Study on the Effect of the Metal Path on the Distribution of Metro Stray Currents in the Power Grid

doi:10.11985/2023.03.010

Abstract

Abstract:

With the rapid development of urban rail transit, the direct current(DC) bias problem of power transformers brought by it has become more and more serious. Metro stray currents gradually become the main cause of DC bias magnetization of transformers in urban areas. Relevant design standards and monitoring results indicate that a metallic connection path exists between the grounding system of the metro and power grid, and this path may be one of the main factors affecting the stray current amplitude in the power grid. However, the path is rarely considered by existing studies and its effect on stray currents is unclear. Therefore, in order to analyze the influencing factors of stray currents invading the power grid and explore the influence of different path on the amplitude of stray currents, a coupling simulation model of metro and power grid is built, by comparing the effect of current amplitude with that of the earth medium as a propagation path, the degree of influence of the cable armored metal path is quantitatively analyzed, and it is found that the distribution of stray currents is significantly affected when a metal connection existed between the metro and the power grid, and the stray current amplitude of the intrusion power grid system is increased by 9 times. The research results show that the cable armor connection between grounding grids of two systems provide the good conductive paths for stray currents to invade the power grid.

Key words: Urban rail transit, stray current, metal armor, soil layering, urban power grid, coupling model

CLC Number:

U231
TM727

WEI Ru, LIU Jiangtao, GAO Haiyang, CHEN Tingji, YAN Qiaona, KONG Weijun. Study on the Effect of the Metal Path on the Distribution of Metro Stray Currents in the Power Grid[J]. Journal of Electrical Engineering, 2023, 18(3): 90-98.

Figures/Tables 20

References 25

[1]	蔡力, 王建国, 樊亚东, 等. 地铁走行轨对地过渡电阻杂散电流分布的影响[J]. 高电压技术, 2015, 41(11):3604-3610.
	CAI Li, WANG Jianguo, FAN Yadong, et al. Influence of the track-to-earth resistance of subway on stray current distribution[J]. High Voltage Engineering, 2015, 41(11):3604-3610.
[2]	韩宝明, 李亚为, 鲁放, 等. 2021年世界城市轨道交通运营统计与分析综述[J]. 都市快轨交通, 2022, 35(1):5-11.
	HAN Baoming, LI Yawei, LU Fang, et al. Statistical analysis of urban rail transit operation in the world in 2021:A review[J]. Urban Rapid Rail Transit, 2022, 35(1):5-11.
[3]	伍国兴, 肖黎, 张繁, 等. 城轨杂散电流在电网系统中的分布特性仿真分析[J]. 南方电网技术, 2019, 13(10):39-43.
	WU Guoxing, XIAO Li, ZHANG Fan, et al. Simulation analysis of distribution characteristics of urban rail transit stray current in power system[J]. Southern Power System Technology, 2019, 13(10):39-43.
[4]	CHEN Dezhi, FENG Zhiyu, WANG Qingpeng, et al. Study of analysis and experiment for ability to withstand dc bias in power transformers[J]. IEEE Transactions on Magnetics, 2018, 54(11):1-6.
[5]	ZHU Jinli, MAO Chengxiong, WANG Zhaoyuan, et al. A novel suppression method for grounding transformer against earth current from urban rail transit[J]. IEEE Transactions on Industrial Electronics, 2021, 68(12):11651-11662. doi: 10.1109/TIE.2020.3047044
[6]	牟龙华, 史万周, 张明锐, 等. 排流网情况下地铁迷流分布规律的研究[J]. 铁道学报, 2007, 29(3):45-49.
	MU Longhua, SHI Wanzhou, ZHANG Mingrui, et al. Metro stray current distribution with current drainage net[J]. Journal of the China Railway Society, 2007, 29(3):45-49.
[7]	邓琴. 地铁排流网系统的设计研究[D]. 成都: 西南交通大学, 2012.
	DENG Qin. Research on design of the stray current net system in subway[D]. Chengdu: Southwest Jiaotong University, 2012.
[8]	杜贵府, 张栋梁, 吴培林, 等. 城市轨道交通多层排流网投入运行研究[J]. 城市轨道交通研究, 2015, 18(11):80-82.
	DU Guifu, ZHANG Dongliang, WU Peilin, et al. Study on the operation of multi-layer current drainage net in urban rail transit[J]. Urban Mass Transit, 2015, 18(11):80-82.
[9]	全江涛, 童歆, 文习山, 等. 复杂运行工况下变压器直流偏磁的抑制[J]. 高电压技术, 2015, 41(7):2464-2472.
	QUAN Jiangtao, TONG Xin, WEN Xishan, et al. Mitigation of transformer dc bias in complicated operation conditions[J]. High Voltage Engineering, 2015, 41(7):2464-2472.
[10]	刘连光, 赵夏瑶, 张述铭, 等. 接地极偏磁治理对电网 GIC 的影响[J]. 电网技术, 2018, 42(11):3594-3600.
	LIU Lianguang, ZHAO Xiayao, ZHANG Shuming, et al. Influence of dc bias suppression of grounding electrodes on power grid GIC[J]. Power System Technology, 2018, 42(11):3594-3600.
[11]	阮羚, 唐泽洋, 张波, 等. 城市轨道交通杂散电流与电网直流偏磁电流耦合关系与检测的研究展望[J]. 湖北电力, 2021, 45(2):33-48.
	RUAN Ling, TANG Zeyang, ZHANG Bo, et al. Research and prospect of detection and coupling relationship between stray current in urban rail transit and grid DC bias magnetic current[J]. Hubei Electric Power, 2021, 45(2):33-48.
[12]	吴晓文, 周年光, 胡胜, 等. 城市轨道交通引起的变压器直流偏磁噪声与振动特性[J]. 电测与仪表, 2017, 54(17):117-122.
	WU Xiaowen, ZHOU Nianguang, HU Sheng, et al. Audible noise and vibration characteristics of DC-bias in power transformers caused by urban mass transit system[J]. Electrical Measurement & Instrumentation, 2017, 54(17):117-122.
[13]	彭平, 周卫华, 谢耀恒, 等. 关于地铁杂散电流引起的变压器直流偏磁的分析与研究[J]. 变压器, 2017, 54(11):26-30.
	PENG Ping, ZHOU Weihua, XIE Yaoheng, et al. Analysis and research on DC bias of transformer caused by metro stray current[J]. Transformer, 2017, 54(11):26-30.
[14]	李晓华, 褚福源, 时胜寒. 轨道交通对沿线220kV变电站中性点电流及振动影响[J]. 电工技术学报, 2021, 36(S2):423-429,437.
	LI Xiaohua, CHU Fuyuan, SHI Shenghan. Influence of rail transit on neutral current and vibration of 220 kV substation along the line[J]. Transactions of China Electrotechnical Society, 2021, 36(S2):423-429,437.
[15]	蔡茂, 李佳, 彭卿, 等. 城市地区主变直流偏磁研究与处理[J]. 电气自动化, 2017, 39(1):7-9,15.
	CAI Mao, LI Jia, PENG Qing, et al. Research and treatment of main transformer dc magnetic bias in urban areas[J]. Electrical Automation, 2017, 39(1):7-9,15.
[16]	何俊佳, 叶会生, 林福昌, 等. 土壤结构对流入变压器中性点直流电流的影响[J]. 中国电机工程学报, 2007, 27(36):14-18.
	HE Junjia, YE Huisheng, LIN Fuchang, et al. Influence of soil structure on direct current flowing into neutral point of power transformer[J]. Proceedings of the CSEE, 2007, 27(36):14-18.
[17]	李亚宁, 李猛, 高晓红, 等. 基于CDEGS建模的城市轨道交通杂散电流仿真与实验验证[J]. 铁道学报, 2021, 43(12):49-54.
	LI Yaning, LI Meng, GAO Xiaohong, et al. Simulation and experimental verification of stray current in urban rail transit based on CDEGS modeling[J]. Journal of the China Railway Society, 2021, 43(12):49-54.
[18]	李雷, 刘楠康, 曾文, 等. 轨道交通杂散电流在复杂地质条件下的分布[J]. 广东电力, 2019, 32(8):133-140.
	LI Lei, LIU Nankang, ZENG Wen, et al. Distribution of stray current in rail transit under complex geological conditions[J]. Guangdong Electric Power, 2019, 32(8):133-140.
[19]	肖黎, 张晶焯, 陈龙, 等. 地铁杂散电流造成的电网变压器直流偏磁特征量分析[J]. 南方电网技术, 2021, 15(5):129-134.
	XIAO Li, ZHANG Jingzhuo, CHEN Long, et al. Analysis on the DC magnetic bias characteristic of transformer in power system caused by the subway stray current[J]. Southern Power System Technology, 2021, 15(5):129-134.
[20]	中华人民共和国住房和城乡建设部, 北京市规划委员会. GB 50157—2013地铁设计规范[S]. 北京: 中国建筑工业出版社, 2013.
	Ministry of Housing and Urban-Rural Development of the People’s Republic of China,Beijing Municipal Commission of Urban Planning. GB 50157—2013 Code for design of metro[S]. Beijing: China Architecture & Building Press, 2013.
[21]	中华人民共和国住房和城乡建设部, 中华人民共和国国家质量监督检验检疫总局. GB/T 50065—2011 交流电气装置的接地设计规范[S]. 北京: 中国计划出版社, 2011.
	Ministry of Housing and Urban-Rural Development of the People’s Republic of China,General Administration of Quality Supervision,Inspection and Quarantine of the People’s Republic of China. GB/T 50065—2011 Code for design of AC electrical installations earthing[S]. Beijing: China Planning Press, 2011.
[22]	王爱民, 林圣, 李俊逸, 等. 城市轨道交通长线路杂散电流仿真模型[J]. 高电压技术, 2020, 46(4):1379-1386.
	WANG Aimin, LIN Sheng, LI Junyi, et al. Stray current simulation model of the long line of DC metro systems[J]. High Voltage Engineering, 2020, 46(4):1379-1386.
[23]	LI Chunmao, DU Qing, GUO Yujun, et al. Modelling of stray currents from metro intruding into power system considering the complex geological conditions in modern megacities[J]. IEEE Transactions on Transportation Electrification, 2023, 9(1):1653-1663. doi: 10.1109/TTE.2022.3179559
[24]	刘连光, 郭世晓, 魏恺, 等. 基于全节点模型的三华电网地磁感应电流计算[J]. 电网技术, 2014, 38(7):1946-1952.
	LIU Lianguang, GUO Shixiao, WEI Kai, et al. Calculation of geomagnetically induced currents in interconnected north China-Central China-East China power grid based on full-node GIC model[J]. Power System Technology, 2014, 38(7):1946-1952.
[25]	贺威俊. 轨道交通牵引供变电技术[M]. 成都: 西南交通大学出版社, 2016.
	HE Weijun. Power supply and substation techniques for electric traction of rail transit[M]. Chengdu: Southwest Jiaotong University Press, 2016.

类别	参数	数值
钢轨	单位长度电阻/(Ω/km)	0.02
钢轨	半径/m	0.068 3
轨地过渡电阻	电阻率/(Ω·km)	200 000
轨地过渡电阻	厚度/mm	10
混凝土隧道	单位长度电阻/(Ω/km)	180
接地网	单位长度电阻/(Ω/km)	2
土壤介质	电阻率/(Ω·km)	200
TPS	单位长度电阻/(Ω/km)	0.01
TPS	半径/m	0.01
接触线	单位长度电阻/(Ω/km)	0.01
接触线	半径/m	0.01
排流网	单位长度电阻/(Ω/km)	0.11
排流网	半径/m	0.057 6
结构钢筋	单位长度电阻/(Ω/km)	0.046
结构钢筋	半径/m	0.049

类别	单位长度电阻/(Ω/km)
接地网	2
地线	0.5
500 kV变压器	1
220 kV变压器	2
110 kV变压器	2
输电线路	0.01
35 kV电缆铠装	0.34

工况	列车数量	列车运行情况
工况1	2	全部加速
工况2	2	混合运行
工况3	4	全部加速

工况	土壤分层	土壤电阻率/(Ω·m)
工况A	单层	200
工况B	单层	400
工况C	上层	200
工况C	下层	400
工况D	上层	400
工况D	下层	200

工况	地铁系统TPS接地网及其电缆铠装连接	地铁与电网系统间的电缆铠装连接
工况I	无	无
工况II	有	无
工况III	有	有