Dissertations / Theses on the topic 'PERMANENT MAGNET SYNCHRONOUS MMOTOR DRIVE'

This paper discusses a permanent magnet synchronous motor (PMSM) variable frequency drive (VFD) system developed for an all-terrain Wifi-HaLow connected (802.11ah, 900 MHz) modular electric vehicle that competed in the Mars University Rover Challenge (URC). The quadrature axis flux linkage for each motor was estimated using on-board voltage and current measurements. A synchronous control algorithm tracked the electromagnetic operating parameters, which are highly dependent on variations in motor construction and load conditions. A feed-forward model-driven observer solution calculated flux linkage angles by direct-quadrature-zero transformation of three-phase shunt currents using DSP processors.

Use of permanent magnets made of rare earth materials such as samarium cobalt and neodymium-boron-iron in Permanent Magnet Synchronous Motor (PMSM) drives has resulted in high flux density and improved performance of the drive. Field Oriented Control (FOC) has become one of the most popular speed and torque control techniques for AC motors. In PMSM drive detection/computation of rotor position is crucial for ensuring high performance during FOC. Rotor position is often sensed by incremental encoders or resolvers. The use of positon sensors in motor speed control increases the cost, size, weight and wiring complexity, and reduces the mechanical robustness and reliability of the PMSM drive systems. Sensor-less speed control techniques overcome these drawbacks related to estimation of speed and rotor position. The PMSMs are generally employed in industrial servo applications because of their fast dynamic performance. However, PMSMs suffers from ripples in the torque produced. Torque ripples in PMSM are produced because of cogging, current measurement error, switching of inverter and harmonics in magnetic flux. Torque ripples also leads to fluctuations in speed thus limiting the use of PMSM in several servo applications. Torque ripples could be minimized in applications that demand accurate speed/position tracking. The present work aims to explore use of different modern control techniques to minimize torque ripples in the operation of PMSM drives in comparison to previously reported control techniques. The objectives of the research include – a) modelling, design and development of laboratory prototype of PMSM drive, b) design and implementation of improved artificial neuro fuzzy inference system (ANFIS) based model reference adaptive control (MRAC) observer for sensor-less control of PMSM, v c) minimization of stator current ripples and torque ripples in PMSM drive using advanced predictive current controller (APCC) based on Dead Beat (DB) control theory d) minimization of torque ripples using intelligent hybrid controller (IHC) and e) torque ripple minimization by model predictive control of PMSM using proportional-plus- integral resonant (PI-RES) controller. The strategies to reduce torque ripples, that have been reported in the literature, may be classified into a) approaches based on the design improvement of the motor, b) methods based on control techniques or c) a combination of these two. The most critical aspect in high performance drive is the choice of the control algorithm that minimizes the torque ripples effectively for a given application. In this research work, a laboratory hardware prototype is designed and developed for real time analysis of PMSM drive based on sensor-less field-oriented control. An experimental setup is developed for implementation of FOC on PMSM using dSPACE DS1104 controller and performance of the drive is analysed using different control techniques. An improved ANFIS based MRAC observer is designed and implemented for FOC of PMSM with space vector PWM (SVPWM). In the proposed method adaptive model and adaptive mechanism are replaced by an improved ANFIS controller, which neutralize the effect of parametric variation and results in improved performance of the drive. The required rotor position and speed are estimated using the proposed MRAC observer. Simulation studies using MATLAB/Simulink and comparative analysis of the conventional MRAC based observer with improved ANFIS based MRAC observer show that better dynamic performance of the PMSM drive is achieved using the improved ANFIS based MRAC. vi An advanced predictive controller (APCC) based on deadbeat (DB) control theory is also developed and analysed for reduction of torque ripples in PMSM. The performance of the proposed APCC based on DB control theory are compared with hysteresis based direct current controller (DCC) and duty cycle-based model predictive controller (Duty-MPCC) under different operating condition through simulation studies using MATLAB/Simulink. It is observed that the implementation of proposed APCC results in better dynamic performance with less ripples in torque and stator currents, and lesser THD in stator current as compared to DCC and Duty-MPCC. An intelligent hybrid controller (IHC) has also been developed and implemented for FOC of PMSM to minimize torque ripples for constant torque operation. The proposed IHC is designed by combining a fuzzy logic controller (FLC) with PI controller with a novel switching capability. The intelligent switching decision of the developed IHC is based on overshoots, undershoots and oscillations observed in the system. Simulation studies for the FOC of PMSM using the proposed IHC indicates better dynamic performance with lesser torque ripples and lower THD in stator current in comparison with conventional PI controller. In addition, a proportional-plus-integral resonant (PI-RES) controller is designed and implemented for FOC of PMSM with model predictive controller (MPC) to minimize torque ripples for constant torque operation. The MPC is designed to provide the optimal voltage vector by minimizing the objective function calculated from stator current prediction for k th instant. The PI-RES controller is developed by combining a resonant controller with PI controller. Due to the compensating torque current produced by the resonant controller and reference current from the PI controller, ripples in the speed response are minimized. A PI- RES controller generates the reference pulsating torque current, which counteracts the ripples vii in load torque. The FOC of PMSM with MPC using PI-RES is simulated in MATAB/Simulink and the performance of the drive is compared with MPC using PI controller. The proposed FOC of PMSM with MPC using PI-RES demonstrate better dynamic performance, lower torque ripples and lower THD in stator current in comparison with conventional PI controller based MPC.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.
Includes bibliographical references (p. 258-263).
Interior permanent magnet (IPM) synchronous machines are attractive because they can achieve constant-power operation over a wide speed range with limited magnet strength requirements and reduced power electronics cost. These characteristics provide the IPM machine with advantages over alternative machine types in applications such as spindle and traction drives. An important challenge for high-performance IPM machine design is to model the magnetic saturation of the core in a manner that is accurate, flexible, and computationally fast for design optimization. A magnetically-saturable lumped parameter model (LPM) is developed for the optimized design of high-performance IPM synchronous machine drives. Using equivalent magnetic circuit analyses, the dq-frame inductances and magnet flux linkage are calculated for transversely-laminated IPM machines. The lumped parameters are employed to predict machine drive system performance for both rated-torque and constant-power operation. The results of saturable model calculations and finite element analysis (FEA) match very closely for the machine inductances, magnet flux linkage, and converted torque. Further validation is presented by comparing measurements of existing experimental machines to predictions from the saturable lumped parameter model. Agreement of measurements and predictions for the highly nonlinear saturable q-axis inductance is within 5% in the saturated excitation range. The utility of the saturable LPM is then demonstrated by developing a cost-optimized design for an automotive integrated starter/generator (ISG) that is rated at 4 to 6 kW during generating operation. This ISG machine is mounted in a direct-drive mechanical configuration on the engine crankshaft. Agreement between the saturable LPM and FEA calculations for q- and d- axis inductances and PM flux linkage are all within 5% for the entire excitation range. Results of this model have been combined with structural FEA and demagnetization studies to produce a machine design that is predicted to meet all key ISG performance requirements. For this application and the chosen cost model, it is shown that optimizing the combined machine and drive system versus optimizing only the machine reduces the overall cost prediction by 12%.
by Edward Carl Francis Lovelace.
Ph.D.

This doctoral study mainly considers the Wind Energy resource and focuses on the electromagnetic aspects of generators for direct drive solutions in this field. Despite the strong employing by many constructor of geared technology in Wind Turbines Generators, a transmission/gear box reduces both, eciency and reliability: the losses due to the transmission potentially compromise the sustainability of the electromechanical system. A better solution is the multipolar low speed direct drive train. Permanent magnet machines offer compactness and the absence of brushes with respect to traditional machines. Material in the armature can be saved using fractional slot windings. This type of machine exhibits many advantages such as short end windings, high slot fill factor, high efficiency and power density together with electrical redundancy, which allows the modularization of the active part and fault-tolerance capabilities. However, space harmonics of the magneto-motive force (MMF) in fractional slot windings lead to considerable rotor losses. The computation of these losses according to standard procedures (e.g. Steinmetz equation or models for massive body within homogeneous field) is not satisfactory. The MMF harmonics move asynchronously with respect to the rotor, inducing currents in any conductive rotor parts, e.g. the metallic iron yoke which supports the magnetic poles and the rare earth permanent magnets (PMs), acting on their working temperature which is strictly related to the performance of PMs. The reduction of the residual ux density causes a decrease both in the back electromotive force (EMF) and in the electromagnetic torque. The reduction of the magnetic eld increases the risk of an irreversible demagnetization of the PMs. The MMF space harmonic amplitude and frequency depend on the particular combination of number of slots and poles. The amount of such losses increases dramatically with the size of the machine becoming a crucial aspect in the design of a large diameter (v 2 - 3m) multipolar direct drive generators with PMs. A proper selection of the winding of the machine,fixing the number of slot and poles represents an improvement in the sustainability of the electromechanical conversion process: losses are limited and a higher eciency is achieved. If efficiency is better even less active material is wasted. This part of the doctoral study has been accomplished at the Electric Drives Laboratory at the Department of Industrial Engineering of the University of Padova during a partnership with Leitwind A.G.(in Sterzing, Italy), which operates in the Wind Energy Market. The aim is to design a large diameter generator (v 4m), which will be employed in the prototype of a 3 MW wind turbine. The will of Leitwind to implement a method to predict rotor losses in large machines with permanent magnet and fractional slot windings is the key basic point to be solved. The existing LW15C generator for LTW77 (1.5 MW rated power) wind turbine is analyzed by means of analytical relations and finite elements: it represents the starting point of this study. A method to calculate rotor losses due to the high harmonic contents of the fractional slot winding is applied. Such estimated losses are then compared with the results of experimental test benches with "full-scale" prototypes. The same study is then repeated on SFA motor (500 kW rated), employed in ropeways transport in Leitner A.G. plants. Both Leitner and Leitwind belong to the Leitner Technologies Group. Test bench results are finally compared with the values from the analysis. Starting from both the experience on LW15C generator and SFA motor the design of LW30A prototype generator for Leitwind 3MW wind turbine is chosen. Dierent topologies of PM machines with fractional slot winding are then investigated and compared with the switching ux configuration (SFPM), both with rare earths and ferrite PMs. The possibility to integrate a huge magnet quantity in the armature of the SFPM machine and the ux concentration principle can lead to a cost eective solution which must be carefully evaluated without considering the performance of the machine only. The structure of the rotor is robust and simple, like in classical reluctance machines. The robustness against PMs demagnetization is a crucial point to investigate. To extend the scenario of renewable energy, the wave energy resource is brie y overviewed and some topologies for linear direct drive generator in this field are investigated. In order to increase the thrust density the possibility of employing a double-sided structure is analyzed. The employing of ferrite PMs is also considered: despite their low energy with respect to rare earth magnets they have a lower impact on environment and human health. The extraction process of ferrite is similar to the iron one, while rare earths must be separated from radio elements. Main contributions of the thesis To the knowledge of the author, the contributions of this thesis for the upcoming researchers in electrical machines for renewable energy eld are: • The application of straight lined model and of the current sheet method to calculate rotor losses in large direct drive permanent magnet machines. The results of the test bench activity on real machines are then described and compared with the prediction. • Selection of number of slots and poles for fractional winding direct drive large generators. • Comparison of the switching ux machine with other well known machine topologies, including demagnetization behavior and ferrite PMs, more sustainable than rare earth ones. • Investigation on dierent linear modules topologies for wave energy, including double side switching ux topology. Outline of the thesis Chapter 1 provides an overview on renewable energy conversion field and presents the company Leitwind A.G. Chapter 2 describes the analysis and modeling of the LW15C generator for 1.5 MW wind turbine. Then a similar study has been performed for the SFA motor for ropeways applications. Both analytical and finite elements model have been developed/implemented and are compared to the results of experimental test bench activities. The same models are applied to the analysis of the new LW30A generator. Chapter 3 faces the topic of rotor losses in order to model them with the straight lined model and the current sheet method. The rotor losses computation is considered and described. Predicted values are compared with the test bench ones. Chapter 4 establishes a scaling law for rotor losses in fractional slot PM machines. Chapter 5 provides the selection of the number of slots and poles to design the new LW30A generator for 3.0 MW wind turbine. The validity of the Index of Rotor Losses obtained from the straight lined model is investigated and applied. Chapter 6 describes the comparison of fractional winding machine with a small switching ux permanent magnet machine, both with rare earth and ferrite PMs. The demagnetization behavior of the different machine topologies is analyzed. Chapter 7 considers linear drives for Wave energy conversion with different topologies, including the double side switching flux machine
Questo lavoro di dottorato considera principalmente la Risorsa Eolica e si focalizza sulle caratteristiche elettromagnetiche dei generatori a presa diretta per questa applicazione. Malgrado molti Costruttori di turbine eoliche usino congurazioni comprendenti il moltiplicatore di giri, la presenza di quest'organo di trasmissione causa una perdita di ecienza del sistema elettromeccanico che va a comprometterne la sostenibilità. Una soluzione multipolare a bassa velocita di rotazione e presa diretta tra generatore e pale della turbina e quindi adottata. Si sceglie l'utilizzo del magnete permanente grazie alla sua compattezza e all'assenza di spazzole in paragone alle soluzioni di macchina sincrona tradizionale. L'avvolgimento frazionario e adottato per risparmiare materiale nell'avvolgimento di armatura della macchina. Questo tipo di congurazione presenta evidenti vantaggi come la lunghezza ridotta delle testate, il buon fattore di riempimento delle cave, elevati rendimento e fattore di potenza. Essa si presta inoltre a soluzioni circuitalmente ridondanti che consentono una struttura modulare della parte attiva, con la capacita di tollerare i guasti. D'altro canto, le armoniche spaziali della forza magneto motrice (MMF) dovuta all'avvolgimento frazionario causano perdite nel rotore di entita notevole. I metodi tradizionali di calcolo delle perdite (formula di Steinmetz o modelli di corpi solidi in campo magnetico uniforme) non forniscono risultati soddisfacenti per queste perdite. La forza magneto motrice risulta non sincrona con il rotore della macchina, con conseguente indursi di correnti parassite in ogni parte conduttrice del rotore, come nel giogo metallico che sorregge i poli magnetici e nei magneti stessi (terre rare). Le perdite nei magneti ne causano il riscaldamento, con conseguente calo delle prestazioni della macchina. La riduzione del campo dei magneti dovuta all'aumento di temperatura aumenta il rischio di smagnetizzazione irreversibile. L'ampiezza delle armoniche spaziali di forza magneto motrice e la loro frequenza vista dal rotore dipendono dalla particolare combinazione cave{poli dell'avvolgimento scelto. L'entita di queste perdite cresce notevolmente con l'aumentare delle dimensioni della macchina, divenendo un aspetto cruciale nella progettazione di macchine multipolari a presa diretta di grande diametro (. 2m) con magnete permanente. Una scelta adeguata del rapporto cave{poli dell'avvolgimento, signica un notevole miglioramento della sostenibilita del processo di conversione elettromeccanica: le perdite vengono ridotte e il rendimento migliora. Se il rendimento migliora, signica che meno materiale e stato sprecato. Questa parte del lavoro di tesi si e svolta presso il Laboratorio di Azionamenti Elettrici nel Dipartimento di Ingegneria Industriale dell'Universita di Padova nell'ambito di un contratto di ricerca voluto da Leitwind SpA (VIpiteno, Italia). Leitwind e un costruttore di turbine eoliche. Lo scopo e progettare un generatore di grande diametro (v 4m) per il prototipo di turbina eolica da 3 MW. Compresa l'importanza del fenomeno delle perdite rotoriche, la volonta di Leitwind e svilupparne calcolo per scegliere l'avvolgimento della nuova macchina. Il generatore Leitwind esitente, denominato LW15C, per la turbina LTW77 (potenza nominale 1.5 MW) e analizzato sia con modelli analitici che con gli elementi niti. Questo generatore e la base di partenza di questo studio. Viene applicato un metodo per il calcolo delle perdite rotoriche indotte dall'elevato contenuto armonico dell'avvolgimento frazionario. Le perdite cos ottenute sono confrontate con i risultati dell'attivita del banco prova su macchine reali. Con lo stesso approccio si studia e si modella il motore diretto per trazione funiviaria SFA (500 kW di potenza nominale) negli impianti Leitner. Leitner e Leitwind appartengono al Gruppo Leitner Technologies. I risultati del banco prova sono confrontati con i valori calcolati. La progettazione del nuovo generatore LW30A e sviluppata a partire dai modelli creati per il generatore LW15C e il motore diretto SFA. Vengono poi studiate dierenti topologie di macchina a magnete permanente con avvolgimento frazionario per confrontarle con la congurazione switching ux (SFPM). Lo studio prende in considerazione sia magneti di terre rare, che di ferrite. La possibilità di integrare una notevole quantita di magnete nella parte di armatura della macchina SFPM e il principio di concentrazione di usso portano ad una soluzione con un buon rapporto costi prestazioni, che pero deve essere valutata non solo da un punto di vista di prestazioni. La struttura del rotore di questa macchina e semplice e robusta, come per le macchine a riluttanza. Il comportamento della topologia SFPM a smagnetizzazione dei magneti permanenti risulta un punto cruciale da indagare. Per allargare lo studio ad un'altra Fonte Rinnovabile, l'energia da moto ondoso e brevemente descritta e vengono confrontate alcune topologie di generatori lineari per questa applicazione. Uno struttura a doppio statore viene studiata con l'intento di massimizzare la spinta sulla parte mobile. Si considera inoltre l'utilizzo dei magneti in ferrite: malgrado il loro basso prodotto di energia rispetto ai magneti in terre rare, essi risultano meni nocivi per l'ambiente e la salute dell'uomo: il processo di estrazione delle terre rare coinvolge infatti elementi radioattivi, mentre l'estrazione della ferrite e in tutto simile a quella del ferro. Contributi principali della tesi I principali contributi di questo lavoro di tesi alla ricerca futura nell'ambito delle energie rinnovabili si possono cos sintetizzare: • L'applicazione del modello a strati e del metodo dei punti corrente nel calcolo delle perdite rotoriche di macchine elettriche a presa diretta di grande diametro, con magneti permanenti. I risultati dell'attivita sperimentale su banco prova di grosse macchine reali sono confrontati con i valori calcolati. • La scelta del numero di poli e di cave nella progettazione di macchine a presa diretta di grande diametro, con avvolgimento frazionario. • Confronto della macchina switching ux con topologie di macchina note, comprendendo la smagnetizzazione del magnete e l'utilizzo della ferrite, materiale più sostenibile delle terre rare. • Studio di diverse topologie di generatore lineare per generazione da moto ondoso, includendo la topologia switching ux a doppio statore. Struttura della tesi Capitolo 1 : presenta una breve panoramica sull'energia rinnovabile eolica e da moto ondoso e descrive l'azienda Leitwind SpA. Capitolo 2 : descrive la modellazione e l'analisi delle macchine studiate, sia con metodi analitici che con gli elementi niti: sono inclusi i risultati dell'attivita sul banco prova. I modelli, sviluppati sul generatore LW15 e sul motore SFA sono poi applicati al nuovo generatore LW30A. Capitolo 3 : aronta la tematica del calcolo delle perdite rotoriche, sviluppando il modello a strati e il metodo dei punti corrente. Viene descritto il calcolo delle perdite rotoriche. Si aronta la validazione dei metodi di calcolo al banco prova. Capitolo 4 : ricava una legge di scala per le perdite rotoriche per macchine a magnete permanente ad avvolgimento frazionario. Capitolo 5 : presenta la scelta del rapporto cave{poli nel progetto del nuovo generatore LW30A per la turbina da 3.0 MW LTW 101. Viene investigata la possibilità di applicare l'Indice delle Perdite Rotoriche, ricavato dal modello a strati. Capitolo 6 : confronta diverse topologie di macchine ad avvolgimento frazionario con la congurazione switching ux, sia con terre rare che con ferrite. Si aronta il fenomeno della smagnetizzazione sulle diverse topologie di macchina. Capitolo 7 : prende in considerazione topologie di macchina lineare per conversione da moto ondoso. Include la congurazione switchng ux a doppio statore

This research is concerned with the evolution of an advanced drive system for use with permanent magnet synchronous motors. The proposed drive system incorporates state-of-the art control strategies with a switching matrix current loop which is a special case of the sliding mode control loop, implemented using field programmable gate array (FPGA) devices. This significantly increases the bandwidth of the current control loop, in comparison with systems using PI current controllers and therefore improves the dynamic performance of the drive system. The hard-wired FPGA implementation of a current control loop greatly reduces the processing and computational burden imposed on the controller. Most importanUy, in contrast to the OSP technology, independent functions may be implemented without the constraint of a shared arithmetic unit. In this research a novel hard-wired algorithm implementation is proposed for advanced control of brushless permanent magnet synchronous motor (PMSM) servo-drives. The PM servomotor control system has been developed as a set of modular subsystems in the form of algorithms, which can be easily interconnected at the top-level. The novel features of the control system have been made possible by the FPGA implementation with the creation of special algorithms and multiple sampling periods. The application under study is the speed and position control of synchronous motor drives. Initially, a conventional proportional and integral (PI) speed controller was implemented to enable comparison of performance to be made with the forced dynamic control (FOC) law emerging during the final stage of the research programme, which takes advantage of the flexibility offered by digital FPGA implementation. This offers high robustness to uncertainties in the dynamics of the driven load and unknown external load torques and yields a prescribed closed-loop dynamic response to reference inputs. The proposed system not only has the prescribed mutual orthogonality between the magnetic flux and stator current vectors, but also the realisation of a chosen form of speed response transient These FOC strategies have not yet been commercially exploited and it is emphasised that the recent advances in FPGA technology render such control methods highly cost effective. It is therefore anticipated that the outcomes of the research work will provide significant benefits in the development of a new generation of high performance and competitive servo drives.

Fault tolerant machine drives are key enabling technologies for safety critical applications such as electric vehicle traction, and aerospace power generation, actuation and propulsion. High performance in healthy conditions and excellent fault tolerance against various faults are required for a fault tolerant drive, however, these two aspects usually conflict with each other. Thus, this PhD study aims to develop a fault tolerant machine drive which exhibits high performance and good fault tolerance, and can be realised in a simple and cost-effective manner. First, a novel triple redundant 3x3-phase permanent magnet assisted synchronous reluctance machine (PMA SynRM) with segregated windings is proposed. Its performance under healthy conditions and its ability to tolerate various faults with appropriate mitigation measures are investigated and assessed. Based on outcomes of the investigation, a 40kW machine is designed to tolerate all key electrical faults, including the worst single turn short circuit, and is optimised to maximise the efficiency in healthy conditions whilst satisfying the electrical, thermal and mechanical constraints. To analyse and realise a fault tolerant machine drive, fault modelling and fault detection techniques are essential. Thus, a general model is proposed based on the magneto-motive force (MMF) decomposition. The model is capable of predicting the machine behaviour in various operation modes, including the healthy condition, open circuit, short circuit and inter-turn short circuit fault with different number of turns and different coil locations. With the aid of the fault modelling technique, a turn fault detection technique is developed using the 2nd harmonics in the instantaneous reactive and active powers as fault indicators for motoring and generating modes, respectively. By cross-reference of the fault indicators of the three 3-phase sets, the technique can detect the turn fault during transient without false alarm. The optimised machine drive is constructed and the developed fault detection technique together with fault mitigation strategies is implemented in a DSP based controller. The performance of the drive under healthy conditions and its fault tolerant capability are validated by extensive tests. The accuracy of the fault modelling and the effectiveness of the detection technique are also experimentally evaluated. The test results demonstrate that the developed fault tolerant machine drive can be a competitive candidate for safety critical applications.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
Includes bibliographical references (p. 306-310).
by John Ofori-Tenkorang.
Ph.D.

Many geared electric drives can benefit from removing the gearbox and driving directly the load at low speed using a permanent-magnet synchronous machine (PMSM). PMSMs with non-overlapping concentrated windings are particularly attractive in low-speed direct drives since they allow, among other advantages, a high number of poles with a limited number of slots. Therefore, this thesis is dedicated to PMSMs with non-overlapping concentrated windings designed for low-speed directdrive applications.First, the design features specific to PMSMs with non-overlapping concentrated windings are presented and illustrated with examples based on finite-element (FE) simulations. Especially, it is shown that the selections of the stator core manufacturing method, the number of winding layers, the combination of pole and slot numbers, and the geometry of the tooth tips are crucial during the design stage of the machine.Second, the benefits of removing the gearbox in a 4.5 kW, 50 rpm mixer used in a waste-water treatment plant are investigated. With its PMSM having buried ferrite magnets and concentrated windings, the designed direct-drive mixer has a higher efficiency than the commercialized geared mixer, but it is also heavier and more expensive due to the larger required housing, shaft and seals. In addition, the cost of the stator core and coil assembly was also higher than expected. Therefore, the difficulties in manufacturing a stator core with concentrated windings are investigated. Mainly due to economical aspects, no prototype motor has been built for the direct-drive mixer.Finally, measurements on a prototype motor at disposal having a large constantpower speed range are performed. Three methods to measure the inductances without using a position sensor are provided and compared. One of the methods is a new test at load conditions to determine the inductance without the knowledge of the rotor position. Results from this method agree well with a conventional blocked rotor test, as well as with results from 3D-FE simulations. Furthermore, the measurements of the magnetic flux obtained with search coils placed in different parts of the stator are analyzed. The analysis allows highlighting the zigzag flux flowing from one magnet to another through a tooth tip, which is characteristic of PMSMs with non-overlapping concentrated windings. It is shown that this zigzag flux leakage causes high iron losses in the tooth tips that represent approximately 50% of the stator iron losses under field weakening operation. Using these measurements, the 3D-FE model of the prototype is also validated thoroughly.
QC 20100826

In recent times, researchers show a growing interest in the control of permanent magnet synchronous motor, which is superior to conventional induction motor in several performance and efficiency aspects. Particular attention is given to the brushless dc motor (BLDC), as it is gaining popularity in low to medium power applications including adjustable speed drive and electric vehicle. Most works pertaining to BLDC control focus on dynamic performance improvement. However, limited works have been reported for BLDC efficiency optimisation. From an energy perspective, maximum efficiency operation is desired, as energy saving closely ties to the operating capacity and thermal dissipation, particularly for battery powered systems. This dissertation presents a comprehensive motor modelling and analytical power loss modelling in the Matlab/Simulink environment that account for major loss mechanisms in a three phase inverter-fed BLDC motor through closed form equations. To explore the change in motor power losses under variable current excitation, two well-known current excitation schemes, namely sinusoidal and square current excitations, have been implemented to facilitate comparison of efficiencies of the resulting motor operations. Key power loss components are identified and examined, for both current excitation schemes, under the context of variable motor operating speed. The closed-loop system model is simulated under MATLAB/Simulink environment. Power losses under two current excitation schemes are investigated across different speed regions under nominal load. The complete motor drive has been experimentally implemented using digital signal processor based control board for a low power BLDC. The experimental results validate the higher efficiency due to sinusoidal current excitation across a wide speed region, compared to square wave current excitation. The resulting work contributes methodologically to the broader problem of efficiency optimising control.

M.TECH
The present work involves the study, development and implementation of a semi-automated system using a Programmable Logic controller for the control and monitoring of a Three phase Servodrive (Permanent Magnet Synchronous Motor drive). Three Phase Servodrives using PMSM are increasingly used for precision control applications in process industries due to their high torque to inertia ratio and operation at higher power factor as compared to Induction Motor. Most of the earlier research on PMSM focused on performance improvement through the use of advance control algorithms such as Vector control, sensorless control, direct torque control, etc. However modern industrial processes which involve multimotor drives require a co-ordinated sequential control through PLC and SCADA system. So far there has been very limited work on the PLC-SCADA control of a PMSM. The present work is an effort to explore this aspect of the PMSM control. An integrated system comprising of a Workstation (PC), the PLC(GE-Fanuc), Permanent Magnet AC Servo Drive, three phase Servomotor(PMSM) and the software for Supervisory Control and Data Acquisition system are configured and developed in co-ordination with each other to ultimately control the three phase Permanent Magnet synchronous drive in multiple ways. The PMSM is configured and controlled in position and speed control modes. An effort is made to monitor the PMSM runtime variables like speed, torque and current. The necessary communication protocols are established between the various devices to ensure flawless communication. The real time Performance of the Permanent Magnet Synchronous motor is experimentally verified and captured on the Drive software. Various virtual animated screens are developed to explain the PMSM precise position control applications.

碩士
明志科技大學
電機工程研究所
99
This thesis studies the high-quality surface permanent magnet synchronous motor drive. High-strength permanent magnets are installed on the rotor to provide rotating rotor magnetic field. Because there exist stator windings only in the stator, cooling would be easier, torque ripple becomes less, and motor’s efficiency is higher. To respond energy efficiency and carbon reduction, when the design of the high-performance motor drives is required, the following factors must be considered： high efficiency and low-power consumption. Detection of the rotor’s position is difficult before the motor is running. Therefore, a multiplexer was adopted to operate open-loop speed control firstly. Once the motor is running, the traditional vector control may be employed to achieve high-performance speed control. When the surface permanent magnet synchronous motor is operated at higher speed, the rotor magnetic field of the motor can also be weakened. To demagnetize the rotor flux in the direct axis of the motor, a current phase-angle-advancing technique is used so that the high-efficiency can be still maintained under high-speed operation. The drive was implemented by the hardware circuit to verify the effectiveness of the proposed control method.

碩士
明志科技大學
電機工程系碩士班
102
This thesis using the highly efficient Permanent-Magnet Synchronous Motor, third harmonic current injection and current-phase advancing technologies are incorporated to effectively reduce the motor’s reactive power, improve motor’s torque and acoustic noise, directly increase its power factor, and indirectly increase its electromagnetic torque, optimize the dynamic response of the motor speed. To reduce drive cost and volume, in this thesis implementation of Programmable System-On-Chip(PSOC) as the control core with surrounding components based on a Permanent-Magnet Synchronous Motor to verify the effectiveness of the proposed control method。Its energy conservation for the future application of automation industry will have considerable benefit.

碩士
中原大學
電機工程研究所
86
Adaptive and variable-structure controllers are designed to enhancethe robustness of a permanent magnet (PM) synchronous motor drive systemwith regard to external load disturbance and plant parameter variations inthis thesis. First, a robust controller, which combines the merits of integral-proportional (IP) position control and adaptive control, is designed.Then, a novel sliding mode controller with an integral-operation switchingsurface and an adaptive sliding mode controller, in which a simple adaptivealgorithm is utilized to estimate the bound of uncertainties, are investigated.Moreover, a newly designed variable-structure controller, a variable-structure adaptive (VSA) controller and a variable-structure direct adaptive (VSDA)controller, are introduced. In both the VSA and VSDA, simple adaptive algorithmsare utilized to estimate the uncertainty bounds. Numerical simulation andexperimental results are presented to show that the proposed controllers aresuitable for the PM synchronous motor drive system with enhanced controlcharacteristics.

碩士
國立勤益科技大學
電機工程系
101
A sensorless vector control permanent magnet synchronous motor drive without magnet-position sensor and shaft-position sensor is presented in this thesis. First, a stator flux estimator is developed utilizing measured stator voltage and current, and the flux position and rotor speed are acquired from the flux estimator. Then, the sensorless vector control permanent synchronous motor drive is established base on space vector pulse width modulation skill. In the proposed system, the currents of the motor are obtained applying the Hall-Effect current sensors, the switching frequency of PWM is 15 kHz, dead-time is 1μsec, and the sampling rate of the current control loop and the speed control loop are 15 kHz and 1 kHz, respectively. The control algorithms are realized by a 32 bit micro-controller RX62T of Renesas company and, to generate PWM signals to the power stage, drive the motor to experimentally validate the proposed approach.

碩士
國立臺灣科技大學
電機工程系
97
This thesis proposes the implementation of a permanent-magnet synchronous motor drive system for elevator applications. First, the configuration, characteristics and mathematical model of the permanent magnet synchronous motor are discussed. Next, an initial rotor position estimator is proposed to avoid the motor operating in an opposite rotating direction. Finally, a three-phase ac/dc converter is implemented to improve the ac input power factor and reduce the ac input harmonics. In addition, the energy can flow from the load to the ac source when the system is operated in the energy recovery. A digital signal processor (SH-7137) is used as the control center unit. As a result, the whole control algorithm is implemented by software. The experimental results can validate the feasibility and correctness of the proposed drive system. Several measured results are obtained by using on-line measured results of the elevator system.

碩士
明志科技大學
電機工程系碩士班
103
This thesis studies the permanent magnet-assisted synchronous reluctance motor drive. Three layers of high-strength permanent magnets are installed on therotor, and by the permanent magnet as well as reluctance torques to provide rotating magnetic field. Because there exist stator windings only in the stator, cooling would be easier, torque ripple becomes less, and motor’s efficiency is higher. This thesis proposes a vector control method that can improve permanent-magnet synchronous motor’s torque ripples. Indirectly increase the electromagnetic torque and all system’s efficiency. The experimental results show that the motordrive system efficiency around 89% can be achieved when motor’s speed is 3000 rpm and the loading is 1.5Nm. In this thesis, fuzzy speed control is also applied such that a fast speed response can be obtained. In this thesis the Programmable-System-on-Chip(PSoC5) is used as the control core, and the three-phase full-bridge power module (PS21265-AP) with peripheral hardware components produced by Mitsubishi's company are also adopted to implement the permanent magnet-assisted synchronous reluctance motor drive.

碩士
大葉大學
電機工程學系
101
This paper focuses on space vector modulation based sinusoidal current driver control of permanent magnet brushless DC motor, and build a three-phase permanent magnet synchronous motor drive system with Microchip's digital signal processor (DSP) dsPIC30F2010 as a control core. First, Hall Effect sensors are captured, rotor position and speed information are provided, and then digital signal processor is used to calculate the required parameters, such as amplitude, period, phase of reference voltage vector. Space Vector Pulse Width Modulation (SVPWM) technique is adopted to generate six independent PWM signals sending to the inverter, and driving permanent magnet brushless DC motor. The experimental results show the feasibility of the control method. The driver is able to generate the appropriate current to drive motor, and adjusting the motor speed.

碩士
國立臺灣科技大學
電機工程系
89
This thesis presents the analysis and implementation of a high efficiency, wide-speed control system for salient-pole permanent-magnet synchronous motors. A digital signal processor (DSP TMS320C32) is used to deal with the feedback of output current signal with analog-to-digital circuit, and to complete the whole digital control system to fully utilize the saliency of permanent-magnet motor by means of the counter which is encoded by field programmable gate array. It is also used in the pulse-width-modulated controller and thus simplifies the control circuit. The saliency of permanent-magnet motor yields larger quadrature-axis inductance than that of the direct-axis. This results in reluctance torque accordingly. By appropriately adjusting the direct-axis current, the reluctance torque can be controlled to achieve efficiency operation. In addition, field-weakening is also exercised to extend speed control range with constant DC-link voltage. Experimental evaluation for a 1 kW drive system has been conducted. The result indicates that the efficiency can be raised to as high as 87% under rated torque, while the operating speed can be extended to 4.67 times the rated speed at no-load.

碩士
國立臺灣科技大學
電機工程系
89
This thesis presents the design and implementation for a position control of a linear permanent magnet synchronous motor drive. By using a personal computer with some hardware circuits and a digital-to-analog interface card, a position control system can be achieved. In order to obtain a good transient response and a good load disturbance rejection capability, a two-degree-of-freedom controller is proposed in this thesis. The two-degree-of-freedom controller includes a forward-loop controller and a load compensator. For the forward-loop controller, this thesis discusses several different control laws, which consist of a proportional-integral controller and three different optimal controllers. The parameters of the optimal controller are computed by using frequency factorization. On the other hand, the load compensator is a proportional-integral compensator and its parameters are obtained by using an optimization technique. Moreover, a drive system has been implemented to verify the feasibility and correctness of the proposed method. Several experimental results are shown to validate the theoretical analysis and computer simulated results as well.

碩士
國立清華大學
電機工程學系
97
This thesis is mainly concerned with the development of a DSP-based position sensorless permanent-magnet synchronous motor (PMSM) drive with single-phase switch-mode rectifier (SMR) front-end. First, a standard SMR-fed PMSM drive is established with the control schemes being designed to yield satisfactory motor driving performance and AC line drawn power quality. The control algorithms of two power stages are realized in a common digital signal processor (DSP). Then the key issues affecting the operation characteristics of PMSM drive are explored and evaluated experimentally, these include commutation shift, field excitation and DC-link voltage boosting, etc. Particularly, the static and dynamic field-weakening control approaches are proposed to enhance the PMSM performance under higher speed. Next, the possible origins of torque ripple and vibration of PMSMs are explored, and some existing remedies in their reductions are understood. Then the experimental observation of vibration characteristics for the established PMSM drive is made. And the random pulse width modulation (PWM) is applied to randomize the winding current harmonic spectrum distribution, and thus to effectively achieve its vibration reduction. Finally, having reviewed some commonly used existing position sensorless control methods of PMSM drive, a sensorless control scheme based on high-frequency signal injection is developed. It possesses the following features: (i) unidirectional starting is achieved based on magnetic anisotropy via narrow voltage pulse excitation; (ii) rotor absolute position is estimated to yield good low-speed driving performance; and (iii) a simple robust control is employed to enhance the dynamic response of rotor position estimation.

碩士
國立勤益科技大學
電機工程系
100
In this thesis, we mainly use the TMS320F2808 Digital Signal Processor (DSP) and Intelligent Power Module (IPM) to the implementation of Permanent Magnet Synchronous Motor (PMSM) drive design. The control software is programmed by C language in TI CCS 3.3 (Code Composer Studio 3.3) console, and most of the data and control results are also shown by it. The inverter to deliver the power to the PMSM is made by IPM module to minimize the board. Speed control signal is from the encoder feedback, and current feedback signals are from two Hall sensors filtered by second-order Low-Pass Filter (LPF). The Space Vector Pulse Width Modulation (SVPWM) strategy is used to convert the 48V DC power supply into AC voltage source to the motor according to the vector control structure. Three digital PI controllers are used to complete the speed and currents control. Finally, experimental results including the performance testing of DSP and the drive system are both given to shown the performance of hardware and software design.

碩士
國立清華大學
電機工程學系
91
Owing to its many remarkable advantages, the interior permanent magnet synchronous motor (IPMSM) is usually utilized as the actuator in many application fields. To further promote its application capability, some key technologies are developed in this thesis to improve the performance of a sensorless IPMSM drive. In order to profoundly understand the torque generating characteristics of an IPMSM, its structure and governing equations are studied first. The equivalent circuit parameters of a motor are necessary for performing its switching driving control. However, for an IPMSM they are not easy to obtain accurately via derivation owing to their nonlinear and variant properties. To solve this problem, the estimation approach is applied to find them alternatively. For performing the experimental tests, a standard DSP-based IPMSM drive is established. The DSP-based control environment possesses the capability of realizing all control schemes using digital control. As to the sensorless control for an IPMSM, the control approach based on the sensed winding terminal voltage is proposed for avoiding the undesired noise effects caused by the time derivative in making the back electromotive force (back-EMF) estimation, and the effects of phase difference between terminal voltage and back-EMF and the driving performance improvement of the IPMSM drive will be covered by the proposed commutation tuning control. A bumpless starting technique is devised in this thesis to let the motor start from the synchronous motor mode and smoothly switch to IPMSM sensorless running mode. In the tuning control for IPMSM drive, the equivalent performance of field excitation and commutation instant tuning is observed analytically and experimentally. Then accordingly, an intelligent tuning approach is developed to automatically determine the advancing angle of commutation instant. The minimum current command is achieved to obtain better torque generating capability equivalently. In dynamic control improvement, for improving the dynamic performance of the IPMSM drive, a simple robust current controller is developed to improve the winding current tracking control response. Incorporating with the commutation instant tuning, the winding current tracking performance under higher speeds can be further improved. Validity and effectiveness of the control approaches developed in this thesis are manifested and demonstrated experimentally.

碩士
國立勤益科技大學
電機工程系
102
A sensorless vector controlled permanent magnet synchronous motor drive without magnet-position sensor and shaft-position sensor is applied in fan coil unit. First, a stator flux estimator is developed utilizing measured stator voltage and current, and the flux position and rotor speed are acquired from the flux estimator. Then, the sensorless vector control permanent synchronous motor drive is established based on voltage space vector pulse width modulation skill. In the proposed system, the stator currents of the motor are obtained from the Hall-Effect current sensors, and all the control programs are developed by Infineon micro-processor MCU XE164FM-72F80L to drive the fan coil unit to validate the proposed approach.

碩士
國立臺灣科技大學
電機工程系
105
This thesis investigates the rotor position estimation and optimal speed controller for an interior permanent magnet synchronous motor. By using a high-frequency injection method, the rotor position and speed can be estimated based on the saliency of the interior permanent magnet synchronous motor. First, the frequency and amplitude are selected according to the current resolution and the testing results. Next, the high-frequency voltage is injected into the estimated d ̂-axis. Then, the rotor position estimated error is computed via the d ̂-q ̂ axis feedback currents. Finally, an iterative method is used to compute the estimated rotor position. The speed-loop controller is an optimal controller, which is designed based on the motor dynamic equation and performance index. A digital signal processor TMS320F2808, is used as a control kernel to execute the rotor position estimation and the control algorithm. Experimental results show the feasibility and correctness of the proposed methods.

碩士
國立聯合大學
電機工程學系碩士班
106
This thesis presents the vector control and position-sensorless speed control of permanent magnetic synchronous motor (PMSM) auxiliary designed with PSIM software. For the driver using incremental type encoder position sensor, a rotor position and counter reset method is presented first to make the PMSM be started form electrical zero degree. The problems of reverse rotation and start-fail can be prevented. As for the PMSM parameters, the on-line parameter measurement and estimation methods are presented to acquire the electrical and mechanical parameters accurately and ensure well vector control performance. As for the position-sensorless speed control, a quantitative design of sliding-mode observer combining phase-lock loop method is proposed to estimate the motor speed as well as rotor angle. The resulted speed control is accurate and the speed range is wide. This thesis also presents a developing platform based on PSIM that can finish circuit design, circuit model derivation, controller design, circuit simulation, drive circuit implementation and verification with a step-by-step procedure. The TI TMS320F28335 DSP IC is adopted for realizing the digital controllers. A 400W drive circuit is implemented, the effectiveness of the proposed methods is confirmed with some simulation and experimental results.

碩士
中原大學
電機工程學系
88
The purpose of this thesis is to develop sensorless control of a permanent-magnet synchronous motor (PMSM). Owing to the advancement of magnet material, power semiconductor components and control theories in recent year, the PMSM has been widely used in many industrial applications for low and medium power. Because of the limitations and drawbacks for the PMSM equipped with position sensor, the research of sensorless control for PMSM becomes much important and necessary. However, the schemes of sensorless control can not self-start for the sensorless field-oriented control PMSM drive. Therefore, a special start-up strategy for a non-salient PMSM is proposed in this thesis to solve the problem of smooth motor starting from standstill, and the PMSM can be speeded up to a certain speed. In addition, the estimation algorithm of rotor flux position and speed based on the back electromagnetic force (EMF) is studied to develop the sensorless control algorithm for PMSM drive. However, the coefficients of the estimation algorithm based on back EMF are dependent on electrical parameters of the PMSM and these parameters are varied during on-line operation due to the temperature or saturation effect. Therefore, an adaptive stator resistance estimator based on fuzzy neural network (FNN) is proposed to estimate the variation of stator resistance. The robustness of the sensorless algorithm based on back EMF can be much increased by the addition of the adaptive stator resistance estimator. Finally, a sliding-mode observer, which is based on sliding-mode control theory, is proposed to estimate the rotor flux position and speed of PMSM. Due to the robustness of the sliding-mode control theory, the estimation algorithm based on sliding-mode not only avoids the problem of integration drift but much reduces the effects caused by the parameter variations of PMSM. According to the simulated and experimental results, the effectiveness of sliding-mode observer is obviously.

碩士
國立臺灣科技大學
電機工程系
93
In the proposed system, a low-cost 16-bit digital sig-nal processor (DSP,TMS320-LF2407 ) is used to serve as the core control device. The control and measurement system of six-phase permanent-magnet synchronous mo-tors are accomplished by magnetic rotary encoder, six-phase inverter, current and voltage detected devices, as well as associated software for digital signal processor.

碩士
國立臺灣科技大學
電機工程系
93
The thesis investigates the design and implementation of the rotor estimating technique and control algorithm for a sensorless interior permanent magnet synchronous motor (IPMSM) drive system. First, the structure, characteristics and mathematical model of the IPMSM are discussed. Then, a new rotor position estimator is proposed. This estimator is easily implemented and is unrelated to the parameters of the motor. Next, a nonlinear adaptive backstepping controller is proposed. The controller design procedures can be applied to both speed control and position control systems. In addition ,it can achieve a maximum torque per ampere control for the IPMSM drive. The implemented system has a wide adjustable speed range, fast response, and good load disturbance rejection ability. A 16-bit digital signal processor, TMS320LF2407 is used to achieve current, velocity, and position control. As a result, the hardware circuit is very simple. Experimental results show that the proposed algorithms are feasible and correct.

碩士
國立臺灣科技大學
電機工程系
95
This thesis studies the design and implementation of speed control and position control systems for a micro-permanent magnet synchronous motor. In this thesis, first, the structure, characteristics, and mathematical model of the micro-permanent magnet synchronous motor are introduced. Next, the different configurations of the proportional, integrational, and derivative controller are investigated to achieve fast responses and good load disturbance responses. A digital signal processor, TMS320F2407, is used as a control center to execute the feedback signal process, controller law computation, and then achieve a closed-loop control system. Most jobs are executed by the digital signal processor; as a result, the hardware is quite simple. Experimental results can validate the simulated waveforms to show the feasibility and correctness of the proposed methods. The thesis establishes a foundation for a micro-permanent magnet synchronous motor.

博士
國立臺灣科技大學
電機工程系
99
This dissertation investigates the performance improving methods and the pratical applications of micro permanent magnet synchronous motors. In this dissertation, first, a novel state estimator is proposed to obtain the estimated rotor position or rotor speed of the micro motor. By using this proposed state estimator, a wider range of adjustable speed control system and a more precise position control system can be achieved when compared with using the micro encoder, which is attached to the micro motor. In addition, an adaptive inverse control and an optimal control are designed and implemented for the micro permanent magnet synchronous motor. The proposed control methods can improve the transient reponse, load disturbance capability, and tracking ability of the closed-loop micro permanent magnet synchronous motor systems. A digital signal processor, TMS320F28335, which is made by Texas Instrument Company, is used as the control center to excute the state estimator, control algorithoms, and coordinate transformation. As a result, the hardware is simple. Experimental results show that the proposed methods can effectively improve the performance of the micro permanent magnet synchronous motor drive systems. Finally, a multi-dimentional position table is controlled by using the implemented system. The experimental results show the feasibility of using the proposed micro permanent magnet synchronous motor drive system in a practical application.

碩士
國立宜蘭大學
機械與機電工程學系碩士班
97
Universal variable-voltage-variable-frequency (VVVF) inverters have been widely used with induction motors over the past 20 years. The squirrel-cage induction motor is rugged, low cost and easy to get, however the general purpose induction motor drive has many drawbacks, such as poor efficiency, sluggish dynamics, low starting torque, etc. This study presents the design, analysis and implementation of a universal drive for various permanent magnet synchronous motors, namely it can provide the sinusoidal and rectangular shaped current with low cost position sensor to achieve high efficiency. In order to avoid mismatching between the position sensors and phase sequence of the motor, this study proposed an intelligent starting process, the correct commutation logic can be built even when the phase sequence of the motor and the position sensor is not given. The motor efficiency will be decreased if the armature current is lagged the back electromagnetic-force, previous studies use complex compensators to solve this issue. Without the complex algorithm and expensive current sensors, this study proposed a low cost algorithm based on the single current sensor technique to compensate the annoying lagging angle of the armature currents. Theoretical analysis, computer simulation, and various experimental results are demonstrated the effectiveness of the proposed method.

碩士
健行科技大學
電機工程系碩士班
102
This paper proposes a model reference adaptive system (MRAS) for the design of a speed estimator for a direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drive system. First, A MRAS is developed by utilizing the instantaneous reactive power of the motor, then the adaptation mechanism is guaranteed to be globally asymptotically stable by Popov’s criterion. Second, in order to solve the uncertainty of the nonlinear dynamic system and to raise the noise rejection capability, the sliding mode control is used to achieve this goal. Further a three phase voltage commands are produced with the DTC based on voltage space vector to drive the PMSM. To verify the effectiveness of the proposed method, the Matlab/Simulink software is used to prove the feasibility of this system. Then, the control algorithm is developed on a digital signal processor (TMS320LF2407A). Finally, the experimental system is constructed by integrating the DSP chip and the relative hardware circuit. Both simulation and experimental results show that good transient and steady-state performance is obtained by the proposed method.

碩士
國立勤益科技大學
電機工程系
98
In this thesis the sensorless permanent magnet synchronous motor drive by using high frequency signal injection is presented. Today, reducing carbon emission and energy is the goal for world development. Permanent magnet synchronous motor（PMSM）compare with other type motors has the merits for low noise, high power density, high efficiency, and less maintenance, which has been widely used in industry and household appliances. Furthermore, the high power semiconductor devices is continued development, the exploitation of micro processing technology which has ability to operate high speed, and the research for intelligent control skill, the PMSM drives are used in high performance application. In this research, the high frequency voltage signal is injected to the permanent magnet synchronous motor, and the resultant injected frequency current signal is used to estimate the rotor position. Then, the PMSM drive system based on decoupling rotor field oriented controlled is established, which used the estimated rotor position of the motor. The simulated programs are realized by MATLAB/Simulink to confirm the proposed approach.

碩士
國立清華大學
電機工程學系
98
This thesis develops a motor drive system for condensing unit applications. The system consists of a position sensorless sinewave excited interior permanent-magnet synchronous motor (IPMSM) driven compressor, a square-wave excited surface mounted PMSM (SPMSM) driven fan, and a single-phase boost-type switch mode rectifier (SMR) front end to establish their common DC-link voltage from utility with satisfactory line drawn power quality. All the constituted power stages are fully digitally controlled in a common digital signal processor (DSP). For the compressor IPMSM drive, two types of sensorless control schemes based on the devised internal model based back-EMF estimators are developed and comparatively evaluated. As to the square-wave SPMSM fan drive, its position sensorless control is conducted based on the sensed motor terminal phase voltage. For these two types of PMSM drives, the proper commutation instant shifts are applied to enhance their driving performances, which may be deteriorated due to non-ideal sensorless controls, particularly under higher speeds. In addition, the smooth starting with less current transient is also considered. Finally, in the established single-phase boost SMR front-end, it possesses the inner hysteresis current-controlled PWM (H-CCPWM) scheme and outer voltage control loop. The simple robust control approach is applied to yield improved current and voltage control performances. Moreover, various types of the randomly varying bands for the H-CCPWM schemes are proposed, and their effects on the current harmonic spectral spreading characteristics and the SMR operating performance are observed experimentally.

碩士
國立臺灣科技大學
電機工程系
97
This thesis investigates performance improvement of micro-permanent magnet synchronous motor drive systems. Two estimators, which include a state estimator and a rotor position/speed estimator, are proposed. First, the state estimator has been designed to improve the low speed performance of a micro permanent magnet synchronous motor drive system due to its low resolution encoder. Next, a novel position/speed estimator has been designed, which can obtain the position/speed by detecting the zero-current crossing signals. The position/speed estimator combines a zero-current signal processor and a phase angle compensator. In addition, by adjusting the stator current, the low speed performance of the position/speed estimator can be effectively improved. A digital signal processor, TMS320F28335, is used as a control unit to execute the state estimating algorithm and the rotor position/speed estimating algorithm. Experimental results validate the theoretical analysis and show the correctness and feasibility of this thesis.

碩士
國立臺灣科技大學
電機工程系
91
This thesis presents the analysis and implementation of a unity power factor, low current harmonics drive for permanent-magnet synchronous motors. In this system, a three-level, three-switch boost converter is used to substitute a full-bridge rectifier circuit. In order to reduce the switching loss, a new switching algorithm is proposed. As to the drive of permanent-magnet synchronous motors, the rotor-flux-oriented vector control algorithm is implemented to regulate the rotor speed stably. Besides, an inverter using sinusoidal-pulse-width-modulation technique is implemented to drive the motor. In addition, a fast power compensation algorithm is proposed to balance the power between input side and motor drive in order to improve the voltage response of the dc-link. The performance of the system is first simulated by MATLAB SIMULINK. Then, a 16-bits digital signal processor (DSP TMS320LF2407) is used to implement three-level, three-switch boost rectifier with 740W resistance load and the combined system with 460W capacity under 120volts, 60Hz power input. When dc-link is at 310 volts with 740W resistance load, experimental results show that the power factor is around 0.98 and total harmonic distortion of input current is less than 10%. Besides, The result of the combined system with 460W capacity shows the voltage ripple is improved from 15V to 7V.

碩士
國立臺灣科技大學
電機工程系
99
This thesis is composed of two parts. One is concerned with the design of permanent-magnet synchronous motor (PMSM), where Maxwell 2D produced by Ansoft company is used to obtain the optimum design with cost reduction as well as the assurance of motor performance. The other is the design of ac-dc-ac power converter which uses three-phase full-controlled full-bridge type power factor corrector in place of traditional diode rectifiers to drive the designed PMSM. The proposed control strategy not only reduces harmonic current and improves power factor in the power supply, but also keeps dc-bus voltage stable under load variation. The PMSM control can rotate in both directions. The proposed variable-frequency power inverter can reduce power dissipation and provide elevator-like performance. In addition, the inverter can also reduce harmonic current and torque pulsation for PMSM in the fully adjustable speed range. The 32-bit digital signal processor, TMS320F28335, is adopted to implement the control functions of the system. The control of the closed-loop rectifier voltage and current as well as the inverter control of motor speed and current are realized by software to reduce circuit components, and thereby improving reliability. An experimental system is built with input voltage of three-phase 220V, 60 Hz, dc-bus voltage of 340V, and PMSM as output. Experimental results show that under 1300 rpm, 11.3N-m load condition, the total harmonic distortion of current is 5.88% on the supply side, while the total harmonic distortion of current is 3.48% on the load terminal.

碩士
國立中正大學
電機工程研究所
103
This thesis is mainly about implementation of a motor driver for permanent-magnet synchronous motor. Proportional-integral (PI) control is mainly applied to motor drive control. If the capability of load variation rejection is good, the tracking ability might become poor. Therefore, this study adopts the T-S Fuzzy control method, which can design a controller with good tracking ability and load variation regulation for the system. First, the model of permanent magnet synchronous motors is introduced. Second, the tracking control strategy of permanent magnet synchronous motor speed is established. Then, the details of T-S Fuzzy control method is proposed. It contains defuzzification process and design of parallel distributed compensation. Lyapunov stability analysis shows the stability of the motor system, and Linear Matrix Inequality Toolbox is used to obtain control gains. Finally, the space vector pulse width modulation (SVPWM) is achieved through the microcontroller to drive the motor.

博士
國立臺灣科技大學
電機工程系
104
This dissertation proposes a dual-permanent-magnect-synchronous- motor drive system to increase its efficiency and to extend its constant-torque operation speed range. The proposed drive system can be separately operated at a low-speed operation mode and a high-speed operation mode. In the low-speed operation mode, the output torque is shared by the dual motors. A maximum efficiency control is proposed by suitably adjusting the distribution ratio between the two motors, so a maximum efficiency of the whole drive system can be achieved. In the high-speed operation mode, one motor is maintained at standstill and its stator windings are used as inductances of a boost converter to increase the dc-bus voltage. As a result, the second motor can extend its constant-torque high speed operation range. In addition, the energy recovery is investigated to charge the batteries and to reduce charging current ripple during a braking action. A predictive speed-loop controller and a predictive current-loop controller are designed to improve the fast transient responses, load regulation responses, and tracking responses. Finally, a fault tolerant control method is investigated. When a power device of the inverter is short circuited or open circuited, a simple method is proposed to make the output torque keep near a constant; therefore, the reliability of the drive system can be improved. A digital signal processor, TMS-320-F-2808, is used as a control conter to realize the proposed control methods. Experimental results can validate the correctness and feasibility of the proposed method. The proposed method can be applied in electric vehicle because of its simplicity.

碩士
國立清華大學
電機工程學系
96
This thesis presents the development and control of a position sensorless permanent-magnet synchronous motor (PMSM) drive for freezer applications. First, a digital signal processor (DSP) based PMSM drive with necessary sensing devices and control schemes is designed and implemented. The off-the-shelf intelligent power module is employed to construct the inverter, and the auxiliary power supplies for the constituted subsystems are properly designed. Secondly, a single-phase front-end switch mode rectifier is established to provide the well-regulated and/or boostable DC-link voltage for the motor drive with good line drawn power quality. To further enhance the operating performance of the SMR, a robust hysteresis current-controlled pulse width modulation (HCC-PWM) scheme is proposed to yield closer current waveform tracking around zero-crossing points of AC cycles. Moreover, the random switching methods for classical fixed-band and sinusoidal-band HCC-PWM schemes are developed to yield more uniformly distributed current harmonic spectrum. Thirdly, an internal model following controller based PMSM back electromotive force (EMF) estimator is devised for performing the sensorless vector control of PMSM. As the motor is started in synchronous motor mode and reaches a sufficient speed, the estimated and suitably compensated back-EMF is utilized for making the PMSM vector control. Through proper mode operation arrangement, very stable operation and good driving performance are obtained. Finally, the application of the developed sensorless PMSM drive in freezer compressor driving is studied with some experimental results being provided to evaluate its driving performance. To enhance the performance in high-speed of a freezer, the voltage boosting and commutation advanced shift control strategies and their effectiveness are also explored. In the realization of control schemes, all the developed control algorithms of SMR and motor drive are implemented in a command DSP to facilitate the miniaturization of whole motor drive system.

碩士
明新科技大學
電機工程研究所
102
In the conventional field-weakening control of the surface-mounted permanent -magnet synchronous motor (SMPMSM) drive, there are several drawbacks, which are high copper loss, serious current chattering phenomena, poor current transient response, and sensitivity to the variation of dc-link voltage. Therefore, the aim of this thesis is to propose a integrated SMPMSM drive to improve the above drawbacks. Basically, the major contributions of this thesis can be summarized as follows, First, the proposed integrated SMPMSM drive can obtain two different levels of dc-link voltage. Compare with the conventional SMPMSM control scheme with field-weakening control and MTPA operation, lower copper loss, good current transient performance, wider operational range and reduced sensitivity to the variation of dc-link voltage are achieved in the proposed integrate drive. Second, an integrated control strategy is also proposed to fully exhaust the capability of the integrated drive, and the proposed control strategy can be implemented with single low-cost DSP chip. Third, a DSP-based drive prototype is constructed according to the structure of the proposed power stage and integrate control strategy. Finally, the experimental results are given to verify the feasibility of the proposed integrated drive, and wide operation range, low copper loss, automatic and smooth transformation between different operational mode, fast dynamic response, and reduced sensitivity to the variation of dc-link voltage can be observed from the above experimental results.