Optimal high-order super-twisting sliding mode controller based on multi-objective equilibrium optimizer to accurately track maximum power point of photovoltaic system

Abstract The Photovoltaic (PV) system has been recently attained a considerable interest around the world due to their sustainability, limitlessness and cleanliness. Despite that, the PV system must be equipped with an accurate and robust tracker to enhance its operational efficiency using maximum power point tracking (MPPT) control system. In virtue of inefficient performance of traditional MPPT controller, high fluctuation occurs around the MPP during irradiation and temperature variations. To reach an exact and reliable solution, Sliding Mode Controller (SMC)-based MPPT as a robust and non-linear tracker has been structured. But, the chattering phenomenon in conventional SMC can considerably impact on the controller tracking performance and system stability. Hence, this paper proposes a novel high-order super-twisting SMC (HOSTSMC)-based incremental conductance strategy as MPPT controller of PV system to accurately and smoothly track MPP with low chattering ripple and steady-state error under varying irradiation and temperature conditions. The imprecise adjustment of controller parameters according to the several objectives cannot lead to correct result. So, the MPPT control scheme is improved by the multi-objective equilibrium optimizer (MOEO) thanks to its exploration-exploitation dominance technique. To evaluate the performance of proposed MPPT controller, it has been compared with conventional incremental conductance-based MPPT, SMC-based MPPT and fuzzy SMC-based MPPT. The chattering ripple percentage (|P PV,max -P PV,min |/P ref *100) has been respectively extracted 0.0467%, 0.207%, 0.473% and 0.234% for proposed HOSTSMC controller, Fuzzy-SMC controller, conventional SMC controller and conventional incremental conductance, and also steady-state deviation percentage (|P PV -P ref |/P ref *100) has been respectively attained 0.3681%, 0.403%, 0.624% and 0.971% for these mentioned controllers. At last, both the prominent factors have clearly validated the high tracking performance of HOSTSMC-based incremental conductance with low steady-state deviation and chattering ripple as compared to other controllers.