Switching-Gain Adaptation Current Control for Brushless DC Motors

In this paper, a current control scheme with switching-gain adaptation is proposed for brushless DC motors. The scheme includes two components, namely a continuous control component and a switching control component. The continuous control component is employed with model reference adaptive control (MRAC) to approximate the parametric uncertainties, and the switching control component is used with integral sliding-mode control (ISMC) to eliminate the general disturbance caused by both the approximation errors and the unstructured uncertainties. Due to the variation in general disturbance in different operating conditions, a switching-gain adaptation method based on the unknown disturbance estimation is proposed, which improves the transient performance of the current controller and eliminates the high-frequency noise of current caused by chattering. Finally, the effectiveness of the proposed method is verified by experimental results.