Design of Weak Current Sensor Based on Rogowski Coil

In order to expand the application scenarios of the Rogowski coil and extend its limitations in weak signal measurements, a comprehensive design approach for the Rogowski coil is integrated. This paper begins with an analysis of the basic structure and measurement principles of the Rogowski coil. Derivations are made to understand how various parameters impact the performance of the Rogowski coil, and simulation validations are employed. The study investigates the specific influence of structural parameters on measurement performance and proposes a set of design procedures for Rogowski coils tailored to different performance metrics and signal types. Finally, using a specific scenario as an example, a Rogowski coil measurement sensor is designed based on the conclusions drawn earlier. The designed sensor features a nickel-zinc ferrite core with a 10 MHz wide bandwidth, high sensitivity, high mutual inductance coefficient, and a compact size for weak signal measurements. Experimental results demonstrate the excellent performance of the designed Rogowski coil, meeting the measurement requirements for high-frequency weak signals.