UPS (Uninterruptible Power System), also known as uninterruptible power supply, is a constant voltage and frequency uninterruptible power supply that contains energy storage devices and is mainly composed of inverters. Mainly used to provide uninterrupted power supply to a single computer, computer network system, or other power electronic equipment. When the mains power input is normal, UPS stabilizes the mains power and supplies it to the load for use. At this time, UPS is an AC mains power stabilizer, and it also charges the internal battery. When the mains power is interrupted (accident power outage), UPS immediately supplies 220V AC power from the internal battery to the load through inverter conversion, maintaining normal operation of the load and protecting the load's software and hardware from damage.