2006 Volume 126 Issue 11 Pages 1112-1120
This paper describes the improving method of Rogowski coil for the measurements of zero-phase-sequence current. For the measurements of zero-phase-sequence current, the error made by the influence of external magnetic field and residual current is explained and verified in this paper. In new winding method, two wires are used to wind with different winding directions at the start. This winding method makes the crossing point at the opposite side of the coil, and two wires should be crossed up and down alternately to form the same size of cross section of the coil. The coil is divided to several pieces of small coils. The outputs of these coils are connected in parallel. It is observed that the influence of external magnetic field and residual current is improved tremendously by this new improvement.