METHOD AND CIRCUIT ARRANGEMENT FOR DETECTING AN ARC, AND PHOTOVOLTAIC (PV) INVERTER HAVING A CORRESPONDING CIRCUIT ARRANGEMENT

The disclosure is directed to a method for detecting an arc in a direct-current circuit including a DC load, a DC source supplying the DC load, and a circuit arrangement arranged between the DC source and the DC load. A power flow between the DC source and an output of the circuit arrangement is cyclically interrupted by a switching circuit, such that the power flow is enabled in an active time window with the first period Δtand the power flow is suppressed in an inactive time window with the second period Δt. Detection of a current I characterizing the power flow P and/or a voltage U characterizing the power flow P in two consecutive active time windows and comparison of the detected values of current I and/or voltage U of the active time window with the corresponding detected values from the preceding active time window can signal an arc if these values of the active time window differ from the corresponding values of the preceding active time window by more than a threshold value. The application also describes a circuit arrangement for detecting an arc and a photovoltaic (PV) inverter comprising such a circuit arrangement.