Feasibility Study on the Audible Noise Measurement of Partial Discharge in Transformer Oil

Abstract

Partial discharge fault detection based audible noise is a kind of new method. This paper set up a needle-plate discharge system, and investigates the feasibility of measuring the audible noise of partial discharge in transformer oil. A needle-plate discharge system is built, and audio noise of partial discharge inside and outside of transformer oil is measured by a microphone and a specially designed hydrophone. According to signal processing, it’s found that the characteristics of internal and external noise have good consistency on time domain wave, spectrum distribution, and time-frequency distribution, except that the former is much larger than the latter in amplitude. The experiment results show that it’s feasible to measure the noise of partial discharge in the transformer oil and have significant advantage in signal to noise ratio.