UPS (Uninterruptible Power System), which is an uninterruptible power supply, is an uninterruptible power supply with a constant voltage and constant frequency with an energy storage device and an inverter as a main component. Mainly used to provide uninterrupted power supply to a single computer, computer network system or other power electronics. When the mains input is normal, the UPS will supply the mains to the load for use. The UPS is an AC mains regulator, and it also charges the battery inside the unit; when the mains is interrupted (accident blackout) At the same time, the UPS immediately supplies the 220V AC power to the load through the inverter conversion method, so that the load maintains normal operation and protects the load soft and hardware from damage. UPS devices typically provide protection against excessive voltage and low voltage.