1. Anti-backflow device, which can ensure that the electric energy generated by the photovoltaic power generation system is self-generated and used, and prevents it from being fed into the public grid.2. When the current flows from the grid to the load, the device should have no reverse current signal;3. When the current flows from the inverter to the grid, a reverse current signal should appear.4. When reverse current occurs, the power of the inverter will be limited.