Knowledge Inference Concept of Control Sharing - Mitigation of Power Quality Disturbances in Grid Tied PV Systems

This paper presents a study on a Unified Power Quality Conditioner (UPQC) designed for grid-tied PV systems, combining distributed generation and active power filtering. Advanced control methods for UPQC are explored, including SRF theory with sliding mode control for dynamic response to voltage sag/swell and novel ANN control algorithm for cost-effective performance enhancement. Simulations in MATLAB/Simulink compare THD in load and grid voltage/current under different conditions, along with response times and performance under unbalanced loads. This research paper highlights a novel control sharing method for mitigating extreme sag and swell values in grid-tied photovoltaic (PV) systems. Leveraging knowledge domain principles, this approach integrates two Unified Power Quality Conditioners (UPQCs) into the system. Operational parameters of both UPQCs are stored in a knowledge domain, determined by sag and swell values. The primary UPQC, controlled by sliding mode control (SMC), manages operations under mild sag and swell conditions, while the secondary UPQC supplements the primary UPQC during instances of extreme sag and swell. Results indicate enhanced system performance, particularly under non-linear and unbalanced loads, showcasing superior efficacy compared to single UPQC systems in grid-tied PV applications.