Multi-objective Design Optimization For High-bandwidth Printed-Circuit-Board Shielded Rogowski Coils

Existing Rogowski coil sensors suffer from insufficient measurement bandwidth, which limits their ability to accurately capture the switching transient current of wide-bandgap devices. A combination Rogowski coil is proposed to extend the overall measurement bandwidth to address this limitation. This concept involves combining the self-integrating region of a shielded Rogowski coil with its differentiating region. The selection of suitable geometrical parameters is crucial as it directly affects the measuring performance, including bandwidth and sensitivity. This paper explores the methodology of employing a multi-objective optimization workflow to design Printed Circuit Board (PCB) shielded Rogowski Coils. Eight geometrical parameters are considered as design variables to maximize the objective functions. Utilizing the distributed model of the shielded PCB Rogowski coil, the geometry of the PCB shielded Rogowski coil is optimized using JMP. The factors that have a significant impact on bandwidth and sensitivity are identified through the optimization process. To validate the proposed optimized approach, an optimized current sensor is designed, prototyped, and tested. A comparison is made between the optimized design and state-of-the-art alternatives to assess its performance.