A combinational maximum power point tracking algorithm in photovoltaic systems under partial shading conditions

Abstract

Under partial shading conditions (PSCs), photovoltaic (PV) systems have multiple local maximum power points while only one of them is the real maximum power point (RMPP), so maximum power point tracking (MPPT) is different under PSCs. In this paper, a method for maximum power point tracking (MPPT) is proposed which is a combination of conventional hill climbing and a modified version of current sweep method. If the panel is under normal irradiations, we apply conventional hill climbing method to find MPPT because this method is fairly efficient for uniform irradiation conditions. However in partial shading conditions (PSCs), it is unable to track RMPP; therefore we suggest applying current sweep method in PSC. In the proposed current sweep method, we limit search space so that the current sweep procedure takes less time, the RMPP is found faster and consequently efficiency of the current sweep method increases. To verify the validity of the proposed method, simulation results are given.