云母粉改性及其在复合绝缘材料的应用研究

Modification of Mica Powder and Its Application in Composite Insulating Materials

大型发电机定子绕组的主绝缘损伤威胁发电机运行安全,主绝缘优良的材料可减少电机安全隐患。以质量比为3∶1的环氧丙烯酸酯和聚氨酯丙烯酸酯的混合树脂为基体,硅烷偶联剂改性云母粉作为绝缘填料,制备复合绝缘材料。探究改性云母粉不同添加量对复合绝缘材料电气性能的影响。结果表明:表面改性后云母粉在基体中分散均匀。随着改性云母粉添加量的增大,复合绝缘材料的击穿强度整体先提升后下降。改性云母粉添加量为20%时,复合绝缘材料的电气性能相对较好,击穿场强为22.89 kV/mm,体积电阻率为4.73×10^(15)Ω·m,此时表面电阻率为1.23×10^(15)Ω。

The main insulation damage of the stator winding of the large generator threatens the safe operation of the generator,and the excellent material of the main insulation can reduce the potential safety hazard of the motor.The composite insulating material was prepared by using the mixed resin of epoxy acrylate and polyurethane acrylate with mass ratio of 3∶1 as matrix and silane coupling agent modified mica powder as insulating filler.The effects of different additions of modified mica powder on the electrical properties of composite insulation materials were investigated.The results show that the mica powder is uniformly dispersed in the matrix after surface modification.With the increase of the amount of modified mica powder,the breakdown strength of the composite insulation material increases first and then decreases.When the amount of modified mica powder is 20%,the electrical properties of the composite insulation material are relatively good.The breakdown field strength is 22.89 kV/mm,the volume resistivity is 4.73×10^(15)Ω·m,and the surface resistivity is 1.23×10^(15)Ω.