Research and Simulation of Hybrid AC/DC Microgrid

This paper mainly discusses the structure and control strategy of hybrid AC/DC microgrid. The AC/DC hybrid microgrid under consideration consists of photovoltaic (PV) panel, battery, DC load, AC load, induction motor and several converters. Using maximum power point tracking (MPPT) technology to optimize the output power of PV, the battery and bidirectional DC/DC converter with two loops control is applied to regulate the DC bus voltage and DC/DC buck converter with similar control method helps regulate the voltage of DC load. The controller of the three-phase AC/DC converter which connects the AC subgrid and DC subgrid in hybrid microgrid is also designed. Different control strategies are used for the converter in grid-connected mode and islanded mode of microgrid. Finally, the model of hybrid microgrid is built in Matlab/Simulink and the results in grid-connected mode and isolated mode are analyzed. The results show that, when the hybrid grid operates under varying load and weather conditions, the stable operation of the hybrid AC/DC microgrid can be maintained by the control strategy.