Single-phase-to-earth fault processing device and method for neutral non-effectively grounded distribution network

A single-phase-to-earth fault processing device for a neutral non-effectively grounded distribution network includes a split-phase arc quenching device connected between earth and a three-phase bus of the distribution network, and a controller with an input end connected with a single-phase-to-earth phase selection device of the distribution network. The split-phase arc quenching device includes a multiphase switching device which operates independently for each phase, and a fuse connected in series with the multiphase switching device. The controller is for controlling opening and closing of three single-phase switches in the multiphase switching device. A single-phase-to-earth fault processing method firstly controls the split-phase arc quenching device to preprocess the fault. If the fault still exists, through a ground resistor a zero-sequence current is generated on a fault line. After delaying to wait for a line to isolate a fault section, a ground connection of the neutral is cut to restore the distribution network.