An Improved Speed Observer Based on Current Prediction Compensation for PMSM Sensorless Control

Traditional natural speed observer of PMSM sensorless control system has shortcomings such as poor dynamic response and large chattering. To solve these problems, this paper proposes an improved speed observer by replacing the exponential approaching law with a power-exponent approaching law. And the proposed observer further combines a current prediction compensation algorithm to reduce the digital control delay and sampling filtering delay of control system. It can optimize the input current signal of the speed observer and improve the dynamic and steady-state performance of rotor speed estimation. The experiment verified the effectiveness of the algorithm.