An Enhanced Time Delay Based Reference Current Identification Method for Single Phase System

Abstract

This paper proposes an enhanced time delay based current component identification method for single-phase systems to overcome the absence of filtering and poor grid frequency response of conventional method. The proposed technique integrates a delayed signal cancellation (DSC) with a time delay unit, to incorporate a dc offset rejection feature, while maintaining speedy and precise extraction of orthogonal current components. The frequency adaption is also developed through the incorporation of linear interpolation. The dynamic and steady-state performance of the proposed method is analysed and compared with two advanced second-order generalised integrator (SOGI) based methods, namely, modified SOGI and cascaded SOGI under different operating scenarios. The simulation and experimental results substantiate the advantage of zero steady-state error and lower settling time of the proposed solution while exhibiting comparable overshoot with advanced SOGI based methods.