Magnetoelectric Composite Metglas/PZT-Based Current Sensor

This paper presents an electric current sensor employing an unsymmetrical magnetoelectric composite Metglas/Pb(Zr,Ti)O₃ (PZT) consisting of magnetostrictive Metglas and piezoelectric PZT. As the Metglas foils with excellent magnetic characteristics induce the magnetic field around a current-carrying cable, an output voltage is generated in Metglas/PZT. The influence of the numbers of Metglas foil (L) on resonance output voltage (V_{o, r}) is experimentally investigated in detail. The results demonstrate that the maximum V_{o, r} is 223 mV for Metglas/PZT with L = 4 under 190.2 Hz frequency and dc biased magnetic field H_dc = 16 Oe. By adding a 1.3 g tip mass at the free end of Metglas/PZT, the resonant frequency of Metglas/PZT with L = 4 can be adjusted to 50 Hz, where the V_{o, r} is 211 mV at H_dc = 16 Oe. With the excellent linearity and large current sensitivity (114.2 mV/A) when measuring low-frequency alternating magnetic fields of 50 Hz, this sensor is ideally suited for power-line current measurement.