一种新型的内置式永磁同步电机无位置传感器低速控制策略

A Novel Position Sensorless Control for Interior Permanent Magnet Synchronous Motor at Low Speed

在基于高频注入的内置式永磁同步电机(interior permanent magnet synchronous motor,IPMSM)无位置传感器低速控制场合,需要使用滤波器提取位置信息和反馈电流环基频分量,但滤波器会导致信号延迟、减小电流环带宽。同时,为提高观测位置的精度,必须对逆变器电压误差进行补偿,由于数字控制系统有一个开关周期的延迟,采用先计算后补偿的方式复杂且准确度不高。针对以上两个问题,该文提出一种基于dq轴电压信号注入的转子位置观测方法。通过将磁场定向控制(field oriented controller,FOC)周期与电压信号注入周期相分离,避免了滤波器的使用。通过在估计差的补偿。最后在一套1.5k W IPMSM无位置传感器矢量控的d轴或q轴依次注入正反电压信号实现了对逆变器电压误制系统实验平台验证了控制策略的有效性。

In sensorless control system of IPMSM based on high frequency signal injection at low speed, filters are needed for extracting the position information and fundamental current However, filters will cause signal delay and limit the bandwidth of current-loop. At the same time, inverter voltage error should be compensated to get a better performance, but the traditional compensation method is complicated and less accurate because of a delay in digital control. To solve these two problems, a novel signal injection method was proposed by separating the FOC period and the injection period so filters are not needed, then injected two opposite voltage vectors to reduce the inverter voltage error. The experimental results demonstrated the feasibility of the proposed estimation strategy by a 1.5kW IPMSM sensorless vector controlled drive.