CAD-based Design of Three Phase Transformer and Comprehensive Analysis for Wind Turbine Using Coupled Electromagnetic Field, Circuit and Thermal Model for 3.8 MVA Power

Abstract

In this study, by using co-simulation technique, dry type transformer is designed for wind turbine with 3.8MVA, 690V/36kV power and voltages. Transformer used in wind turbine needs extra effort on design stage with respect to the transformer used in transmission and distribution systems due to higher inrush currents, resonance overvoltage, higher voltage and load fluctuations, possible high frequency transients causing the damage of insulation of the transformer. Also, variable output because of the variable wind speed is expressed as a common failure of the transformer stated in, although by power converters the problem can be minimized. Furthermore, transformer design and analysis of its effect to the system, cannot be realized through one simulation software. Therefore, another approach using different simulation software at the same time called as co-simulation or multiphysics solution is needed. In this paper, by using, co-simulation technique including ANSYS Maxwell 3D, Simplorer and Mechanical, transformer design and its effect to the system is investigated. After realizing, three-dimensional transformer design, its lumped parameter consisting of inductance matrix, leakage inductances and resistances are determined analytically and by using eddy current solver. Also, its effect on the system is shown by Simplorer in transients. Core losses of the transformer, high and low voltage windings voltages, their harmonic spectrums, under different load conditions including ohmic and inductive loads defined and also, steady state thermal solution performed and conclusions are made. It is proved that the transformer designed works as it desired.