Instantaneous power theory-fuzzy intelligent controller (IPT-FIC) based improved low voltage ride-through strategy for grid connected photovoltaic system

Abstract

The installation of Renewable Energy Sources (RESs) has increased tremendously over the past few decades. Due to the large-scale grid integration of RESs, many countries have had to modify their grid codes. For smooth operation during contingencies, the grid code mandates Low Voltage Ride-Through (LVRT) operation of the inverter, requiring it to remain connected for a stipulated duration and provide necessary support to the grid. In this article, an Instantaneous Power Theory-Fuzzy Intelligent Controller (IPT-FIC) based improved LVRT strategy is implemented to control a grid-connected Photovoltaic (PV) inverter. This enhanced strategy efficiently provides the necessary active and reactive power support to the grid during faults or voltage sags. The IPT-FIC is proposed to make the controller intelligent, accurate, and faster. Simulations were performed in a MATLAB/SIMULINK 2021 environment, and the feasibility of the proposed technique was verified through the dSPACE DS1103 driven Hardware-in-the-Loop (HIL) platform, achieving an accuracy level of 96.67%. The proposed technique improves system response time during transient scenarios by 19.88%. The technique ensures the active power loss is limited to 7.91% during LVRT operation while maintaining a very low ride-through time.