Research on sensorless control system of low speed and high power PMSM based on improved high frequency signal injection

Abstract

With more and more applications of high-power PMSM in low-speed applications, the accuracy of the control system has also become more demanding. It is difficult to detect the position and control the speed of the motor according to the counter EMF because its amplitude is small. This paper adopts an improved high frequency signal injection method and the filtering method of single synchronous shafting filter and PLL, a set of high-power sensorless AC speed regulating system is designed based on the NPC three-level back-to-back converter with IGBTs which improves the robustness and control accuracy of low-speed high-power PMSM. The experimental and simulation results show that the control system meets the design requirements of engineering application.