Split-type magnetoelectric current sensor based on optimized structured magnetic cores and Metglas/PZT/Metglas material

Abstract In practical current measurement, the split-type magnetoelectric current sensor is often unable to achieve a zero air-gap upon magnetic core closure. This limitation primarily stems from machining tolerances and installation deviations. To reduce the impact of air-gaps on sensing performance, this paper proposes a split-type closed-loop magnetoelectric current sensor by optimizing the structure of split magnetic cores to ensure a larger contact area. The sensor consists of Metglas/PZT/Metglas magnetoelectric composite with high permeability and low hysteresis, three optimized silicon steel magnetic cores, a pair of neodymium iron boron permanent magnets, and packaging components. The optimized magnetic cores feature a fully closed structure at the junction between the Metglas/PZT/Metglas composite and the core itself, while incorporating a tooth-shaped structure at the sensor’s opening-closing interface. For a 50 Hz current within the 0.1–10A range, the sensitivity of the sensor with an optimized magnetic core reaches 28.80 mV/A, which is an approximately 65.1% improvement compared to that of the sensor with planar-structure magnetic cores. Furthermore, experimental results indicate that the proposed current sensor not only has minimal output voltage fluctuations in 1h measurement. These findings further confirm that the sensor is well-suited for current measurement applications.