A Complex Repetitive Controller Based on the Generalized Delayed Signal Cancelation Method

In this paper, a generic complex repetitive controller (nk + m RC, k ∈ Z), based on the inverse transfer function of the generalized delayed signal cancelation transformation is proposed. The presented complex controller can be designed for regulating different positiveand negative-sequence harmonic components through a spacevector error signal, with improved response time as compared to traditional repetitive controllers. An evaluation of the proposed control scheme stability, based on phase margin, Nyquist diagram, and sensitivity function is presented. The effects of the controller parameters on the system's stability and also on its dynamic response are shown and allow the definition of some control design guidelines. Experimental results are presented to validate the theoretical assumptions through applying the proposed controller for regulating the currents in a three-phase active power filter.

I. Introduction

In Order to design a control system, it is advisable to recognize the performance requirements. Also, it is useful to know the plant model and the characteristics of the reference signals for the choice of the most appropriate control strategy.