Power conversion apparatus and method for controlling output impedance of power conversion apparatus

A method for controlling an output impedance of a power conversion apparatus comprising a power conversion circuit, an impedance adjustable circuit comprising a switch and a load circuit, and a control circuit, the control circuit connected to both the power conversion circuit and the impedance adjustable circuit, and an output end of the power conversion circuit being connected to the impedance adjustable circuit, the method comprising steps of:

• determining whether or not the power conversion apparatus satisfies a start condition;
• adjusting the output impedance of the power conversion apparatus to a first impedance upon determination that the power conversion apparatus does not satisfy the start condition;
• or
• adjusting the output impedance of the power conversion apparatus to a second impedance upon determination that the power conversion apparatus satisfies the start condition, wherein the first impedance is not equal to the second impedance.

A photovoltaic power system, comprising a photovoltaic module, an optimizer comprising a power conversion circuit, an impedance adjustable circuit comprising a switch and a load circuit, and a control circuit, the control circuit connected to both the power conversion circuit and the impedance adjustable circuit, and an output end of the power conversion circuit being connected to the impedance adjustable circuit, and an inverter, wherein

• the photovoltaic module is configured to:
• convert solar energy into electrical energy, and output the electrical energy to the optimizer;
• the optimizer is configured to:
• adjust an output impedance of the optimizer to a first impedance upon determination that the optimizer does not satisfy a start condition, or adjust an output impedance of the optimizer to a second impedance upon determination that the optimizer satisfies a start condition, wherein the first impedance is not equal to the second impedance;
• and
• upon determination that the optimizer satisfies the start condition and the optimizer needs to control output power, adjust output power of the photovoltaic module and output adjusted power;
• and
• the inverter is configured to:
• convert the power output by the optimizer into electrical energy satisfying a specified condition, and output the converted electrical energy to a power grid or a load.