Reduction in ac Partial Discharges by using Organic Insulating Material with Additive of Electron-Donating Type.

本研究的目的是通过在有机绝缘材料（PMMA和PE）中添加偶氮化合物来降低三结和空隙中的pd。PD在受交流电压作用的试样上或试样内产生。添加剂主要为对氨基偶氮苯（Ab）和对硝基苯偶氮苯（Nb）。以下是本研究的主要结果。在三重结处PD降低；在Ab为0.05% wt的情况下，PD脉冲的大小和数量比未添加添加剂的情况下减少了约50%。在电场强度略高于PD起始的情况下，PD的降低是有效的。由PD充电引起的表面电压分布取决于添加剂的类型。从表面电压分布与添加剂的关系可以解释Ab膜PD降低的原因。结果表明，添加剂在薄膜中的电离作用改变了表面电压的分布。空腔PD降低；结果表明，偶氮化合物的加入降低了孔隙（直径0.1mm）的PD。Ab和Nb两种添加剂均能有效降低空穴中PD。在Ab为0.05-0.1% wt的情况下，PD脉冲的大小和数量比未添加添加剂的情况下减少了约90%。在电场强度略高于PD起始的情况下，PD的降低是有效的。PD的减少是由于偶氮化合物分子捕获表面电荷造成的。实验表明，添加剂在孔洞内表面的激发对孔洞PD的降低贡献很小。

The purpose of this study is to decrease PDs at a triple junction and in void by addition of azocompound to an organic insulating material (PMMA and PE). PD was produced on or in a test specimen subjected ot ac voltage. The additives mainly used were p-aminoazobenzene (Ab) , and p-nitorobenzeneazoresorcinol (Nb). The following are main results obtained in this study.1.Decrease in PD at a triple junction ; In the case of the film with Ab at 0.05% wt, the magnitude and number of PD pulses were reduced to about 50% less than those in the case of the film without the additive. The decrease in PD was effective under an electric field strength slightly higher than the PD initiation. The surface voltage distribution due to the charge by PD depended upon the type of additive. The decrease in PD for Ab film was explained form the dependence of surface voltage distribution on the additive. It was concluded that ionization of the additive in the film changes the distribution of surface voltage.2.Decrease in PD in void ; It was found that PD in void (diameter : 0.1mm) was decrease by addition of azocompound in PE.The both of additives, Ab and Nb were effective for the decrease in PD in void. In the case of Ab at 0.05-0.1% wt, the magnitude and number of PD pulses were reduced to about 90% less than those in the case of the film without the additive. The decrease in PD was effective under an electric field strength slightly higher than the PD initiation. The effect of the reduction in the PD resulted from the trapping of surface charge by the molecules of the azocompounds. The experiments indicated that the excitation of the additive at the inner surface of void was small contribution to the reduction in PD in void.