Computation of electrodynamic forces acting on clamping beams of windings in power transformers

Abstract

In response to the growing demand for electrical load driven by socio-economic development, the national transmission grid is being gradually
upgraded. In this context, conventional power transformers with capacities of 3x150 MVA-500kV and 3x200 MVA-500kV are increasingly
being replaced by higher-capacity units, most notably the 3×300 MVA transformers. To meet this trend and reduce dependence on imported
equipment, the research, design, and manufacturing of power transformer with 3x300 MVA-500kV present a significant technological
challenge for the domestic industry and remain a current topic of interest among both national and international researchers. During operation,
short-circuit events subject the windings to extremely high electrodynamic forces, posing a risk of severe deformation or insulation failure if
not properly designed. In the winding structures, the clamping beam plays a critical role in directly withstanding these forces, preserving the
mechanical integrity of the winding, and maintaining insulation stability throughout operation. This paper develops an analytical approach
combined with the finite element method (FEM) to compute, analyze and simulate the electrodynamic forces and deformation acting on the
clamping beam in supper-high voltage transformers with power ratings up to 300 MVA-500kV under various operating conditions. Accurate
assessment of the mechanical behavior during short-circuit events is essential to ensure the structural integrity and safe operation of the
equipment.