| 引用本文: | 滕予非,李小鹏,陈福锋,宋新尧,焦在滨,张尧.高压直流接地极线路断线故障高频阻抗特性及阻抗监视系统适应性[J].电力自动化设备,2019,39(9): |
| TENG Yufei,LI Xiaopeng,CHEN Fufeng,SONG Xinyao,JIAO Zaibin,ZHANG Yao.High frequency impedance characteristics of HVDC grounding electrode line under breakage fault and adaptability of impedance monitoring system[J].Electric Power Automation Equipment,2019,39(9): |
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| 摘要: |
| 基于输电线路分布式参数模型，对高压直流输电系统接地极线路断线故障下高频阻抗特性进行推导和分析。研究发现，当接地极线路长度超过高频注入信号半波长时，一旦接地极线路出现双回断线故障，首端高频测量阻抗的虚部将随故障距离呈周期性变化，但变化量超过正常运行时的阻抗值；当线路长度与注入信号半波长的整数倍接近时，线路某些特定位置发生单回断线故障，测量高频阻抗与正常运行时几乎相等，阻抗监视系统存在明显死区。为了提升阻抗监视策略的可靠性，提出了一种高频注入信号频率优化选择策略，基于线路实测参数，选择注入信号频率，消除保护策略死区。根据某实际 ±800 kV/8 000 MW特高压直流系统参数，搭建PSCAD电磁暂态仿真模型，仿真算例验证了分析及结论的有效性。 |
| 关键词: 高压直流输电系统 接地极线路 阻抗监视系统 故障检测 断线故障 高频阻抗特性 |
| DOI：10.16081/j.epae.201909017 |
| 分类号:TM773 |
| 基金项目:国家自然科学基金资助项目(51707019)；国家电网公司总部科技项目(特高压直流输电系统接地极线路绝缘配置与故障防护措施研究) |
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| High frequency impedance characteristics of HVDC grounding electrode line under breakage fault and adaptability of impedance monitoring system |
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TENG Yufei1, LI Xiaopeng1, CHEN Fufeng2,3, SONG Xinyao4, JIAO Zaibin4, ZHANG Yao2,3
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1.State Grid Sichuan Electric Power Research Institute, Chengdu 610041, China;2.Guodian Nanjing Automation Co.,Ltd.,Nanjing 210032, China;3.Nanjing SAC Power Grid Automation Co.,Ltd.,Nanjing 211153, China;4.School of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
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| Abstract: |
| Based on the distributed parameter model of transmission line, the high frequency impedance cha-racteristics of HVDC(High Voltage Direct Current) grounding electrode line under breakage fault are deduced and analyzed. When the length of grounding electrode line is longer than the half-wavelength of injected signal, for breakage faults in double transmission lines, the imaginary part of high frequency measured impedance at the head end of the grounding electrode line changes periodicity with fault position, but the variation exceeds the impedance value at normal operation. When the length of grounding electrode line is close to the integer multiple of half-wavelength of the injected signal, the measurement of high frequency impedance is almost equal to that of normal operation, breakage faults at some special position cannot be identified. To improve the reliability of impedance monitoring device, a strategy based on frequency optimization selection for high frequency injected signal is proposed. Based on the measured parameters of line, the injection signal frequency is selected to eliminate the dead band of protection strategy. Finally, an electromagnetic transient simulation model is established in PSCAD according to the parameters of an actual ± 800 kV/8 000 MW UHVDC(Ultra HVDC) system, and the validity of the analysis and conclusion is verified. |
| Key words: high voltage direct current power transmission system grounding electrode line impedance monitoring system electric fault detection breakage fault high frequency impedance characteristic |
