Protection Scheme for Subsea Observatory Power Supply System Based on Control and Protection Coordination
Chu Xu1, Liu Qi1, Lü Haoze1, Yan Yabing2, Xu Liqiang2
1. National Electric Power Conversion and Control Engineering Technology Research Center Hunan University Changsha 410082 China; 2. Electric Power Research Institute of State Grid Hunan Electric Power Co. Ltd Changsha 410007 China
Abstract:The power supply system of submarine observation network with cable provides energy supply for submarine observation equipment, communication equipment and control and protection equipment, and its security and stability are directly related to the continuous and reliable operation of the whole submarine observation network. Among them, the constant voltage power supply system of the seabed observation network has the advantages of strong expansion ability and high energy conversion efficiency, which has been adopted by many subsea observation networks already in operation or under construction. Some submarine cable fault detection methods based on photoelectric technology and traveling wave analysis have been proposed, but there are some problems such as too long detection time and difficult implementation. To address these issues, this paper proposes a protection for subsea observatory power supply system based on control and protection coordination, which can limit the rapid spread of fault current, and accurately identify and reliably isolate fault optic-electric composite submarine cable. Firstly, the overall structure of the constant voltage subsea observatory network is introduced, and the operating mode and control characteristics of shore converter, branch unit, connection box and photoelectric composite cable are analyzed in detail. Then, the active control of shore stations is proposed to limit the output current during faults. Then, the fault identification criterion of branch cable and fault location criterion of backbone cable based on branch unit current polarity are proposed. The inverse time low voltage protection based on the instantaneous voltage of branch unit and shore station is constructed to determine the switch position to be switched. Finally, the protection outlet to switch can realize the rapid action of branch unit or shore station break switch under limited current level, and achieve effective fault isolation. The simulation model of the power supply system of the negative constant voltage submarine observation network is built on the PSCAD/EMTDC electromagnetic simulation platform, which verifies the feasibility and effectiveness of the proposed protection strategy of the power supply system of the submarine observation network. Simulation results on the waveforms in various fault scenarios show that in the fault scenario, if the current limiting control is not put into operation, the DC side voltage will drop to zero quickly in a short time, the amplitude of the DC side current will increase rapidly, and fault current will reach the normal operating value -7.2 A dozen times. If the fault is timely put into current limiting control, the amplitude of the DC side voltage will gradually decrease and stabilize at -8 kV, the DC side current will stabilize at -9.3 A, and the peak value of the current only fluctuates to about twice the rated current during the control adjustment process. When the branch cable fails, the switch connected to the branch cable in the branch unit can reliably act to remove the fault, and other switches do not malfunction. When the main cable fails, the fault section can be accurately identified, and the branch unit switches on both sides of the fault point can be effectively disconnected. The protection can achieve a fault response of up to 20 Ω transition resistance in about 50 ms, and the protection performance will not deteriorate under severe noise interference with SNR=30 dB. The following conclusions can be drawn from the simulation analysis: (1) The proposed protection covers the whole section of the submarine cable without relying on communication, and the selective discrimination and isolation of submarine cable faults can be realized only by local measurement of shore station and branch unit. (2) The proposed protection has high tolerance to transition resistance, and has the ability to cope with interference of noise. (3) The protection criterion and shore power supply current limiting control are coordinated to realize the cooperation of control and protection, which can effectively suppress the fault current and realize the rapid fault identification and isolation.
褚旭, 刘琦, 吕昊泽, 严亚兵, 许立强. 基于控保协同海底观测网供电系统保护方案[J]. 电工技术学报, 2023, 38(7): 1780-1792.
Chu Xu, Liu Qi, Lü Haoze, Yan Yabing, Xu Liqiang. Protection Scheme for Subsea Observatory Power Supply System Based on Control and Protection Coordination. Transactions of China Electrotechnical Society, 2023, 38(7): 1780-1792.
[1] 翟方国, 李培良, 顾艳镇, 等. 海底有缆在线观测系统研究与应用综述[J]. 海洋科学, 2020, 44(8): 14-28. Zhai Fangguo, Li Peiliang, Gu Yanzhen, et al.Review of the research and application of the submarine cable online observation system[J]. Marine Sciences, 2020, 44(8): 14-28. [2] 张扬, 周学军, 王希晨, 等. 海底观测网恒压远程供电系统[J]. 光通信技术, 2014, 38(1): 18-21. Zhang Yang, Zhou Xuejun, Wang Xichen, et al.Remote power feeding system of underwater observatory network[J]. Optical Communication Technology, 2014, 38(1): 18-21. [3] 贾科, 施志明, 张旸, 等. 基于电缆早期故障区段定位的柔性直流配电系统保护方法[J/OL]. 电力系统自动化, 2022: 1-15. (2022-09-22). https://kns.cnki.net/kcms/detail/32.1180.TP.20220921.0922.002.html. Jia Ke, Shi Zhiming, Zhang Yang, et al. Incipient fault section location based protection for a flexible DC distribution system Chinese full text[J/OL]. Automation of Electric Power Systems, 2022: 1-15. (2022-09-22). https://kns.cnki.net/kcms/detail/32.1180.TP.20220921.0922.002.html. [4] 张大海, 张晓炜, 孙浩, 等. 基于卷积神经网络的交直流输电系统故障诊断[J]. 电力系统自动化, 2022, 46(5): 132-145. Zhang Dahai, Zhang Xiaowei, Sun Hao, et al.Fault diagnosis for AC/DC transmission system based on convolutional neural network[J]. Automation of Electric Power Systems, 2022, 46(5): 132-145. [5] 吕安强. 基于分布式光纤应变和温度传感的光纤复合海底电缆状态监测方法研究[D]. 北京: 华北电力大学, 2015. [6] 陈小玲, 叶银灿, 李冬. 东海国际海底光缆故障原因分析研究[J]. 海洋工程, 2009, 27(4): 121-125. Chen Xiaoling, Ye Yincan, Li Dong.Analysis of the factors affecting submarine optical cable safety in the East China Sea[J]. The Ocean Engineering, 2009, 27(4): 121-125. [7] 张政, 周学军, 王希晨, 等. 缆系水下信息网恒流远供系统短路故障诊断及区间定位方法[J]. 浙江大学学报(工学版), 2019, 53(6): 1190-1197. Zhang Zheng, Zhou Xuejun, Wang Xichen, et al.Short-circuit fault diagnosis and interval location method for constant current remote supply system in cabled underwater information networks[J]. Journal of Zhejiang University (Engineering Science), 2019, 53(6): 1190-1197. [8] 叶胤, 王超, 莫仁芸. 海底光缆通信系统技术发展分析[J]. 广东通信技术, 2021, 41(1): 19-23. [9] 陈鹰, 杨灿军, 陶春辉. 海底观测系统[M]. 北京: 海洋出版社, 2006. [10] 陈燕虎. 基于树型拓扑的缆系海底观测网供电接驳关键技术研究[D]. 杭州: 浙江大学, 2012. [11] Chen Yanhu, Howe B M, Yang Canjun.Actively controllable switching for tree topology seafloor observation networks[J]. IEEE Journal of Oceanic Engineering, 2015, 40(4): 993-1002. [12] Zang Yujia, Chen Yanhu, Yang Canjun, et al.A new approach for analyzing the effect of non-ideal power supply on a constant current underwater cabled system[J]. Frontiers of Information Technology & Electronic Engineering, 2020, 21(4): 604-615. [13] El-Sharkawi M A, Upadhye A, Lu Shuai, et al. North east Pacific time-integrated undersea networked experiments (NEPTUNE): cable switching and protection[J]. IEEE Journal of Oceanic Engineering, 2005, 30(1): 232-240. [14] 陈曦, 王霞, 王增彬, 等. 温度梯度对直流电压极性反转过程中瞬态电场的影响[J]. 高电压技术, 2010, 36(5): 1222-1227. Chen Xi, Wang Xia, Wang Zengbin, et al.Effects of temperature gradient on transient electric field under DC voltage reversal[J]. High Voltage Engineering, 2010, 36(5): 1222-1227. [15] 郑欢, 刘乐乐, 李忠华. 直流叠加冲击电压下HVDC电缆暂态电场分布特性研究[J]. 中国电机工程学报, 2016, 36(24): 6682-6692, 6921. Zheng Huan, Liu Lele, Li Zhonghua.Research on the transient electric field distribution in HVDC cable under DC voltage superimposed impulse voltages[J]. Proceedings of the CSEE, 2016, 36(24): 6682-6692, 6921. [16] 徐志钮, 胡宇航, 赵丽娟, 等. 基于单斜坡法的光电复合海缆温度、应变快速测量方法[J]. 电力自动化设备, 2020, 40(5): 202-209. Xu Zhiniu, Hu Yuhang, Zhao Lijuan, et al.Rapid temperature and strain measurement method for optic-electric composite submarine cable based on slope-assisted method[J]. Electric Power Automation Equipment, 2020, 40(5): 202-209. [17] 束洪春, 代月, 安娜, 等. 基于线性回归的柔性直流电网纵联保护方法[J]. 电工技术学报, 2022, 37(13): 3213-3226, 3288. Shu Hongchun, Dai Yue, An Na, et al.Pilot protection method of flexible DC grid based on linear regression[J]. Transactions of China Electrotechnical Society, 2022, 37(13): 3213-3226, 3288. [18] 黄文焘, 邰能灵, 刘剑青, 等. 微电网多层级协同反时限保护方案[J]. 电工技术学报, 2021, 36(3): 623-633. Huang Wentao, Tai Nengling, Liu Jianqing, et al.Multi-layer collaborative inverse-time protection schemes for microgrids[J]. Transactions of China Electrotechnical Society, 2021, 36(3): 623-633. [19] 宋国兵, 陶然, 李斌, 等. 含大规模电力电子装备的电力系统故障分析与保护综述[J]. 电力系统自动化, 2017, 41(12): 2-12. Song Guobing, Tao Ran, Li Bin, et al.Survey of fault analysis and protection for power system with large scale power electronic equipments[J]. Automation of Electric Power Systems, 2017, 41(12): 2-12. [20] 王守相, 刘琪, 薛士敏, 等. 直流配电系统控制与保护协同关键技术及展望[J]. 电力系统自动化, 2019, 43(23): 23-30. Wang Shouxiang, Liu Qi, Xue Shimin, et al.Key technologies and prospect for coordinated control and protection in DC distribution system[J]. Automation of Electric Power Systems, 2019, 43(23): 23-30. [21] 冯迎宾, 李智刚, 王晓辉, 等. 海底单极直流输电中海水作为输电回路的原理实验及分析[J]. 电力系统自动化, 2013, 37(7): 119-122. Feng Yingbin, Li Zhigang, Wang Xiaohui, et al.Principle experiment and analysis of seawater as a transmission circuit in seafloor monopolar DC transmission system[J]. Automation of Electric Power Systems, 2013, 37(7): 119-122. [22] 约瑟.切斯尼, 左名久, 王红霞, 等. 海底光缆通信系统(下册): 设备及运行维护[M]. 2版. 北京: 机械工业出版社. [23] 刘座辰, 林磊, 殷天翔, 等. 一种模块化多电平换流器子模块开路故障的快速检测与诊断方法[J]. 电工技术学报, 2022, 37(19): 4883-4894. Liu Zuochen, Lin Lei, Yin Tianxiang, et al.A fast open-circuit fault detection and diagnosis method for sub-modules of modular multilevel converters[J]. Transactions of China Electrotechnical Society, 2022, 37(19): 4883-4894. [24] 戴志辉, 陈思琦, 李毅然, 等. 复杂环状柔直配电网单极断线故障特性分析[J]. 电工技术学报, 2022, 37(5): 1229-1241. Dai Zhihui, Chen Siqi, Li Yiran, et al.Characteristic analysis of single-pole breakage fault in complex ring flexible DC distribution systems[J]. Transactions of China Electrotechnical Society, 2022, 37(5): 1229-1241. [25] Lu Shuai, El-Sharkawi M A, Kirkham H, et al. NEPTUNE power system: startup power supply for 10 kV to 400 V DC-DC converters[C]//Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, 2006, Dallas, TX, USA, 2006: 1-5. [26] Vorperian V.Synthesis of medium voltage dc-to-dc converters from low-voltage, high-frequency PWM switching converters[J]. IEEE Transactions on Power Electronics, 2007, 22(5): 1619-1635. [27] 陈燕虎, 杨灿军, 李德骏, 等. 基于模块堆叠的同步整流变换器[J]. 电力自动化设备, 2012, 32(7): 62-65, 75. Chen Yanhu, Yang Canjun, Li Dejun, et al.Synchronous rectifier converter based on module stack[J]. Electric Power Automation Equipment, 2012, 32(7): 62-65, 75. [28] Lu Shuai.Infrastructure, operations, and circuits design of an undersea power system[D]. Washington: University of Washington Electrical Engineering, 2006. [29] Barnes C R, Best M M R, Johnson F R, et al. Challenges, benefits, and opportunities in installing and operating cabled ocean observatories: perspectives from NEPTUNE Canada[J]. IEEE Journal of Oceanic Engineering, 2013, 38(1): 144-157. [30] Zhang Zheng, Zhou Xuejun, Wang Xichen, et al.A novel diagnosis and location method of short-circuit grounding high-impedance fault for a mesh topology constant current remote power supply system in cabled underwater information networks[J]. IEEE Access, 7: 121457-121471. [31] 王希晨, 周学军, 忽冉, 等. 海光缆远程供电系统可靠性研究[J]. 上海交通大学学报, 2013, 47(3): 428-433. Wang Xichen, Zhou Xuejun, Hu Ran, et al.Reliability simulation of remote power feeding system[J]. Journal of Shanghai Jiao Tong University, 2013, 47(3): 428-433. [32] Chan Ting, Liu C C, Howe B M, et al.Fault location for the NEPTUNE power system[J]. IEEE Transactions on Power Systems, 2007, 22(2): 522-531. [33] 曾祥君, 毛宇, 邓丰, 等. 基于多端行波时差的海底观测网故障定位方法[J]. 电网技术, 2019, 43(9): 3280-3287. Zeng Xiangjun, Mao Yu, Deng Feng, et al.Fault location method for seafloor observation network based on multi-terminal traveling wave time difference[J]. Power System Technology, 2019, 43(9): 3280-3287. [34] 葛平娟, 肖凡, 涂春鸣, 等. 考虑故障限流的下垂控制型逆变器暂态控制策略[J]. 电工技术学报, 2022, 37(14): 3676-3687. Ge Pingjuan, Xiao Fan, Tu Chunming, et al.Transient control strategy of droop-controlled inverter considering fault current limitation[J]. Transactions of China Electrotechnical Society, 2022, 37(14): 3676-3687. [35] Zheng Tao, Lü Wenxuan, Wu Qiong, et al.An integrated control and protection scheme based on FBSM-MMC active current limiting strategy for DC distribution network[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2021, 9(3): 2632-2642. [36] Seyedi Y, Karimi H.Coordinated protection and control based on synchrophasor data processing in smart distribution networks[J]. IEEE Transactions on Power Systems, 2018, 33(1): 634-645. [37] 郭振威, 姚建刚, 康童, 等. 一种输电线路超高速方向保护方法[J]. 电工技术学报, 2016, 31(22): 168-177. Guo Zhenwei, Yao Jiangang, Kang Tong, et al.A method for directional ultra-high-speed protection of transmission lines[J]. Transactions of China Electrotechnical Society, 2016, 31(22): 168-177. [38] 张政, 周学军, 王希晨, 等. 缆系水下信息网恒流远供系统短路故障诊断及区间定位方法[J]. 浙江大学学报(工学版), 2019, 53(6): 1190-1197. Zhang Zheng, Zhou Xuejun, Wang Xichen, et al.Short-circuit fault diagnosis and interval location method for constant current remote supply system in cabled underwater information networks[J]. Journal of Zhejiang University (Engineering Science), 2019, 53(6): 1190-1197.