Simulation-based parameter optimization and development of a split-core fluxgate DC current sensor

Abstract

Fluxgate current sensors (FGCSs) are increasingly employed in power systems due to their high-precision characteristics, yet their measurement flexibility remains constrained by conventional closed-core designs. To address this limitation, we proposed a split-core sensor structure comprising four magnetic core strips, which achieved non-intrusive current measurement while maintaining detection accuracy. An analytical model of the induced electromotive force was established based on the probe’s geometric configuration, followed by finite element simulations to optimize key parameters including core radius, core width, excitation coil turns, and sensing coil configuration. A complete prototype integrating the measurement probe, excitation circuit, and signal processing circuitry was developed and experimentally validated. The experimental results show a sensitivity of 0.109 9 V/A, a hysteresis error of 0.559%, and a repeatability error of 1.574% over a measurement range of ±10 A. After polynomial fitting-based error compensation, the nonlinearity error was reduced to 0.208%, achieving performance comparable to closed-core sensors. This work provided a practical solution for applications demanding both high measurement accuracy and installation flexibility.

Keywords

fluxgate current sensor / second harmonic method / finite element simulation / parameter optimization / circuit design / DC measurement

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