Partial Discharge Signal Detection by Piezoelectric Ceramic Sensor and The Signal Processing

Abstract

Partial discharge (PD) in an insulator or on surface of defective conductor emits acoustic wave trans- mitting through an air or an insulator. The acoustic wave between 20 kHz and several hundred of kHz can be detected by piezoelectric ceramic sensor that converts the acoustic wave into an electrical signal. Piezoelectric ceramic sensor has either the wide resonant band or the local resonant band depending on the ceramic material or the various combinations of each different component in the manufacturing process. This paper presents the piezoelectric ceramic sensor with 0.95 PZT-0.05 PMNS that yields the piezoelectric properties of high kp, high Qm .I thas the frequency characteristics of local resonant band, such that it can be applied to PD detection. We have demonstrated the properties of the proposed piezoelectric ceramic sensor by comparing with the conventional electrical PD detector. Quantitative analysis is accomplished by comparing the ψ-qmax from a PD detector and the ψ-vmax from the proposed sensor while ψ-n distributions are the same for both the conventional phase-resolved PD analysis method and the proposed one.