Gassing in Windfarm Transformers

Abstract

This paper goes on to describe gas generation in windfarm transformers. (WTTs – Wind Turbine Transformers). Local transformers, those directly linked to the turbine of a wind farm, generate abnormally high amounts of dissolved gases. This is virtually independent of the type of transformer (pad mount or distribution) and the type of fluid (mineral oil or synthetic ester) contained in the transformer.The causes of this anomalous gas formation are not fully understood yet, although some possibilities have been proposed, such as a breakage or delamination of the core, harmonics, low voltage fault ride through, over voltage size limitation, variable loading cycle or switching surges and transient overvoltages.Nor can it be ruled out that the cause of these gases could be the interaction of the transformer with the electrical system: windfarm design.These causes are discussed in the paper.