Multilayered magnetoelectric composites for precise and wide-range current sensing

Abstract

Magnetoelectric (ME) sensors are widely studied and well suited for current condition monitoring in smart grids due to their high sensitivity, low power consumption, and compact size. However, designing ME sensors that simultaneously achieve low magnetic noise and a large linear range remains challenging. In this work, we propose and systematically study a multilayered magnetoelectric sensor (MLMS). We experimentally demonstrate that the voltage noise is effectively suppressed by connecting the piezoelectric elements of the MLMS in series. Additionally, the magnetic flux concentration effect is weakened by magnetic shielding from the outer Metglas laminates, which increases the optimized bias field to 52 Oe for the MLMS. Consequently, an equivalent magnetic noise as low as 16.7 pT/rtHz at 1 Hz is obtained and an enlarged linear range from 20 pT to 2 mT is achieved. Furthermore, we demonstrate that the proposed MLMS could linearly detect a wide range of power currents from 0.1 mA to 400 A, with nonlinear error and current resolution as low as 0.05% and 0.1 mA, respectively.