Phase Locked Loop Based Techniques for Compensation of Voltage Based Power Quality Issues in Distribution System

Abstract

Abstract This article describes the comparison of different phase locked loops (PLLs) based control algorithms for removal of voltage based power quality problems such as voltage sag/swell, distortions and unbalances etc. For this purpose, Dynamic Voltage Restorer (DVR) is designed with heuristic optimization technique called Multi-objective Grey wolf Optimizer (MOGWO) for PI gains calculation. Three PLLs namely adaptive transfer delay phase locked loop (ATD-PLL), multi complex coefficient filter phase locked loop (MCCF-PLL), and multi synchronous reference frame phase locked loop (MSRF-PLL) are implemented for the control of DVR in a three-phase system. These PLLs are employed for compensation of distortions and imbalances in supply along with voltage sag/swell. Basically, estimation of fundamental and positive sequence components are the basic function of these PLLs that is used for further extraction of reference load voltage. The optimization approach has been implemented for estimation of proportional integral (PI) gains of dc bus as well as ac bus in the system. This approach of tuning PI controller-gains reduces the time by integrating the fixed sized external archive to the GWO for saving and retrieving optimal solutions. Three wires DVR with developed control algorithms are implemented using MATLAB/Simulink and tested in a laboratory environment. The recorded results show satisfactory performance of DVR for compensation of voltage based power quality problems.