电动汽车用开关磁阻电机五电平功率变换器

A Five Level Power Converter for Switched Reluctance Motor for Electric Vehicle

功率变换器是开关磁阻电机控制系统的重要组成部分,为相绕组提供励磁和退磁电压,其性能的好坏会对系统性能产生直接影响。提出了一种新型五电平功率变换器,直流侧串联2个电容,电容中点通过2个横向桥分别与每一相绕组两端相连。通过主桥臂和横向桥配合,为相绕组提供不同等级的电压,可使电机工作在5种不同的工作模式。相对于传统的功率变换器,五电平功率变换器提供了更多的电压选择,有利于提高电机输出性能。通过仿真对比传统半桥式功率变换器和五电平功率变换器在直接瞬时转矩控制中的控制效果,证明了新拓扑能够更好地抑制转矩脉动。

Power converter is an important part of switched reluctance motor control system. It provides excitation and demagnetizing voltage for phase windings, and its performance will directly affect system performance. A five level power converter is proposed in this paper. The DC side is connected in series with two capacitances. The capacitances＇ midpoint is connected to each end of the winding through two transverse bridges respectively, and it can operate in five different working modes by controlling the on-off of switches. Compared with the traditional power converter, the proposed power converter provides more voltage selection, which is beneficial to improve the output performance of the motor. Finally, two simulation models of the power converter are established through the simulation model. The control method is direct instantaneous torque control. Simulation results prove that the control topology proposed in this paper has better control effect.