面向永磁同步电机无传感器控制的二阶改进扩展状态观测器

In view of the problem that the conventional extended states observer (ESO) increases the gain of the correction term in order to ensure convergence and improve the dynamic performance of the system, and thus aggravates the sensitivity to high-frequency noise, an improved ESO (IESO) for sensorless control of permanent magnet synchronous motor (PMSM) is proposed in this paper. First, combined with PMSM extended back electromotive force model, extended back electromotive force is regarded as the extended state of ESO. Then, IESO is designed by using the output of the low-order dynamic equation as the input of the high-order dynamic function to effectively reduce the gain of the correction term, and thus reduce the sensitivity of the system to high-frequency noise. Then, the saturation function is introduced into the correction term to limit the peaking phenomenon that may be introduced by the high gain observer, and the convergence analysis is carried out. The numerical simulation results reveal that, compared with the conventional linear ESO, through the IESO proposed in this paper, the dynamic performance of the PMSM sensorless control system is improved when the motor is started, the speed is adjusted and the load is suddenly applied. The maximum value of error is reduced and the convergence speed is accelerated by about 25%. Besides, when 0. 5 A random high-frequency noise is added to the measured current, the convergence time of the traditional method increases by about 25 %, and the maximum speed error increases by about 40%, while those of IESO do not increase significantly. Compared with traditional methods, IESO's angle error high-frequency noise is reduced by about 60%, so IESO can significantly suppress system high-frequency noise.