Analysis and comparison of two current sensorless servo control methods for permanent magnet synchronous motor

Abstract

The cost of motor control system can be reduced by adopting current sensorless control strategy in the application of small power servo motor, and the position control accuracy of the system can be guaranteed. Among the current sensorless control methods, the no current loop method and current estimation method are commonly used. In this paper, the principle and realization process of the two methods are introduced in detail. The performance of the two methods is compared by the open-loop bode diagram of the system, and the parameter robustness of the two methods is compared by the closed-loop zero pole map of the system. The two kinds of current sensorless servo control methods are realized by simulation based on a small power surfaced permanent magnet synchronous motor, and the results of theoretical comparison are verified. Finally, the two control methods are compared in terms of system performance and parameter robustness.