Finite Element Analysis of Temperature Field of Main Circuit in Low Voltage Apparatus

Electric bridge model was used to simulate current constriction between contacts and joule heating effect.Based on the electric thermal analysis of the finite element software Ansys,the static temperature field of main circuit in low voltage apparatus with nominal current of 200 A was simulated.The results were verified by ex-periments.The transient thermal analysis model was built on the basis of the static thermal analysis.The tempera-ture field was simulated using the transient model when the short time high current applied.The criterion of the contact static welding was presented.The thermal stability of switchgear devices was researched.The results were useful in the designing and optimizing of low voltage apparatus.