Power Balance Control Strategy Battery Storage-PV Systems for Isolated Microgrid

This paper presents a power balance control strategy for an off grid DC microgrid. It is composed by a photovoltaic system, storage system and an electronic load. In this type of system, when the power available from the photovoltaic arrangements is larger than the load demand, the excessive power generation leads to overvoltage on the DC bus. Besides that, due to the partial shading of the PV panels, the DC bus can become dynamically unstable. So, a power balance control (PBC) strategy is used to stabilize the system and avoid overvoltage problems. To achieves such a goal, the implemented topology provides two DC bus voltage levels, 150 Vdc and 300 V dc, where the first is responsible for the power transfer between the PV and the battery and the second is provide for the power transfer to the load. The algorithm monitors the power level generated by the PV and the load's energy demand and constantly balances the power generation and consumption with the help of an electronic load control. Simulation results are presented to validate the proposed strategy.