基于双锁相环的永磁同步电机转子初始位置估算方法

针对永磁同步电机(permanent magnetic synchronous motor, PMSM)无位置传感器控制中转子初始位置难以精确估算的问题，提出了一种基于注入变频方波电压的双锁相环结构转子位置估算的方案。首先对电机施加振幅相同方向相反的低频方波电压判别转子极性。然后提高方波电压频率至3 kHz，使用一种新型的双锁相环结构对转子位置估算值进行适应性误差补偿，以提高估算精度。最后保持高频信号注入进行电机空载、负载启动，全程无需中断和改变注入信号。实验表明，该方法对转子初始位置估算误差最大不超过3.73°，平均估算时间为0.18 s，估算过程中电机保持静止。当电机启动时，双锁相环结构比传统锁相环结构估算时间缩短18 ms，最大补偿角度为38.39°。估算过程未引入电机敏感参数，系统具有良好的稳定性和快速性。

Rotor initial position estimation method of PMSM based on a double phase-locked loop

In sensorless control of a permanent magnet synchronous motor (PMSM), the initial position estimation is difficult. An accurate estimation method based on square-wave voltage injection with frequency conversion and double phase-locked loop is proposed. First, the polarity of the rotor is determined by applying a low frequency square wave voltage in the opposite direction of the same amplitude. Then, the frequency is increased to 3 kHz, and a double phase-locked loop is used to compensate the rotor position adaptively to improve estimation accuracy. Finally, it keeps signal injection for PMSM start-up with no-load and load experiments. The injected signal is not interrupted nor changed during the whole process. Experiments show that the maximum error is less than 3.73°, and the average estimate time is 0.18 s. The motor remains stationary. When the PMSM is started up, the double phase-locked loop shortens the time by 18 ms compared with the PLL and the maximum compensation angle is 38.39°. The estimation process does not introduce sensitive parameters, and the system has good stability and speed. This work is supported by the National Natural Science Foundation of China (No. 51707195).