A technique for modeling the magnetic fi elds of power transformers in the environment of the software product FEMM 4.2 is developed taking into account the design scheme and real geometric dimensions of the magnetic system and tank, quasi-permanent current components in high-voltage windings, and the experimental magnetization characteristics of electrical and structural steel. Modeling of magnetic fi elds of magnetic systems of rod and armored rod structures is carried out on the example of serial power transformers TRDN- 63000/115 / 6.3 / 6.3 and TDTs-400000/242/20. The dependences of the mean values of induction in the central cross sections of the rods and side yokes on the quasi-constant currents are determined. It is shown that the saturation of the magnetic system of the rod structure begins with the outer rods at a multiplicity of quasi-constant current equal to 2.2 relative to the nominal phase current of the high-voltage winding. The saturation of the magnetic system of the armored rod structure begins with the lateral yokes at a multiplicity of the quasi-constant current equal to 2.63 with respect to the idle current rating.
High Voltage Insulating Materials—Current State and Prospects
