An applied study of microwave-free magnetic balance DC measurements based on diamond NV center

The booming development of China's electric power industry makes the power system requirements for current transformers are also increasing, the traditional current transformer has been unable to meet the needs of the use of extreme conditions. The diamond NV center quantum magnetometry technology nearly has the advantages of high accuracy, high sensitivity, no temperature drift, etc., so the power system researchers turn their attention to the quantum current transformer. In this paper, a magnetic balancing DC current measurement scheme based on diamond NV center is proposed, which uses the magnetic field generated by the balancing coil to balance the magnetic field excited by the current to be measured, and uses the modulation coil to track the change of the balancing point, and realizes the current measurement function after calibration. The measurement accuracy of the system can reach 0.2 level, which lays the foundation for subsequent engineering applications.