UPS（Uninterruptible Power System ）， Uninterruptible power supply is a constant voltage and constant frequency uninterruptible power supply that includes energy storage devices and an inverter as the main component. Mainly used to provide uninterrupted power supply to a single computer, computer network system, or other power electronic equipment. When the mains input is normal, the UPS stabilizes the mains voltage and supplies it to the load for use. At this time, the UPS is an AC mains voltage stabilizer, and it also charges the internal battery; When the mains power is interrupted (accident power outage), UPS immediately supplies 220V/380V AC power from the internal battery to the load through inverter conversion, so as to maintain normal operation of the load and protect the software and hardware of the load from damage. UPS equipment typically provides protection against both high and low voltage.

Photovoltaic inverters convert power on a single photovoltaic (PV) panel, with a typical rated power of 400W for a single PV panel and up to 1.5KW for multiple PV panels. Photovoltaic inverters are typically based on a two-stage power conversion system. Firstly, the DC to DC stage or boost circuit converts the variable DC voltage into a fixed DC voltage (usually between 40 V and 60 V). Meanwhile, maximum power point tracking technology can maximize energy extraction from photovoltaic panels (typically FSW=100 KHz). Firstly, in the DC to DC stage or boost circuit, the variable DC voltage is converted into a fixed DC voltage (usually 40 V to 60 V). At the same time, maximum power point tracking technology is used to ensure the extraction of maximum current from the photovoltaic panel. Secondly, during the DC to AC conversion stage, the inverter stage converts the DC power supply into a 1 Φ AC power supply compatible with the power grid. Unlike string inverters, micro inverters can connect one, two, or four photovoltaic panels and perform MPPT tracking on each PV module separately.