Mine uninterrupted power supply system

The utility model relates to a mine uninterrupted power supply system. The coal mine gas accidents occur frequently, and are mainly caused by that a main fan or a local fan is power off and stops working suddenly, and can not recover the power supply timely after stopping work. Therefore, the mine uninterrupted power supply system comprises an external power line I, an external power line II, a self-contained power line I, a self-contained power line II, a power supply bus I, a power supply bus II, a power supply bus III, and a power grid safety and stability control system. A mine circuit comprises a ventilation machine room power supply loop, a descent power supply loop and a cuttable load line, the power grid safety and stability control system is connected with the power supply bus I, the power supply bus II and the cuttable load line, and the ventilation machine room power supply loop and the descent power supply loop are both connected with a fiber longitudinal differential protection device. The mine u