Closed-Loop Diamond Quantum Sensor for Large Range and High Precision Current Measurement
Qihui Liu, Fei Xie, Xiao Peng, Yonggui Zhang, Nan Wang, Yuqiang Hu, Lihao Wang, Yichen Liu, Yang Wang, Shaoxiong Nie, Hao Chen, Jiangong Cheng, Zhenyu Wu
Abstract
Magnetic field sensors based on quantum effects have shown superior performance in sensitivity, wherein the nitrogen-vacancy (NV) center in diamond has emerged as a microfabrication compatible solid-state platform for measuring magnetic fields at room temperature. Here, a closed-loop current sensor based on a compact diamond sensor is presented. Adapting dual-frequency driving mode and magnetic balance approach, a magnetic-temperature dual-loop architecture is established to extend the dynamic range and suppress the temperature drift, simultaneously. The proposed current sensor demonstrates an accuracy of 0.061% at a measuring range of ±1000 A. An isolation factor of 30.3 dB for temperature against magnetic field is obtained via the dual-loop calibration. The closed-loop strategy permits rapid adjustment of the output signal to align with fluctuations in the primary current and the response speed is achieved up to 107.6 kA <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot \text{s}^{-{1}}$ </tex-math></inline-formula> . Our proposed closed-loop current sensor has potential applications in power grid and electric vehicle monitoring systems.