Micro inverter and modulation method thereof

A method for modulating a micro inverter, wherein the method is applied to the micro inverter and the method comprises:

• detecting a direct-current side voltage of each first switching circuit of the micro inverter, a transmission power, and a grid voltage of a power grid connected to an output terminal of the micro inverter;
• and
• controlling a second switching circuit and the first switching circuit of the micro inverter to emit waves, based on the direct-current side voltage of each first switching circuit of the micro inverter, the transmission power, and the grid voltage of a power grid connected to an output terminal of the micro inverter;
• wherein the controlling a second switching circuit and the first switching circuit of the micro inverter to emit waves, based on the direct-current side voltage of each first switching circuit of the micro inverter, the transmission power, and the grid voltage of a power grid connected to an output terminal of the micro inverter comprises:
• calculating, based on the direct-current side voltage of each first switching circuit, the transmission power and the grid voltage, an internal phase-shift angle between a leading arm and a lagging arm in an H-bridge of each first switching circuit and an external phase-shift angle between the leading arm and the second switching circuit of the micro inverter;
• determining a duty cycle of a signal pulse of the micro inverter based on the internal phase-shift angle and the external phase-shift angle;
• and
• performing, based on the duty cycle, phase shifting or frequency conversion to control the second switching circuit and the first switching circuits of the micro inverter to emit waves.