Shutdown device, communication method for shutdown device, and rapid shutdown photovoltaic system

A shutdown device, wherein the shutdown device comprises:

• a first input port, configured to be coupled to a first direct-current power supply;
• at least one second input port, configured to be coupled to a second direct-current power supply;
• an output port, configured to be coupled to a power bus;
• a first shutdown module, connected to the first input port, wherein the first shutdown module comprises a first switching device, and the first switching device is configured to control an output power of the first direct-current power supply coupled to the first input port;
• and
• at least one second shutdown module, connected to the second input port, wherein the second shutdown module comprises a second switching device, and the second switching device is configured to control an output power of the second direct-current power supply coupled to the second input port, wherein
• an output of the first shutdown module and an output of the at least one second shutdown module are connected in series, and are connected to the output port;
• a control module, configured to modulate a power control signal and a first communication signal, to generate a first composite control signal, wherein the power control signal adjusts the output power of the first direct-current power supply coupled to the first input port, and the first composite control signal controls the first switching device to work in a high-frequency switching state, to superimpose a current ripple signal comprising the first communication signal onto the power bus;
• and
• the control module being further configured to generate a switching control signal, to control a switching of the second switching device.

The shutdown device according to claim 1, wherein the control module comprises:

• a power control unit, configured to generate the power control signal according to the power bus current;
• a modulation unit, configured to receive the first communication signal and the power control signal, and modulate the first communication signal and the power control signal to generate the first composite control signal;
• and
• a switching control unit, configured to generate the switching control signal that controls the switching of the second switching device.

A communication method for a shutdown device, wherein the method comprises:

• modulating a power control signal and a first communication signal, to generate a first composite control signal, wherein the power control signal is used to adjust an output power of a first direct-current power supply coupled to a first input port of the shutdown device;
• and
• controlling a first switching device of the first input port of the shutdown device to work in a high-frequency switching state by the first composite control signal, to superimpose a current ripple signal comprising the first communication signal onto a power bus;
• and providing a switching control signal, wherein the switching control signal is used to control a switching of a second switching device of a second input port of the shutdown device.

A rapid shutdown photovoltaic system, wherein the system comprises a plurality of shutdown devices, a plurality of photovoltaic modules, a main controller, and a photovoltaic inverter, each shutdown device is connected to a first photovoltaic module and a second photovoltaic module, the plurality of shutdown devices are connected in series to a power bus, the power bus is connected to a direct-current input port of the photovoltaic inverter, the shutdown device comprises a first input port, at least one second input port, a first shutdown module connected to the first input port, a second shutdown module connected to the second input port, an output port, and a control module, the first shutdown module comprises a first switching device, and the second shutdown module comprises a second switching device, wherein

• the shutdown device is configured to modulate a power control signal and a first communication signal to generate a first composite control signal, wherein the power control signal adjusts an output power of a first photovoltaic module coupled to the first input port, and the first composite control signal controls the first switching device to work in a high-frequency switching state, to superimpose a current ripple signal comprising the first communication signal onto the power bus, and the shutdown device is further configured to generate a switching control signal, to control a switching of the second switching device;
• and
• the main controller is configured to extract the current ripple signal on the power bus, and demodulate and parse the current ripple signal, to obtain the first communication signal transmitted by the shutdown device.