双极性振荡衰减冲击电压作用下油浸绝缘纸的绝缘累积效应特性  

Accumulative Effect Characteristics of Oil-impregnated Paper Insulation Under Damped Alternating Oscillation Voltage

作　　者：司马文霞[1] 吴婧瑜 华杰方 孙魄韬 SIMA Wenxia;WU Jingyu;HUA Jiefang;SUN Potao(State Key Laboratory of Power Transmission Equipment ＆ System Security and New Technology, Chongqing University, Chongqing 400044, Chin)

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400044

出　　处：《高电压技术》2017年第12期3827-3834,共8页High Voltage Engineering

基　　金：国家重点基础研究发展计划项目(973计划)(2015CB251003);国家重点研发计划(2017YFB0902702);国家自然科学基金(51707023)~~

摘　　要：变压器内油纸绝缘在雷电冲击电压的重复作用下会产生累积损伤,从而对变压器的安全运行产生威胁。实际侵入变压器的雷电冲击电压波受变电站进线衰减、折反射及绕组谐振等因素的影响,具有显著的振荡特性,该波形与IEC规定的标准雷电波形有显著差异。为此基于变电站实测的雷电侵入波形,通过试验方法产生了不同波形参数的双极性振荡衰减冲击电压,采用柱–柱电极结构测量了冲击电压幅值与冲击电压累积次数之间的关系特性(U-N特性)。通过观察累积冲击作用前后油浸绝缘纸的微观形貌变化并测量其相对介电常数和介质损耗角正切,探索了多次冲击电压作用对油浸绝缘纸的累积损伤效应。研究表明,多次双极性振荡衰减冲击电压作用下油浸绝缘纸表现出明显的累积效应,随着冲击次数的增加,电极覆盖区域的试品表面会出现乳白色胶状附着物,且试品表面的纤维结构发生变化,粗糙程度逐渐增大,其相对介电常数和介质损耗角正切值均呈明显上升趋势。In the life cycle, oil-paper insulation in power transformers will suffer from repetitive lightning impulse, which is a serious threat to the safe operation of the transformer. Due to the influence of factors such as attenuation, reflection, and winding resonance of the lightning impulse voltage of the transformer, the intrusion waveform has the oscillation attenuation and bipolarity. The waveform differs greatly from the standard lightning waveform specified by IEC. In this paper, based on the actual recorded invading lightning impulses in a substation, damped alternating oscillation voltage was applied to the colunm-to-column insulation model. The characteristics of relationship between the amplitude of applied voltage and the accumulative number of times （U-N characteristics） under damped alternating oscillation voltages were determined. To study the accumulative damage effect, the surface morphology was observed, and the electric parameters, such as relative dielectric constant, were measured before/after the accumulative tests. As a result, the experimental results showed an evident accumulative effect of oil-impregnated paper insulation under multiple damped alternating oscillation voltages. Ivory colloidal attachments can be found on the samples within the electrode covering area and the surface roughness of samples increases. Also, both the relative dielectric constant and the dielectric loss factor obviously increase with the increasing of accumulation times.

关 键 词：油浸绝缘纸 双极性衰减振荡冲击电压 累积效应 U-N特性 表面形貌 频域介电谱法 

分 类 号：TM855[电气工程—高电压与绝缘技术]