Tough Silica-Hybridized Epoxy Resin/Anhydride System with Good Corona Resistance and Thermal Stability for Permanent Magnet Synchronous Wind-Driven Generators through Vacuum Pressure Impregnation

The biggest obstacle to fabricate permanent magnet synchronous wind-driven generators (PMSWG) is lack of high-performance resins for vacuum pressure impregnation (VPI) technique. A novel resin system was developed by hybridizing epoxy resin/anhydride (EA) with specially modified silica (mSiO 2 ) and grinding technology. EA/mSiO 2 resins have good processing features for VPI technique reflected by suitably low viscosity and very long work life (≥24 months), and they also show much higher impact and flexural strengths, corona resistance, and thermal stability than EA resin. For the EA/mSiO 2 resin with 9 wt % mSiO 2, its impact strength and corona resistant life are 25.2 kJ/m 2 and 806 min, more than 3.4 and 16.1 times those of EA resin, respectively. Simulation stator coils impregnated with EA/mSiO 2 resins exhibit much better electrical insulation than those with EA resin, demonstrating that EA/mSiO 2 resins are the right candidate for fabricating PMSWG and other high-voltage motors, generators, and transformers.