关键词: 无位置传感器控制, 二阶广义积分器, 锁相环, 自适应频率补偿

Abstract: In sensorless control based on back-EMF, the sliding mode observer ( SMO ) is used for back-EMF estimation,but its output results contain high-frequency chattering and noise, which necessitates additional filtering. The second-order generalized integrator ( SOGI) ,with its excellent frequency-selective characteristics,is suitable for extracting the fundamental component of the back-EMF. However,the filtering performance of SOGI is highly dependent on its center frequency,which is typically provided by a phase-locked loop ( PLL) and therefore vulnerable to frequency deviations. To address this issue, this paper proposes an adaptive frequency compensation method in which the compensation gain is adaptively adjusted according to the frequency deviation to achieve dynamic correction of the SOGI center frequency,and a stator-voltage-based center frequency estimation is introduced to eliminate the dependence on the PLL. To verify the effectiveness of the proposed method, a MATLAB / Simulink simulation model was built. Simulation results show that the method can effectively reduce center frequency deviation and improve both the filtering quality of the back-EMF and the accuracy of rotor position estimation.

Key words: sensorless control, second-order generalized integrator, phase-locked loop, adaptive frequency compensation