The present invention relates to an active shunt installed at the upper and the lower of a three-phase wire. The active shunt is formed along the curve of the three-phase wire. The active shunt is installed on the lateral surface of the lower part of the three-phase wire or the lateral surface of the upper part. Both sides of the active shunt are round to maximize the inflow of magnetic leakage flux and to improve the flow of magnetic flux by reducing a distance from a core bar.
