Fractional Order PID Controller Incorporated Decoupled Control of Grid Connected Solar Photovoltaic System

Abstract

In this paper, Fractional-order PID controller incorporated Decoupled Control (FOPID-DC) method is designed for a grid-connected solar PV system. The fractional calculus-based PID controller is used to estimate the effect of harsh weather changes on the inverter dynamics. The outer active and reactive current control loop and the inner DC link voltage control loop of the proposed FOPID-DC operate in a d-q reference frame that is coupled to the grid voltage vector. The suggested FOPID-DC avoids the drawbacks of the traditional PID controller while maintaining the advantages of the fractional controller. The performance of error tracking is greatly enhanced by the use of fractional operators. The studies are carried out in MATLAB Simulink. To establish the improved dynamic performance of the FOPID-DC, a comprehensive comparative study was carried out between the conventional PID controller combined with decoupled controller (PID-DC) and the FOPID-DC. The performance of the FOPID controller incorporated decoupled controller is assessed under different environmental conditions. Under various stochastic climatic conditions, the key performance indicators, such as DC ink voltage, PV power, and the grid-side quadrature axis current, are plotted. Under these climatic test conditions, time domain metrics such as rise time, maximum overshoot, and settling time are tabulated for PID-DC and FOPID-DC. To illustrate the supremacy of the recommended controller, a radar plot of the DC link voltage error was also plotted. The proposed FOPID-DC is more resilient, efficient, and effective at mitigating the uncertainties brought on by abrupt changes in weather and has a simple control structure.