Common-mode current measurement of high voltage inverter based on Rogowski coil

Abstract

It is used to measure common-mode current (CMC) by Holl current transducer and traditional current transformer. In allusion to their limitation, a novel method of measuring CMC based on Rogowski coil is proposed in this paper. Take example for common-mode circuit of five-phase H-bridge three-level inverter, simulation indicates CMC belongs to a typical high frequency pulse current. The model of its equivalent circuit is built and feasibility is validated in theory. The measuring projects of motor with single coil, filter with two coils and filter with single coil are introduced. After compared the three projects, the third project is choosed at last. Finally, Simulation and experimental results verify the validity and feasibility of the novel method proposed in this paper.