Enhanced Diagnosis of Power Transformers using On- and Off-line Methods: Results, Examples and Future Trends
RWE Energie AG, U Sundermann, Germany
H. Matthes PreussenElektra Netz GmbH u. Co. KG, Germany
S. Tenbohlen*, D. Uhde, J. Poittevin ALSTOM T&D
H. Borsi, P. Werle Schering-Institute of High-Voltage Technique and France Engineering, University of Hannover, Germany
ABSTRACT
Both, on- and off-line measurements have been performed through the last years on several large power transformers. This paper describes the most recent devel- opments of sensor technology, such as an electronic Buchholz Relay, an OLTC monitoring based on the power consumption of the motor drive and on-line PD- measurement. The presentation of results gained from the combination of on- and off-line methods shows, that they are powerful tools to take decisions on the operation of the transformers. Even more it allows to define concepts for efficient assessment of the transformers condition
Keywords: Power Transformer, Monitoring, Lifetime As- sessment, Buchholzgas sensor, OLTC, PD-Measurement, Fre- quency Response Analysis, Thermal control
