直流ZnO电阻片的研究

为了满足特高压直流避雷器保护特性的要求,对ZnO压敏电阻片的电位梯度、非线性性、老化等电气特性进行深入研究。试验表明:当X(Bi2O3)/X(Sb2O3)的掺杂比例为一定值时,获得较低的残压比和较高的电位梯度;改变侧面无机绝缘层的成分使侧面绝缘层与电阻体在烧结时能紧密结合,同时增加有机绝缘保护层,提高电阻片侧面的表面电阻和侧面的防污能力及抗闪络能力,并可改善电阻片的老化特性;在较低的烧成温度下1 070～1 150℃和较长的保温时间4～7 h可获得高性能的特高压直流避雷器用直流电阻片。

Study on D.C.ZnO Varistors

To meet the protective characteristics of UHVDC arresters,a deep study on DC varis-tors was performed to respects of voltage gradient,non-linear coefficient and aging properties.The test show that the voltage ratio of ZnO varistors reached to minimum at the suitable X(Bi2O3)/X(Sb2O3) dosing ra-tio,while the voltage gradient of ZnO varistors is to maximum.Amending composition of inorganic lat-eral coating for tight connection with resistor body at sintering it and applying an organic protective coating for increasing surface electrical,anti-pollution and flashover resistance on lateral side and en-hancing anti-aging performance,the quality varistors for UHVDC arrestor can be obtained at lower tem-perature(1 070～1 150 ℃) with long maintaining duration(4~ 7h).