Large bandwidth and dynamic range current sensor based on micro-PCB Rogowski coil

Abstract

A micro-PCB Rogowski coil with a volume of only 0.032 cm3 was proposed in this paper, and a magnetic flux concentration structure was introduced while ensuring the high-frequency performance of the coil to improve the measurement ability of the Rogowski coil sensor for weak current characterization. We have systematically investigated the magnetic core materials suitable for high-frequency current sensing, and the performance of core at high frequency has also been verified theoretically and experimentally. In addition, a high-precision signal processing circuit, whose main functions are amplification and integration, has also been developed. Experiments have shown that the developed PCB Rogowski coil current sensor can measure the current in the μA level with a bandwidth of 10 MHz, a sensitivity of up to 180 V A−1 and a resolution of up to 50 μA. The response time of the sensor to a step signal is within 30 ns, and it also has good waveform following ability. Compared with commercial TMR sensors, the sensor proposed in this work also has certain advantages in terms of noise.