The Study Of Influence Of Magnetic Shunt To The Stray Loss Of Transformer And Temperature Rise Of Structure Part

In recent years,with the rapid development of national economy,electric power industry has also been developed rapidly.As the main equipment in the power grid,power transformer is moving toward large capacity,ultra-high voltage and extra-high voltage.Due to the limitation of transportation,large capacity,the structure of large capacity,ultra-high voltage and extra-high voltage transformer is becoming more and more compact,stray loss problem and local overheating are more and more prominent and serious,which are caused by transformer magnetic flux leakage.With the mature of numerical calculation technology,promotion of equipment performance of computer hardware and software,There are a lot of electromagnetic field simulation software based on the finite element technology,like Maxwell,Ansys,Elmag-3D,MagNet/ThermNet etc.are playing important role in electrical engineering design and effectively reducing the test cost and the product development cycle.This paper mainly study the magnetic shunt of tank,bar-type magnetic shunt of clamping,magnetic shunt of active part and "L" type magnetic shunt of clamping according to current electromagnetic shielding and magnetic shunt in transformer industry,and using Elmag-3D software,calculates and compares the stray loss,spot temperature rise for structure parts under no magnetic shunt,different magnetic shunt and integrated magnetic shunt conditions for 780MVA 500kV power transformer and 400MVA 500kV auto-transformer.Finally,this paper compiles Maxwell parametric numerical simulation calculation program based on Excel VBA language through the open Visual Script scripting interface of Maxwell to the insufficiency of Elmag-3D software to nonstandard structure transformer solid modeling,and establishes the nonstandard structure transformer parametric modeling,parametric simulating calculation function,and fulfill the leading-in of geometric model as SAT interaction file form to Elmag-3D software,which greatly boost the simulation calculation speed,shortening the simulation calculation period.