A General Parallel Disturbance Controller for PMSM Drives Based on Frequency Domain Design

Improving the dynamic disturbance rejection capability is of vital importance to the motor drive system. In this article, a general parallel disturbance controller is proposed, and the concrete implementation in continuous domain and discrete domain is given under the speed loop and current loop, respectively. By integrating feedforward and feedback branches, the parallel controller inherits the design in disturbance observer which is independent of the closed-loop feedback controller, and focuses on system robustness against uncertainties. Besides, the parameter in the controller can be directly adjusted by frequency domain analysis. Compared with traditional disturbance observer and linear extended state observer, theoretical analysis shows that the disturbance controller has satisfied disturbance rejection performance, noise suppression, and stability. Experimental results validate the effectiveness of the proposed design in a permanent magnet synchronous machine (PMSM) test rig.