Photovoltaic System Dynamic Performance Improvement with Disturbance Rejection Based Controller Tuned Using the Equilibrium Optimizer Algorithm

Abstract

This work investigates the issues found in the dynamic performance of the PV system associated with a cascade-controlled DC-DC converter in the current source region (CSR). The overall system time response in the CSR exhibits oscillatory behavior which has been found to be caused by the outer voltage control loop. Instead of a commonly used tracking controller, a novel disturbance rejection-based cascade controller is proposed in order to improve dynamic system performance and robustness. The proposed controller is composed of a sliding mode controller for the inner current control loop and a feedback linearization combined with the fractional order PID controller for the outer voltage control loop. The voltage controller is tuned using the Equilibrium Optimizer (EO) algorithm where a new performance index has been considered. Simulation results are given to demonstrate the higher performance of the proposed control strategy in different operating regions including the CSR region.