Shutdown control system and method

A shutdown control method, applied to a shutdown control system comprising a main circuit and a control circuit, wherein

• the main circuit is a series circuit formed by connecting output ends of a plurality of shutdown circuits in series or a series-parallel circuit formed by connecting output ends of a plurality of shutdown circuits in series to form a series circuit and connecting output ends of a plurality of the series circuits in parallel, wherein an input end of each of the plurality of shutdown circuits is connected to at least one of direct current power supplies in a distributed power generation system;
• and
• the control circuit comprises a system control unit (SCU) and a plurality of power source control units (PCU) corresponding to the plurality of shutdown circuits, and
• wherein the method comprises:
• transmitting, by the SCU, a first mode control instruction to each of the plurality of PCUs when a first condition is satisfied, wherein the first mode control instruction comprises an ID of the PCU receiving the first mode control instruction;
• transmitting, by each of the plurality of PCUs, a second mode control instruction to all other PCUs upon receiving the first mode control instruction comprising the ID of the PCU from the SCU;
• and
• determining, by each of the plurality of PCUs, a target operation mode of the shutdown circuit corresponding to the PCU based on the first mode control instruction transmitted from the SCU and the second mode control instruction transmitted from another PCU in the plurality of PCUs, and controlling, by the PCU, the shutdown circuit corresponding to the PCU to operate in the target operation mode;
• wherein the target operation mode comprises a security mode and a normal operation mode being a mode other than the security mode, and in the security mode, an output voltage of the shutdown circuit corresponding to the PCU is limited to control an output voltage of the series circuit to be in a security voltage range.