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减少三结处和空隙中的PD。在交流电压作用下，在试件上或试件中产生Pd。主要使用的添加剂是对氨基偶氮苯(AB)和对硝基苯偶氮间苯二酚(NB)。本研究获得的主要结果如下：1.降低了三结处的局部放电；在含有0.05%wt的AB的薄膜中，局部放电脉冲的大小和数量比没有添加剂的薄膜减少了约50%。当电场强度略高于Pd引发时，Pd的降低是有效的。由Pd带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依赖关系解释了AB膜Pd的降低。结果表明，添加剂在薄膜中的电离改变了膜的表面电压分布。2.孔洞中Pd的减少：在PE中加入偶氮化合物后，孔洞中的Pd(直径为0.1 mm)减少。添加剂AB和Nb对减少孔洞中的Pd是有效的。在质量分数为0.05-0.1%Ab的情况下，放电脉冲的大小和数目比不加添加剂的薄膜减少了约90%。当电场强度略高于Pd引发时，Pd的降低是有效的。Pd的还原效应是由于偶氮化合物分子对表面电荷的捕获所致。实验表明，添加剂在孔洞内表面的激发对孔洞中Pd的降低贡献不大。

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.