A Novel Control Strategy for On-Grid Photovoltaic Systems Based on Adaptive PI Control

This paper presents a novel control strategy for grid-connected photovoltaic system based on adaptive PI. The proposed control strategy has following steps: implementation of beta algorithm for maximum power point tracking (MPPT) in photovoltaic system; dc link voltage stabilization; and grid current control utilizing model reference adaptive control (MRAC-PI) method. In the proposed control method, the coefficients of PI are continuously estimated based on MIT rule in order to decrease error between reference values and controlling variables. Simulation results of the proposed controller confirm the robust performance in uncertainty of irradiance. Comparing with optimized classic PI controllers, utilizing PSO algorithm, proposed controller has a better performance in the both transient and steady state conditions.