An Improved Device for the Dynamic Testing of OLTCs Un dispositif amélioré pour l’essai dynamique des OLTCs

In this article, a new device to test the on- load tap changer (OLTC) is proposed. The presented device, which is called OLTC tap scan (OLTCTS), enables the user to find the location of the error without opening the transformer and removing OLTC. The proposed device applies the electrical parameters to the bushings of transformers and utilizes electrical parameters, such as voltage, current, current and voltage slopes, and resistance. All the mentioned electrical parameters are evaluated both statistically and dynamically in the presented device. Dynamic current ripple and dynamic voltage ripple are the main parameters that are evaluated for OLTC testing in this article. After designing and building this device, it was used for practical testing on three power transformers, and the results obtained from those tests are analyzed in this article.