METHOD AND DEVICE FOR DETECTING DIRECT CURRENT ARC, AND STRING INVERTER

A method and a device for detecting a direct current arc, and a string inverter are provided. The method includes: for each of N photovoltaic strings connected to an input end of an MPPT circuit in a string inverter, acquiring a current detection result of the photovoltaic string; removing a background noise signal from the N current detection results corresponding to the MPPT circuit based on a principle that characteristics of photovoltaic strings connected to the same MPPT circuit are relatively consistent, so that the result including no background noise signal includes only an electricity arc signal; and performing data processing and harmonic characteristics analysis on the result corresponding to the MPPT circuit including no background noise signal, to obtain a direct current arc detection result for the N photovoltaic strings corresponding to the MPPT circuit. Therefore, accuracy in detection of the direct current arc and safety of the string inverter are improved compared with the conventional technology.