Noninvasive on-line condition monitoring of on load tap changers

Abstract

The paper describes a condition monitoring and diagnostic monitoring system developed for power transformer On-Load-Tapchangers (OLTCs). The system has been installed in distribution substations to continuously monitor the operation of OLTCs on 33fllkV power transformers. The field trials have demonstrated that the system can provide reliable indication regarding the actual condition of OLTC contacts. Also presented in the paper are the details about an industry survey on failure modes of commonly used OLTCs in Queensland electricity transrmss ion and supply industries. in 1987 and 1990 respectively. Currently, he is a PhD. candidate at Queesland University of Technology (QUT), Australia. His interests are in the areas of System control and signal processing with application to power equipment condition monitoring. David Blrtwhistle is an Associate Professor of Electrical Engineering and the Director of Research Concentration in Electrical Energy at QUT. His research deals broadly with aspects of high powex equipment including switching devices, lines, and high voltage insulation. John &ley is the head of Substation Standards Department of Energex, Australia His intemts are in areas of substation asset management and condition monitoring.

Methodology for Vibration Signal Processing of an On-load Tap Changer

“…In addition, it is expensive and requires a skilled staff. Vibration is a suitable parameter to monitor the mechanical condition of an OLTC (P. Kang,et al,2000). Vibrations from a working OLTC are often readily available, but obtaining them from a defective OLTC is not as easy.…”

Instrumentation system for industrial transformers

“…The OLTCs have shown to be elements that need a more intensive maintenance and that cause more failures, from all the ones concerned in a power transformer [1] [2]. This is because OLTC is the only mechanical mobile element that is present in a power transformer.…”

Characterisation of Vibration Sigsnals Using Continuous Wavelet Transform for Condition Assessment of on-Load Tap-Changers

“…Vibrations, produced by the contact movements of OLTCs, are transient signals with well-defined oscillation bursts as the main components. Measuring the OLTC vibration signals provides a source of information for the assessment of the equipment condition [3,4]. However, the original vibration signals bear only a qualitative relationship to the condition of the equipment.…”