In order to improve the ability of fluxgate current sensor to detect weak residual current

starting from the key magnetic ring of the fluxgate current sensor

the key technology of the magnetic ring design of the open-loop fluxgate current sensor is introduced from the selection of magnetic ring materials and structural design by using Comsol simulation analysis method.The experimental results show that the sensitivity of the sensor after adding the magnetic ring can reach 1.54 V/A

and the frequency can reach 6.7 kHz

which meets the detection of AC and DC complex leakage current.