Partial shaded conditions introduce multiple peaks in the voltage-power characteristics of photovoltaic (PV) array. Conventional tracking algorithms cannot differentiate between local and global peaks and results in lower harvest efficiency. This inadequacy has led to the development of global tracking algorithms. This paper proposes a new dichotomous search based global peak power tracking (GMPPT) algorithm that can track the maximum power under all irradiation conditions. The algorithm is a two-stage algorithm where the first stage narrows down the search range to the vicinity of the global peak while the second stage locates the global maximum by dichotomous search algorithm. The reliability of the algorithm is tested for various shading patterns. The simulated and experimental results show that the algorithm tracks the global peak reliably under both uniform and non-uniform irradiation conditions.

Keywords: Photovoltaic array, Partial shading, Maximum power point tracking (MPPT), Dichotomous search