基于电流响应包络线的永磁同步电机转子初始位置检测

Rotor Initial Position Detection of Permanent Magnet Synchronous Motors Based on Current Envelope

针对无位置传感器永磁同步电机转子初始位置检测存在的多次信号注入、过程复杂及依赖参数等不足,提出了一种基于电流响应包络线的新型检测方法。该方法仅在估算两相坐标系上注入一次脉振高频电压信号,同时控制估算坐标系低频旋转。通过提取直轴电流响应正包络线最大值对应的估算坐标系位置确定永磁体正方向,经位置补偿后获得转子初始位置。为提高检测精度,进一步提取交轴电流响应正包络线最小值对应的估算坐标系位置,并以其修正转子初始位置。此外,还分析了注入电压信号幅值及频率对该方法的影响。实验结果表明,该方法实现过程简单快速,检测最大误差为4.1？,平均误差为1.8？。

The existing rotor initial position detection for sensorless permanent magnet synchronous motor （PMSM） has some common issues such as the multiple signal injection, complicated process and dependency on the parameters. To deal with these problems, a novel method based on the current envelope was proposed. The high frequency fluctuating voltage signal was injected into the estimated two-phase coordinate system only once, which rotated at low frequency. The positive direction of permanent magnet was obtained by extracting the reference value of the coordinate system, which corresponded to the maximum value of d-axis current positive envelope. Furthermore, the rotor position was determined after the position compensation. On the basis of previous process, the reference value of the coordinate system was extracted, which corresponded to the minimum value of q-axis current positive envelope, then the more accurate rotor initial position was obtained after a rotor position correction. In addition, the effect of the injected voltage signal on the presented method was analyzed. With a maximum error of 4.1° and an average error of 1.8°, the experimental results show that the proposed method is simple and feasible.