关键词: 永磁同步电机, 增益控制, 方波注入, 转子位置估算

Abstract: When the permanent magnet synchronous motor works in the zero low speed domain, the traditional differential demodulation method for high frequency pulse vibration square wave voltage injection will have the problems of system instability and dynamic performance degradation due to the influence of system delay time. In order to improve the stability and convergence of the system, a gain control strategy under unitary error coefficient was proposed. The open-loop gain variation trend of position tracker under different delay time in traditional differential demodulation method was analyzed, and the conclusion was drawn that the delay time affected the amplitude and sign of the gain. The stability and convergence of the system were improved by solving the actual open-loop gain expression when the delay time changed and using the actual gain value to scale the error function. Experimental results show that the method not only improves the stability of the position estimation system, but also converges faster than the existing differential modulation method.

Key words: permanent magnet synchronous motor ( PMSM ), gain control, square wave injection, rotor position estimation