Two-degree-of-freedom sensorless control of permanent magnet linear synchronous motor based on nonlinear observer

This paper presents a sensorless control method, which can estimate the stator magnetic pole position and mover speed by detecting the voltage and current of permanent magnet linear synchronous motor based on nonlinear observer. The H/sub /spl infin// control theory is used to guarantee good performance at low speed. A two-degree-of-freedom controller is obtained by solving model-matching problem. Simulation results show that the system can satisfy the servo requirement of tracking and disturbance suppressing in a wide speed range.