The anhydride curing agent is widely used in the epoxy resin composite casting system for power equipment due to its such advantages as good heat resistance

small curing shrinkage and good insulation performance. The power system is developing in the direction of high voltage and large capacity

which puts forward higher requirements on the performance of power equipment. For obtaining high-performance epoxy composite insulation materials

the influence of five common anhydride curing agents on the performance of epoxy resin composite material is studied

finding that the phthalic anhydride has excellent performance

but there are problems of weak curing process and large dispersion of cured properties. Furthermore

a phthalic anhydride/hexahydrophthalic anhydride compound curing agent is prepared. The influence of the compound curing agent on the mechanical and electrical properties of epoxy composites is also studied. The experimental results show that when the molar ratio of phthalic anhydride/hexahydrophthalic anhydride is 1∶3

the melting point of the compound curing agent has the lowest melting point and better curing process. The maximum tensile

flexural and breakdown strength of the cured product are slightly reduced

yet the average value has increased significantly

the dispersion is significantly reduce and the arc resistance performance has increased by 49%.