电动汽车轮毂用盘式无铁心永磁同步电机的控制策略研究

发布时间：2018-03-18 00:04

本文选题：无铁心电机　切入点：串电感　出处：《天津大学》2014年博士论文　论文类型：学位论文

【摘要】：盘式无铁心永磁同步电机具有功率密度高、轴向尺寸短、过载能力强、无齿槽转矩等一系列的优点,特别适合应用在对电机有扁平结构要求的驱动场合。但由于电机采用的是无铁心结构,电机定子绕组的电感值很小,如果使用传统的电压型逆变器驱动电机,绕组内的电流不能连续,从而导致电机产生较大的电磁转矩脉动。本课题的研究目的是解决盘式无铁心永磁同步电机控制的难点,研发出适合此类电机的驱动控制系统。为此,本文针对盘式无铁心永磁同步电机结构及参数的特点,在详细分析了电流波动产生的机理后,借助于传统电机的控制理论,对以下几种控制策略在盘式无铁心永磁同步电机控制上的应用进行了详细的理论分析和研究:1.主回路串电感的控制方法。采用传统的两电平电压型逆变器供电,控制算法上采用基于转子磁场定向的矢量控制。探讨了控制系统在串入不同感值的电感情况下的转矩波动,以及控制系统在不同转速和负载下的运行特性。2.基于前置电流型斩波电路的控制方法。控制策略上采用两两导通、每相导通120°的控制方式。根据角度传感器反馈的转子角度值,结合提出的电流控制算法来实时调整给定的参考电流矢量。通过控制电流型斩波电路的占空比,来实现对处于导通状态下的电机定子绕组内电流的调整,从而实现对电机转矩的控制。3.基于三电平逆变器的控制方法。为提高逆变器的开关频率,减小由于电感小所导致的电流波动问题,系统采用MOSFET作为功率驱动开关管,对基于二极管箝位型的三电平逆变器在盘式无铁心永磁同步电机控制系统上的应用进行了详细的研究和探讨。结合基于转子磁场定向的空间矢量控制算法,实现了对电机的转矩控制,并减小了由于小电感所导致的转矩脉动。4.由于电机的无铁心结构,盘式无铁心电机的电枢反应很弱,对转子磁场的弱磁控制非常困难。而当电机的反电动势接近母线电压时,想要进一步提高电机的转速,就需要提高母线电压。基于以上分析,本文采用Buck-Boost变换器来实现对母线电压的升降压控制,从而减小盘式无铁心永磁同步电机的电流波动和拓宽电机的调速范围。
[Abstract]:The disk core free permanent magnet synchronous motor has a series of advantages, such as high power density, short axial dimension, strong overload ability, no tooth slot torque, etc. It is especially suitable for driving the motor with flat structure. However, the inductance of the stator winding of the motor is very small because of the iron-free structure of the motor. If the traditional voltage source inverter is used to drive the motor, The current in the winding is not continuous, which leads to the large electromagnetic torque ripple of the motor. The purpose of this paper is to solve the difficulties in the control of the disc iron-less permanent magnet synchronous motor, and to develop a drive control system suitable for this kind of motor. In this paper, according to the characteristics of structure and parameters of disk core free permanent magnet synchronous motor (PMSM), the mechanism of current fluctuation is analyzed in detail, and the control theory of traditional motor is used. In this paper, the application of the following control strategies in the control of the disk core free permanent magnet synchronous motor (PMSM) is analyzed and studied in detail. The control method of the main loop series inductance is analyzed and studied in detail. The traditional two-level voltage source inverter is used to supply the power. The vector control based on rotor flux orientation is used in the control algorithm. The torque ripple of the control system under the condition of different inductance with different inductance is discussed. And the operating characteristics of the control system under different speed and load. 2. Based on the control method of the front current chopper circuit, the control strategy is based on two switches and 120 掳per phase. According to the rotor angle value feedback from the angle sensor, Combined with the proposed current control algorithm, the given reference current vector can be adjusted in real time. By controlling the duty cycle of the current mode chopper circuit, the current in the stator winding of the motor in the state of conduction can be adjusted. In order to improve the switching frequency of the inverter and reduce the current fluctuation caused by the small inductance, MOSFET is used as the power driven switch tube. The application of the three-level inverter based on diode clamping in the control system of the disc iron-less permanent magnet synchronous motor (PMSM) is studied and discussed in detail, combined with the space vector control algorithm based on rotor magnetic field orientation. The torque control of the motor is realized, and the torque ripple caused by the small inductance is reduced. 4. Because of the iron-free structure of the motor, the armature reaction of the disc iron-less motor is very weak. It is very difficult to control the weak magnetic field of the rotor. However, if the back EMF of the motor is close to the bus voltage, it is necessary to increase the bus voltage to further increase the speed of the motor. In this paper, the Buck-Boost converter is used to control the bus voltage, which reduces the current fluctuation and widens the speed range of the disc core free permanent magnet synchronous motor (PMSM).
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM341;U469.72

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