Method for processing arc fault, inverter and photovoltaic system

An inverter, comprising a controller, an inversion circuit and at least one DC/DC conversion circuit, wherein

• a power supply side of the at least one DC/DC conversion circuit, serving as an interface corresponding to a direct-current side of the inverter, is configured to be connected to at least one direct-current power supply;
• a bus side of the DC/DC conversion circuit is connected to a direct-current side of the inversion circuit through a direct-current bus;
• an alternating-current side of the inversion circuit, serving as an alternating-current side of the inverter, is configured to be connected to a power grid and/or an alternating-current load;
• the controller is configured to control the inversion circuit and the DC/DC conversion circuit;
• wherein the controller is further configured to:
• in a case that a suspected arc is detected, stop outputting a control signal to a first DC/DC conversion circuit where the suspected arc occurs, and maintain remaining DC/DC conversion circuits operating normally;
• wait for a first preset period, and determine whether a current at a power supply side of the first DC/DC conversion circuit is less than a first preset current;
• and
• determine that an arc fault occurs, in a case that the current at the power supply side is less than the first preset current.

A photovoltaic system, comprising at least one photovoltaic string and an inverter, wherein the inverter comprises:

• a controller, an inversion circuit and at least one DC/DC conversion circuit, wherein
• a power supply side of the at least one DC/DC conversion circuit, serving as an interface corresponding to a direct-current side of the inverter, is configured to be connected to at least one direct-current power supply;
• a bus side of the DC/DC conversion circuit is connected to a direct-current side of the inversion circuit through a direct-current bus;
• an alternating-current side of the inversion circuit, serving as an alternating-current side of the inverter, is configured to be connected to a power grid and/or an alternating-current load;
• the controller is configured to control the inversion circuit and the DC/DC conversion circuit;
• wherein the controller is further configured to:
• in a case that a suspected arc is detected, stop outputting a control signal to a first DC/DC conversion circuit where the suspected arc occurs, and maintain remaining DC/DC conversion circuits operating normally;
• wait for a first preset period, and determine whether a current at a power supply side of the first DC/DC conversion circuit is less than a first preset current;
• and
• determine that an arc fault occurs, in a case that the current at the power supply side is less than the first preset current;
• and
• the interface corresponding to the direct-current side of the inverter is connected to the at least one photovoltaic string, and the alternating-current side of the inverter is connected to the power grid and/or the alternating-current load.