中文摘要：

提出一种基于滑模观测器与分数阶锁相环（FO-PLL）的无传感器永磁同步电机（permanent magnet synchronous motor，PMSM）矢量控制算法．首先用滑模观测器估计出反电势，然后设计FO-PLL对转子位置和速度进行估计．切换函数采用饱和函数代替开关函数，有效地削弱了滑模观测器存在的抖振．所提出的FO-PLL包含一个可调的分数阶次r，因此与传统锁相环（PLL）相比，该FO-PLL具有一个额外的自由度，传统PLL也可以看成是FO-PLL的一个特例．通过选择合适的分数阶次r，能够获得更好的转子位置和速度观测性能．仿真结果证明了所提方法的有效性．

英文摘要：

A sliding mode observer and fractional-order phase-locked loop （FO-PLL） method is proposed for the sensorless speed control of a permanent magnet synchronous motor （PMSM）. The saturation function is adopted in order to reduce the chattering phenomenon caused by the sliding mode observer. In this proposed FO-PLL method, a regulable fractional order r is involved, which means that the FO-PLL provides an extra degree of freedom. In fact, the conventional phase-locked loop （PLL） applied in sensorless PMSM control can be seen as a special case of the proposed FO-PLL. By selecting a proper fractional order r a better performance may be achieved. The computer simulation results demonstrate the effectiveness of the proposed method.