| 引用本文: | 张书琴,张克选,骆常璐,等.GIS外壳绝缘隔断处的过电压分析与控制措施研究[J].电力系统保护与控制,2025,53(11):181-187.[点击复制] |
| ZHANG Shuqin,ZHANG Kexuan,LUO Changlu,et al.Analysis of overvoltage and control measures at the insulation partition of GIS enclosures[J].Power System Protection and Control,2025,53(11):181-187[点击复制] |
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| 摘要: |
| 运行中的气体绝缘开关设备(gas-insulated switchgear, GIS)现场操作中时有弧光放电现象的发生。现有研究对其产生的机理只是笼统地归咎于开关操作时产生的特快速暂态过电压(very fast transient over-voltage, VFTO)所引起的壳体地电位升高，并没有从理论层面进行更深层次的研究与分析。从理论上推导出了GIS开关设备分合空载母线时的瞬变电流及其时变率的数学表达式，以及由瞬变电流在GIS外壳绝缘隔断部位感生的瞬变电压计算式。对于126~1100 kV GIS，其开关设备分合操作时的充电及放电电流时变率分别高达106及109以上，如此高时变率的瞬变电流将会在GIS外壳的绝缘隔断部位感生出数值较高的瞬变电压。而分合过程中开关触头间的多次重击穿又会在绝缘隔断部位感应出数值很高的次生VFTO，致使该部位气隙击穿而产生弧光放电现象。最后，对现场出现的各种弧光放电现象也进行了简要的说明，并给出了消除弧光放电的有效措施，即缩小包含外壳绝缘隔断部位在内的回路面积可以有效降低绝缘隔断部位两侧的次生VFTO，从根本上消除弧光放电。 |
| 关键词: 绝缘隔断 弧光放电 电流时变率 感生的瞬变电压 次生的VFTO |
| DOI：10.19783/j.cnki.pspc.240709 |
| 投稿时间：2024-06-06修订日期：2024-08-20 |
| 基金项目:国家电网公司科技项目资助(5500-201947427A- 0-0-00)；平高集团公司科技项目资助(PGKJ2022-054) |
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| Analysis of overvoltage and control measures at the insulation partition of GIS enclosures |
| ZHANG Shuqin,ZHANG Kexuan,LUO Changlu,GAO Yanfeng,MAI Xiaofei,CHEN Huailiang,ZHANG Lei,LIU Feng |
| (Henan Pingzhi High-Voltage Switchgear Co., Ltd., Pingdingshan 467013, China) |
| Abstract: |
| In-service gas-insulated switchgears (GIS) often experience arc discharge phenomena. Existing studies generally attribute this to the rise in enclosure ground potential caused by the very fast transient overvoltage (VFTO) generated during switching operations, without conducting in-depth theoretical analysis. This paper theoretically derives the mathematical expressions for the transient current and its rate of change during the switching of unloaded busbars in GIS, as well as formulas for calculating the transient voltage induced at the insulation partition of the GIS enclosure by the transient current. For GIS rated from 126 kV to 1100 kV, the rate of change of charging and discharging currents during switchgear switching can reach as high as 106 and 109 A/s, respectively. Such high rate of change in transient current can induce significant transient voltage at the insulation partition of the GIS enclosure. Multiple re-breakdowns between switch contacts during operation can induce secondary VFTO at the insulation partition, leading to air-gap breakdown and arc discharge. Finally, this paper briefly describes observed various arc discharge phenomena in the field and proposes an effective mitigation measure: reducing the loop area that includes the insulation partition of the enclosure can effectively lower secondary VFTO on both sides of the insulation partition, fundamentally eliminating arc discharge. |
| Key words: insulation partition arc discharge change rate of current induced transient voltage secondary VFTO |
