Design and real-time implementation of a new auto-tuned adaptive MPPT control for a photovoltaic system

This paper presents design of an auto-tuning based adaptive maximum power point tracker (ATAMPPT) for a photovoltaic (PV) system. The maximum power point (MPP) of a PV system varies continuously in accordance with changing weather conditions. To cope up with fast varying weather conditions, there is a necessity of an adaptive MPPT system in which MPP of the PV system needs to be quickly estimated and tracked. The proposed ATAMPPT comprises of a DC/DC boost converter equipped with an adaptive MPPT algorithm. This ATAMPPT is incorporated between the PV system and load. In this new MPPT system, a polynomial curve-fitting approach is employed to model the PV system whose parameters are identified on-line using a Recursive-Least-Square (RLS) algorithm. Further, the real-time performance of the proposed MPPT system is validated by using a prototype PV control system set-up developed in our laboratory. The performances of the proposed ATAMPPT have been compared with that of three existing MPPTs namely Perturb and Observe (P&O) and an adaptive P&O MPPT. From the obtained results it is observed that the overall approach of the proposed ATAMPPT control is simple, user-friendly and it exhibits accurate MPP tracking.