Entwicklung eines neuartigen Sensors zur Ermittlung des aktuellen Zustands der Papierisolierung von Transformatoren

In this study, the condition of kraft paper as an insulating material is investigated using a novel sensor. For this purpose, insulating paper and insulating oil are homogeneously aged using an accelerated ageing process. In order to create a possibility to directly measure the DP-value of the insulating paper during operation and at the weakest point, an optical measurement concept for determining the DP-value is developed and investigated in this study. The DP-value of the aged paper is determined according to DIN EN 60450 and compared with the value of the optical sensor, whereby the measurement is carried out using optical fibers. The aim of the future application in the transformer under real operating conditions is always pursued. For this purpose, the system of a freely breathing transformer is examined with an inhibited insulating oil. During the development of the final sensor concept, a very good correlation of the measured value with the DP-value determined in the laboratory was shown, which allows an optical measurement of the insulating paper together with aged insulating oil, as it is also conceivable in the real transformer.