The effects of axial displacement of transformer windings on impulse and transferred voltage distribution

Mechanical forces due to short circuit currents especially near the power transformer will cause the axial displacement or radial deformation of transformer windings. Therefore, it is possible to have a transformer with mechanical faults in the electrical power system. Hence, it is necessary to design the insulation arrangement in order to get sufficient withstand against the impulse voltage distribution in case of such faults. In this paper, the effects of axial displacement on impulse and transferred voltage distribution are investigated with the help of two particular windings having the rated power of 1.3 MVA as a test object and its detailed model. The results show the significant influences of axial displacement on impulse voltage distribution so they should be considered in the design of insulation.