CASE STUDY OF THE GROUNDING CURRENT FOR A TRANSFORMER WITH MULTIPLE CORE GROUNDING POINTS

This month’s Featured Technical Paper is from the Proceedings of the 2019 International Conference of Doble Clients. The paper is titled: Case Study of the Grounding Current for a Transformer with Multiple Core Grounding Points

Abstract

A 500kV single-phase autotransformer in BC Hydro system experienced a big increase of combustible gas content in the oil. A case study is presented to identify the gassing source in this transformer with grounding current measurements and demonstrate the variation of the grounding current under different loading conditions. This paper will also introduce the measures adopted to stop gassing due to multiple core grounding points. The magnitudes of the core and tank grounding current from both the field and factory measurement will be compared and analyzed. A baseline could possibly be established for future diagnostic tests. Finally, considerations on the future work procedure to cope with issues from multiple core grounding points are introduced.

Doble Service Agreement Clients

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