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-电气工程专业论文.docx

ABSTRACT The disc coreless permanent magnet synchronous motor (DCPMSM) has several advantages, such as strong overload capacity, zero cogging torque, sinusoidal distribution of flux density and back EMF and linear parameters. It is particularly suitable for the workplace where are special requirements of the motor volume, low-speed performance, fast response and strong overload ability. The motors tend to have low inductance because of the coreless structure. There is a stringent current ripple in the motor winding that produces unacceptable torque ripple if driven from conventional drivers with a PWM control method based on voltage source inverter (VSI). The purpose of this project is to research a drive system for the DCPMSM, and it will give full play to the advantages of its structure and dynamic performance. The analysis of the mechanism of current fluctuations was made based on the characteristics of the DCPMSM. The following several control strategies for the DCPMSM were analyzed and researched: The control method of the series inductance in the stator winding circuit. Three inductances were added in the stator winding circuit to increase the value of the stator inductance, and a rotor flux oriented control algorithm was adopted in the DCPMSM driver. The torque ripple with different values of the series inductor was discussed, as well as the operating characteristics at different speed was discussed. The control method based on the current chopper converter. The six-step conduction method was used in the system, each phase conducted 120° (electrical angle). The reference current vector was adjusted by the proposed current control algorithm according to the rotor angle. To control the motor electromagnetic torque, the amplitude of output current and duty cycle of the switching device of the current source chopper is calculated by a feedback loop of instantaneous torque control. The control method based on the three-level inverter. In order to improve the swit