Effect of Barriers on Windings Temperature Rises of Dry-type Transformers: Measurements and Network Simulations

This paper presents the investigation results of a study on how dielectric barriers between low and high voltage windings influence the winding temperature rises of dry type transformers. Dedicated heat run tests have been performed for two transformer designs that have been assembled with 0, 1, 2 and 3 cylindrical barriers in the space between LV and HV windings. For each barrier configuration a Computational Fluid Dynamics (CFD) model as well as a coupled pressure-thermal network model have been built for comparison with the measurements, which confirmed the significance of the barrier influence and could further enable potential improvement of the simulation tools used by transformer designers.