杭州地区环境工频电磁场现状分析

目的]评价杭州地区环境工频电磁场强度。方法]采用德国Narda公司制造的EFA-300电磁场分析仪,在无雨雪天气,对杭州地区的典型电磁环境进行现场测试,并按照现行的电磁环境评价标准对测试结果进行分析。结果]杭州市四大城市广场环境工频电场在3.30~3.52V/m之间,均值为3.42V/m;环境工频磁场在0.022~1.094μT之间,均值为0.13μT。10kV小型变电站工频电场强度均值为0.078V/m,磁感应强度均值为0.325μT。110kV变电站的工频电场强度为3.33~11.56V/m,磁感应强度为0.028~9.650μT。220kV变电站的工频电场强度3.37~546.2V/m,磁感应强度为0.027~1.969μT。500kV变电站内部的电场强度为16~5805V/m,磁感应强度为0.379~22.040μT。所测两条220kV线路的最大电场强度在线下中央投影点,分别为322.66V/m和880V/m,然后随距离的增加快速衰减;对单组架空线而言,其磁感应强度在0.2μT左右,当三组架空线在一起时,情况稍显复杂,但线下最大处也只有1.081μT。结论]杭州地区居民活动可及区域中的环境工频电磁场暴露场强不仅符合国内外有关标准、导则和技术规范的要求,而且处于很低水平。

Current Status of Environmental Power Frequency Electromagnetic Fields in Hangzhou Metropolitan Area

Objective] To evaluate the current environmental power frequency electromagnetic fields（EMF）intensity in Hangzhou Metropolitan Area.Methods] An electromagnetic field analyzer EFA-300 from Narda company,Germany was employed to measure the power frequency EMF intensities of typical environmental places under weather condition without raining and snowing,and analyze the data according to the current EMF environment evaluation criteria.Results] The environmental power frequency electric fields（EF）at the four city squares ranged from 3.30 to 3.52V/m with a mean value of 3.42V/m,and the power frequency magnetic fields（MF）ranged from 0.022 to 1.094μT with a mean value of 0.13μT.As for the transformer substations,10kV ones had a mean EF intensity of 0.078V/m and MF intensity of 0.325μT;the EF and MF intensities for 110kV ones ranged from 3.33 to 11.56V/m and from 0.028 to 9.650μT;whereas 3.37-546.2V/m and 0.027-1.969μT for 220kV ones,and 16-5805V/m and 0.379-22.040μT for 500kV ones,respectively.The highest EF intensity of two 220kV power lines were 322.66V/m and 880V/m at the central projection points just under the lines,and the EF intensities decreased quickly as the distances increased. As for the single overhead line,the MF intensity was around 0.2μT,but the condition got little complicated while three overhead lines combined together with the highest MF of 1.081μT.Conclusion] The environmental power frequency EMF intensity in Hangzhou Metropolitan Area not only meets the requirements of domestic and international standards,guidelines and technical specifications,but also stays at very low level.