Fractional Delay Based Repetitive Control with Application to PWM DC/AC Converters

Abstract

In repetitive control system, the period of exogenous signals must be the integer number of sampling points. However, it can not be always satisfied in real applications. In this paper, a systematic approach for non-integer delay repetitive control system with fixed sampling rate is proposed. The proposed fractional delay based repetitive control scheme employs the design techniques in digital signal processing theory and two different implementation structures are presented. One is easy to design and the other has optimized performance. Application of the proposed method to PWM DC/AC converter systems is studied to illustrate the design procedure and performance. Experimental results demonstrate the effectiveness of the proposed approach.