A systemic scheme for improving microgrids' reliability under distribution network fault condition by adopting microgrids-interconnection

A systemic scheme of electric distribution network restoration using microgrids' interconnection is put forward in this paper. The quantitative feasibility analysis of the proposed scheme mainly contains the judgment based on the risk of low frequency and the discharging time limit of battery energy storage system (BESS). The automatic generation control (AGC) is also applied in the control of interconnection and two control modes, which are FFC-TBC (flat frequency control - tie-line bias frequency control) and TBC-TBC (tie-line bias frequency control - tie-line bias frequency control), based on different operation conditions are put forward. Finally, a simulation example developed in PSCAD/EMTDC proved the correctness and efficiency of the detailed restoration process and control strategy.