A novel variable step size adaptive conductance ratio algorithm for MPPT in solar PV systems

Abstract

Maximum power point tracking is a concept employed to adjust the operating point of a solar cell such that the maximum possible power is extracted from it regardless of variation in solar irradiation, ambient temperature and loading conditions. In this paper, a novel variable step size algorithm called the Adaptive Conductance Ratio algorithm has been proposed. The proposed algorithm dynamically adjusts the step size of converter duty cycle variation based on a proportional-integral control strategy, thus eliminating the traditional compromise between speed of convergence and steady-state efficiency. It solves the drawbacks found in certain other variable step size algorithms proposed hitherto. It also promises complete removal of steady-state oscillations, thus achieving true maximum power point and an observable improvement in tracking efficiency. The performance of the proposed algorithm has been analysed via simulation under various environmental conditions, in comparison with an existing variable step size algorithm. The concept and efficacy of the proposed algorithm and its supremacy over the existing algorithm have been established in principle.