Photovoltaic switching device and method based on load change

The invention provides a photovoltaic switching device and method based on a load change. The photovoltaic switching device comprises a photovoltaic switching cabinet. The photovoltaic switching cabinet is used for achieving the purposes that when the air temperature is smaller than the preset air temperature, a photovoltaic system is switched to be connected with a direct-current bus, and when the air temperature is larger than or equal to the preset air temperature, the photovoltaic system is switched to be connected with a photovoltaic direct-driving variable-frequency centrifugal type water cooling unit. According to the photovoltaic switching device and method based on the load change, due to the fact that the photovoltaic switching cabinet is arranged, the photovoltaic system can beswitched between the direct-current bus and the photovoltaic direct-driving variable-frequency centrifugal type water cooling unit. The photovoltaic direct-driving variable-frequency centrifugal typewater cooling unit only wo