SHUTDOWN DEVICE CONTROL METHOD, SYSTEM AND APPARATUS, AND SHUTDOWN CONTROLLER

A shutdown device control method, system and apparatus, and a shutdown controller. If the shutdown controller detects that an input voltage of the shutdown controller is reduced, when the input voltage of the shutdown controller is reduced to a preset protection voltage but has not been reduced to an undervoltage protection threshold voltage, the shutdown controller controls the shutdown of a shutdown device connected to a power supply photovoltaic assembly that supplies power to the shutdown controller, so that a bypass diode connected to the power supply photovoltaic assembly bypasses the power supply photovoltaic assembly, so that the power supply photovoltaic assembly only supplies power to the shutdown controller. After the shutdown device connected to the power supply photovoltaic assembly is shut down, the power supply photovoltaic assembly cannot output any voltage to a photovoltaic inverter apparatus, but voltages outputted by the power supply photovoltaic assembly are all supplied to the shutdown controller to ensure the normal operation of the shutdown controller, thereby ensuring that photovoltaic assemblies, other than the power supply photovoltaic assembly, among photovoltaic assemblies corresponding to the shutdown controller still output voltages to the photovoltaic inverter apparatus, and avoiding large fluctuations in the voltage of the photovoltaic inverter apparatus.