摘要
GIS因大容量、高可靠性、环境友好等优点在电力系统获得了广泛应用,局部放电检测作为GIS绝缘状态监测和缺陷诊断的重要手段,但存在误报和漏报现象,需要针对其检测有效性进行研究。文中针对球—板带尖刺电极模型和绝缘子沿面附着金属微粒两种典型绝缘缺陷展开研究,研究不同缺陷类型下局放起始电压和击穿/闪络电压的关系,提出局部放电检测有效性系数α以表征脉冲电流法对绝缘缺陷检测的难易程度。研究结果表明,两类缺陷的局部放电起始电压和击穿/闪络电压均随缺陷尺寸增大而显著降低,球—板带针电极引发的局部放电起始电压与间隙击穿电压差别较大,且局部放电量较高,而绝缘子表面金属微粒引发的局部放电起始电压与闪络电压更为接近,且局部放电量相对间隙缺陷较小,因此,绝缘子沿面金属微粒的局部放电检测有效性系数相对间隙电场集中缺陷更低,通过局部放电检出的难度相对较大,因而危害也更大。此外,随着气压升高,两种典型缺陷局部放电检测有效性系数α均呈现降低趋势,因而可通过适当降低气压开展局部放电试验来提高GIS局部放电检测的有效性。
Partial discharge detection is an essential method for insulation condition monitoring and insulation diag nosis of GIS. However, the partial discharge detection sometimes gives false alarm or omits alarm, so it is necessary to study the detection effectiveness. In this paper, two typical insulation defects of the sphereplate gap with spine and the metallic particle on contaminated insulator are simulated, and the relationship between partial discharge inception voltage and breakdown/flashover voltage are investigated. A partial discharge detection effectiveness factor α is proposed to evaluate the effectiveness of partial discharge detection via the pulse current method. The results show that both partial discharge inception voltage and breakdown/flashover voltage decrease significantly with the increase of defect size. For the sphereplate gap with spine, its partial discharge inception voltage has a big difference from the gap breakdown voltage and its partial discharge magnitude is large. While for the metallic particle on contaminated insulator, the partial discharge inception voltage is closer to the flashover voltage and the partial discharge magnitude is smaller. As a result, the partial discharge detection effectiveness factor for the metallic particle on contaminated in sulator is smaller than that for the sphereplate gap with spine, so it is harder to detect the partial discharge of metal lic particle on contaminated insulator. In addition, the partial discharge detection effectiveness factor becomes small er with the increase of air pressure, so partial discharge test under reduced pressure can enhance the effectiveness of partial discharge detection.
作者
王国利
高超
杨芸
周福升
黄若栋
张乔根
李晓昂
马径坦
许谱名
WANG Guoli;GAO Chao;YANG Yun;ZHOU Fusheng;HUANG Ruodong;ZHANG Qiaogen;LI Xiao＇ang;MA Jingtan;XU Puming(Electrical Power Research Institute of CSG,Guangzhou 510800,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi＇an Jiaotong University,Xi＇an 710049,China)
出处
《高压电器》
CAS
CSCD
北大核心
2018年第11期62-72,共11页
High Voltage Apparatus
关键词
GIS
局部放电
缺陷
检测有效性
GIS
partial discharge
insulation defects
detection effectiveness
