An enhanced MPPT approach under partial shadowing condition (PSC) combining fiatness control and direct P&O method

The maximum power point of photovoltaic (PV) system shifts when external condition changes. The frequent variation of power shifting causes energy loss, which significantly affects the overall performance of the system. Conventional P&O method is efficient and easy to implement, however, in multi power peaks system it usually falls into local maximum point problem. This paper presents a maximum power point tracking (MPPT) strategy to achieve fast and accurate response to external changes in order to reduce energy loss and improve efficiency. A tracking strategy combining P&O method and fiatness control is proposed. According to our model, when tracking process is triggered, fiatness control is adopted to acquire PV system characteristics and locate approximate global maximum point, and then P&O method tracks global maximum power point. The conditions that tracking process is triggered or stopped are also discussed. The controller's performance is verified by several simulations, which show that our model outperforms than current conventional system.