基于复合暂态能量的多端柔性直流电网自适应差动保护

doi:10.19595/j.cnki.1000-6753.tces.240195

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Abstract

Flexible HVDC transmission systems offer significant advantages in solving the challenges of large-scale renewable energy integration and long-distance power transmission, indicating a major trajectory for the future transformation and growth of power systems. Compared to traditional HVDC systems, flexible HVDC systems are weakly damped, and their fault current rise rate is rapid. If faults are not cleared promptly, converter blockages may occur, demanding higher requirements for quick fault identification. Current engineering practices typically install current-limiting reactors at both ends of flexible HVDC lines. However, with the development of flexible DC grids, a single converter station may have multiple outgoing lines. In such cases, concentrating the current-limiting reactors at the converter station outlet can effectively reduce construction costs and improve economic efficiency.
Existing traveling wave protection schemes for multi-terminal flexible HVDC grids typically use the blocking effect of current-limiting reactors on high-frequency components to construct protection criteria. However, when current-limiting reactors are concentrated at the converter station outlet, there are no obvious boundary elements between adjacent lines, significantly reducing the adaptability of traditional protection schemes in boundary-less grid structures. Therefore, new protection schemes that do not rely on boundary elements need to be further investigated.
To address these issues, this paper first analyzes the transmission characteristics of fault current traveling waves and constructs a composite transient energy with both amplitude and directional features. To further clarify the variation patterns of the composite transient energy's amplitude and directional characteristics with wave transmission, the paper qualitatively analyzes the waveform characteristics of fault currents at both ends of the line for faults occurring at different locations. For internal faults, the composite transient energy at both ends of the line has the same direction, and the amplitude difference is the largest when the fault occurs at either the near end or remote end of the line, while it is the smallest when the fault occurs near the midpoint of the line. For external faults, the composite transient energy at both ends of the line has opposite directions, and the amplitude difference is minimal. Based on these conclusions, this paper introduces an adaptive restraint correction function into the traditional ratio differential protection criterion. For internal faults, without changing the operating quantity, the adaptive correction function can reduce the restraint quantity, and the greater the energy difference at both ends of the line, the lower the correction function value, effectively enhancing the sensitivity of the protection. For external faults, the proposed adaptive correction function can effectively increase the restraint quantity to ensure reliability.
Finally, extensive PSCAD/EMTDC simulation experiments verify the effectiveness of the proposed adaptive differential protection scheme based on composite transient energy for multi-terminal flexible HVDC grids. The simulation results show that the proposed scheme significantly improves the sensitivity of protection for near-end or remote-end internal faults compared to traditional differential protection and ensures reliability during external faults. The scheme does not rely on line boundaries and does not require threshold setting, offering good engineering applicability and being less affected by transition resistance and noise interference.

Key words： Multi terminal flexible DC power grid current traveling wave composite transient energy restraining quantity correction function adaptive differential protection

Received: 29 January 2024

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TM77

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	Zheng Tao
	Chen Yunfei
	Ma Ying
	Li Zixiao

Cite this article:

Zheng Tao,Chen Yunfei,Ma Ying等. Differential Protection for Multi Terminal Flexible DC Power Grid Based on Composite Transient Energy[J]. Transactions of China Electrotechnical Society, 0, (): 240195-240195.

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https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.240195 OR https://dgjsxb.ces-transaction.com/EN/Y0/V/I/240195

[1] 雷顺广, 束洪春, 李志民. 基于桥臂功率特征的全-半混合型柔性直流输电线路保护[J]. 电工技术学报, 2023, 38(13): 3563-3575.
Lei Shunguang, Shu Hongchun, Li Zhimin.Full-half bridge hybrid VSC-HVDC transmission line protection method based on power characteristics of bridge arms[J]. Transactions of China Electrotechnical Society, 2023, 38(13): 3563-3575.
[2] 饶宏, 周月宾, 李巍巍, 等. 柔性直流输电技术的工程应用和发展展望[J]. 电力系统自动化, 2023, 47(1): 1-11.
Rao Hong, Zhou Yuebin, Li Weiwei, et al.Engineering application and development prospect of VSC-HVDC transmission technology[J]. Automation of Electric Power Systems, 2023, 47(1): 1-11.
[3] 刘海金, 李斌, 温伟杰, 等. 柔性直流系统的线路保护关键技术与展望[J]. 电网技术, 2021, 45(9): 3463-3477.
Liu Haijin, Li Bin, Wen Weijie, et al.Review and prospect on transmission line protection in flexible DC system[J]. Power System Technology, 2021, 45(9): 3463-3477.
[4] 孙栩, 王华伟, 雷霄, 等. 架空线柔性直流电网的直流短路电流限制研究[J]. 电力自动化设备, 2017, 37(2): 219-223.
Sun Xu, Wang Huawei, Lei Xiao, et al.Restriction of DC short circuit current for overhead lines of flexible DC grid[J]. Electric Power Automation Equipment, 2017, 37(2): 219-223.
[5] 李斌, 何佳伟, 李晔, 等. 基于边界特性的多端柔性直流配电系统单端量保护方案[J]. 中国电机工程学报, 2016, 36(21): 5741-5749.
Li Bin, He Jiawei, Li Ye, et al.Single-ended protection scheme based on boundary characteristic for the multi-terminal VSC-based DC distribution system[J]. Proceedings of the CSEE, 2016, 36(21): 5741-5749.
[6] 束洪春, 刘可真, 朱盛强, 等. ±800 kV特高压直流输电线路单端电气量暂态保护[J]. 中国电机工程学报, 2010, 30(31): 108-117.
Shu Hongchun, Liu Kezhen, Zhu Shengqiang, et al.±800 kV UHVDC transmission line protection based on single end electrical transient signal[J]. Proceedings of the CSEE, 2010, 30(31): 108-117.
[7] 束洪春, 田鑫萃, 张广斌, 等. ±800kV直流输电线路的极波暂态量保护[J]. 中国电机工程学报, 2011, 31(22): 96-104.
Shu Hongchun, Tian Xincui, Zhang Guangbin, et al.Protection for ±800 kV HVDC transmission lines using pole wave transients[J]. Proceedings of the CSEE, 2011, 31(22): 96-104.
[8] 何佳伟, 李斌, 李晔, 等. 多端柔性直流电网快速方向纵联保护方案[J]. 中国电机工程学报, 2017, 37(23): 6878-6887.
He Jiawei, Li Bin, Li Ye, et al.A fast directional pilot protection scheme for the MMC-based MTDC grid[J]. Proceedings of the CSEE, 2017, 37(23): 6878-6887.
[9] 郑涛, 宋祥艳. 适用于多端直流电网的电压极性比较式行波保护方案[J]. 电网技术, 2022, 46(12): 4690-4698.
Zheng Tao, Song Xiangyan.Traveling wave protection scheme of voltage polarity comparison formula for multi-terminal DC power network[J]. Power System Technology, 2022, 46(12): 4690-4698.
[10] 童宁, 林湘宁, 张雪松, 等. 不依赖于边界元件的架空型多端柔直电网就地测距式接地保护原理[J]. 中国电机工程学报, 2019, 39(7): 2049-2059.
Tong Ning, Lin Xiangning, Zhang Xuesong, et al.Fault location based single-ended protection strategy for overhead VSC-MTDC independent on boundary component[J]. Proceedings of the CSEE, 2019, 39(7): 2049-2059.
[11] 林湘宁, 刘琦, 范理想, 等. 基于相关分析的多端直流电网线路纵联保护新原理[J]. 电力系统保护与控制, 2020, 48(13): 45-55.
Lin Xiangning, Liu Qi, Fan Lixiang, et al.A novel pilot protection for VSC-MTDC based on correlation analysis[J]. Power System Protection and Control, 2020, 48(13): 45-55.
[12] 苏煜, 汤士明, 石勇. 直流输电线路差动保护新原理[J]. 电力系统及其自动化学报, 2022, 34(10): 152-158.
Su Yu, Tang Shiming, Shi Yong.Novel differential protection principle for DC transmission lines[J]. Proceedings of the CSU-EPSA, 2022, 34(10): 152-158.
[13] 董杏丽, 董新洲, 张言苍, 等. 基于小波变换的行波极性比较式方向保护原理研究[J]. 电力系统自动化, 2000, 24(14): 11-15.
Dong Xingli, Dong Xinzhou, Zhang Yancang, et al.Directional protective relaying based on polarity comparison of travelling wave by using wavelet transform[J]. Automation of Electric Power Systems, 2000, 24(14): 11-15.
[14] 李晔, 李斌, 刘晓明, 等. 基于反向行波幅值比的对称单极柔性直流系统行波方向保护[J]. 电工技术学报, 2023, 38(9): 2418-2434.
Li Ye, Li Bin, Liu Xiaoming, et al.The direction protection based on the amplitude ratio of the backward traveling wave for the symmetrical monopole flexible DC system[J]. Transactions of China Electrotechnical Society, 2023, 38(9): 2418-2434.
[15] 刘佳硕, 李永丽, 陈晓龙, 等. 基于暂态电流比值的多端柔性直流电网保护[J]. 电网技术, 2023, 47(4): 1439-1449.
Liu Jiashuo, Li Yongli, Chen Xiaolong, et al.Novel protection based on transient current ratio for MTDC grid[J]. Power System Technology, 2023, 47(4): 1439-1449.
[16] 束洪春, 刘力滔, 唐玉涛, 等. 基于行波暂态能量的半波长输电线路高灵敏增强型纵联保护方案[J]. 电工技术学报, 2022, 37(24): 6372-6387.
Shu Hongchun, Liu Litao, Tang Yutao, et al.Highly sensitive enhanced pilot protection of half-wavelength transmission line based on directional traveling wave energy[J]. Transactions of China Electrotechnical Society, 2022, 37(24): 6372-6387.
[17] 徐政. 柔性直流输电系统[M]. 2版. 北京: 机械工业出版社, 2017.
[18] Dong Xinzhou.The theory of fault travel waves and its application[M]. Singapore: Springer Singapore, 2022.
[19] 陈淼, 贾科, 王康达, 等. 基于前行波波形特征的柔性直流输电线路单端行波保护[J]. 电网技术, 2022, 46(6): 2386-2392.
Chen Miao, Jia Ke, Wang Kangda, et al.Single terminal traveling wave protection for flexible HVDC transmission lines based on forward wave shape information[J]. Power System Technology, 2022, 46(6): 2386-2392.
[20] 陈田田, 李银红. 基于电压折射波幅值正负差异的柔性直流电网两段式行波保护[J]. 电力系统自动化, 2022, 46(3): 129-136.
Chen Tiantian, Li Yinhong.Two-section traveling wave protection for flexible DC grid based on positive and negative difference of voltage refractive wave amplitude[J]. Automation of Electric Power Systems, 2022, 46(3): 129-136.
[21] 王聪博, 贾科, 毕天姝, 等. 基于暂态电流波形相似度识别的柔性直流配电线路保护[J]. 电网技术, 2019, 43(10): 3823-3831.
Wang Congbo, Jia Ke, Bi Tianshu, et al.Protection for flexible DC distribution system based on transient current waveform similarity identification[J]. Power System Technology, 2019, 43(10): 3823-3831.
[22] 邓丰, 徐帆, 曾哲, 等. 基于多源暂态信息融合的单端故障定位方法[J]. 电工技术学报, 2022, 37(13): 3201-3212.
Deng Feng, Xu Fan, Zeng Zhe, et al.Single-ended fault location method based on multi-source transient information fusion[J]. Transactions of China Electrotechnical Society, 2022, 37(13): 3201-3212.
[23] 贾科,姚昆鹏,刘子奕等. 基于故障行波差异性的柔性直流输电线路纵联保护 [J/OL]. 中国电机工程学报, 1-13.
Jia Ke, Yao Kunpeng, Liu Ziyi.Pilot Protection for Flexible HVDC Transmission Lines Based on the Difference of Fault Traveling Waves [J/OL]. Proceedings of the CSEE, 1-13.
[24] 戴志辉, 刘自强, 刘雪燕, 等. 基于首行波曲率的柔性直流输电线路单端量保护[J]. 电工技术学报, 2021, 36(9): 1831-1841.
Dai Zhihui, Liu Ziqiang, Liu Xueyan, et al.Single-ended protection for flexible DC transmission line based on curvature of initial traveling wave[J]. Transactions of China Electrotechnical Society, 2021, 36(9): 1831-1841.
[25] 杨亚宇, 邰能灵, 谢卫, 等. 利用单端边界能量的直流输电线路全线速动保护[J]. 电工技术学报, 2023, 38(9): 2403-2417.
Yang Yayu, Tai Nengling, Xie Wei, et al.A whole-line fast protection scheme for HVDC transmission line based on single-ended boundary energy[J]. Transactions of China Electrotechnical Society, 2023, 38(9): 2403-2417.
[26] 吴通华, 黎钊, 李新东, 等. 适配柔直系统快速性及可靠性需求的雷击干扰识别方法[J]. 电力系统保护与控制, 2022, 50(24): 1-12.
Wu Tonghua, Li Zhao, Li Xindong, et al.Lightning interference identification method for the speed and reliability of a flexible DC system[J]. Power System Protection and Control, 2022, 50(24): 1-12.
[27] 顾垚彬, 宋国兵, 郭安祥, 等. 针对直流线路行波保护的雷击识别方法研究[J]. 中国电机工程学报, 2018, 38(13): 3837-3845.
Gu Yaobin, Song Guobing, Guo Anxiang, et al.A lightning recognition method for DC line travling-wave protection of HVDC[J]. Proceedings of the CSEE, 2018, 38(13): 3837-3845.
[28] 薛士敏, 陈硕, 顾诚, 等. 一种基于暂态量的柔性直流系统保护及雷击识别方法[J]. 电力系统保护与控制, 2022, 50(9): 45-53.
Xue Shimin, Chen Shuo, Gu Cheng, et al.A method for protection and lightning identification in a flexible DC system based on transient quantities[J]. Power System Protection and Control, 2022, 50(9): 45-53.
[29] 林湘宁, 刘琦, 范理想, 等. 基于相关分析的多端直流电网线路纵联保护新原理[J]. 电力系统保护与控制, 2020, 48(13): 45-55.
Lin Xiangning, Liu Qi, Fan Lixiang, et al.A novel pilot protection for VSC-MTDC based on correlation analysis[J]. Power System Protection and Control, 2020, 48(13): 45-55.