| 引用本文: | 蔡泽祥,徐 敏,李晓华,辛镇瀚.考虑直流控制的直流输电线路短路电流变化特性研究[J].电力自动化设备,2014,34(12): |
| CAI Zexiang,XU Min,LI Xiaohua,XIN Zhenhan.Variation characteristics of HVDC line short circuit currents under control[J].Electric Power Automation Equipment,2014,34(12): |
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| 摘要: |
| 推导了考虑分布参数特性的直流线路固有短路电流时域解析表达式，指出在不考虑控制作用时固有短路电流随故障持续时间增加而逐渐上升，近距离故障时的短路电流大于远距离故障时的短路电流，符合短路电流发展的时间约束和物理边界条件约束。分析了直流控制对短路电流变化的影响，揭示了在控制作用下短路电流幅值的空间非单调变化特性和时间离散变化特性，突破了传统短路电流变化特性的认识局限。短路电流幅值的空间非单调特性使得直流线路保护电流变化量判据的保护特征量电气边界与输电线路物理边界不一致，时间离散性使得保护特征量电气边界随故障时刻呈锯齿状变化，在进行直流线路保护电流变化量判据的整定计算时应予以考虑。 |
| 关键词: 短路电流 时空变化特性 直流输电 控制系统 电力系统保护 |
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| 基金项目:国家高技术研究发展计划（863计划）资助项目（2012AA-050209）；国家自然科学基金资助项目（51077055） |
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| Variation characteristics of HVDC line short circuit currents under control |
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CAI Zexiang1, XU Min1, LI Xiaohua1, XIN Zhenhan2
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1.School of Electric Power，South China University of Technology，Guangzhou 510640，China;2.CSG EHV Power Transmission Company，Guangzhou 510405，China
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| Abstract: |
| The time-domain expression of HVDC line short circuit current is derived with the consideration of distributed parameter characteristics. It is figured out that，the short circuit current without control increases along with the increase of fault duration and the short circuit current of short-distance fault is bigger than that of long-distance fault，in conformance with the time constraint of short circuit current and the condition constraint of physical boundary. The influence of HVDC control on short circuit current is analyzed，which shows that，the magnitude of short circuit current varies non-monotonically with the fault distance and discretely with the fault time，different from the traditional recognition of short circuit current variation characteristics. Its non-monotonic characteristic makes the electrical boundary of current protection different from the physical boundary of HVDC transmission line and its discrete characteristic makes the electrical boundary of current protection varying with the fault time in a zigzag way，which should be considered during the setting calculation of HVDC line protection for current criteria. |
| Key words: short circuit currents spatial-temporal variation characteristic HVDC power transmission control systems electric power system protection |
