Influence of screen structure on high-frequency bandwidth and dv/dt noise immunity for PCB Rogowski coils

PCB Rogowski coil renowned for its non-saturation, flexibility and miniaturization advantages, plays a pivotal role in monitoring the condition of SiC devices. While the screen enhances the dv/dt noise immunity, it also poses a trade-off by reducing the high-frequency bandwidth of PCB Rogowski coil. Therefore, this paper analyzes the effect of screen structure on PCB Rogowski coils. Initially, an equivalent circuit model is presented and validated for effectively estimating the high-frequency bandwidth of PCB Rogowski coil. Subsequently, it is derived that the coupling capacitance between the coil and the dv/dt noise source conductor can linearly reflect the dv/dt noise immunity of the sensor. The paper then analyses the effects of diverse screen designs, including hole structure, screen height, inner and outer radius, on the coil using finite element analysis software. The simulation results are validated through experiments. Laws of simulation can be helpful for customized design of PCB Rogowski coils.