Maximum power point tracking of multi-input inverter for connected hybrid PV/Wind power system considering voltage limitation in grid

In this paper, a new control method is proposed for a multi-input inverter to track the maximum power point of hybrid photovoltaic (PV) and wind turbine generator (WTG) systems connected to a 380 V grid. This new control scheme has two main functions, namely, shifting the voltage of PV and WTG to the optimum condition and maintaining stability of the grid system. The proposed maximum power point method shifts the voltage of PV and WTG step-by-step until the delta voltage is close to zero, which indicates that the grid power is adequate. The delta voltage is the point at which the controller must stop shifting the voltage to maintain grid stability. From the simulation results, the power of a hybrid PV/WTG system using the proposed maximum power point tracking controller is the maximum, while the voltage and frequency of the grid system are kept constant, compared to that possible with the perturbation & observation method.