Research on Acoustic-Vibration Joint Detection Fault Diagnosis of Abnormal Transformer

Power transformer is one of the key equipment in the power grid. Due to its complex structure and frequent on-site malfunctions, it is necessary to study targeted detection methods. The acoustic-vibration joint detection method has become the current research hotspot because of its advantages such as no direct electrical connection with electrical equipment, safety and reliability, high sensitivity and strong anti-interference ability. In this paper, a transformer with abnormal vibration and operation noise in a power plant becomes the key analysis object. In order to explore the source of abnormal signal and accurately distinguish the operation condition of transformer, acoustic-vibration joint detection method is adopted. It is found that the vibration spectrum of the abnormal transformer has abnormal vibration peak at A-phase 600 Hz and abnormal vibration peak at C-phase 300 Hz. In the noise 1/3 octave band sound pressure level diagram, the amplitude of the abnormal transformer is larger at 100 Hz, 200 Hz and 300 Hz, followed by at 400 Hz and 600 Hz. Based on comprehensive judgment, the abnormal transformer may have faults such as loose A-phase core or windings, and deteriorated C-phase core quality, with underlying causes possibly attributed to environmental factors such as ground micro-subsidence. The research process can provide reference for on-site fault maintenance personnel of transformers.