Design of an Accuracy Current Sensor Using Amorphous Fine Wire of FeCoSiB

In this paper, we are interested in electric current reconstruction from magnetic field measurements. The major difficulty of this principle is in the ability to reject magnetic field perturbations which affect the accuracy of the measurements. The first experimental validation of the approach of gradient measurement shows large errors in the current reconstruction using two independent fluxgate sensors. These errors were attributed to mechanical alignment and different residual magnetic states of the fluxgate sensors. We then suggested an effective solution able to overcome these problems. This solution consists of a fluxgate gradiometer placed above U-shaped conductor carrying the unknown current to be reconstructed. The experimental results of this system show a good rejection of uniform and non-uniform magnetic field perturbations and furthermore an improvement of the accuracy of the measurements. (author)