中文摘要：

针对一阶滑模观测器（F-SMO）存在的抖振和相位延迟问题,提出了基于二阶滑模观测器（S-SMO）的线反电势（LBEMF）估计策略,将不连续控制作用在滑模变量的高阶微分上,采用超螺旋算法设计控制率,能较好地削弱抖振,得到连续光滑且无滞后的反电势估计值.针对相反电势法存在的相移问题,采用线反电势过零点直接作为换相点的换相策略.仿真和实验结果表明,所提策略能够准确估计无刷直流电机线反电势,获得准确的转子位置换相点,实现无刷直流电机的无位置传感器控制.

英文摘要：

To solve the chattering and phase delay problems existing in first-order sliding mode observer （F-SMO）,line back-electromotive force （LBEMF）was estimated by a second-order sliding mode observer （S-SMO）which applied the discontinuous control function on the high order differential of sliding mode variable and employed a supertwisting algorithm in control design.To deal with the phase shift problem,a new commutation strategy based on LBEMF zero-crossing point was proposed.Simulation and experiment results show that the sensorless control system can estimate LBEMF exactly,and accurate rotor position commutation point is gained.