Station Service Voltage Transformer Impedance Calculation Using the Finite Element Method Compared with Measurements

In this paper, the percentage of short-circuit impedance is calculated using the Finite Element Method (FEM) for a Station Service Voltage Transformer (SSVT). Traditional formulations consider the dimensions of the windings, core and the respective gaps but not consider the behavior of the magnetic flux, these formulations are efficient for common geometries, but the FEM consider all aspects according to the geometry selected, 2D and 3D models are good approximations to reach the real value of the impedance and it can compute the leakage fluxes and obtain the leakage inductances of the under different configurations. An improvement on the determination of the impedance was observed in simulations compared with the measurements obtained from the short-circuit test and with typical formulations, the computation of the impedance helps to determine the magnitude of the short-circuit current, optimize the manufacturing reducing the material costs and obtain the leakage reactance.