In the AC PV power generation system, the inverter is an indispensable part. At present, due to various technical or policy reasons, it takes a long time to connect all the independent PV AC power generation systems to the national unified power grid. Therefore, the market distinguishes PV inverters from off-grid inverters and on-grid inverters. The off-grid inverter is a power conversion device that pushes and pulls the input DC power and then inverts it into 220V AC through the SPWM sinusoidal pulse width modulation technology of the inverter bridge. Off-grid inverters have higher efficiency requirements for inverters than on-grid inverters; require high reliability; require DC input voltages to have a wide range of adaptation; medium and large capacity In a PV power generation system, the output of the inverter power supply should be a sine wave with less distortion.