Abstract: Permanent magnet synchronous motors are suitable for direct diving of high precision numerically controlled servo systems. However, the high sensitivity of disturbance influence the position accuracy. Aiming at the problem, an improved active disturbance rejection control strategy of permanent magnet linear synchronous motors was proposed. A new nonlinear function was introduced into the extended state observer to overcome the rough of nonlinear function in extended state observer of conventional ADRC. By using the extended state observer of improved ADRC, the total disturbance of the system was estimated for realtime dynamic compensation. The proportional differentiator was used to replace the nonlinear state error feedback(NLSEF), and the difficulty of system parameter adjustment was reduced. The Matlab was used to simulate PMLSM speed control system based on the improved ADRC control strategy, and the effects of systems noload start response characteristics and suddenlyapplied load disturbances on the steadystate performance of the system were tested. The results indicate that the improved ADRC strategy has better load disturbance rejection and smaller overshoot than the traditional ADRC control strategy. It can make the system has a good control accuracy.
Key words: improved active disturbance rejection control; nonlinear function; improved extended state observer; permanent magnet linear synchronous motor(PMLSM)