基于端电压平均值和准滑模观测器的无刷直流电机控制

Control of BLDC motor based on average terminal voltage and quasi sliding mode

无位置传感器控制是未来的发展趋势。为了提高无刷直流电机无位置传感器控制系统的精确度,提出了一种基于端电压平均值的线反电势准滑模观测器。为了减小传统滑模观测器存在的抖振,该观测器引入一种具有边界层的饱和函数,并采样端电压的平均值。该控制策略不需要滤波电路和相位补偿模块就能得到线反电势,而且以线反电势作为换相信号能消除以相反电势作为换相信号滞后30°电角度的问题。通过得到的线反电势对应虚拟的霍尔信号从而确定换相信号。与传统的滑模控制方法相比,该方法具有转矩脉动小、响应速度快等优点。仿真和实验结果证明了该方法的可行性和正确性。

Sensorless control is the trend of development in the future. In order to improve the accuracy of a sensorless brushless DC (BLDC) motor control system, based on an average terminal voltage, a quasi sliding mode observer with a line back electromotive force (EMF) was proposed. To reduce chattering in the traditional sliding mode observer, a saturation function with boundary layer was employed and the average terminal voltage was sampled. In the control strategy, line back EMF without filter circuit and phase compensation module were obtained, and by using of the line back EMF as commutation signal the problem of phase back EMF as commutation signal lagging 30° electrical degree was eliminated with the actual commutation signal. The virtual hall signals corresponding the line back EMF determine the commutation signals. Compared with the traditional sliding mode control method, the proposed method can be used to obtain low torque ripple and fast response speed. The simulation and experiment results show that the proposed method is effective and correct .