Determination of the saturation curve of power transformers by processing transient measurements

Abstract

The sudden energization of large power transformers may lead to the saturation of the magnetic core and induce resonant overvoltage on weak networks due to low frequency high module inrush currents. The magnetization curve of the transformer and the value of its air-core inductance play a key role in the constraints that can be applied to the equipment due to the switching. The method set out in that document allows to identify the saturation curve of three-phase power transformers from measurements recorded during switching transients.