DC-AC Converter with Dynamic Voltage Restoring Ability Based on Self-Regulated Phase Estimator-DQ Algorithm: Practical Modeling and Performance Evaluation

Abstract

A self-regulated phase estimator (SRPE)-based DQ algorithm for a DC-AC converter with dynamic voltage restoring (DVR) ability is presented in this paper. When compared to the conventional phase-locked loop (PLL), the provided controller can significantly reduce phase distortions and low-order harmonics from the load voltage while attaining quicker dynamic response. Furthermore, the fundamental attribute of the load voltage allows the integrated DC-AC converter to operate at a consistent frequency eliminating frequency oscillations. The SRPE is utilized primarily in the DQ control theory as the reference voltage generator which can compensate for the grid voltage. SRPE has good band-pass filtering properties and a mathematically simple structure that can thoroughly attenuate voltage imbalance and has quick dynamic response. The SRPE has been made to be frequency-adaptive using a damping factor and robust grid frequency estimation. The SRPE can maintain the fundamental frequency at 50 Hz and keep the total harmonic distortions (THD) within the 5% limit even during grid disruptions. The DC-AC converter and SRPE-DQ’s stability are thoroughly examined. The experiment is carried out to show the efficacy of the suggested complete control system. There are also comparative simulation studies to show the benefits of the suggested technique. The results reveal that the suggested approach can immediately identify and correct for any grid voltage imbalance while also assisting in maintaining the constant voltage at the load side despite voltage sag/swell and distortions.