-Utility priority mode. When the power supply is normal(in line with the machine power input voltage range), on the one hand, the power supply and PV charge the battery at the same time; on the other hand, the power supply only supplies power to the load(the load does not consume PV and battery energy); • When the mains power is abnormal(the mains power is beyond the working range of the machine or the mains power is interrupted), the machine will switch to the battery inverter power supply, and the battery will supply power to the load, when the PV power is greater than the load power, the load will be completely supplied by the PV power, and the excess energy will charge the battery; when the PV power is less than the load power, the insufficient part will be supplemented by the battery The load is supplied by PV and battery together.