A flexible power point tracking algorithm for photovoltaic system under partial shading condition

This paper proposes a novel flexible power point tracking (FPPT) method under partial shading conditions (PSC) to control the power delivered to the grid and make it less than the highest generated PV power for sake of protection. Turning point data from a power-voltage characteristic curve is used to separate peak points in different areas, and maximum power value is indirectly obtained via the hill-climbing method for local optimization at various intervals. Additionally, particle swarm optimization algorithm is used to calculate reference voltage value to achieve the FPPT control. Through simulations on the PV system, validity and advantages of the proposed method over the traditional FPPT algorithm in terms of dynamic and steady-state performance are verified under different operation environments. In particular, the proposed algorithm can effectively avoid trapping into a local maximum power point under PSC, which often occurs in traditional algorithms.