Transformers Magazine, Vol. 8 No. 3, 2021.
Izvorni znanstveni članak
Optical sensor for determining the degree of polymerization of the insulation paper inside transformers
Tobias Münster
Prof. Dr.-Ing. Peter Werle
Kai Hämel
Raimund Barden
Joerg Preusel
Sažetak
Effective lifetime and maintenance management of a transformer fleet requires precise monitoring of the electrical insulation conditions of each transformer. Currently, the condition assessment of the insulating paper of transformers in operation is done indirectly, by oil samples and evaluation of aging markers in the liquid with only limited accuracy. In fact, sampling of the paper for direct analysis of insulation paper quality is only possible when the transformer is under maintenance or decommissioned. In this paper, the methodology and product development of a novel patented optical sensor is presented, which provides a possibility to determine the degree of polymerization (DP) of insulating paper online and in real-time with high precision via optical spectroscopy inside operating transformers. The measurement is carried out non-destructively and within seconds by a specific evaluation of the reflection spectrum of the insulating paper inside the oil or ester filled environment. The investigation has shown that measurement under strongly aged insulating oil is possible, and the medium surrounding the paper has no influence on the determination of the DP-value. Product development involves materials and technologies to ensure long-time accuracy under mechanical, vibrational, chemical, thermal, and electromagnetic challenges of the transformer environment. This novel, innovative sensor is designed to enable online monitoring of the quality of insulating paper in the transformer at various points, like the hotspot, in order to improve operational safety and economical operation. The optical measuring method provides very high reliability and high accuracy. Deviation analysis shows higher accuracy for lower DP-values, which supports the determination of the end-of-life DP-values.
Ključne riječi
Hrčak ID:
261404
URI
Datum izdavanja:
8.7.2021.
Posjeta: 967 *