预加直流电压对绝缘纸板放电过程的影响特性  

Effect of Pre-applied DC Voltage on Discharge Process of Insulating Pressboard

作　　者：刘书铭[1] 王明渊[2] 周远翔[2] 代双寅[1] 

机构地区：[1]国网河南省电力公司电力科学研究院,郑州450052 [2]清华大学电机工程与应用电子技术系,北京100084

出　　处：《绝缘材料》2015年第1期64-69,共6页Insulating Materials

基　　金：国家电网公司科技项目(20132001192)

摘　　要：为研究预加直流电压对油纸绝缘局部放电过程的影响特性,采用球-板电极模拟油纸绝缘系统中的稍不均匀电场,仿真计算出预加直流电压下球-板电极油纸绝缘系统的电势和场强分布,用脉冲电声法测试绝缘纸板去极化过程空间电荷时空变化特性与界面空间电荷衰减速率,并对试样进行交流局部放电试验,研究预加直流电压与局部放电起始电压之间的定量关系。结果表明:预加直流电压会在绝缘纸板界面产生残留空间电荷,升压过程中使局部放电起始电压和绝缘临界击穿电压均下降;降压过程中局部放电特性不受预加直流电压的影响,且局部放电熄灭电压与预加电压大小无关;随着预加直流电压的提高,每升高相同幅值的预加直流电压,交流局部放电起始电压降低的幅值有所减小。To study the effect of pre-applied DC voltage on the partial discharge process of oil-paper insulation, we used ball-plate electrode to simulate the slightly non-uniform electric field in oil-paper insula- tion system. The distribution of voltage and electric field intensity of the oil-paper insulation system under pre-applied DC voltage was calculated through simulation. The spatial and temporal variation and decay rate of space charge of the pressboard during the depolarization process was tested by PEA（Pulsed Electro-acoustic） method. The AC partial discharge test was carried out, and the quantitative relationship between pre-applied DC voltage and partial discharge inception voltage was studied. The results show that the pre-applied DC voltage would leave residual space charge on the surface of the pressboard, which make the partial discharge inception voltage（PDIV） and critical breakdown voltage（CBV） decrease in the voltage process. While the pre-applied DC voltage almost has no effect on the voltage reduction process and the partial discharge extinction voltage （PDEV） is independent of the pre-applied voltage. With the increase of the pre-applied DC voltage, the decrease amplitude of AC partial discharge inception voltage decrease.

关 键 词：换流变压器 油纸绝缘 局部放电 预加直流电压 空间电荷 

分 类 号：TM206[一般工业技术—材料科学与工程] TM835[电气工程—电工理论与新技术]