On the background of the Luxi Island grid-connected microgrid project

the three-layer control system based on IEC 61850 is presented with the emphases on seamless switching strategies. To accommodate the strategies

the converter control logic of energy storage is improved on the switching process between power control mode and voltage/frequency control mode by analyzing the characteristics of fast-switching breaker and converter. And transient surge of unbalance power has reduced by the coordination of microgrid central controller (MGCC) and mode switching controller (MSC). The setting values of coordination time in strategies are determined through field tests to guarantee the seamless switching of operation modes. This work is supported by National High Technology Research and Development Program of China (863 Program) (No. 2011AA05A107).