基于幂次趋近律滑模观测器的无刷直流电机无位置传感器控制系统研究

Research on Sensorless Control System of Brushless DC Motor Based on Power Reaching Law Sliding Mode Observer

为了实现无刷直流电机无位置传感器控制,提出一种基于幂次趋近律的滑模观测器对无刷直流电机进行反电动势观测,为了减小系统的抖振,讨论了幂次趋近律指数α对反电动势的影响。选取合适的α值能有效地削弱抖振,得到光滑的线反电动势。仿真和实验表明,与传统滑模观测器相比,基于幂次趋近律的滑模观测器能够准确的观测出无刷直流电机的反电动势,具有较高的稳态精度,对于负载突变具有较好的适应性。

In order to realize the position sensorless control of brushless DC motor,this paper proposed a sliding mode observer based on the power reaching law to estimate the back electromotive force(back-EMF) of the brushless DC motor. In order to reduce the chattering of the system,the effect of the index α on the back-EMF was discussed. Selecting the appropriate value of α could weaken the chattering and obtain a smooth line back-EMF. The simulation and experiments results show that compared with the traditional sliding mode observer,the proposed method can accurately estimate the line back-EMF of the brushless DC motor,which has high steady-state accuracy and has a better adaptability to load mutations.