The invention provides a current full compensation method and a
system based on single-phase earth fault. When zero sequence
voltage is not in a preset
voltage value range, namely, the happened single-phase earth fault is instant ground connection, an
arc extinction coil device with high flexibility in high-resistance ground connection can compensate ground connection
capacitive current. When thezero sequence
voltage is in the preset voltage value range, namely, the happened single-phase earth fault is not instant ground connection, a breaker in a fault phase transfer ground connection deviceconnected with a fault phase is turned off, fault current is converted into earth current, and a compensable compensation device is further utilized to output full compensation fault residual current. The fault current is converted into the earth current, the earth current can serve as tracking compensation signals of the compensable compensation device, and judgment reference is provided for a
compensation effect of the compensable compensation device. In addition, the earth current can be determined by measurement; furthermore, measurement is convenient, and
complex calculation is avoided;thus, compensation quickness and accuracy are ensured, compensation precision is improved, and fault points are shielded.