Screen-Returned PCB Rogowski Coil for the Switch Current Measurement of SiC Devices

The measurement of the switch current (SC), which is essential for a SiC devices-based system, however faces challenges related to the bandwidth, noise-immune ability and invasiveness due to the high switching speed and low junction capacitance of SiC devices. Featuring inherent non-intrusive property, the printed circuit board (PCB) Rogowski coil is particularly suitable for sensing the SC of SiC devices. Nevertheless, existing 4-layer PCB Rogowski coils are unable to tackle the disturbance voltage noise and the perpendicular magnetic noise simultaneously. This paper carries out a systematical study on the 4-layer PCB Rogowski coils, with a screen-returned Rogowski coil presented for the SC measurement. Theoretical analysis shows that the presented coil can obtain the enhanced noise-immune ability and high-frequency bandwidth at the same time. Experimental results validate the effectiveness of the proposed method.