关键词: 无刷直流电动机, 滑模观测器, 锁相环, 凹凸性

Abstract:

In order to alleviate the chattering in conventional sliding mode observer, a new concave control function was studied under the condition of analyzing the existing control function, and was theoretically proved that the observed back electromotive force(back-EMF) chattering by using this concave control function was smaller. A sliding mode observer based on the concave control function was proposed to estimate the back-EMF,and the estimated back-EMF of the sliding mode observer was processed by the normalization method, and phase locked loop method was adopted to extract the rotor speed and position.The simulation results show that the proposed method can accurately estimate the back-EMF and position of the rotor, effectively weaken the chattering and improve the angular accuracy of the rotor position.

Key words: brushless DC motor (BLDCM), sliding mode observer (SMO), phase-locked loop (PLL), convexity