直流电压下油纸复合绝缘积聚电荷极性特性

Polarity Characteristics of Accumulated Charge in Oil-pressboard Composite Insulation Under DC Voltage

为了研究油纸复合绝缘积聚电荷极性特性,该文设计2种平板电极试验模型,搭建直流高压油纸复合绝缘电流测试平台,通过对电流的积分获得吸收电荷,在不同外施电压和不同老化时间下对油纸复合绝缘积聚电荷特性进行了试验研究,并利用吸收电荷表征了积聚电荷极性特性。研究结果表明:随着直流电压幅值增加,正极性与负极性吸收电荷均逐渐增加,相同电压下,负极性吸收电荷比正极性吸收电荷积聚的更多;随着绝缘纸板老化时间增加,负极性吸收电荷逐渐减少,正极性吸收电荷基本保持不变。稳态电荷量与外施电压呈线性关系变化,油浸纸板静态电容大于位移极化电容,积聚负极性电荷时静态电容大于积聚正极性电荷时静态电容。随老化时间增加,负极性稳态电荷量呈线性比例关系减少,正极性稳态电荷量基本相同,油浸纸板静态电容与稳态电荷量变化规律一致。

To investigate the polarity characteristics of accumulated charge of oil-pressboard composite insulation,two kinds of parallel-plane three-electrode test models were designed,and a current test platform under DC high voltage was built in this paper.The absorbed charges were obtained by integrating the current,and the polarity characteristics of accumulated charges of oil-pressboard composite insulation were experimentally studied and characterized by absorption charge under different applied voltages and different aging time.The results show that,with the increase of DC voltage amplitude,the positive and negative absorbed charges both increase gradually.Under the same voltage,the negative absorbed charges are more than the positive absorbed charges.As the aging time of the insulation pressboard increases,the negative absorbed charges decrease,while positive absorbed charges are basically the same.The steady-state charge quantity changes linearly with the applied voltage.The static capacitance is larger than the displacement polarization capacitance and the static capacitance when accumulating negative charges is larger than that when accumulating positive charges of the oil-impregnated pressboard.The negative steady-state charge quantity decreases linearly with the aging time,while the positive steady-state charge quantity remains basically the same,and the change law of static capacitance of oil-impregnated pressboard is consistent with that of steady-state charge quantity.