VPI-based high-voltage bar manufacturing. The main insulation materials of the stator bar largely determine the operational reliability and lifespan of the generator. Mica tape, impregnated resins, and other materials are the basic insulation materials of the stator. With the increase of unit capacity and rated voltage, there are higher requirements for main insulating materials such as mica tape and impregnated resins. Vacuum Pressure Impregnation (VPI) is currently the best insulation technology in the world, and it improves moisture resistance and heat dissipation of the motor for stronger operational reliability, and makes it more suitable for harsh environments. In addition, the VPI-treated insulating layer is free of air space and has decent integrity. The development of 18kV high-voltage bars for generators can ensure products secure and reliable.