In recent years, the electro-magnetic effect of underground power cables in cities on the environment and the public has caused widespread concern. The 2-D finite element analysis on magnetic field was used to set up simulation models for typical cable tunnels and to calculate the power frequency magnetic field inside and outside the tunnel, and the space distribution law and influence factors were discussed. It is found that the more the circuit number is, the denser cables are laid, or the higher the current is transmitted, the stronger the power frequency magnetic field inside and outside the tunnel will be. The distance from the cables is the key factor to determine the magnitude of the power frequency magnetic field. Magnetic cable brackets will cause the accumulation of magnetic field, so as to reduce the economy and safety of cable lines. In-site measurements of power frequency magnetic field were carried out in several cable tunnels, and the test data were in good agreement with the calculated values. The magnetic field strength levels at the pavement and ground surface of the cable tunnels discussed are lower than the exposure limits recommended by current standards.
Key words
AC power cables /
tunnel laying /
power frequency magnetic field /
safety limit
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
References
[1]World Health Organization. Environmental health criteria 238: Extremely low frequency fields[M]. Switzerland: WHO Press, 2007.
[2]National Radiological Protection Board. Advice on limiting exposure to electromagnetic fields (0~300 GHz)[J]. Documents of the NRPB, 2004, 15(2): 5-35.
[3]李妮, 邬雄, 刘兴发,等. 国际标准工频电磁场公众曝露限值比较及启示[J]. 现代电力, 2013, 30(3): 54-59.
[4]International Commission on Non-Ionizing Radiation Protection (ICNIRP). Guidelines for limiting exposure to time varying electric, magnetic and electro-magnetic fields (up to 300 GHz)[J]. Health Physics, 1998, 74(4): 494-522.
[5]International Commission on Non-Ionizing Radiation Protection (ICNIRP). Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz)[J]. Health Physics, 2010, 99(6): 818-836.
[6]IEEE Standards Coordinating Committee 28. C95.6-2002 IEEE standard for safety levels with respect to human exposure to electromagnetic fields in the frequency range 0-3 kHz[S]. New York: The Institute of Electrical and Electronics, Inc., 2002.
[7]国家环境保护局. HJ/T 24-1998 500 kV超高压送变电工程电磁辐射环境影响评价技术规范[S]. 北京: 中国环境科学出版社, 1998.
[8]中国电力企业联合会. GB 50545-2010 110 kV~750 kV架空输电线路设计规范[S]. 北京: 中国计划出版社, 2010.
[9]刘振亚. 特高压交流输电工程电磁环境[M]. 北京: 中国电力出版社, 2008: 2-47.
[10]万保权, 邬雄. 750 kV单回紧凑型输电线路的电磁环境[J]. 高电压技术, 2009, 35(3): 597-600.
[11]蒋宏济, 万力, 王继纯. 110 kV电缆电磁辐射对环境的影响[J]. 高电压技术, 2005, 31(1): 87-88.
[12]万保权, 干喆渊, 何旺龄,等. 电力电缆线路的电磁环境影响因子分析[J]. 电网技术, 2013, 37(6): 1536-1541.
[13]郭剑, 曹玉杰, 胡士信, 等. 交流输电线路对输油输气管道电磁影响的限值[J]. 电网技术, 2008, 32(2): 17-20.
[14]Liu Ying, Liu Ming, Cao Xiaolong, et al. Evaluation of the magnetic induction on metal pipelines by AC power cable circuits[C]//8th International Conference on Insulated Power Cables, Paris, 2011.
[15]刘明. 高压XLPE电缆线路的工频磁场影响研究[D]. 西安: 西安交通大学,2011.