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 \(_{\rm dc}= 16\) 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 \(_{\rm dc} =16\) 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.