Modeling and Measurement of a Self-Oscillating Fluxgate Current Sensor for AC and DC Application

This paper studies fluxgate current sensors used for DC to high - frequency current measurement in various industrial fields. Traditional fluxgate technologies have drawbacks in circuit complexity and cost, while the self-oscillating fluxgate technology has model - related issues. An analytical model for the open-loop self-oscillating fluxgate circuit is developed. Key parameters affecting circuit performance are identified, and a trade-off between sensitivity and linear range is found. A three-core four-winding self-oscillating fluxgate sensor is proposed. Experimental results show that DC and power - frequency AC accuracy better than ±0.1%, and high -frequency AC accuracy better than ±1% within 20kHz. This research provides useful insights for self-oscillating fluxgate current sensor design and optimization.