Design of a dual-range current sensor using fluxgate technology: a five-magnetic-ring probe with adaptive range switching for high-resolution and wide-range current detection

Abstract Our study introduces a novel dual-range current sensor design based on fluxgate technology, featuring a probe structure composed of five magnetic rings. This innovative design enables the multi-range detection of direct current (DC) within a single sensor system. Specifically, it enhances both the resolution and sensitivity for small current measurements, while also supporting the detection of larger currents, reaching several 100 A. In addition, the sensor is capable of measuring alternating current measurements across a wide bandwidth. The proposed current sensor is capable of adaptively selecting and switching between different current ranges. To minimize signal interference and ensure measurement accuracy, the design employs a second harmonic analysis method in conjunction with a zero-flux closed-loop circuit. Experimental results confirm the sensor’s exceptional performance, with a resolution of 100 μA, a linearity of 0.339%, an accuracy of 0.604%, and a broad operational bandwidth extending from DC to 920 kHz for current detection. In conclusion, we have successfully developed a highly sensitive and reliable dual-range fluxgate current sensor capable of accurately measuring currents across various applications, establishing it as a versatile tool for diverse electrical measurement applications.