM. Also, totally invariant state feedback is applied to optimal control problem to guarantee the performance designed by LQ method. Moreover, this dissertation proposes multi-segment sliding mode control to solve a particular incremental motion control problem specified by a trapezoidal velocity profile. Each segment of the multi-segment switching surfaces is designed to match the corresponding part of the trapezoidal velocity profile, so that the motor dynamics on the specified-segment switching surface have the desired velocity or acceleration corresponding to the trapezoidal profile. The synchronous reluctance motor system is used to demonstrate the effectiveness of the multi-segment sliding mode control. Finally, a PC-based experimental SynRM system is built to demonstrate all the proposed algorithms.

碩士
國立臺灣科技大學
電機工程研究所
82
This thesis proposes a DSP based, fully digital control synchronous-motor-drive system. A new control algorithm is developed to improve the chattering of the motor speed, which is produced by sliding mode controller. In addition, the new algorithm can provide a fast response and robust servo system. First, the construction, characteristics, and modeling of the motor are studied. Then, the vector control strategies with their torque characteristics are explained. Next, a fuzzy- sliding mode controller is derived. The slope of the sliding line is on-line adjusted by the fuzzy controller. The proposed method in the thesis can not only obtain a better performance than sliding mode controller, but also achieve a better load disturbance than the traditional PI controller.This paper uses only a DSP to execute current-loop control, speed-loop control, and d-q to a-b-c axis transformation. Moreover, the switching frequency can achieve as high as 20 KHz. The experimental results show that the proposed system can achieve a wide speed range, a good transient response and a good steady-state characteristics. Experimental results and computer simulation validate theoretical analysis. This thesis provides a new direction to design a synchronous reluctance motor drive system.

碩士
國立雲林科技大學
電機工程系碩士班
97
This thesis presents the research of chaotic phenomenon for the synchronous reluctance motor. Chaotic phenomenon looks like confused but it is regular. Chaotic phenomenon happens due to nonlinear characteristic of the systems. System parameters and initial value variations cause the output dramatically. Dissimilar system need not cause chaotic phenomenon in the same method because every motor’s parameters are different.. We establish the synchronous reluctance motor chaos model, the equilibrium points and characteristic equation by motor model. We utilize the Routh-Hurwitz stability criterion to obtain speed controller parameters. The initial value is determined by Lyapunov exponent to decide the chaotic phenomenon. We simulate it by using Matlab/Simulink software.The proposed method is implemented by using DS1104 processor board. Simulation and experiment results show that the proposed theory is correct.

博士
國立雲林科技大學
工程科技研究所
104
In this thesis, a procedure is proposed wearable device health care platform development including synchronous reluctance motor (SynRM) control. The wearable device consists wireless Bluetooth and optics Oximeter spec which monitors user heart rate and oxygen data to any Bluetooth receiver. We used health care wearable device with SynRM to design the breathing assistance system. Firstly, we used the mathematical model equation of SynRM and maximum torque control algorithm to control motor command current. Secondly, we proposed robust compensation with adaptive fuzzy Hermite neural network controller and reference model adaptive Hermiter neural network controller which estimated motor mathematical state and system lumped uncertainty to improve motor nonlinear dynamic online. We used a microcontroller of MSP430 to implement the wearable device system that included Oximeter, memory LCD, Bluetooth Low Energy (BLE) and power bank. The MSP430 is ultra low power consumption than other microcontroller in system standby mode. SynRM system supplies suitable body oxygen rate when user oxygen rate is unsatisfactory. The experimental results show wearable device to calculate oxygen rate in real time, and has satisfactory speed output responses according to the data transmitted from wearable device.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1994.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 250-267).

碩士
國立雲林科技大學
電機工程系
104
In this thesis, we propose wearable device to apply in health care system. Synchronous reluctance motor(SynRM) uses speed predictive algorithm to drive oxygen supply system which provides user proper oxygen. Wearable device uses MSP430 low power consumption chip to achieve long time use. Oxygen rate is an important index of health. Long-term oxygen rate surveillance makes medical staff to know the user’s health conditions. Medical staffs know the user healthy or not by user’s physiological parameters of wearable device. This wearable system provides user a better medical care. The oximeter is a non-invading measurement. User doesn’t feel uncomfortable when uses the oximeter. The wearable device is a multi-function watch which has oximeter to measure oxygen rate, IR remote control, bluetooth function and memory LCD to display time and oxygen rate. The relationship between oxygen rate and motor speed is established in wearable device. SynRM system supplies proper oxygen for user to achieve health care in unsatisfactory oxygen rate. The controller realization of SynRM speed predictive algorithm uses DS1104 controller card which is the product of dSPACE company.

碩士
國立雲林科技大學
電機工程系碩士班
101
This thesis develops a digital signal processor (dSPACE inc. DS1104) based synchronous reluctance motor (SynRM) drive system. Elman neural network and modified Elman neural network controller are proposed in the SynRM when the SynRM has parameters variations and external disturbances. Recurrent Neural Network (RNN) and Elman neural network (ENN) are compared which ENN has faster convergence for special recurrent structure. The on-line parameters learning of the neural network used the back-propagation (BP) algorithm. We use the discrete-type Lyapunov function to guarantee the output error convergence. Finally, the proposed controller algorithms are shown in experimental results effectively.

碩士
國立雲林科技大學
電機工程系碩士班
101
This thesis presents wavelet neural network (WNN) speed control for a synchronous reluctance motor. The activation function of the back-propagation network (BPN) is replaced by wavelet function in WNN. Wavelet transform of WNN controller has time domain and scale analytical capabilities. Neural network of WNN controller has high fault tolerance for inexact information and strong learning ability. The recursive structure of wavelet neural network controller is also presented in this thesis. The recursive wavelet neural network (RWNN) controller has better convergence. We ensure the system stability via the discrete Lyapunov theorem. Finally the experimental results validate the proposed wavelet neural network controller and recursive wavelet neural network controller in synchronous reluctance motors speed control.

碩士
國立成功大學
電機工程學系
105
In this paper, the direct torque control on synchronous reluctance motor and the flux Luenberger observer scheme are proposed to avoid the error accumulation and the stator voltage-drop caused by the back electromotive force integral in the traditional flux estimation. Three simulation software, i.e., Maxwell, Simplorer and MATLAB were used to implement the multi-physics coupled-simulation for designing the model of the synchronous reluctance motor direct torque control. MATLAB simulation was used to build the direct torque control model for determining the switching signal of the motor drive system, which was then delivered to the driver circuit built by Simplorer software. After which, Simplorer software exported the electric information such as current and voltage values to the synchronous reluctance motor model developed by Maxwell software for simulating the characteristics of the motor. Finally, the information collected was further delivered to MATLAB as the feedback signal to achieve the goal of multi-physics coupled-simulation. Our experimental results showed that the accuracy of the proposed method was higher than the traditional flux linkage estimation method. In addition, the co-simulation results of DTC collected had further confirmed that the capability/performance of the proposed method was better than the conventional method as well.

碩士
國立臺灣大學
機械工程學研究所
106
In this paper, the magnet-assisted synchronous reluctance motor magnet reduction is used as the research topics. A finite element software is used to design a 48-slot 8-pole Integral-slot distribution winding motor to maintain the same target specifications, including maximum torque, maximum power, rated point efficiency and torque density, as a research limitation of magnet reduction. The method of reducing magnet is to change the flux barrier shape and core width of the magnet-assisted synchronous reluctance motor, increase the q-axis inductance and reduce the d-axis inductance, thereby increasing the reluctance torque content in the overall torque, and the overall torque is increased to exceed the torque design target. After the target, the space for reducing the magnet torque content is given, and the amount of the magnet is reduced to achieve the effect of magnet reduction. Firstly, the permanent magnet synchronous motor is used as the original motor design, and the magnet amount of the original motor is used as a comparison benchmark. Then the parameters of the magnet-assisted synchronous reluctance motor are discussed, and an optimized software is combined to establish an optimized set. The process is optimized for the width of the flux barrier, the length of the flux barrier, the width of the core, the size of the magnet, and the angle of the flux barrier. Under the constraint conditions, the best parameter matching is obtained, and the purpose of the magnet reduction is achieved.