基于固定开关频率的永磁同步电机滑模控制

Sliding Mode Control of Permanent Magnet Synchronous Motor Based on Fixed Switching Frequency

为了提高永磁同步电机(PMSM)驱动系统的性能,获取优于传统磁场定向控制(FOC)的瞬态响应,并避免传统直接转矩控制(DTC)带来的开关频率变化问题,设计了一种基于固定开关频率的PMSM滑模控制(SMC)方案。新型SMC策略使用解耦技术,将滑模曲面设计在abc参考坐标系中,由于恒定斜率允许通过计算调整滞环带宽,从而可实现开关频率控制。离散化数字控制器降低了滞环比较器的性能,即用前一个步长计算结果难以准确调节开关频率,为此设计了一种专门的预测算法以克服该问题。最后,进行了转矩和转速控制试验,试验结果验证了新控制方法的效果。

In order to improve the performance of permanent magnet synchronous motor(PMSM)driving system,a sliding mode control(SMC)of PMSM based on fixed switching frequency was designed,which has better transient response compared to the traditional field oriented control(FOC)and has no problem of the variable switching frequency in traditional direct torque control(DTC). In the new SMC strategy,the decoupling technique was used to design the sliding surface in the abc reference frame,and the constant slope allowed the adjustment of the hysteresis bandwidth,so the switching frequency could be controlled. The discrete digital controller reduces the performance of the hysteresis comparator,that is,it is difficult to accurately adjust the switching frequency with the previous step. Therefore,a special prediction algorithm was designed to overcome this problem. Finally,the torque and speed control tests were carried out,and the test results validate the effect of the new control method.