Disturbance Suppression and System Design Based on Parallel-Equivalent-Input-Disturbance Approach

The conventional equivalent-input-disturbance (EID) approach exhibits two estimation errors that degrade the disturbance-suppression performance. This article aims to suppress the effects of estimation errors and improve disturbance-suppression performance. Taking the errors to be an artificial disturbance, several other EID compensators are connected to suppress the disturbance. Simplifying the connected EID compensators yields the design of a parameter, p , in the conventional EID estimator. Based on such an idea, this article presents a parallel-EID (PEID) approach, which has many merits. The disturbance-suppression performance of this approach is better than that of previous related studies, while its configuration is simple and universal. The physical meaning of p is clear and explains the reason why the disturbance-suppression performance improves. Furthermore, this article designs a novel virtual filter for transforming the PEID-based control system into an equivalent configuration that is easy to derive stability conditions. Finally, the PEID approach is applied in controlling the speed of a permanent magnet synchronous motor. Additionally, comparisons between the conventional EID, improved EID, PEID, and modified EID approaches show the validity and superiority of the PEID approach.

Automated summary

This article aims to suppress the effects of estimation errors and improve disturbance-suppression performance by connecting multiple artificial disturbances. A parameter p is designed to simplify the conventional EID estimator, and a parallel-EID (PEID) approach is proposed, which has many advantages. The PEID approach outperforms previous studies in disturbance-suppression performance, with a simple and universal configuration. Additionally, a novel virtual filter is designed to transform the PEID-based control system into an equivalent configuration for deriving stability conditions easily. The PEID approach is applied to control the speed of a permanent magnet synchronous motor, and comparisons with other approaches confirm its validity and superiority.