Development of Lightweight EMU On-board Traction Transformers
The weight reduction of the on-board traction transformer,the heaviest electrical equipment of the EMU,helps the EMU save energy and improve transportation efficiency.As existing on-board traction transformers are all oil-immersed,dry-type transformers are the main solution for lightweighting them.However,dry-type transformers cannot meet heat dissipation requirements due to likely cracking epoxy resin insulation used.To this end,using silicone rubber with good mechanical properties as the base material,this paper first studied the thermal conductivity requirements of the insulating material through temperature rise analysis.Then experiments were carried out after sample preparation.With e-lectrical and mechanical properties as constraints,a method was studied for improving the thermal conductivity of insula-ting materials,while a lightweight design method for the on-board traction transformer was studied.Finally,based on the developed insulation materials and lightweight design methods,a small lightweight on-board traction transformer prototype with a capacity of 250 kVA was designed and developed.The results show that the properties of the prepared high thermal conductive silicone rubber composite insulation material meet the requirements of insulation and mechanical properties of dry-type on-board transformers.The weight of the developed small transformer prototype is 780 kg,46.2％lighter than the oil-immersed on-board traction transformer of the same capacity.According to experimental testing,the hot spot temperature value of the prototype under rated conditions is 167.68 ℃,which meets the operation requirements of the on-board traction transformer.
万方数据
维普
