Micro-grid and main commercial grid undergo grid-connected operation under the circumstance that they are normal. The capacity generated by the micro-grid is prioritized to meet utilization requirement of local users' loads. It dispatches with the main commercial grid in case of remaining or insufficient electric quantity. The micro-grid will actively disconnect from the main commercial grid and operate independently to guarantee normal operation of main loads in case its system detects fault of the main grid and serious issue of power quality.
Since some regions have no commercial power deployment or have unstable commercial grid with less capacity, micro-grid (as the main power) supplies power to loads to guarantee their normal operation.