Abstract:
In order to solve the problem of mutually-supplied capacity variation between sub-microgrids and the reliability of power supply affected by the state of charge(SOC) of energy storage units in AC/DC hybrid microgrid, a multi-mode coordinated power control strategy is proposed considering both of the operation states and the SOC of sub-microgrids. The operation mode is divided into 4 states, namely, surplus mutual operation, defective mutual operation, independent operation, and power sharing operation, according to the proposed strategy. The principles of power transfer and the calculation of power references are researched in detail for four kinds of different operation states. Therefore, both the power balance of system and the relatively equilibrium of SOC in sub-microgrids are realized to improve the reliability of power supply and utilization efficiency of energy storage units in AC/DC hybrid microgrid. Finally, a simulation model is established by Matlab/Simulink to verify the effectiveness of proposed control strategy.