Partial discharge detection and localization in power transformers

An enhanced partial discharge (PD) measurement and evaluation techniques used for an improved condition assessment on power transformers are introduced and discussed. The PD measurement system itself is based on a wide-band electrical decoupling of the PD signals using special sensors, a superior signal transmission technology and the transfer function, thus the PD can be detected, localized and furthermore the influences of disturbing noise be significantly reduced during the online measurement. Remaining noises and pulses from outside the transformer are afterwards suppressed using improved digital signal processing tools. The measurements in the laboratory and on-site show reasonable results and the PD measuring system can be integrated as a component in a comprehensive monitoring and diagnostic system.