Chapter 21 - A BSA Tuned Fractional-Order PID Controller for Enhanced MPPT in a Photovoltaic System

Abstract

With the characteristic of a photovoltaic (PV) system being nonlinear, extracting maximum power from it has always been a challenging task. To extract maximum power from a PV system, its operating point needs to be maintained at the maximum power point throughout its operation. This process is called maximum power point tracking (MPPT). The classical techniques employed for MPPT in PV systems are perturb and observe (P&O) and incremental conductance (IC). More recently, the dP/dV feedback MPPT technique has also been explored, which essentially makes use of a classical proportional integral derivative (PID) controller. Though these techniques are cost effective and easy to implement, each of them has its own merits and demerits. Therefore, advanced techniques leading to a more efficient MPPT are always in demand. In this context, this chapter is a seminal effort to explore the application of the fractional-order proportional integral derivative (FOPID) control scheme for improving the performance of the dP/dV feedback MPPT method. The MPPT performance of the proposed FOPID control scheme is compared with that of the PID control scheme, both tuned using a backtracking search algorithm for minimum integral time absolute error (ITAE), P&O, and IC under realistic environmental conditions including variations in both temperature and irradiation. MATLAB-based intensive experiments on performance parameters such as ITAE, integral absolute error, MPPT efficiency, and energy study indicated the clear superiority of the dP/dV feedback FOPID MPPT scheme, and therefore, it is concluded that the dP/dV feedback FOPID controller is a better control scheme as compared to the dP/dV feedback PID, P&O, and IC for MPPT application.