Design of Controller for the Integration of Solar PV and Battery in DC Microgrid

Due to the significant increase of Renewable Energy Sources in Distributed Generation, the modern Power Systems has advanced in its ability and reliability. Because of irregularities in solar energy, the battery enhanced systems are used to provide the additional power backup when required. The effectiveness of DC microgrid can be observed only with the coordinated control among the DC and AC sources connected. In this paper, the DC microgrid topology is achieved by the integration of Solar PV, Battery and Three phase AC grid for continuous operation of the power system. The DC-DC boost converter is connected to the solar PV by incorporating the P&O algorithm to track the maximum power point. Also the battery is equipped with the bidirectional DC-DC buck-boost converter for the uninterrupted operation due to changing solar irradiance. The advantage of this proposed system configuration is mainly the reduction of charging and discharging cycles of the battery in order to improve its lifetime. The DQ control of the active bridge rectifier is employed to extract unity power from the three phase grid. The simulations are carried out in MATLAB/Simulink software by considering the modelling of the solar PV, battery and also the design parameters of the boost and bidirectional converters. The performance of the developed controller is found satisfactory under steady state and dynamic conditions.