Study of parameters influencing the performance of connectors used for load and temperature tests on transformers

This paper emphasizes the factors to be considered when designing power connectors used in the load and temperature tests of power transformers. External conductors used to perform load and temperature tests in transformers are referred as power connectors in this contribution. Electrical and thermal investigations of a single-phase shell-type, 300 MVA, 400 kV-21.5 kV power transformer connector were performed. To analyze the behavior of the connector, a harmonic analysis to calculate losses by Joule effect generated in the electrical connector was first performed, followed by a thermal, finite element based analysis to determine temperature distribution. As heat sources, harmonic losses analyses were performed. Temperature distribution obtained by the finite element simulation was compared with measurements recorded by an infrared camera during the tests