New Synthetic Accelerator of Porous Mica Tapes for Vacuum Pressure Impregnation Insulation Systems of High Voltage Windings of Large Generators

Porous mica tapes containing Zinc Naphthenate accelerator are used to insure sufficient and effective curing of the vacuum pressure impregnated insulation systems by varnishes based on Bisphenol A Epoxy resins and anhydride hardeners. Typically the stator windings of large high-voltage generators have this kind of multi-layered insulation systems. The Zinc Naphthenate, as a natural product, has no definite structure, therefore it can cause some variances in the curing processes of the insulation systems. A synthetic accelerator with stable composition of chemicals was tested to limit the curing process variances. The technological characteristics (e.g. storage stability, applicability, impregnability) of porous tapes containing standard and synthetic accelerator and electric properties…