针对传统超螺旋滑模观测器精确性差、收敛速率慢以及抖振较高的问题，提出一种基于改进超螺旋算法的永磁同步电机（permanent magnet synchronous motor, PMSM）转速观测技术。首先，采用一种分段指数型函数替代开关函数以消除因低通滤波器所产生的相位延迟问题，并设计自适应滑模增益以实现对不同速度情况下的稳定跟踪。然后，针对传统正交锁相环在电机转向改变时失效的问题，提出一种改进正交锁相环，使其输出与旋转方向无关，从而实现对正反转的正确跟踪。最后，由于所提改进正交锁相环具有错误收敛点，且该错误会导致转子估计位置与实际位置存在180°相位差，设计一种调整函数以解决该问题。仿真结果表明：相较于传统滑模观测器，所提出的改进方法响应速度更快，动态性能更好。

Aiming at the problems of poor accuracy, slow convergence rate and high jitter of traditional super-twisting sliding mode observer, a permanent magnet synchronous motor(PMSM) speed observation technique based on the improved super-twisting algorithm was proposed. Firstly, a segmented exponential function was used to replace the switching function to eliminate the phase delay problem due to the low-pass filter, and the adaptive sliding mode gain was designed to achieve stable tracking at different speeds. Then, in order to solve the problem that the traditional quadrature phase-locked loop failed when the motor steering was changed, an improved quadrature phase-locked loop was proposed, so that its output was independent of the rotation direction, so as to realized the correct tracking of the forward and reverse rotation. Finally, due to the wrong convergence point of the proposed improved quadrature phase locked loop, there was a 180° phase difference between the estimated position and the actual position, an adjustment function was designed to solve this problem. The simulation results show that compared with the traditional sliding mode observer, the proposed improvement method has faster response and better dynamic performance.