Photovoltaic power generation system control method, photovoltaic power generation system, and switching apparatus

A photovoltaic power generation system control method comprising:

• detecting electrical signals of a first direct-current/alternating-current (DC/AC) converter, a second DC/AC converter, each of a first plurality of direct-current/direct-current (DC/DC) converters, and each of a second plurality of DC/DC converters to obtain detected electrical signals;
• and
• determining, based on the detected electrical signals and when a second difference between a first absolute value of a first input voltage of the first DC/AC converter and a second absolute value of a second input voltage of the second DC/AC converter exceeds a preset threshold and a third absolute value of a third input voltage of a second target DC/AC converter exceeds a preset voltage interval, a switching solution for reducing a component loss of a photovoltaic power generation system,
• wherein the switching solution comprises disconnecting the second target DC/AC converter from a DC/DC converter and controls a connection between each of the first plurality of DC/DC converters and the second plurality of DC/DC converters and the first DC/AC converter or the second DC/AC converter.

A switching apparatus, applied to a photovoltaic power generation system, wherein the switching apparatus comprises:

• a switching device comprising:
• a first output end configured to connect to an input end of a first direct-current/alternating current (DC/AC) converter of the photovoltaic power generation system;
• a second output end configured to connect to an input end of a second DC/AC converter of the photovoltaic power generation system;
• a first plurality of input ends configured to connect to a first plurality of direct-current/direct current (DC/DC) converters of the photovoltaic power generation system in a one-to-one correspondence;
• and
• a second plurality of input ends configured to connect to a second plurality of DC/DC converters of the photovoltaic power generation system in a one-to-one correspondence,
• wherein the switching device is configured to:
• control a connection between each of the first plurality of DC/DC converters and the first DC/AC converter;
• and
• control a connection between each of the second plurality of DC/DC converters and the second DC/AC converter;
• a detector separately configured to connect to the first DC/AC converter, the second DC/AC converter, each of the first plurality of DC/DC converters, and each of the second plurality of DC/DC converters, wherein the detector is configured to:
• detect electrical signals of the first DC/AC converter, the second DC/AC converter, the plurality of first DC/DC converters, and the plurality of second DC/DC converters;
• and
• output the electrical signals;
• and
• a controller separately configured to connect to the detector and the switching device, wherein the controller is configured to:
• receive the electrical signals from the detector;
• determine, based on the electrical signals, a switching solution for reducing a component loss of the photovoltaic power generation system;
• control the switching device to perform the switching solution;
• calculate input power of the first DC/AC converter and input power of the second DC/AC converter based on the electrical signals;
• determine, when at least one of the input power of the first DC/AC converter or the input power of the second DC/AC converter is less than a first preset power threshold, that the switching solution is calculating a first difference between input power of a first target DC/AC converter and the first preset power threshold, wherein input power of the first target DC/AC converter is less than the first preset power threshold;
• and
• disconnect, based on the first difference and a second preset power threshold, a first part of the first plurality of DC/DC converters connected to the first target DC/AC converter.