Research on the Evolution Mechanism of Partial Discharge Signals for Arcing Faults in Transformers

Effective monitoring and identification of partial discharge (PD) signals caused by arcing faults is essential for the prevention of transformer explosions. However, there is still a deficiency in the comprehension of the evolution of PD signals resulting from arcing faults. This study investigated the characteristics of PD signals, including electricity, sound, and pressure, during arc discharge through transformer arc discharge experiments. During the experiment, the ultra-high frequency (UHF) electromagnetic PD signal excited by arc discharge demonstrated good continuity, yet the amplitude of the pulse signal was low. The high-frequency current PD signal merely generates a pulse signal at the instant of arc initiation. The mediate-frequency current PD signal emerges in the form of periodic pulse signals. The amplitude of the low-frequency current PD signal is the highest and shows a continuous periodic pattern. Additionally, arc discharge leads to rapid pressure variations accompanied by audible and ultrasonic signals. The experimental results bridge the gap in the study of the PD signal characteristics during arc discharge in transformers, offering data support for the identification and early warning of transformer arcing faults.