Design of Fuzzy based PLL for Grid Connected Inverter under Non-Ideal Grid Conditions

Abstract

This research paper discusses about design of phase lock loop (PLL) for grid connected inverter under the presence of different non-idealities. In most applications, the ability to detect the grid voltage phase angle is a crucial component of control, especially when synchronizing the current injected by grid-connected solar inverters. It is very important to track an accurate phase angle, frequency, and amplitude for the proper functioning of the grid connected inverter. This research article mainly deals with synchronous reference frame (SRF) PLL design using proportional integral (PI) controller and fuzzy logic based intelligent controller under both ideal and abnormal grid voltage conditions. The proposed model is designed and tested in MATLAB/Simulink. Obtained outputs are contrasted with the conventional PI controller and the fuzzy logic controller proposed. Simulation results shows the Fuzzy logic-based controller has a better accuracy when compared to PI controller for non-ideal grid conditions.