Transformers Magazine, Vol. 10 No. 4, 2023.
Original scientific paper
Online Monitoring of Transformer Oil Breakdown Voltage: Applying laboratory BDV test results to transformer operation in real-time
Anatoliy Mudryk
Marco Tozzi
Nathan Jacob
Viktor Berezhny
Abstract
The standard oil BDV test is performed on oil samples removed from the transformer and is representative only for the oil condition during the laboratory test due to changes in the oil sample’s relative humidity between the time of sampling and the time of the test. The water content in oil is continuously changing during transformer operation due to moisture migrating to and from the cellulose. Furthermore, an oil temperature gradient exists inside the transformer from top to bottom, and variations in loading and active cooling during operation dynamically change the oil’s relative humidity, and thus change the BDV depending on internal location and time. To provide an accurate assessment of oil dielectric condition under a range of operating conditions, an online estimation for the oil BDV is needed. In this paper, an online BDV calculation methodology is proposed.
Keywords
dielectric breakdown voltage; BDV; relative humidity; temperature; transformer; online monitoring
Hrčak ID:
308709
URI
Publication date:
10.10.2023.
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