应用附件系统提高高压穿墙套管的工频干闪电压和污秽闪络电压

Improvement of Power Frequency Dry Flashover Voltage and Pollution Flashover Voltage of High-voltage Wall Bushing with the Introduction of Accessories System

套管与一般的绝缘子在电极布置上有所不同,它是一种“插入式”的电极结构,其法兰边缘处的电场十分集中。为了提高套管的外绝缘强度,根据电场分布理论、气体放电理论和沿面放电理论,在现有高压穿墙套管的结构形式上,即在绝缘子的电极形状、电极距离和尺寸参数保持不变的情况下,考虑空间电荷的因素,在绝缘子的电极上或者绝缘体上设置一重和多重主要由有机材料组成的附件系统,将传统绝缘子的二元素结构(电极和绝缘体)改变为三元素结构,即绝缘子由电极、绝缘体和有机材料附件系统三部分组成。试验结果表明,在没有改变套管的电极形状、电极距离和尺寸参数的情况下,应用附件系统可将工频干闪电压提高7.1%,将污秽闪络电压提高81.74%。研究结果对提高高压穿墙套管的外绝缘有一定的指导意义。

Bushing, with its‘plug-in’electrode structure, is different from general insulators in the electrode arrangement, and its electric field is very concentrated at the edge of bushing flange. In order to improve the external insulation strength of the bushing, according to the electric field distribution theory, gas discharge theory and surface discharge theory, in the existing structure of the HV bushing, namely, keeping electrode shape, electrode distance and dimension parameters of the insulator unchanged, and considering space charge factor, we placed the single or multiple accessories system mainly made of organic material on electrodes or insulator material, and converted the two-element structure (electrodes and insulator) of conventional insulator into a three-element structure. Namely, the insulator is made of three parts which are electrodes, insulator material, and organic material accessories system. Experimental results show that applied accessories system can raise the power frequency dry flashover voltage by 7.1% and raise pollution flashover voltage by 81.74% without changing the electrode shape, electrode distance and dimension parameters of the bushing. The findings have certain guiding significance as far as improving external insulation of HV wall bushing.