Composite Sliding Mode Speed Control for Sinusoidal Doubly Salient Electromagnetic Machine Drives Using Fast Reaching Law and Disturbance Compensation

Abstract

The proportional-integral speed controller is widely used in field-oriented control due to its simplicity in implementation; however, parameter variations and load disturbance easily lead to the deterioration of its dynamic performance. To address the above problem, a composite sliding mode speed control (CSMSC) is proposed in this article, which is composed of a sliding mode controller based on a new fast reaching law (FRL-SMC) and an extended state observer (ESO). The FRL-SMC can effectively solve the contradiction between response time and chattering amplitude, which is superior to the traditional SMC approaches; the lumped disturbance is estimated online by the ESO, and then the estimated value used as feedforward compensation is introduced into the FRL-SMC to enhance the disturbance reject ability. The sinusoidal doubly salient electromagnetic machine (SDSEM) speed regulation system applying the proposed CSMSC obtains a fast startup response and load step response, an excellent anti-disturbance performance, and a small <i>q</i>-axis current steady chattering. Finally, the effectiveness of the proposed method is verified by experimental results for a SDSEM test platform.