The conductors utilize oxygen-free copper with acceptable conductivity. Coil connections are welded using a silver-copper soldering process, then multi-layered with epoxy mica tape and cured by heat to form a unified insulation structure. Insulation materials primarily include organic materials (such as insulating varnish and insulating paper) and inorganic materials (such as mica and ceramics). Insulation classes are classified as A, E, B, F, and H, with class F insulation having a maximum permissible temperature of 155°C. VPI (vacuum pressure impregnation) technology improves the insulation performance and mechanical strength of the windings. For example, F-resin insulation (using mica tape as the insulation layer and vacuum impregnating it with epoxy resin) is a high-performance insulation method for stator coils of large high-voltage generators.
The insulation system must be moisture-resistant and maintain elasticity to ensure no damage during disassembly.
