Cylindrical magnetoelectric FeGa/PZT composite for lightning current sensing applications

Magnetoelectric (ME) composites have been proven to apply to current sensors. However, the previously reported ME materials-based current sensors mainly focus on direct current and sine alternating current sensing, which put a critical limit on the measurement of transient current. In this paper, a cylindrical ME composite consisting of a magnetostrictive Fe83Ga17 (FeGa) cylinder and a piezoelectric Pb(Zr, Ti)O-3 (PZT) circular tube is fabricated for lightning current sensing applications. The time-domain output voltage of the FeGa/PZT composite is simulated and measured in detail. Under the excitation of 8/20 mu s lighting current, the output voltage of the composite can change with the current. But the damping oscillation at its resonant frequency is observed. Furthermore, to obtain an obvious ME response, the FeGa/PZT cylinder and current-carrying wire should be arranged closely and in an orthogonal way. When the amplitude of 8/20 mu s lightning current is in the range of 500 A-9 kA, the ME FeGa/PZT composite shows a sensitivity of 1.36 mV A(-1), a linear response (R (2) = 0.9993), and a small return error (0.12 V). These results provide that the ME composite is suitable to be used in non-contact lightning current measurements.

Automated summary

In this study, a magnetoelectric composite consisting of a magnetostrictive FeGa cylinder and a piezoelectric PZT circular tube was fabricated for lightning current sensing applications. The composite showed a time-domain output voltage that changed with the current, with damping oscillation observed at its resonant frequency. The arrangement of the FeGa cylinder and current-carrying wire in an orthogonal way was found to result in a significant magnetoelectric response. The composite exhibited a sensitivity of 1.36 mV A(-1), a linear response (R(2) = 0.9993), and a small return error (0.12 V) for lightning currents in the range of 500 A-9 kA.