Current sensors are widely used in power systems, defense, industrial production, measurement, and scientific research. Tunnel magnetoresistance (TMR) current sensors offer advantages of compact size, high sensitivity, wide measurement bandwidth, and low power consumption, making them well‐suited for harmonic current measurement in modern power grids with high penetration of renewable energy sources. In this study, a hybrid TMR current sensor combining a double‐air‐gap closed‐loop core and a symmetrical ring‐array sensing unit was designed to achieve wide‐band and wide‐range measurement. The structural parameters were determined, and a double‐layer shielding structure was optimized through simulation to ensure stable performance in complex electromagnetic environments. A prototype sensor was fabricated and experimentally validated. The results show that the sensor accurately measures DC and power‐frequency currents up to 3000 A, and harmonic currents up to 500 A within 2.5 kHz, with measurement errors within ±0.2%, demonstrating excellent stability and accuracy over the entire range. © 2026 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.
Liu et al. (2026) studied this question.