A New Exponential Power Combined Reaching Law Sliding-mode Control for Permanent Magnet Synchronous Motor

In order to meet the high precision speed regulation requirement of permanent magnet synchronous motor (PMSM) and to overcome the influence of chattering caused by disturbance on speed, a new variable-exponent power combination reaching law is proposed. The reaching law has the characteristics of fast reaching speed and small chattering. The sliding-mode speed controller of permanent magnet synchronous motor designed based on this law is analyzed by using Lyapunov stability criterion, and compared with fast power law, double power law and variable exponential fast power law. The results show that the sliding-mode controlled variable can converge to the given value in finite time, and the convergence speed of the reaching law controller is faster when the system has bounded disturbance. It is proved that the new exponential power combination reaching law controller has fast response speed, strong robustness and good dynamic and static characteristics.