Localization of partial discharges using UHF sensors in power transformers

Transformer failure is usually triggered by external events such as lightning strikes, switching transients, or short circuits. However, susceptibility to these events is usually due to some incipient weakness in the insulation system, which may be detected at an earlier stage by monitoring partial discharge activities. Usually, PDs are detected acoustically, chemically, or electrically. The acoustic and chemical PD detection technology has been successfully used on power transformers for many years. However, in this paper, The PD´s UHF phenomenon in power transformers is simulated by MATLAB and FEMLAB, and the monitoring method of using UHF sensors is analyzed. Furthermore, a new PD localization method using three UHF sensors is also proposed