High-Frequency Common-Mode Leakage Current Suppression in Motor Drive Systems Using Rogowski Coil Current Sensing

Compared with traditional current transformers, Rogowski coils offer advantages such as simple design, low cost, and non-intrusive measurement. This paper proposes an active filtering structure based on Rogowski coil current sensing. The fundamental sensing principle of the Rogowski coil is first analyzed. Then, based on equivalent circuit models, the coil structure and signal conditioning circuit parameters are designed. Finally, the effectiveness of the proposed structure is verified through simulation. Simulation results show that the proposed active filter achieves approximately 15–23 dB attenuation of common-mode leakage current in the 150 kHz to 30 MHz frequency range.