A Method to Suppress Noise in Position Sensorless Control of PMSM Based on High-Frequency Signal Injection

In this paper, an improved sensorless control method based on high-frequency square-wave signal injection of PMSM is proposed. The frequency spectrum of high-frequency current is expanded by injecting random-frequency and high-frequency square-wave voltage into the d-axis, thereby reducing audible noise. The optimal amplitude of the injected voltage is investigated. This paper designs and verifies the optimization program by calculating the root-mean-square error of the selected estimates. The performance of the proposed method is verified through MATLAB/Simulink simulation.