Disclosure of Invention
The invention aims to provide a method for determining public electric field exposure dose near an extra-high voltage direct current transmission line, which can determine the public electric field exposure dose caused by the extra-high voltage direct current transmission line without adopting an electric field dosimeter, and is more convenient and more universal.
In order to achieve the above object, the present invention provides a method for determining public electric field exposure dose in the vicinity of an extra-high voltage direct current transmission line, comprising the steps of:
1) constructing an extra-high voltage direct current transmission line-building or vehicle-earth-human body electromagnetic simulation model, respectively establishing a relation model between the human body exposed field intensity E and the voltage grade U of the extra-high voltage direct current transmission line, the ground clearance H of a lead, the number g of loops and the horizontal distance x between the center of the line and the human body in the outdoor, indoor and automobile through simulation calculation, wherein the relation model is respectively Eout=fout(U,H,g,x)、Ein-b=fin-b(U, H, g, x) and Ein-c=fin-c(U,H,g,x);EoutExposing field intensity for outdoor human body; ein-bExposing the field intensity for the indoor human body; ein-cExposing the field intensity for human bodies in the automobile;
2) acquiring voltage grades and loop numbers of all domestic ultrahigh voltage direct current transmission lines, positions of all iron towers on a line and stringing height information of the iron towers, and establishing an ultrahigh voltage direct current transmission engineering information base;
3) according to the position of an iron tower of the extra-high voltage direct current transmission line, numbering the iron tower from south to north by using 1,2,3, 1, n-1 and n;
4) sequentially acquiring the positions of the human body through a mobile phone positioning system according to equal sampling time intervals delta T, wherein the delta T is Ti+1-tiWhere i is 1,2,3, …, m, i is the human body position sampling point number, tiThe moment when the position of the human body is acquired for the ith time;
5) at tiAt the moment, a dichotomy is adopted to search the number j (j belongs to [1, n ]) of the iron tower closest to the position of the human body]) According to the line where the iron tower j is located, two iron tower numbers (marked as j 'and j') adjacent to the iron tower j on the line are further found on the basis;
6) establishing a three-dimensional coordinate system, respectively determining the coordinates of a human body and iron towers with the numbers of j, j 'and j', simulating a direct current line between two base iron towers by using a straight line segment connecting height points of overhead lines on adjacent iron towers, and calculating and determining a direct current transmission line closest to the human body and the closest horizontal distance x between the direct current transmission line and the human body;
7) searching the extra-high voltage direct current transmission project information base to obtain tiThe voltage grade, the number of loops and the ground clearance of the conducting wire of the ultra-high voltage direct current transmission line which is closest to the human body at any moment;
8) the signal intensity of a GPS or Beidou satellite and the positioning position of a human body are obtained through a mobile phone positioning system, the moving speed and the acceleration of the human body are determined according to the signal intensity and the positioning position of the human body, and t is judgediThe state of the human body position (outdoor, indoor or in the automobile) at the moment, and stores tiSuch information of the time of day;
9) according to the position state (outdoor, indoor or in an automobile) of the human body determined in the step 8), substituting the horizontal distance from the actual human body to the center of the nearest extra-high voltage direct current line, the ground clearance of the point on the line closest to the human body, the voltage grade of the line and the number of loops into the corresponding electric field exposure intensity calculation model established in the step 1), and calculating to obtain the sampling time tiHuman body exposure field strength Ei;
10) According to D
i=E
iΔ T calculation to obtain T
iTo t
i+1Electric field exposure dose D between moments
i(ii) a According to
Calculating to obtain the human body electric field exposure dose D within the time T
TAnd m is the number of sampling points in the time T.
According to the technical scheme, according to simulation calculation results, a relation model between outdoor, indoor and automobile human body exposure field intensity E and the voltage level U of the extra-high voltage direct current transmission line, the ground clearance H of a conducting wire, the loop number g and the horizontal distance x between the center of the line and a human body is respectively fitted and established, the direct current transmission line closest to the human body and the position state (outdoor, indoor or automobile) of the human body are determined according to mobile phone positioning signals, and public electric field exposure dose is calculated.
The method comprises the following steps of 1), establishing a relation model between human body exposed field intensity and the direct current transmission line, namely, establishing a geometric model after appropriately simplifying actual ultrahigh voltage direct current transmission lines, the earth, buildings, automobiles and human bodies by using professional software, setting model parameters such as voltage levels and loop numbers of the direct current transmission lines, relative dielectric constants and conductivities of the earth, the buildings, the automobiles and the human bodies, and establishing an ultrahigh voltage direct current transmission line-building (or automobile) -earth-human body electromagnetic simulation model. Considering that the distribution of an electromagnetic field is closely related to boundary conditions, the existence of a human body can cause electric field distortion, the human body models which are positioned on the open ground (namely outdoor), the ground central point in a building model (namely indoor) and the bottom central point in an automobile model (namely in an automobile) are respectively arranged at different horizontal distances from a direct current transmission line with different voltage grades, wire ground clearance and wire loop numbers, the field intensity of the human body surface is calculated based on the simulation of an electric field calculation model near a direct current wire on the infinite ground, and corresponding models are established according to the maximum electric field fitting of the human body surface of the human body model at different positions.
The building model simplify to hollow parallelepiped, and its top surface and four side thickness homogeneous phase are the same, and the bottom surface is the ground, offers a plurality of rectangular holes on each side of building model for simulate open window.
The automobile model constructed after simplification is a hollow parallelepiped, the thicknesses of six faces of the automobile model are the same, and a plurality of rectangular holes or rectangular areas with different dielectric constants and conductivities are arranged on each side face of the automobile model and used for simulating an open or closed glass window (including a front windshield of an automobile).
The human body is simplified into a male human body model with the total height of 1.73m and composed of five parts, namely a head part, a neck part, an upper body part, arms and legs, and the method is specifically referred to the human body size of Chinese adult (GB/T10000) 1988. Wherein, the head is a sphere with the radius of 0.11 m; the neck is a cylinder with the radius of the bottom surface of 0.05m and the height of 0.06m (the lowest distance from the head sphere); the upper body is a cuboid with a cambered surface, the length of the cuboid is 0.32m, the height of the cuboid is 0.55m, and the thickness of the cuboid is 0.23 m; the arm is two cylinders spliced by a cylinder and a bent cylinder, the radius of the bottom surface is 0.045m, and the total height is 0.58 m; the legs are two cylinders with the radius of the bottom surface of 0.07m and the height of 0.9 m.
In step 4), the shorter the sampling interval Δ T is theoretically, the more accurate the measurement result of the exposure dose of the electric field in each interval is. Generally, the minimum moving speed of an adult is about 0.8m/s (in slow walking), the positioning precision provided by a mobile phone positioning system is about 5-10 m, and in order to ensure that the moving distance of a human body (not at rest) in a position sampling time interval Delta T is greater than the positioning precision, the Delta T is not too short, and preferably 10-15 s.
And 7), taking the ground clearance of the closest point on the wire to the human body according to the ground clearance of the wire of the ultrahigh-voltage direct-current circuit closest to the human body.
The method for determining the human body position state (outdoor, indoor or in-car) in step 8) refers to sampling time interval delta t (delta t is t) according to the mobile phone satellite positioning signalk+1-tkK is 1,2,3, …, l, k is the satellite positioning signal sampling time sequence number, tkFor the kth sampling time, the delta T is an integral fraction of the sampling time interval delta T of the human body position, preferably 1/10), and a satellite is sequentially acquired at different times T by a mobile phone positioning systemkSignal intensity W ofk(signal-to-noise ratio), human body position longitude and latitude, and human body moving speed vkAnd acceleration ak. Not provided with tkThe moment is at the sampling moment t of the human body positioniAnd ti+1In between, will tiHuman body position longitude and latitude and moving speed v at any momentiAnd acceleration aiAs tkCorresponding data of time of day, wherein vi=si/ΔT,ai=(vi+1-vi)/ΔT,siIs tiTo ti+1The distance the human body moves between moments. Normally, the satellite signal intensity inside and outside the automobile is greater than the critical value Wmax(WmaxSignal-to-noise ratio for weak satellite signals, preferably 20dB), satellite signal strength less than or equal to W for indoor and outdoor partial areas (e.g. mountainous areas)max. Furthermore, if tk-1To tkThe interventricular body enters the outdoor from the indoor and has stronger signal tk-1To tkAbsolute value | Δ W of inter-signal strength variationk-1|
(ΔWk-1=Wk-Wk-1) Greater than or equal to critical value | Δ Wmin|(|ΔWmin| is the absolute value of the difference in satellite signal strength between where the indoor and outdoor signals are stronger, preferably 20dB), if tk-1To tkThe interventricular body enters the stronger signal place from the weaker outdoor signal place, | Δ Wk-1I is less than | Δ WminL. If a certain satellite signal WkAlways small and sudden appearance of Wk>WmaxOr WkAlways large and suddenly appearing Wk≤WmaxThe moving speed, acceleration and satellite signal intensity of human body are combined with tkTime (including t)k) The previous human body position state is judged, and the specific judgment steps are shown in figure 2.
And 9), if the horizontal distance between the actual human body and the nearest direct current transmission line center exceeds 100m, taking the exposure field intensity (which is close to the background value) when the distance is 100 m.
Compared with the prior art, the invention has the advantages that:
the method for determining the public electric field exposure dose near the ultra-high voltage direct current transmission line by using the mobile phone positioning signal can be realized by depending on the mobile phone positioning signal based on the electromagnetic simulation result, can determine the ultra-high voltage direct current transmission line closest to the human body and the position state (outdoor, indoor or in an automobile) of the human body in real time, calculates the actual electric field exposure dose of the human body offline, does not need to use a professional electric field dosimeter for actual measurement, has low cost, is more convenient and faster, and is more suitable for the public near the ultra-high voltage direct current transmission line.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the following embodiments and accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments without any inventive step, are within the scope of protection of the invention.
Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of the word "comprise" or "comprises", and the like, in the context of this application, is intended to mean that the elements or items listed before that word, in addition to those listed after that word, do not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.
Examples
The embodiment carries out off-line calculation on the public actual electric field exposure dose in a certain day near the extra-high voltage direct current transmission line.
Referring to fig. 3, the building model is simplified to a hollow rectangular parallelepiped with a length × width × height of 12m × 10m × 4m and a top surface and four side surfaces of 0.2m thickness, and a rectangular hole with a length × width of 1m × 0.8m is formed in the center of the side surface (12m × 10m) of the building model facing the power transmission line, so as to simulate an open window.
Referring to fig. 4, the human body is simplified to a male human body model with a total height of 1.73m, which is composed of five parts, namely a head part, a neck part, an upper body part, arms and legs, in this embodiment, specifically referring to the human body size of adult people in china (GB/T10000-. Wherein, the head is a sphere with the radius of 0.11 m; the neck is a cylinder with the radius of the bottom surface of 0.05m and the height of 0.06m (the lowest distance from the head sphere); the upper body is a cuboid with a cambered surface, the length of the cuboid is 0.32m, the height of the cuboid is 0.55m, and the thickness of the cuboid is 0.23 m; the arm is two cylinders spliced by a cylinder and a bent cylinder, the radius of the bottom surface is 0.045m, and the total height is 0.58 m; the legs are two cylinders with the radius of the bottom surface of 0.07m and the height of 0.9 m.
Referring to fig. 5, in this embodiment, the automobile model is simplified to a hollow rectangular parallelepiped with a length × width × height of 4m × 1.7m × 1.5m and a thickness of six faces of 0.03m, two side faces of the automobile model are provided with 4 rectangular holes with a length × width of 0.6m × 0.4m for simulating an open glass window, and a front portion of the automobile model is provided with 1 rectangular region with a length × width of 1.6m × 0.6m for simulating a windshield.
Referring to fig. 6, the mannequin located at the center point of the bottom surface in the model building in this embodiment faces the window, and the mannequin located at the center point of the bottom surface in the model car faces the front windshield of the car.
Referring to fig. 1, the electric field exposure dose is determined according to a public positioning signal of a certain day near the extra-high voltage direct current transmission line, and the steps are as follows:
s100, after the ultrahigh voltage direct current transmission line, the earth, the building, the automobile and the human body are properly simplified by using Commol Multiphysics software, a geometric model is constructed, model parameters are set, and an ultrahigh voltage direct current transmission line-building (or automobile) -earth-human body electromagnetic simulation model is constructed. The operating parameters of the direct current transmission line, except the voltage level, the ground height of the wire and the number of loops, are shown in table 1. The geometric shape of the building model is shown in FIG. 3, the material is concrete, and the conductivity is 5X 10-2And (5) S/m. The geometric shape of the phantom is shown in FIG. 4, and the medium parameters are shown in Table 2. The geometric shape of the automobile model is shown in figure 5, the automobile body is regarded as a metal conductor and a front gearThe windshield is not conductive at normal temperature. The ground is regarded as an infinite ideal conductor, the ground potential is 0, the terrain is flat, and the ground does not contain media such as trees, water flow and the like.
Table 1 operating parameters of the embodiment of the extra-high voltage dc transmission line
Table 2 medium parameters of the phantom in the example
S200, respectively placing the human body models positioned on the open ground (namely outdoor), the ground center point in the building model (namely indoor) and the bottom center point in the automobile model (namely in the automobile) on the ground with different horizontal distances x (m) from the direct current transmission line with different voltage grades, wire ground clearance and wire loop numbers, and when x is more than or equal to 0 and less than or equal to x<At 20, the position interval d between adjacent manikins is 0.5 m; when x is more than or equal to 20<At 40, d is 1 m; when x is more than or equal to 40<At 60, d is 2 m; when x is more than or equal to 60<At 100, d is 4 m. Simulating and calculating the human body surface field intensity based on an electric field calculation model near an infinite ground direct current wire, respectively fitting and establishing relational models of outdoor, indoor and automobile human body exposed field intensity E, the voltage level U of an extra-high voltage direct current transmission line, the ground height H of the wire, the number g of loops and the horizontal distance x between the center of the wire and the human body according to the human body surface maximum electric fields of the human body model at different positions, wherein the relational models are respectively Eout=fout(U,H,g,x)、Ein-b=fin-b(U, H, g, x) and Ein-c=fin-c(U, H, g, x); in the formula, EoutExposing field intensity for outdoor human body; ein-bExposing the field intensity for the indoor human body; ein-cExposing the field intensity for human bodies in the automobile.
S300, acquiring all domestic parameters such as the voltage grade, the loop number and the like of the ultra-high voltage direct current transmission line, information such as the position of each iron tower on the line, the height of the overhead line at the iron tower and the like, and establishing an ultra-high voltage direct current transmission engineering information base.
S400, numbering the iron tower from south to north by using 1,2,3, n-1 and n in sequence according to the position of the iron tower of the extra-high voltage direct current transmission line.
S500, sequentially acquiring the positions of the human body through a mobile phone positioning system according to equal sampling time intervals delta T (taking 10S), wherein the delta T is Ti+1-tiWhere i is 1,2,3, …, m, i is the human body position sampling point number, tiM is the time T for calculating the exposure dose of the electric field at the moment of acquiring the position of the human body for the ith timetThe number of sampling points of the inner human body position. The smooth curves are sequentially connected with the human body positions at the sampling moments to obtain the human body motion trail (see fig. 7), and the result shows that after the public starts along the point A on a certain day in the embodiment, the public returns to the point A after passing through the point B, C, D, E in sequence.
S600, at each sampling time tiSearching the iron tower number j (j belongs to [1, n ]) closest to the position of the human body by adopting a dichotomy]) And further finding two iron tower numbers (marked as j 'and j') adjacent to the iron tower j on the line on the basis of the line where the iron tower j is located.
S700, establishing a three-dimensional coordinate system, respectively determining coordinates of the human body and iron towers numbered as j, j 'and j', simulating a direct current line between two basic iron towers by using a straight line segment connecting height points of overhead lines on adjacent iron towers, and calculating the horizontal distance d between the human body and the line between the iron towers j and jj&j’And the horizontal distance d from the line between the iron towers j and j ″j&j”Setting the result to obtain dj&j’<dj&j”And d isj&j’<100m, so the direct current transmission lines between iron towers with the serial numbers of j and j' are the nearest direct current transmission lines within the range of 100m from the human body, and the nearest horizontal distance between the direct current transmission lines and the human body is dj&j’。
S800, searching the extra-high voltage direct current transmission project information base, and setting t obtained in the embodimentiThe ultra-high voltage direct current line (namely the direct current transmission line where the iron towers j and j' are) which is nearest to the human body at the moment is +/-1100 kV doubleThe ground clearance of a lead of the loop direct current power transmission line (namely the ground clearance of the nearest point on the lead to a human body) is 26 m.
S900, sampling time t of different human body positions in the embodiment based on mobile phone positioning signalsiThe human body position state (outdoor, indoor, or in the automobile) is determined, and the determination method is shown in fig. 2. According to the sampling time interval delta t (1 s) of the positioning signal of the mobile phone satellite, the mobile phone positioning system sequentially obtains the satellite at different moments tkSignal strength W of (k 1,2,3, … l, l 10m)k(signal-to-noise ratio), human body position longitude and latitude, and human body moving speed vkAnd acceleration ak. Not provided with tkThe moment is at the sampling moment t of the human body positioniAnd ti+1In between, will tiHuman body position longitude and latitude and moving speed v at any momentiAnd acceleration aiAs tkCorresponding data of time of day, wherein vi=si/ΔT,ai=(vi+1-vi)/ΔT,siIs tiTo ti+1The human body movement distance between moments). Normally, the satellite signal intensity inside and outside the automobile is greater than the critical value Wmax(Wmax20dB in the embodiment) for the signal-to-noise ratio when the satellite signal is weak, the satellite signal intensity in the indoor and outdoor partial areas (such as mountainous areas) is less than or equal to Wmax. Furthermore, if tk-1To tkThe interventricular body enters the outdoor from the indoor and has stronger signal tk-1To tkAbsolute value | Δ W of inter-signal strength variationk-1|(ΔWk-1=Wk-Wk-1) Greater than or equal to critical value | Δ Wmin|(|ΔWminI is the absolute value of the difference in satellite signal strength between where the indoor and outdoor signals are stronger, 20dB in this example), if tk-1To tkThe interventricular body enters the stronger signal place from the weaker outdoor signal place, | Δ Wk-1I is less than | Δ Wmin|。
After the public starts from A, the satellite signal intensity is always smaller and is at tk1(k1W suddenly appears at the moment of belonging to (1, l))k1>WmaxThe public is now at point B. From tk1At the beginning, in stepsΔ t the position state of the body at each instant is acquired in turn, t in this embodimentp(p<k1) The position state of the human body is known as indoor at time tpThe human body position state at the next moment is obtained when the moment stops, the public is positioned at the point A, and the movement from the point A to the point B (namely t) can be determinedpTo tk1M (not containing t)k1) When the public is located indoors.
Further determination of tk1The human body position state at all times. From tk1Firstly, the human body acceleration at each moment is sequentially obtained according to the step length + delta t until a certain moment tq(k1< q) the absolute value of the acceleration of the human body is greater than or equal to the absolute value of the acceleration | a when the automobile is started or braked for the first timemaxL (in this example, 2.7m/s2),tk1To tqThe moving speed of the human body is not 0, and the point B (namely t) can be determinedk1Time of day) the public is located outdoors.
After the public starts from the point B, the satellite signal intensity is always larger and is at tk2(k2∈(k1L)) suddenly appear Wk2<WmaxThe public is now at point E. t is tk2-1To tk2Absolute value | Δ W of satellite signal strength variationk2-1|(ΔWk2-1=Wk2-Wk2-1) Greater than the absolute value of the difference in satellite signal strength between the indoor and outdoor signal strengths | Δ WminI (20 dB in this example), it can be determined at point E (i.e., t)k2Time of day) the public is located indoors.
Further determination of tk2Before time (without t)k2) The position state of the human body. From tk2Firstly, the human body position state at each moment is acquired in sequence according to the step length-delta t, and at tk1(k1<k2) The state of the human body position is known as outdoor at time tk1And stopping acquiring the human body position state at the next moment, wherein the public is positioned at the point B.
Further determination of tk1To tk2The position state of the human body. From tk1To tk2Sequentially acquiring the acceleration of the human body at each moment according to the step length + delta t at tq(k1<q<tk2) The absolute value of the acceleration of the human body at the moment is more than or equal to | amaxAt t |qStopping acquiring the acceleration of the human body at the next moment, wherein aq> 0, public at C, and tq-1A certain time does not exist before, and the time is enabled to reach tq-1The speed of the human body is continuously 0, and the movement from the point B to the point C (namely t) can be determinedk1To tq-1Time) the public is located outdoors, tqThe public is located in the vehicle at the moment.
Further determination of tqTo tk2The position state of the human body. From tqTo tk2Sequentially acquiring the acceleration of the human body at each moment according to the step length + delta t at tr(q<r<tk2) The absolute value of the acceleration of the human body at the moment is more than or equal to | amaxAt t |rStopping acquiring the acceleration of the human body at the next moment, wherein ar< 0, the public is at D, and it can be determined to move from C to D (i.e. t)qTo trTime) the public is located in the car.
Further determination of trTo tk2The position state of the human body. From trTo tk2Sequentially acquiring the human body acceleration at each moment according to the step length + delta t, wherein the human body acceleration at each moment is smaller than | amaxL, and trAt a later time, let trUntil the time when the human body speed is continuously 0, the movement from the point D to the point E (namely t) can be determinedrTo tk2M (not containing t)k2) When the public is located outdoors.
The satellite signal intensity of the public moving from the point E to the point A is always small, and the satellite signal intensity is not suddenly larger than WmaxIn this case, it is not necessary to determine the position state of the human body in the time zone. When t isk2The satellite signal intensity is suddenly greater than W after the momentmaxThen, the electric field exposure dose of the public during this period is calculated again.
And S1000, calculating the electric field exposure dose of the public outdoors. When the public moves from B to C and D to E, the public is outdoors, and the sampling times of the human body position are M
1Taking a value less than [ (q-1-k)
1)+(k
2-1-r)+2]Maximum integer of/10, sampling time t of the public at the human body position
i1(1≤i
1≤M
1) Time-distance closest extra-high voltage direct current transmission line (namely direct current line between iron towers j and j') center horizontal distance x
i1Substituting the line voltage class U of 1100kV, the ground height H of the lead of 26m and the loop number g of 2 into E
out=f
out(U, H, g, x) to calculate t
i1The exposure field strength E of the moment
i1According to D
i1=E
i1Δ T calculation to obtain T
i1To t
i1+1Dose of electric field exposure D between moments
i1According to
Calculating to obtain the electric field exposure dose D of the public outdoors
out。
And S1100, calculating the electric field exposure dose of the public in the automobile. When the public moves from the point C to the point D, the public is in the vehicle, and the sampling times of the human body position are M
2Taking the maximum integer less than (r-q +1)/10, and sampling the public at the human body position at the time t
i2(1≤i
2≤M
2) Time-distance minimum extra-high voltage direct current line (namely direct current line between iron towers j and j') center horizontal distance x
i2Substituting the line voltage class U of 1100kV, the ground height H of the lead of 26m and the loop number g of 2 into E
in-c=f
in-c(U, H, g, x) to calculate t
i2The exposure field strength E of the moment
i2According to D
i2=E
i2Δ T calculation to obtain T
i2To t
i2+1Dose of electric field exposure D between moments
i2According to
Calculating to obtain the electric field exposure dose D of the public in the automobile
in-c。
And S1200, calculating the electric field exposure dose of the public in the room. When the public moves from the point A to the point B (the embodiment does not consider the electric field exposure dose when the public moves from the point E to the point A), the public stays indoors for a time Tin-b=Tt-(tk2-tk1) Wherein T istFor the calculation in this embodimentThe time of public electric field exposure dose is that the center horizontal distance x between the center point in the public house and the nearest extra-high voltage direct current line (namely, the direct current line between the iron towers j and jin-bSubstituting the line voltage class U of 1100kV, the ground height H of the lead of 26m and the loop number g of 2 into Ein-b=fin-b(U, H, g, x) calculating the exposure field intensity E of the public in the roomin-bAccording to Din-b=Ein-b·Tin-bCalculating to obtain the electric field exposure dose D of the public in the roomin-b。