Design of a Fluxgate Weak Current Sensor with Anti-Low Frequency Interference Ability

According to the requirements of weak current measurement in power grid, a weak current sensor with anti-low frequency interference ability is developed. The sensor adopts the principle of fluxgate detection and adds a magnetic ring on the original basis. The structure of the magnetic ring is simulated using comsol to further improve detection sensitivity. In order to solve the problem that the electromagnetic current sensor is vulnerable to the interference of geomagnetic field and power frequency magnetic field in weak current measurement, a magnetic shielding method with low cost is selected, and the shielding shell structure is designed using a finite element analysis method. The experimental results show that the minimum measurable current is 1 mA, the measurement range is 1 mA-1 A, and the bandwidth is DC-16 kHz. The designed magnetic shielding shell can effectively reduce 97.3% of the DC magnetic field interference and 95.7% of the power frequency magnetic field interference. The sensor can realize accurate measurement of weak current in power grid.

Automated summary

In response to the requirements of weak current measurement in a power grid, a weak current sensor with anti-low frequency interference ability is developed. By adopting the principle of fluxgate detection and improving the structure with a magnetic ring, the sensor achieves higher detection sensitivity. Furthermore, a low-cost magnetic shielding method is used to design a shielding shell structure, which effectively reduces interference and enables accurate measurement of weak current in the power grid.