Research on high frequency pulsating voltage signal injection method of IPMSM based on gradient descent method

In the low-speed sensorless control of interior permanent magnet synchronous motor (IPMSM) drive system, the pulsating high frequency signal injection method is often used to estimate the rotor position by tracking the salient polarity of the motor. Because of the influence of inverter nonlinearity and load disturbance, it is difficult to observe the position information in the current response through the traditional phase-locked loop (PLL). Based on the traditional PLL, an improved observer is proposed in this paper. The gradient descent method is used to update the parameters of PLL parameters online, which not only ensures the accuracy of position extraction, but also has certain robustness to load disturbance. The correctness of the method is verified by simulation analysis.