The main advantage of UPS is its ability to provide uninterrupted power. When the AC input is normal, the UPS converts the AC power into DC power and then converts the DC power into stable AC power free of impurities for later loads. If the AC input is abnormal, such as undervoltage, power failure, or abnormal frequency, the ups starts the energy battery, shuts down the ups rectifier circuit, and converts the DC power of the battery to stable AC power without impurities for subsequent loads.