Steady Output and Fast Tracking MPPT (SOFT-MPPT) for P&O and InC Algorithms

Abstract

Among the various MPPT algorithms developed until date, Perturb and Observe (P&O) and Incremental conductance (InC) algorithms are most widely used, mainly due to their simplicity and ease of implementation. However, both algorithms suffer from the drawbacks of continuous steady state oscillations, and inefficient tracking in case of rapid changes in irradiation. In this article, a SOFT-MPPT algorithm has been proposed which, in a simple way, aims to improve both the steady state as well as the tracking performance of both P&O and InC algorithms. An adaptive step size is used to track the MPP, which provides a faster tracking performance. The proposed algorithm identifies the attainment of the steady state and then stops the artificial perturbations. This stops the oscillations around the MPP and provides a steady power output from the PV panel at the MPP value. The SOFT-MPPT algorithm is also able to detect any change in operating conditions while operating in the steady state, and that too without using any additional sensors. Accordingly, it restarts the tracking process in order to track the new MPP. The detailed theoretical discussions of the SOFT-MPPT algorithm, is followed by the simulation and experimental results to validate the proposed performance improvements.