There are two typical traction transformer technologies adopted by Japan's 500 series and Germany's ICE3 high-speed EMUs: ① Take the traction transformer of Japan's Shinkansen 500 series high-speed EMUs as the representative, adopt shell-type pressureless fully sealed structure, integrate the cooling system with the traction transformer body, adopt "Nomex paper insulation+silicone oil" uniform high-temperature insulation system, and cast high-and low-voltage terminals with high-temperature resistant epoxy resin. ② Represented by AVE S 103 traction transformer for high-speed EMU provided by Siemens, Germany. The traction transformer adopts a heart-shaped open structure, and the cooling system is integrated with the traction transformer body. Adopt "Nomex paper insulation+silicone oil" uniform high temperature insulation system.