A micro power grid means

The present invention discloses a micro power grid means, the apparatus comprising: a controllable switch, which is electrically connected between the microgrid and the large power grid, for between OFF signals according turned on or off and large grid microgrid connection; signal acquisition circuit for signal acquisition microgrid controllable switch and the power grid; and a controller electrically connected between the signal acquisition circuit and a controllable switch, a micro grid, grid and large generating an electrical signal of the controllable switch-off signal to control the on-off controllable switch, thereby achieving microgrid grid or off-grid. The present invention is of simple structure, easy connection can be effectively and reliably, completing the handover between the microgrid and the presence and quickly from the network state, can effectively protect the safety of personnel and maintenance of electrical equipment and a large grid microgrid.