Research on transformer Partial discharge monitoring and positioning based on spatial spectra

Insulation defects in power transformers can cause power interruptions or catastrophic failures. PD within a transformer is the main cause of its insulation deterioration. How to effectively locate the PD location and detecting the PD status is one of the difficult points. In response to this problem, this paper proposes a new PD location method based on spatial spectrum estimation technology. The fourth-order cumulant processing technology is used to virtually expand the cross-shaped AE array, and the MUSIC positioning algorithm based on spatial spectrum estimation technology is used to process the covariance matrix of the expanded array to obtain the azimuth and elevation angles of the AE signal; The AE and UHF signals are beam-synthesized at the spatial angle to obtain the transmission delay of the AE signal in the oil, and the distance between the PD point and the sensor is calculated according to the delay, to realize the positioning of the PD. Simulation verification shows that this method has higher positioning accuracy.