Development of 3.3kW PV ESS System with DC Power Supply Function

In this paper, we propose the operation mode and control method of single phase PV (PhotoVoltaic) ESS (Energy Storage System) with DC power supply function. The proposed system uses the electric power generated by solar power generation in the daytime to supply electric power to the LED lamp, charge the battery, and transmit it to the grid when surplus electric the power is generated. In the night, the LED lamp is supplied by the power stored in the battery, and the battery is charged by the grid in the late night. In MPPT algorithm, the conventional P & O technique has a problem that the MPPT efficiency is reduced due to the large amplitude of the voltage oscillation at the maximum power point. We propose an improved P & O algorithm to improve the efficiency by minimizing the width of oscillation to improve the existing problems. For the validity of the given control method, the simulation was carried out and the 3.3 kW PV ESS system was constructed and tested. The inverter control algorithm proposed in this paper is suitable for single phase system, and it is more efficient to apply the space vector algorithm to three phase system.