CAJ | 학술논문

在交直流复合电场下，换流变压器的油纸界面会积聚电荷，使得油纸界面的电场发生畸变，容易引发沿面放电。为揭示交直流复合电场下油纸界面电荷对其沿面闪络电压的影响，采用针-板沿面放电模型，测量了交直流复合电场下油纸绝缘的沿面闪络特性，通过静电电容探头法测量了直流电压作用下沿面放电模型油纸界面的电荷分布。研究发现，负极性直流叠加交流电压下的油纸沿面闪络电压高于正极性直流叠加交流电压下的情况。原因是油纸界面积聚了与外施直流电压极性相同的界面电荷以及相同条件下油纸界面积聚的负极性电荷密度要大于正极性电荷密度。
재교직류복합전장하，환류변압기적유지계면회적취전하，사득유지계면적전장발생기변，용역인발연면방전。위게시교직류복합전장하유지계면전하대기연면섬락전압적영향，채용침-판연면방전모형，측량료교직류복합전장하유지절연적연면섬락특성，통과정전전용탐두법측량료직류전압작용하연면방전모형유지계면적전하분포。연구발현，부겁성직류첩가교류전압하적유지연면섬락전압고우정겁성직류첩가교류전압하적정황。원인시유지계면적취료여외시직류전압겁성상동적계면전하이급상동조건하유지계면적취적부겁성전하밀도요대우정겁성전하밀도。
Under the condition of compound AC-DC electric field the space charge that would be cumulated at the oil-pressboard interface of oil-impregnated pressboard insulation for converter transformer makes the electric field around the oil-pressboard interface distorted, and the surface discharge on the barriers is easy to be caused. To reveal the impact of oil-pressboard interface charge on its surface discharge voltage under compound AC-DC electric field, a needle-plate test is adopted to measure the surface flashover characteristics of oil-impregnated pressboard insulation under this condition, and using electrostatic capacitive probe the surface charge distribution at the oil-impregnated pressboard interface of surface discharge model under DC high-voltage is measured. It is discovered in this study that the surface flashover voltage of oil-impregnated pressboard insulation under negative polarity DC voltage superposed with AC voltage is higher than that under positive polarity DC voltage superposed with AC voltage. The reason of such a phenomenon is that the interface charge, which is of the same polarity as the imposed voltage, cumulates on the oil-pressboard interface and the negative polarity charge density is higher than positive polarity charge density under the same condition.