Energy Management Strategy of AC/DC Hybrid Microgrid Based on Power Electronic Transformer

Owing to the intermittent output power and variable load variability of distributed generation (DG), voltage fluctuation and power mismatch tend to occur during AC/DC hybrid microgrid operation with power electronic transformers (PET). Therefore, a distributed energy coordination strategy is proposed in this paper. This strategy can coordinate the power exchange between PET, AC microgrid, DC microgrid and energy storage to effectively suppress the fluctuation of DC bus voltage. At the same time, the proposed hybrid mode control method, only with on local information, can ensure the full utilization of all subsystems and buffer the energy fluctuations of hybrid microgrids. The simulation results show that the proposed control strategy can accurately control the bidirectional flow of power between the PET interfaces and regulate the power distribution between the main network, the AC microgrid and the DC microgrid to achieve the stable operation of the AC/DC hybrid microgrid.