Operating Behavior of Wind Power Transformers Beyond the Nominal Operation Range

  measurement of effective power Copyright: IEM

Specifications for transmission grid devices are defined by the grid code of the German transmission network operators. For wind power transformers a significant increase of the main flux, compared to the nominal operation can occur for the specified voltage and frequency operating range. Due to this increase the transformers core can be driven into saturation. Subsequently, the transmission behavior may be be influenced. At IEM the magnetic load of the transformer core of a wind power transformer is analysed for critical operating points, specified by the grid code. It is depicted, that the flux density is increased up to 119% related to the rated flux density. For this operating point iron losses increase by 62% compared to rated operation. It is shown that, the transmission behavior of the transformer is not influenced significantly, despite the high flux desity level.