On-grid inverter

The invention discloses a on-grid inverter which comprises a direct current power supply device, a reverse current device, a direct current/direct current converter and a main controller, wherein the reverse current device is connected to an electric supply power grid through a switch device; the direct current/direct current converter is connected between the direct current power supply device and the reverse current device; the main controller is respectively connected with the direct current/direct current converter and the reverse current device; the direct current power supply device comprises devices capable of generating direct current electricity, such as a storage battery, a photovoltaic battery, a wind driven generator and the like; the direct current is converted into alternating current through the on-grid inverter; the direct current is boosted by utilizing the direct current/direct current converter, and a twofold power frequency sine pulse wave width modulation voltage is generated simultaneously, and is converted into a plus-minus semi-cycle sine pulse wave width modulation voltage; and through parallel connection with the power grid, the on-grid output current and power grid voltage in-phase output effective power can be controlled. Thus, the direct current power supply which is generated by various novel energy sources can be used for realizing energy conservation and emission reduction, and the synchronization inverter has the advantages of simple structure, low cost, high efficiency of a finished machine, safety in use and low power consumption.