Power Coordinated Control Strategy of AC-DC Hybrid Microgrid Considering Flexible Energy Storage for Electric Vehicles|考虑电动汽车灵活储能的交直流混合微电网功率协调控制策略

Conventionally it is difficult to avoid the centralized energy storage in an isolated AC-DC hybrid microgrid because the state of the charges tends to be the critical charge/discharge, which may lead to the unreliable power supply of the system. Aiming at this problem, a power coordination control strategy of the AC-DC hybrid microgrid considering the flexible energy storage of the electric vehicles is proposed. First, according to the power surplus and deficit states of a AC-DC hybrid microgrid and its subnets, and considering the coordination between the traditional centralized energy storage and the flexible energy storage in the hybrid energy storage, the operation modes of the AC-DC hybrid microgrid are divided into three types: the normal, the critical balance and the power off-limit modes. On this basis, according to the differences of the control targets in each mode, the detailed operating conditions are further divided. Then, by analyzing the response priorities of the EV flexible energy storage, the traditional centralized energy storage and the interconnected interface converter at the same time scale, the principles of the hybrid energy storage power distribution and the interconnected interface converter power transmission are designed, and the smooth switching methods between the system operation modes and working conditions are proposed. Finally, an AC-DC hybrid microgrid simulation model based on the MATLAB/Simulink is used to verify the effectiveness of the proposed control strategy.