Inverter circuit control method and device thereof

An inverter comprising an inverter circuit and a controller, wherein the controller is connected to a control end of the inverter circuit, and the controller is configured for:

• determining a direct current DC bus voltage and an output leakage current of the inverter circuit;
• determining, according to the DC bus voltage, whether the inverter circuit satisfies a preset modulation condition;
• and
• adjusting, according to the DC bus voltage or the output leakage current, a modulation harmonic wave to be injected into a sinusoidal pulse width modulation (SPWM) signal in a case that the target inverter circuit satisfies the preset modulation condition, such that total harmonic distortion of a current of the inverter circuit is within a preset range.

A photovoltaic system comprising at least one photovoltaic module, a combiner, and an inverter, wherein an output end of each photovoltaic module is connected to an input end of the combiner, an output end of the combiner is connected to DC side of the inverter, and AC side of the inverter is connected to AC power grid, wherein the inverter comprises an inverter circuit and a controller, wherein the controller is connected to a control end of the inverter circuit, and the controller is configured for:

• determining a direct current DC bus voltage and an output leakage current of the inverter circuit;
• determining, according to the DC bus voltage, whether the inverter circuit satisfies a preset modulation condition;
• and
• adjusting, according to the DC bus voltage or the output leakage current, a modulation harmonic wave to be injected into a sinusoidal pulse width modulation (SPWM) signal in a case that the target inverter circuit satisfies the preset modulation condition, such that total harmonic distortion of a current of the inverter circuit is within a preset range.