Abstract:
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 3.52 V/m with a mean value of 3.42 V/m, and the power frequency magnetic fields(MF)ranged from 0.022 to 1.094 μT with a mean value of 0.13 μT. As for the transformer substations, 10 kV ones had a mean EF intensity of 0.078 V/m and MF intensity of 0.325 μT; the EF and MF intensities for 110 kV ones ranged from 3.33 to 11.56 V/m and from 0.028 to 9.650 μT; whereas 3.37-546.2 V/m and 0.027-1.969 μT for 220 kV 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 880 V/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 0.2 μT, but the condition got little complicated while three overhead lines combined together with the highest MF of 1.081 μT.
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.
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