Frequency response analysis — status of the worldwide standardization activities

Frequency response analysis (FRA) is a powerful and sensitive tool to assess the mechanical and geometrical integrity of core, windings and clamping structures within power transformers, by measuring their transfer functions over a wide frequency range. Despite a rapidly increasing number of users throughout the world and a significantly growth of knowledge about the application of the method, the only current, valid and obligatory national standard is in the Peoplepsilas Republic of China. Intensive work is being carried out in organizations such as Cigre and IEEE to create international guidelines for the use of FRA. The paper gives an overview about the status of this work.