Experimental Study on Elimination of Partial Discharge Effect on Detection of Radial Deformation of High Voltage Transformer Winding Using Electromagnetic Waves

Online detection of defects in power transformers attracts attention of researchers because of its technical and economic advantages. Recently, radial deformation detection has been carried out using ultra-high-frequency (UHF) synthetic-aperture radar (SAR) imaging method. Another defect in the transformer winding is partial discharge (PD). When a PD is occurred, UHF signal is propagated in the transformer environment. Because of same frequency band of UHF SAR imaging method and PD emissions, the stepped frequency approach has been proposed to make the system compatible to eliminate the effects of PD on detection of radial deformation. The feasibility of the mentioned strategies has been simulated using CST software in previous studies. In this paper, a monitoring system is designed and implemented on a real transformer winding to simultaneously detect these defects by the mentioned approaches.