Acoustic Emission Property of Cylindrical Cavity Discharge in Power Cable

Abstract

The acoustic emission property and transient process of cylindrical cavity discharge is comprehensively modeled and validated for power cable in this article. An electrostatic field model is established to analyze the discharge duration and power density varying with discharge magnitude and cylindrical cavity height. The relationship between the acoustic source and PD activity is constructed through discharge power density and duration. Furthermore, a transient model for acoustic wave propagation in a multilayer power cable is established. Numerical analysis with finite element analysis is conducted to analyze the effects of different discharge magnitudes under the same cavity height and different cavity heights under the same discharge magnitude on the acoustic waves at the surface of the power cable. The simulation reveals that higher discharge magnitude results in greater intensity of the acoustic wave and longer cavities result in lower acoustic frequencies. Ultimately, a series of validation experiments are implemented to acquire the statistical acoustic characteristics. The intensity of acoustic wave is positively correlated with the discharge magnitude in R-square of 0.9895, while the frequency is negatively correlated with cavity height in R-square of 0. 9589.