Design and anti-interference study of PCB Rogowski coil current sensor

Abstract

To address the trade-off between bandwidth, sensitivity, and anti-interference performance of the Rogowski coil, a combined PCB differential Rogowski coil with high bandwidth, enhanced anti-interference capability, and improved sensitivity was proposed. The measurement principles and equivalent lumped parameter circuit model of the combined PCB Rogowski coil were analyzed to identify key factors influencing measurement bandwidth. A differential design was implemented to enhance anti-interference performance, which was further analyzed in detail. Finite element simulation software was used to evaluate interference in various electromagnetic environments, confirming the high anti-interference characteristics of the loop-combined PCB differential Rogowski coil. Experimental verification showed that the designed sensor achieved a sensitivity of 3. 46 mV / A and a linearity of 0. 56% when measuring power frequency currents ranging from 1 A to 100 A. The maximum relative error during 10 A to 100 A measurements was 1. 73% . In anti-interference tests, the sensor exhibited a maximum relative error variation of - 0. 39%, demonstrating strong anti-interference capability. Comparative experiments revealed that the proposed coil effectively resists electric and magnetic field interference while expanding the measurement bandwidth without compromising sensitivity. This advancement broadens the application scenarios of Rogowski coils, enhancing their versatility and flexibility.