Study On The Influence Electromagnetic Environment Of Transmission Lines And Transformer

With the rapid development of China’s power industry, the capacity of the gridincrease, transmission lines are farther away, the voltage level rise, high voltageoverhead transmission lines and substations are expanding. Electromagneticenvironmental issues around power transmission lines and substations are increasingly acause for concern. In this paper, with the actual measurement of frequencyelectromagnetic field around some110kV,220kV transmission line and substation,according to domestic and international standards we analyzes the impact of itsfrequency electromagnetic fields generated to the environment,we study the followingtwo elements:1、Calculation of110kV,220kV single, double, four back to power frequencyelectromagnetic field intensity of the transmission line. The factors effect frequencyelectromagnetic field of transmission line has been studied.In the result, frequencyelectromagnetic field strength of transmission lines decreases with the height of wires.Comparative analysed of theoretical calculating value and the actual measuredvalues.Found that the theoretical calculation value is greater than the actualvalue.Electric field strength increase with radius of the wires increasing and the numberof splits of wires increasing; wires radius, the number of splits of wires are less affectedto the magnetic field strength. Contrast analysis of the theoretical calculation value andactual measured value, found that the power frequency electromagnetic field strengththeory calculated value is greater than the actual value. Because the actual overheadtransmission line conductor height is greater than the theoretical calculation ofconductor height, the actual current is smaller than the theoretical calculation ofcurrent.From the actual monitoring we found that the frequency electromagnetic fieldstrength of cable line is far less than the overhead lines and national standards, it hasless impact on the surrounding environment. In order to study the characteristics of transmission line power frequency electromagnetic field. Combine with thetransmission line theory and surfer software. Use it to contour a map of powerfrequency electromagnetic field. It can be more intuitive understanding of the change ofthe power frequency electromagnetic field area and electromagnetic environment ofsensitive the area.According to the characteristics of electromagnetic environmentdistribution around transmission lines, recommended on both sides of the transmissionline distance protection of25m from the perspective of environmental protectionrecommendation.2、Using electromagnetic radiation analyzer to monitor the actual electromagneticenvironment around the substation. We analysed of different types of substations powerfrequency electromagnetic field distribution and substation layout relationship.Comparison of three different types substation power frequency electromagnetic fieldintensity attenuation law. From the perspective of environmental protectionrecommendation outdoor substation protection distance of35m，half indoor substationprotection distance of35m. Indoor substations to produce power frequencyelectromagnetic field intensity close to the environmental original value. It is minimalimpact to the environment. According to the characteristics of the different types ofsubstation power frequency electromagnetic field, Indoor substations should beconstruction in more densely populated areas such as schools, hospitals, humansettlement and so on. Outdoor substation should be construction in sparsely populatedareas. Half indoor substations had the advantage of the area small and less investment.So it is suitable for most of the area.