Original scientific paper

SFRA ratio test on transformers

Long Pong ; Doble Engineering Company

Abstract

SFRA test is a powerful and sensitive method for assessing the mechanical and electrical integrity of the transformer core/coil assembly. The two most commonly used tests are open- and
short-circuit tests. Both are used for testing the complex network of inductances, capacitances and electrical resistances and, frequently, have no difficulties in detecting the presence of an electrical fault with the shorted turn(s).
Since windings are electromagnetically coupled, the SFRA trace obtained from one of the windings may be affected by the electrical fault on a different winding. Identifying which winding has the problem is a challenging task. This paper describes the experience with six units, where the faulty winding (if any) was identified by employing an inductive inter-winding SFRA setup. We elected to refer to this test as “SFRA ratio” test.

Keywords

data analysis, detecting fault winding, diagnostics, SFRA ratio, shorted turns

Hrčak ID:

249904

URI

https://hrcak.srce.hr/249904

Publication date:

8.1.2021.

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