Analysis of Ultrasonic Propagation Characteristics of Partial Discharge in Oil Immersed Power Transformer

Oil immersed power transformer is the main electrical equipment in power system. Its operation reliability has an important impact on the safe operation of power system. In the process of production, installation and operation, its insulation structure may be damaged, resulting in partial discharge and even breakdown inside the transformer. Taking S9-M-100\10 oil immersed distribution transformer as the research object, the propagation characteristics of ultrasonic wave generated by partial discharge in transformer in time domain and frequency domain are simulated and analyzed. The simulation results show that the ultrasonic wave generated by partial discharge of transformer propagates to the surrounding in the form of spherical wave. No matter from the analysis of the total sound pressure in the transformer from the time domain or frequency domain, it can be seen that the ultrasonic wave inside the transformer tends to attenuate and oscillate from the point sound source, which conforms to the law of sound propagation. The simulation results can provide reference for explaining the propagation characteristics of variable partial discharge ultrasonic in transformer.