The emergency microgrid can provide emergency power supply to the distribution networks when large-area blackout occurs. But the emergency microgrid is temporarily established
with poor communication conditions
changeable working conditions and frequently plugged and unplugged mobile emergency power sources. The coordination and equalization control strategy for the emergency microgrid is proposed
in which energy storage systems and diesel generators are used as the main power supply. Besides the primary droop control and the secondary control for frequency and voltage recovery
the control strategy adds the auxiliary equalization control based on multiple time scales. The equalization control of diesel generators can adjust the stable operation point based on the feedback frequency control signal in order to correct the speed measurement error and equalize the output of each power source. And the equalization control of energy storage systems can realize state of charge(SOC)balance by dynamically adjusting the droop slope based on the deviation of SOC. The control strategy does not rely on central controller of microgrid to facilitate quick emergency power supply. Finally
simulation results verify the feasibility and effectiveness of the proposed control strategy.