IMPROVED INTEGRAL SLIDING MODE CONTROL METHODS FOR SPEED CONTROL OF PMSM SYSTEM

To improve the disturbance rejection property of permanent magnet syn- chronous motor (PMSM) speed control system, the integral sliding mode control (ISMC) method is introduced in the control design of speed loop. However, the simulation and implementation results show that it is difficult to balance the chattering and the anti- disturbance capacity. To this end, three kinds of improved ISMC control methods are developed. First, ISMC using linear varying gain is developed. Using this method, the switching gain of ISMC controller can be smaller while still ensuring that the speed state reaches its steady state and the steady state uctuations can thus be reduced. Moreover, the anti-disturbance capacity of the PMSM system can also be assured. Second, an in- tegral…