Calculation Of Power Frequency Electric Field From AC Overhead Transmission Lines And Induced Current In Human Body

In order to realize the distribution of power frequency electric field from existentAC overhead transmission lines, explain the environmental concerns of electric fieldfrom AC overhead transmission lines for the public, and support the environmentalprotection departments to set standard. This paper systematically studies theenvironmental problems of electric field from AC overhead transmission lines in fouraspects.①Calculation of non-distorted electric field from AC overhead transmission lines.Calculated the electric field intensity from110kV\220kV\500kV\1000kV typical toweroverhead transmission lines via finite element method. Research shows that the electricfield intensity under overhead transmission lines is not always increasing with voltageclasses; the maximum value of the electric field intensity under overhead transmissionlines usually appears on the area under side lines; the maximum values of the electricfield intensity under500kV and1000kV transmission lines exceed relevant standards;the maximum values of non-distorted electric field intensity from110kV\220kV\500kV\1000kV typical tower overhead transmission lines not exceed relevant standardsoutside the power transmission corridors.②Calculation of distorted electric field of construction near AC overhead trans-mission lines. Calculated the distorted electric field intensity of1\5\10floorconstruction near110kV\220kV\500kV\1000kV typical tower overhead transmissionlines via finite element method; studied the effects of relative dielectric constant andconductivity of object and ground. Research shows that the maximum values ofdistorted electric field intensity exceed ICNIRP reference level when220kV\500kV\1000kV transmission lines near1floor construction; the maximumvalues of distorted electric field intensity in part of floors exceed ICNIRP referencelevel when each voltage classes transmission lines near5\10floors constructions. therelative dielectric constant and conductivity of object can significant impact thedistorted electric field, we can weaken the distorted electric field by changing thedielectric properties of object; the dielectric properties of ground not significant impactthe distorted electric field.③Calculation of induced current in human body from non-distorted electric field.Calculated the induced current via frequency scaling approach based on finite integration technique; considered the impacts of incidence direction of electric field,grounding of human body and dielectric properties of human body; inferred the basiccharacteristics of three-phase composite electric field of AC overhead transmission lines;calculated the distribution of induced current density in human body from circularlypolarized and elliptically polarized electric field; all of the amplitudes of the electricfileds are at ICNIRP reference level. Research shows that the induced current density inhuman body from each incidence direction electric field not exceed ICNIRP basicrestriction; when the incidence of electric field is perpendicular from the top of head,the induced current density in human body is larger; in addition, the induced currentdensity is larger when human body grounding than insulation; the induced currentdensity will increase when increase the conductivity of human body; the incidencedirection electric field will exceed ICNIRP basic restriction when the circularlypolarized and elliptically polarized electric field contain perpendicular component.④Calculation of induced current in human body from distorted electric field.Modeled a equivalent source of distorted electric field of construction near AC overheadtransmission lines; calculated the induced current via frequency scaling approach basedon finite integration technique; considered the impacts of the direction of human body isfacing. Research shows that the induced current of each tissues exceed ICNIRP basicrestriction when people in the distorted electric field of construction near AC overheadtransmission lines; the induced current density is larger when people lateral stand in thedistorted electric field; the case of marrow is the worst, in which the induced current hasexceeded the thresholds.