PHOTOVOLTAIC QUICK TURN-OFF SYSTEM AND CONTROL METHOD THEREFOR

A rapid shutdown system and a method for controlling the rapid shutdown system are provided. For each of shutdown devices in the rapid shutdown system, an electrical signal disturbance is applied to a direct current bus connected to the shutdown device at least once within each pre-shutdown period of the shutdown device, by an inverter in the rapid shutdown system operating in a mode of limited power output. Then, the shutdown device samples its input parameter and/or output parameter and determines, based on the sampled input parameter and/or the sampled output parameter, whether the electrical signal disturbance applied to the direct current bus meets a preset condition. The shutdown device switches itself on or remains in an ON state in response to a determination result that the electrical-signal disturbance already meets the preset condition.