Temporally Coordinated Energy Management for AC/DC Hybrid Microgrid Considering Dynamic Conversion Efficiency of Bidirectional AC/DC Converter

Multiple uncertainties from renewable energy sources, power loads and bidirectional AC/DC converter have brought great challenges to the energy management of AC/DC hybrid microgrid. In view of the issues, this paper proposes a temporally coordinated energy management strategy for AC/DC hybrid microgrid considering dynamic conversion efficiency of bidirectional AC/DC converter. According to the operation and loss characteristics of bidirectional AC/DC converter, a novel dynamic conversion efficiency model of bidirectional AC/DC converter is developed. To maintain high robustness at minimum operation cost, the proposed strategy is divided into two stages. The outputs of renewable energy sources, operation characteristics of microgrid components and time-of-use electricity price are comprehensively considered in the day-ahead economic energy management stage to minimize the daily operation cost. In the intraday rolling energy management stage, day-ahead schedules of controllable units are adjusted based on intraday ultra-short-term forecast data to suppress the intraday power fluctuations induced by day-ahead forecast errors. The simulation results demonstrate that the proposed strategy can effectively mitigate the impact of multiple uncertainties and realize the economic operation of AC/DC hybrid microgrid.