CAJ | 학술논문

绝缘材料在交流电压下的空间电荷特性和直流电压下的空间电荷特性同等重要.输电系统中交流变压器的数量巨大,变压器内绝缘用油纸绝缘材料在交流电压下的空间电荷特性如何,尚未见研究报道.首先采用直流电声脉冲测试系统研究了油浸绝缘纸在正/负极性直流场强下的空间电荷特性,然后采用改进的基于电声脉冲法的空间电荷测试系统研究了油浸绝缘纸在工频电压下的空间电荷特性.结果表明:电场极性对油浸绝缘纸内部的空间电荷分布有决定性影响,在正极性直流场强下,积聚在靠近铝板电极侧绝缘纸-绝缘纸界面处的电荷极性是正极性,而在负极性直流场强下,其是负极性;在工频加压的正半周,铝板电极处的电荷极性为负,而在工频加压的负半周,铝板电极处的电荷极性为正,90°和270°相位下油浸绝缘纸内部界面处积聚的电荷极性相反;与直流电压下相比,工频电压下油浸绝缘纸内部积聚的电荷显著减少.
절연재료재교류전압하적공간전하특성화직류전압하적공간전하특성동등중요.수전계통중교류변압기적수량거대,변압기내절연용유지절연재료재교류전압하적공간전하특성여하,상미견연구보도.수선채용직류전성맥충측시계통연구료유침절연지재정/부겁성직류장강하적공간전하특성,연후채용개진적기우전성맥충법적공간전하측시계통연구료유침절연지재공빈전압하적공간전하특성.결과표명:전장겁성대유침절연지내부적공간전하분포유결정성영향,재정겁성직류장강하,적취재고근려판전겁측절연지-절연지계면처적전하겁성시정겁성,이재부겁성직류장강하,기시부겁성;재공빈가압적정반주,려판전겁처적전하겁성위부,이재공빈가압적부반주,려판전겁처적전하겁성위정,90°화270°상위하유침절연지내부계면처적취적전하겁성상반;여직류전압하상비,공빈전압하유침절연지내부적취적전하현저감소.
@@@@ The space charge characteristics of insulation material under AC voltage and that under DC voltage are of equal importance. There are huge amount of AC power transformers in power transmission systems, however the report related to the research on space charge characteristics of oil-impregnated paper insulation used for internal insulation of power transformers under AC voltage still has not been seen. Firstly, the space charge characteristics of oil-impregnated paper under DC field intensity with positive/negative polarity are researched by DC pulsed electro-acoustic (PEA) method, then the space charge characteristics of oil-impregnated paper under power frequency voltage is researched by PEA method-based space charge test system. Research results show that the polarity of electric field plays a decisive role in the space charge distribution within oil-impregnated paper insulation: under DC field intensity with positive polarity the polarity of charge accumulated at the paper-paper interface near the aluminum plate electrode is positive and under DC field intensity with negative polarity the polarity of the accumulated charge is negative; during positive half-cycle of power frequency voltage the polarity of charge near the aluminum plate electrode is negative and during the negative half-cycle of power frequency voltage the polarity of charge is positive, the polarities of charge accumulated at the internal interface of oil-impregnated paper insulation are opposite when phase angle of applied power frequency voltage is 90° and 270° respectively. The charge accumulated within the oil-impregnated paper insulation under power frequency voltage is obviously less than that under DC voltage.