Dual‐loop control of transfer delay based PLL for fast dynamics in single‐phase AC power systems

Abstract

Phase‐locked loop (PLL) is commonly utilised for AC power systems to detect phase and frequency. With the increasing use of small‐scale distributed power generation, the technique becomes widely available for grid interconnection of renewable power source into single‐phase AC distribution network. Through comprehensive analysis and design, this study proposed a new approach that includes dual independent control loops to enhance the transfer delay‐based PLL capability in terms of speed and accuracy. The effectiveness and advantages of the proposed PLL structure are demonstrated by numerical simulation and verified by experimental test.