Design of High Efficiency Brushless Permanent Magnet Machines and Driver System

The dissertation is concerned with the design of high-efficiency permanent magnet synchronous machinery and the control system. The dissertation first talks about the basic concept of the permanent magnet synchronous motor (PMSM) design and the mathematics design model of the advanced design method. The advantage of the design method is that it can increase the high load capacity at no cost of increasing the total machine size. After that, the control method of the PMSM and Permanent magnet synchronous generator (PMSG) is introduced. The design, simulation, and test of a permanent magnet brushless DC (BLDC) motor for electric impact wrench and new mechanical structure are first presented based on the design method. Finite element analysis based on the Maxwell 2D is built to optimize the design and the control board is designed using Altium Designer. Both the motor and control board have been fabricated and tested to verify the design. The electrical and mechanical design are combined, and it provides an analytical IPMBLDC design method and an innovative and reasonable mechanical dynamical calculation method for the impact wrench system, which can be used in whole system design of other functional electric tools. A 2kw high-efficiency alternator system and its control board system are also designed, analyzed and fabricated applying to the truck auxiliary power unit (APU). The alternator system has two stages. The first stage is that the alternator three-phase outputs are connected to the three-phase active rectifier to get 48V DC. An advanced Sliding Mode Observer (SMO) is used to get an alternator position. The buck is used for the second stage to get 14V DC output. The whole system efficiency is much higher than the traditional system using induction motor

Advances in Rotating Electric Machines

It is difficult to imagine a modern society without rotating electric machines. Their use has been increasing not only in the traditional fields of application but also in more contemporary fields, including renewable energy conversion systems, electric aircraft, aerospace, electric vehicles, unmanned propulsion systems, robotics, etc. This has contributed to advances in the materials, design methodologies, modeling tools, and manufacturing processes of current electric machines, which are characterized by high compactness, low weight, high power density, high torque density, and high reliability. On the other hand, the growing use of electric machines and drives in more critical applications has pushed forward the research in the area of condition monitoring and fault tolerance, leading to the development of more reliable diagnostic techniques and more fault-tolerant machines. This book presents and disseminates the most recent advances related to the theory, design, modeling, application, control, and condition monitoring of all types of rotating electric machines

Medición del sentido de giro, velocidad y posición angular de un eje mediante encoders

En este artículo se presentan algoritmos para la detección del sentido de giro, distintos a los reconocidos en la literatura técnica, y además se estudia la medida de la velocidad y la posición angular por medio de un encoder incremental. El principio básico consiste en utilizar una señal cuasi triangular, en lugar de una onda cuadrada convencional. Se compara la salida del algoritmo de velocidad, el cual es asincrónico, con métodos convencionales, que son sincrónicos; y se concluye que los resultados son satisfactorios. También se verifica el cálculo de la medida de posición, por medio de la comparación con un encoder absoluto.Palabras clave: Adquisición de datos, encoder absoluto, encoder incremental, posición angular, velocidad angular

Development of an Actuation System for Automatic Immobilization Boards for Breast Cancer Radiotherapy

학위논문 (석사)-- 서울대학교 대학원 : 융합과학기술대학원 융합과학부, 2018. 2. 예성준.유방암 방사선 치료는 일반적으로 1일 1회씩 6-7주에 걸쳐 총28-33회로 수행된다. 정확한 방사선 치료를 위해 매회 같은 자세로 치료를 받아야 하고, 이를 위해 상체고정장치가 사용된다. 상체고정장치에는 수동으로 조절되는 여러 개의 조절부가 있으나, 짧은 시간에 환자를 치료 자세로 세팅하기 위해서 실제로는 2-3개의 조절부만이 사용되고 있다. 환자에 따라서 초기에 설정된 치료 자세로 자동으로 고정이 가능하다면, 세팅 시간이 줄어들면서도 모든 조절부를 사용하므로 방사선치료의 정밀성을 높일 수 있게 된다. 본 연구는 현재 유방암 방사선치료에 사용되고 있는 상체고정장치를 개조하여 자동화시키는 것을 목표로, 각 조절부를 구동하기 위한 구동시스템을 개발하는 것을 주 연구내용으로 하고 있다. 이를 위해, 병원에서 가장 널리 사용되고 있는 C 사의 상체고정장치를 사용하였다. 또한 CT 촬영 시 금속 음영이 생기지 않도록 금속 부품을 배치하여 구동시스템을 설계하였다. 환부에 정확히 방사선을 조사하기 위해서 지지부들의 위치는 정확하게 설정되어야 하므로, 본 연구에서는 dual absolute encoder 측정방식을 제안하였고, 이를 구동시스템 일부에 적용하였다. 시작품 제작 및 실험을 통해 dual absolute encoder를 적용한 구동시스템으로 상체고정장치를 자동화 시키는 것이 가능함을 보였다.Radiation therapy for breast cancer is conducted a total of 28–33 times and is generally administered once a day over a period of 6–7 weeks. In order to correctly expose the tumors to radiation, the patient setup should be the same every timefor this reason, an immobilization board is utilized. An immobilization board for breast cancer radiotherapy has many possible manual adjustments, but usually only 2–3 adjustments are used, so as to quickly fix the patient setup. However, for proper radiation therapy, the system of adjustments should be configured in a precise way. If it were possible to automatically set all the adjustments to each patients specific setup as initially configured, then it would take less time to fix each patient, and the radiotherapy could be administered more precisely by employing all the necessary adjustments. This study aims to remodel and automate a currently used immobilization board. The main focus is on developing an actuation system to drive the adjustments. Company Cs immobilization board, which is widely used in hospitals, is employed as the base frame. In designing the actuation system, its metal parts were specifically placed so that metal artifacts do not appear while the CT scan is being conducted. This study proposes a dual absolute encoder measurement and purposefully applies this method to the adjustments. The automation of an immobilization board with this system is demonstrated through prototyping and experimentation.제 1 장 서 론 1 제 1 절 연구 배경 1 제 2 절 연구 내용 5 제 2 장 구동부 절대위치 측정 시스템 6 제 1 절 관련연구 및 듀얼 절대엔코더 시스템 6 제 2 절 이론적 고찰 8 1) 감속비가 정수일 때 최소 분해능 10 2) 감속비가 정수가 아닐 때 최소 분해능 11 3) 최대분해능 13 제 3 절 시뮬레이션 14 제 4 절 실험 및 결과 고찰 16 1) 감속비가 정수일 때 실험 결과 17 2) 감속비가 정수가 아닐 때 실험 결과 21 제 3 장 상체고정장치 자동화를 위한 구동시스템 26 제 1 절 관련연구 및 연구추진방향 26 1) 관련연구 26 2) 연구추진방향 27 제 2 절 각 자유도의 자동화를 위한 메커니즘 설계 28 1) 상박 받침대 위치 조절 메커니즘 설계 29 2) 엉덩이 받침대 위치 조절 메커니즘 설계 34 3) 머리 받침대 위치 조절 메커니즘 설계 35 제 3 절 상박 조절부의 직교좌표 변환 36 제 4 절 실험 및 결과 고찰 41 1) 실험 장치 제작 41 2) 듀얼 절대 엔코더 실험 및 결과고찰 48 3) CT 영상 금속 음영 실험 및 결과고찰 50 4) 위치 반복성 실험 및 결과고찰 51 제 4 장 결론 54 참고문헌 56 부록 59 Abstract 62Maste

Design optimization and performance analysis methodology for PMSMs to improve efficiency in hydraulic applications

Pla de Doctorats Industrials de la Generalitat de CatalunyaIn the recent years, water pumping and other hydraulic applications are increasingly demanding motors capable to operate under different working conditions, including variable pressure and volumetric flow demands. Moreover, the technical evolution trend of pumping components is to minimize the size, offering compact and adaptable hydraulic units. Hence, the need to optimize the electric motor part to reduce the volume according this trend, maximizing the efficiency, decreasing material and fabrication costs, reducing noise and improving thermal dissipation have originated the research field of this project. So far different methodologies have been focused on designing electrical machines considering few aspects, such as the rated conditions with some size limitations. In addition, the optimization strategies have been based on single operation conditions, improving multiple aspects but not considering the overall performance of the machine and its influence with the working system. This research changes the design and optimization paradigm, focusing on defining beforehand the desired performance of the electrical machine in relation with the application system. The customization is not limited to an operating point but to the whole performance space, which in this case is the torque-speed area. Thus, the designer has plenty of freedom to study the system, and define the desired motor performance establishing the size, thermal and mechanical limitations from the beginning of the process. Moreover, when designing and optimizing electrical machines, the experimental validation is of major importance. From an industrial scope so far, the testing methodologies are focused on evaluating point by point the electrical machine performance, being a robust and trustable way to measure and validate the electrical machine characteristics. Nevertheless,this method requires a large time to prepare the experimental setup and to evaluate the whole motor performance. For this reason, there is a special interest on improving parameter estimation and performance evaluation techniques for electrical machines to reduce evaluation time, setup complexity and increase the number of physical magnitudes to measure in order to have deeper information. This research also develops methodologies to extend the electrical machine experimental validation providing information to evaluate the motor performance. This doctoral thesis has been developed with a collaboration agreement between UPC and the company MIDTAL TALENTOS S.L. The thesis is included within the Industrial Doctorates program 2018 DI 019 promoted by the Generalitat de Catalunya.En los últimos años, el bombeo de agua, entre otras aplicaciones hidráulicas, exige cada vez más motores capaces de operar en diferentes condiciones de trabajo, incluyendo las demandas variables de presión y caudal volumétrico. Además, la evolución técnica de los componentes de bombeo está cada vez más minimizando el tamaño ofreciendo unidades hidráulicas compactas y adaptables. De ahí la necesidad de optimizar la parte del motor eléctrico para reducir el volumen de acuerdo con esta tendencia, maximizando la eficiencia, disminuyendo los costos de material y fabricación, reduciendo el ruido y mejorando la disipación térmica. Todos estos factores han creado el campo de investigación sobre el cual se desarrolla este proyecto. Hasta ahora las metodologías se han centrado en diseñar las máquinas eléctricas considerando unos pocos aspectos técnicos, como las condiciones nominales con algunas limitaciones de tamaño. Además, las estrategias de optimización se han basado en condiciones de operación única, mejorando múltiples aspectos sin considerar el rendimiento general de la máquina y su influencia en el sistema de trabajo. Esta investigación cambia el paradigma de diseño y optimización centrándose en definir de antemano el rendimiento deseado de la máquina eléctrica en relación con el sistema de aplicación. La personalización no se limita a un punto de funcionamiento sino a todo el espacio de operación, que en este caso se expresa en el espacio par-velocidad. Así, el diseñador tiene libertad para estudiar el sistema, definir el rendimiento deseado del motor estableciendo el tamaño, limitaciones térmicas y mecánicas desde el inicio del proceso. Además, a la hora de diseñar y optimizar máquinas eléctricas, la validación experimental es de gran importancia. En el ámbito industrial hasta ahora, las metodologías de ensayo han sido enfocadas a evaluar punto por punto la máquina eléctrica, siendo una forma robusta y confiable de medir y validar sus características. Sin embargo, este método requiere mucho tiempo para preparar la configuración experimental y evaluar el motor en toda su zona de operación. Por esta razón, existe un interés especial en mejorar la estimación de parámetros y las técnicas de evaluación de la operación de las máquinas eléctricas reduciendo tiempo, complejidad y aumentando el número de magnitudes físicas a medir teniendo más información sobre la máquina. Esta investigación también desarrolla metodologías para extender la validación experimental de la máquina eléctrica proporcionando información para evaluar el rendimiento del motor. Esta tesis doctoral ha sido desarrollada con un convenio de colaboración entre la Universidad Politécnica de Cataluña UPC y la empresa MIDTAL TALENTOS S.L. La tesis se engloba dentro del plan de Doctorados Industriales 2018 DI 019 impulsado por la Generalitat de Catalunya.Postprint (published version

Precision Control of a Sensorless Brushless Direct Current Motor System

Sensorless control strategies were first suggested well over a decade ago with the aim of reducing the size, weight and unit cost of electrically actuated servo systems. The resulting algorithms have been successfully applied to the induction and synchronous motor families in applications where control of armature speeds above approximately one hundred revolutions per minute is desired. However, sensorless position control remains problematic. This thesis provides an in depth investigation into sensorless motor control strategies for high precision motion control applications. Specifically, methods of achieving control of position and very low speed thresholds are investigated. The developed grey box identification techniques are shown to perform better than their traditional white or black box counterparts. Further, fuzzy model based sliding mode control is implemented and results demonstrate its improved robustness to certain classes of disturbance. Attempts to reject uncertainty within the developed models using the sliding mode are discussed. Novel controllers, which enhance the performance of the sliding mode are presented. Finally, algorithms that achieve control without a primary feedback sensor are successfully demonstrated. Sensorless position control is achieved with resolutions equivalent to those of existing stepper motor technology. The successful control of armature speeds below sixty revolutions per minute is achieved and problems typically associated with motor starting are circumvented.Research Instruments Ltd

High-Performance Control of Switched Reluctance Motors

A general high bandwidth, low ripple, instantaneous torque control strategy with a variable field-angle for extended constant-power speed range is presented. The strategy is based on the SR motor's electromagnetic characteristics measured at the motor terminals and is the nearest functional equivalent to AC vector control for this type of machine. Low torque ripple and high bandwidth are achieved over a wide range of speeds and a constant power range of 3:1. The proposed controller, which is applicable to most SR motors, is found to reduce the torque ripple by a factor of 5 in comparison with conventional square-wave current operation, and has been operated over a speed range of 1:6000

Power Converter of Electric Machines, Renewable Energy Systems, and Transportation

Power converters and electric machines represent essential components in all fields of electrical engineering. In fact, we are heading towards a future where energy will be more and more electrical: electrical vehicles, electrical motors, renewables, storage systems are now widespread. The ongoing energy transition poses new challenges for interfacing and integrating different power systems. The constraints of space, weight, reliability, performance, and autonomy for the electric system have increased the attention of scientific research in order to find more and more appropriate technological solutions. In this context, power converters and electric machines assume a key role in enabling higher performance of electrical power conversion. Consequently, the design and control of power converters and electric machines shall be developed accordingly to the requirements of the specific application, thus leading to more specialized solutions, with the aim of enhancing the reliability, fault tolerance, and flexibility of the next generation power systems

Novel Flux-weakening Control of Permanent Magnet Synchronous Machines with Particular Reference to Stability Issues

For many applications, such as electric vehicles and washing machines, flux-weakening control is required for permanent magnet synchronous machine (PMSM) drives to extend the operation speed range and maximize the power capability under the voltage and current constraints. Voltage magnitude feedback flux-weakening control is widely employed due to its advantages of simple and standard control structure, robustness against parameter variation, both linear and over modulation flux-weakening operation, and automatic flux-weakening operation. However, stability problems are prone to occur in the flux-weakening region since the PMSM drive will operate on the boundary of the voltage limit. In this thesis, based on a non-salient-pole PMSM, the factors that could cause stability problems in the flux-weakening region with voltage magnitude feedback flux-weakening control are investigated and the corresponding solutions are developed. Firstly, based on a d-axis current voltage feedback controller, an adaptive control parameter method is proposed for the PMSM machine without maximum torque per voltage (MTPV) region, which aims to ensure the stability in a wider speed range. Then, a current reference modifier (CRM) and a voltage limit reference modifier (VRM) are incorporated with the conventional voltage feedback controller in order to improve the stability in the over modulation region. As for the PMSM machine with MTPV region, an extra feedback controller is introduced with an MTPV penalty function. The MTPV penalty function is optimized in terms of its effect on the steady-state performance, the dynamic performance, and the stability in the MTPV region. Afterward, the MTPV controller is properly selected and designed. Furthermore, two flux-weakening control methods accounting for MTPV, i.e. dq-axis current based feedback flux-weakening control, and current amplitude and angle based feedback flux-weakening control, are developed and compared in terms of the stability. It shows that the two methods exhibit complimentary merits and demerits in different regions, and consequently, a hybrid feedback flux-weakening control is proposed to combine their synergies and overcome their demerits. As the feedback voltage ripples that origin from the non-ideal drive system can be amplified by a conventional speed PI controller, the oscillation may even occur if a good speed dynamics is required in the flux-weakening region. An adaptive fuzzy logic speed controller is proposed and implemented to reduce the feedback voltage ripples while maintaining good speed dynamics