CN104793065A

CN104793065A - Method of determining radio interference in AC transmission line crossed erection region

Info

Publication number: CN104793065A
Application number: CN201410023081.7A
Authority: CN
Inventors: 陈豫朝; 万保权; 裴春明; 刘兴发; 谢辉春; 路遥; 赵军; 万浩
Original assignee: State Grid Corp of China SGCC; China Electric Power Research Institute Co Ltd CEPRI
Current assignee: State Grid Corp of China SGCC; China Electric Power Research Institute Co Ltd CEPRI
Priority date: 2014-01-17
Filing date: 2014-01-17
Publication date: 2015-07-22

Abstract

The invention relates to a method for determining radio interference in the area where AC transmission lines are crossed, and the method includes determining a three-dimensional model; determining the surface electric field intensity of each phase conductor; determining the excitation function of each phase conductor; determining any point in the crossing area level of radio interference. This method has high reliability and can be used to predict the radio interference in the transmission line crossing area, and it has laid a good foundation for the determination of the radio interference in the transmission line crossing area.

Description

A Method for Determining Radio Interference in Areas where AC Transmission Lines Are Crossed

技术领域： Technical field:

本发明涉及一种确定无线电干扰的方法，更具体涉及一种确定交流输电线路交叉架设区域无线电干扰的方法。 The present invention relates to a method for determining radio interference, and more particularly relates to a method for determining radio interference in an area where AC transmission lines are crossed. the

背景技术： Background technique:

伴随国民经济的持续发展，我国的电网仍处在高速建设阶段。而我国是土地资源紧缺的国家，可以预见电网建设与土地紧缺的矛盾会日益突出。而为了减少占地节约走廊，建设同一走廊不同架设方式的输电形式是十分必要的。由于一次能源中心和负荷中心分布不均衡，我国的输电线路呈现西电东送，南北互供的格局。这样的格局造成了输电线路交叉跨越走线的情况。 With the continuous development of the national economy, my country's power grid is still in the stage of high-speed construction. However, my country is a country with a shortage of land resources, and it is foreseeable that the contradiction between power grid construction and land shortage will become increasingly prominent. In order to reduce land occupation and save corridors, it is very necessary to construct power transmission forms with different erection methods in the same corridor. Due to the unbalanced distribution of primary energy centers and load centers, my country's transmission lines present a pattern of west-to-east power transmission and mutual supply from north to south. Such a pattern has caused the situation that the transmission lines cross and cross the lines. the

交叉跨越处的电磁环境比较复杂，但目前国内外对交叉跨越线路附近的电磁环境仍然没有开展过系统的研究。在近年的一些工程中，已经出现一些居民投诉和阻止施工的状况，部分地方政府也在征地方面设置障碍。因此急需研究交叉跨越区域的电磁环境特性和水平，为科学合理的确定交叉跨越点导线高度和导线排列方式做好基础工作。 The electromagnetic environment at the intersection is relatively complex, but there is still no systematic research on the electromagnetic environment near the intersection at home and abroad. In some projects in recent years, some residents have complained and blocked the construction, and some local governments have also set up obstacles in land acquisition. Therefore, it is urgent to study the characteristics and levels of the electromagnetic environment in the crossing area, and do a good job in scientifically and rationally determining the height of the wires at the crossing point and the arrangement of the wires. the

电磁环境因素主要包括线路的电场、可听噪声和无线电干扰这3项技术因素。目前对于平行或同塔架设几回线路的无线电干扰的计算方法较多，但计算两回线路跨越区域的无线电干扰水平仍然没有较好的方法。 Electromagnetic environment factors mainly include three technical factors: electric field of line, audible noise and radio interference. At present, there are many calculation methods for the radio interference of several lines erected in parallel or on the same tower, but there is still no good method for calculating the radio interference level of two lines crossing the area. the

发明内容： Invention content:

本发明的目的是提供一种确定交流输电线路交叉架设区域无线电干扰的方法，该方法具有高可信度，可用于预测输电线路交叉跨越区域的无线电干扰。 The purpose of the present invention is to provide a method for determining the radio interference in the area where AC transmission lines are crossed and erected. The method has high reliability and can be used to predict the radio interference in the area where the transmission line crosses. the

为实现上述目的，本发明采用以下技术方案：一种确定交流输电线路交叉架设区域无线电干扰的方法，所述方法包括以下步骤： In order to achieve the above object, the present invention adopts the following technical solutions: a method for determining the radio interference in the cross erection area of AC transmission lines, said method comprising the following steps:

（1）确定三维模型； (1) Determine the 3D model;

（2）确定每相导线表面电场强度； (2) Determine the surface electric field intensity of each phase conductor;

（3）确定所述每相导线的激发函数； (3) Determine the excitation function of each phase conductor;

（4）确定交叉跨越区域内任一点的无线电干扰水平。 (4) Determine the level of radio interference at any point within the crossover area. the

本发明提供的一种确定交流输电线路交叉架设区域无线电干扰的方法，所述步骤（1）是根据给定的导线型式、导线对地高度和导线排列方式建立三维坐标系，确定模型。 The present invention provides a method for determining radio interference in areas where AC transmission lines are crossed. The step (1) is to establish a three-dimensional coordinate system and determine the model according to the given wire type, height of the wire to the ground, and wire arrangement. the

本发明提供的一种确定交流输电线路交叉架设区域无线电干扰的方法，所述步骤（2）中的电场强度通过静电场理论确定。 The present invention provides a method for determining radio interference in the area where AC transmission lines are crossed and erected. The electric field strength in the step (2) is determined by electrostatic field theory. the

本发明提供的另一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，任意一点所述电场强度通过式（1）确定： Another preferred method provided by the present invention for determining radio interference in areas where AC transmission lines are crossed is erected. The electric field strength at any point is determined by formula (1):

$\overset{&RightArrow; &Right Arrow;}{E E.} = = \frac{11}{44 πϵ πϵ} \underset{l l}{&Integral; &Integral;} \frac{{ρ ρ}_{l l}^{' '} ((\overset{&RightArrow; &Right Arrow;}{r r} - - {\overset{&RightArrow; &Right Arrow;}{r r}}^{' '}))}{{((\overset{&RightArrow; &Right Arrow;}{r r} - - {\overset{&RightArrow; &Right Arrow;}{r r}}^{' '}))}^{33}} {dl dl}^{' '} - - - - - - ((11))$

式中，ρl'表示线电荷密度，l'为线电荷长度，ε为ε_r×ε₀，ε_r为相对介电常数，ε₀为8.85×10^-12F/m，为空间任一点矢量，为线电荷矢量。 In the formula, ρl' represents the line charge density, l' is the line charge length, ε is ε _r × ε ₀ , ε _r is the relative permittivity, ε ₀ is 8.85×10 ^-12 F/m, is any point vector in space, is the line charge vector.

本发明提供的再一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，所述线电荷为平行Z轴方向的无限长直线，用L表示，设L上的点L1坐标（x‘，y‘，z‘）的方程为： $\{\begin{matrix} x^{'} = a \\ y^{'} = h \end{matrix},$ 空间任意一点的坐标为（x，y，z）； Another preferred method for determining radio interference in the area where AC transmission lines are crossed and erected provided by the present invention, the line charge is an infinitely long straight line parallel to the Z-axis direction, denoted by L, and the point L1 coordinates on L (x' , y', z') is: $\{\begin{matrix} x^{'} = a \\ {the y}^{'} = h \end{matrix},$ The coordinates of any point in space are (x, y, z);

若ρl'为均匀分布线电荷，将线电荷L1坐标代入式（1），得到三维空间均匀分布线电荷的电场强度计算公式（2）； If ρl' is a uniformly distributed line charge, the coordinates of the line charge L1 are substituted into formula (1), and the calculation formula (2) of the electric field intensity of the uniformly distributed line charge in three-dimensional space is obtained;

${E E.}_{11} = = \frac{ρ ρ}{44 πϵ πϵ} {&Integral; &Integral;}_{- - \infty \infty}^{\infty \infty} \frac{11}{{((x x - - a a))}^{22} + + {((y the y - - h h))}^{22} + + {((z z - - {z z}^{' '}))}^{22}} d d {z z}^{' '} - - - - - - ((22))$

令k＝(x-a)²+(y-h)²，则 Let k=(xa) ² +(yh) ² , then

${E E.}_{11} = = \frac{ρ ρ}{44 πϵ πϵ \sqrt{k k}} {tan the tan}^{- - 11} ((\frac{z z - - {z z}^{' '}}{\sqrt{k k}})) {| |}_{- - \infty \infty}^{\infty \infty} = = \frac{ρ ρ}{44 ϵ ϵ \sqrt{k k}} - - - - - - ((33))$

根据式（3）得到平行Z轴方向的无限长直导线三维空间任意一点的电场强度。 According to formula (3), the electric field intensity at any point in the three-dimensional space of an infinitely long straight wire parallel to the Z-axis direction can be obtained. the

本发明提供的又一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，当所述线电荷L2的坐标（x‘，y‘，z‘）的方程为： Another preferred method for determining the radio interference in the area where AC transmission lines are crossed and erected provided by the present invention, when the equation of the coordinates (x', y', z') of the line charge L2 is:

$\{\begin{matrix} {z z}^{' '} = = {px px}^{' '} + + q q \\ {y the y}^{' '} = = h h \end{matrix},,$

空间任意一点的坐标为（x，y，z），则所述式（3）变为式（4）： The coordinates of any point in space are (x, y, z), then the formula (3) becomes formula (4):

${E E.}_{22} = = \frac{ρ ρ}{44 πϵ πϵ} {&Integral; &Integral;}_{- - \infty \infty}^{\infty \infty} \frac{11 + + {p p}^{22}}{{((x x - - {x x}^{' '}))}^{22} + + {((y the y - - h h))}^{22} + + {((z z - - p p \overset{' '}{x x} - - q q))}^{22}} d d \overset{' '}{x x} - - - - - - ((44))$

令 $t = \frac{x + zp + pq}{1 + p^{2}}, r = \frac{p^{2} x^{2} + {(z - q)}^{2} - 2 xzp + 2 xpq + (1 + p^{2}) {(y - h)}^{2}}{{(1 + p^{2})}^{2}},$ 则式（4）变为式(5)： make $t = \frac{x + zp + pq}{1 + p^{2}}, r = \frac{p^{2} x^{2} + {(z - q)}^{2} - 2 xzp + 2 wxya + (1 + p^{2}) {(the y - h)}^{2}}{{(1 + p^{2})}^{2}},$ Then formula (4) becomes formula (5):

${E E.}_{22} = = \frac{ρ ρ}{44 πϵ πϵ \sqrt{r r}} {tan the tan}^{- - 11} ((\frac{{z z}^{' '} - - t t}{\sqrt{r r}})) {| |}_{- - \infty \infty}^{\infty \infty} = = \frac{ρ ρ}{44 ϵ ϵ \sqrt{r r}} - - - - - - ((55)) . .$

本发明提供的又一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，所述步骤（3）中的激发函数通过式（6）确定： Another preferred method for determining radio interference in the area where AC transmission lines are crossed is provided by the present invention. The excitation function in the step (3) is determined by the formula (6):

Γ_大雨=70-（585/g_max）+35lg(d)-10lg(n) （6） Γheavy _rain =70-(585/g _max )+35lg(d)-10lg(n) (6)

式中：g_max——子导线最大表面电位梯度有效值，单位为kV/cm； In the formula: g _max —— the effective value of the maximum surface potential gradient of the sub-conductor, the unit is kV/cm;

d——子导线直径，单位为cm； d——the diameter of the sub-conductor, in cm;

n——分裂导线数。 n - the number of split wires. the

本发明提供的又一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，通过式（7）确定导线中的电晕脉冲电流： Another preferred method for determining the radio interference in the area where AC transmission lines are crossed is provided by the present invention, and the corona pulse current in the wire is determined by formula (7):

电晕脉冲电流 $[i_{0}] = [C] [Γ] / 2^{{πϵ}_{0}} - - - (7)$ corona pulse current $[i_{0}] = [C] [Γ] / 2^{{πϵ}_{0}} - - - (7)$

式中：C——导线电容矩阵； In the formula: C——wire capacitance matrix;

Γ——激发函数； Γ——excitation function;

第1相导线电晕时，[Γ]=[Γ,0,0]^T；通过模变换，所述电晕脉冲电流转换成模电流： During the corona of the first phase conductor, [Γ]=[Γ,0,0] ^T ; through mode conversion, the corona pulse current is converted into a mode current:

[i_0m]＝[N]^-1[i₀] （8） [i _0m ]=[N] ^-1 [i ₀ ] (8)

[O]为模转换矩阵，[N]^-1[N]=1，m=1，2，3，根据计算，三相导线排列方式不同，[N]的元素有差别； [O] is the modulus conversion matrix, [N] ^-1 [N]=1, m=1, 2, 3, according to the calculation, the arrangement of the three-phase wires is different, and the elements of [N] are different;

当电流注入导线后，由注入点向两边传播，向参考点传播的电流为： When the current is injected into the wire, it propagates from the injection point to both sides, and the current propagating to the reference point is:

$[[{i i}_{m m} ((x x))]] = = \frac{11}{22} exp exp (({L L}_{m m} \cdot \cdot x x)) [[{i i}_{00 m m}]] - - - - - - ((99))$

其中L_m＝α_m+jβ_m为传播常数，由[B]=[Y][Z]的特征值得到，[Y]和[Z]分别为线路的并联导纳矩阵和串联阻抗矩阵，把计算的模传播电流反变换成相电流： where L _m =α _m +jβ _m is the propagation constant, obtained from the eigenvalues of [B]=[Y][Z], [Y] and [Z] are the parallel admittance matrix and series impedance matrix of the line respectively, put The calculated mode propagating currents are inversely transformed into phase currents:

[i(x)]＝[N][i_m(x)] （10） [i(x)]=[N][i _m (x)] (10)

通过所述相电流确定每相产生的无线电干扰。 The radio interference generated per phase is determined from the phase currents. the

本发明提供的又一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，每相产生的无线电干扰通过式（11）确定： Another preferred method for determining the radio interference in the area where AC transmission lines are crossed is provided by the present invention. The radio interference generated by each phase is determined by formula (11):

$E E. = = 6060 I I [[\frac{h h}{{h h}^{22} + + {y the y}^{22}} + + \frac{h h + + 22 p p}{((h h + + 22 p p)) + + {y the y}^{22}}]] - - - - - - ((1111))$

式中，h——载流导体的高度； In the formula, h - the height of the current-carrying conductor;

I——相电流； I - phase current;

y——测点到导线对地投影的距离； y——the distance from the measuring point to the projection of the wire to the ground;

p——磁场穿透深度。 p——magnetic field penetration depth. the

本发明提供的又一优选的一种确定交流输电线路交叉架设区域无线电干扰的方法，所述步骤（4）中的无线电干扰水平通过式（12）确定： Another preferred method provided by the present invention for determining the radio interference in the area where AC transmission lines are crossed is erected, the radio interference level in the step (4) is determined by the formula (12):

三相单回线路的无线电干扰场强 $E = \frac{E_{a} + E_{b}}{2} + 1.5 - - - (12)$ Radio interference field strength of three-phase single-circuit lines $E. = \frac{{E.}_{a} + {E.}_{b}}{2} + 1.5 - - - (12)$

式中：Ea、Eb——指线路三相中两相较大的场强值，单位为dB/(μV/m)；当某一相的场强比其余两相至少大3dB,那么忽略其余两项场强，三相单回线路的无线电干扰场强为最大的一相的场强； In the formula: Ea, Eb——refer to the larger field strength value of two phases among the three phases of the line, the unit is dB/(μV/m); when the field strength of a certain phase is at least 3dB greater than the other two phases, then ignore the other two phases Two field strengths, the radio interference field strength of the three-phase single-circuit line is the field strength of the largest phase;

同杆架设的多回路线路的无线电干扰场强为同名相导线产生的场强几何相加，形成叠加后的三相Ea，Eb，Ec。 The radio interference field strength of the multi-circuit line erected on the same pole is the geometric addition of the field strength generated by the phase wires of the same name to form the superimposed three-phase Ea, Eb, Ec. the

和最接近的现有技术比，本发明提供技术方案具有以下优异效果 Compared with the closest prior art, the technical solution provided by the present invention has the following excellent effects

1、本发明的方法具有高可信度，可用于预测输电线路交叉跨越区域的无线电干扰； 1. The method of the present invention has high reliability and can be used to predict the radio interference in the transmission line crossing area;

2、本发明的方法为科学合理地确定交叉跨越点导线高度和导线排列方式奠定基础； 2. The method of the present invention lays the foundation for scientifically and rationally determining the height of the wires at crossing points and the arrangement of the wires;

3、本发明为预测输电线路交叉跨越区域的无线电干扰打下了良好的基础； 3. The present invention has laid a good foundation for predicting the radio interference in the transmission line crossing area;

4、本发明的方法简单易行。 4. The method of the present invention is simple and easy to implement. the

附图说明 Description of drawings

图1为本发明方法的流程图； Fig. 1 is the flowchart of the inventive method;

图2为本发明的三维模型结构示意图； Fig. 2 is the structural representation of three-dimensional model of the present invention;

图3为本发明的三维模型结构示意图； Fig. 3 is the structural representation of three-dimensional model of the present invention;

图4为本发明的无线电干扰与相电流的关系示意图。 FIG. 4 is a schematic diagram of the relationship between radio interference and phase current in the present invention. the

具体实施方式 Detailed ways

下面结合实施例对发明作进一步的详细说明。 Below in conjunction with embodiment the invention is described in further detail. the

实施例1： Example 1:

如图1-4所示，本例的发明的方法为了研究交叉区域导线表面电场分布特性，首先将电场计算模型拓展到三维空间。根据静电场理论，线电荷分布情况下媒介中任意一点电场强度的表达式为： As shown in Figures 1-4, in order to study the distribution characteristics of the electric field on the surface of the wire in the intersection area, the inventive method of this example first extends the electric field calculation model to three-dimensional space. According to the electrostatic field theory, the expression of the electric field intensity at any point in the medium under the condition of line charge distribution is:

式中，ρl'表示线电荷密度，l'为线电荷长度，ε为ε_r×ε₀，ε_r为相对介电常数，ε₀为8.85×10^-12F/m，为空间任一点矢量，为线电荷矢量。线电荷空间分布情况如图2所示：线电荷为平行Z轴方向的无限长直线，用L表示，设L1坐标（x‘，y‘，z‘）的方程为： $\{\begin{matrix} x^{'} = a \\ y^{'} = h \end{matrix},$ 空间任意一点的坐标为（x，y，z）。 In the formula, ρl' represents the line charge density, l' is the line charge length, ε is ε _r × ε ₀ , ε _r is the relative permittivity, ε ₀ is 8.85×10 ^-12 F/m, is any point vector in space, is the line charge vector. The spatial distribution of the line charge is shown in Figure 2: the line charge is an infinitely long straight line parallel to the Z-axis direction, denoted by L, and the equation of the L1 coordinates (x', y', z') is: $\{\begin{matrix} x^{'} = a \\ {the y}^{'} = h \end{matrix},$ The coordinates of any point in space are (x, y, z).

若ρl'为均匀分布线电荷，将线电荷L1坐标代入式（1），可以得到三维空间均匀分布线电荷的电场强度计算公式，见式（2）。 If ρl' is a uniformly distributed line charge, the coordinates of the line charge L1 are substituted into formula (1), and the calculation formula of the electric field intensity of the uniformly distributed line charge in three-dimensional space can be obtained, see formula (2). the

令k＝(x-a)²+(y-h)²，则 Let k=(xa) ² +(yh) ² , then

根据式（3）可以得到特定坐标形式下，无限长直导线三维空间任意一点的电场强度。 According to formula (3), the electric field intensity at any point in the three-dimensional space of an infinitely long straight wire can be obtained in a specific coordinate form. the

下面改变线电荷L2的坐标（x‘，y‘，z‘）如图3所示，设L2的方程为： Next, change the coordinates (x', y', z') of the line charge L2 as shown in Figure 3. Let the equation of L2 be:

空间任意一点的坐标为（x，y，z）。式（2）变为式（4） The coordinates of any point in space are (x, y, z). Formula (2) becomes formula (4)

将式（4）整理成式（3）的形式,见式（5） Arrange formula (4) into the form of formula (3), see formula (5)

${E E.}_{22} = = \frac{ρ ρ}{44 πϵ πϵ \sqrt{r r}} {tan the tan}^{- - 11} ((\frac{{z z}^{' '} - - t t}{\sqrt{r r}})) {| |}_{- - \infty \infty}^{\infty \infty} = = \frac{ρ ρ}{44 ϵ ϵ \sqrt{r r}} - - - - - - ((55))$

其中, $t = \frac{x + zp + pq}{1 + p^{2}}, r = \frac{p^{2} x^{2} + {(z - q)}^{2} - 2 xzp + 2 xpq + (1 + p^{2}) {(y - h)}^{2}}{{(1 + p^{2})}^{2}} .$ in, $t = \frac{x + zp + pq}{1 + p^{2}}, r = \frac{p^{2} x^{2} + {(z - q)}^{2} - 2 xzp + 2 wxya + (1 + p^{2}) {(the y - h)}^{2}}{{(1 + p^{2})}^{2}} .$

比较式（3）和（5），由于线电荷的坐标不同，E1和E2的坐标形式上发生了变化。E1在Z轴方向上没有分量，E2则包含x、y、z三个方向上的分量。上述推导假设导线电荷分布均匀，对于无限长直导线这一假设基本成立，求解方法可以仿照二维模型。对于边界问题的处理也可以采用镜像法，原理与二维模型近似。 Comparing formulas (3) and (5), due to the different coordinates of line charges, the coordinates of E1 and E2 have changed in form. E1 has no component in the Z-axis direction, and E2 contains components in the three directions of x, y, and z. The above derivation assumes that the charge distribution of the wire is uniform, and this assumption is basically established for an infinitely long straight wire, and the solution method can be modeled on a two-dimensional model. The mirror method can also be used to deal with the boundary problem, and the principle is similar to that of the two-dimensional model. the

激发函数法基于试验线路或电晕笼测量而得的大雨条件下的激发函数，通过一定的模量变换，得出各相导线的脉冲电流，再获得这些电流产生的场，即无线电干扰。计算步骤包括：激发函数的计算及气象影响的修正；根据模传播原理计算干扰场强的分布。 The excitation function method is based on the excitation function under heavy rain conditions measured by the test line or the corona cage. Through a certain modulus transformation, the pulse current of each phase conductor is obtained, and then the field generated by these currents is obtained, that is, radio interference. The calculation steps include: the calculation of the excitation function and the correction of the meteorological influence; and the calculation of the distribution of the interference field strength according to the principle of mode propagation. the

所述激发函数采用下式计算： The activation function is calculated using the following formula:

式中：g_max——子导线最大表面电位梯度有效值，kV/cm； In the formula: g _max —— the effective value of the maximum surface potential gradient of the sub-conductor, kV/cm;

d——子导线直径，cm； d——The diameter of the sub-conductor, cm;

n——分裂导线数。 n - the number of split wires. the

由激发函数可求出导线中的电晕脉冲电流，而这种电流是产生干扰场强的来源。 The corona pulse current in the wire can be obtained from the excitation function, and this current is the source of the interference field strength. the

$[[{i i}_{00}]] = = [[C C]] [[Γ Γ]] / / 22^{{πϵ πϵ}_{00}} - - - - - - ((77))$

Γ——激发函数。 Γ——excitation function. the

第1相导线电晕时，[Γ]=[Γ,0,0]^T。通过模变换，电晕电流转换成模电流： When the first phase conductor is corona, [Γ]=[Γ,0,0] ^T . Through mode conversion, the corona current is converted into a mode current:

[i_0m]＝[N]^-1[i₀] （8） [i _0m ]=[N] ^-1 [i ₀ ] (8)

[N]为模转换矩阵，[N]^-1[N]=1，m=1，2，3；根据计算，三相导线排列方式不同，[N]的元素有一定差别。 [N] is the mode conversion matrix, [N] ^-1 [N]=1, m=1, 2, 3; according to the calculation, the arrangement of the three-phase wires is different, and the elements of [N] have certain differences.

当电流注入导线后，由入点向两边传播，向参考点传播的电流为： When the current is injected into the wire, it propagates from the entry point to both sides, and the current propagating to the reference point is:

[i(x)]＝[N][i_m(x)] （10） [i(x)]=[N][i _m (x)] (10)

将相电流带入式（11），即可求出每一相产生的无线电干扰。 Bringing the phase current into formula (11), the radio interference generated by each phase can be obtained. the

载流导体周围存在磁场H，高频电场和磁场存在一定的关系，磁场强度（无线电干扰）与电流的关系为如图3所示： There is a magnetic field H around the current-carrying conductor, and there is a certain relationship between the high-frequency electric field and the magnetic field. The relationship between the magnetic field strength (radio interference) and the current is shown in Figure 3:

$H h = = \frac{I I}{22 π π \sqrt{{h h}^{22} + + {y the y}^{22}}}$

式中：h——载流导体的高度（即导线的实际高度，或最低高度）； In the formula: h - the height of the current-carrying conductor (that is, the actual height of the wire, or the lowest height);

y——测点到导线对地投影的距离。 y——the distance from the measuring point to the projection of the wire to the ground. the

所以载流导线在对地投影距离y处产生的电场为： Therefore, the electric field generated by the current-carrying wire at the projected distance y to the ground is:

式中：p——磁场穿透深度。 In the formula: p——magnetic field penetration depth. the

三相单回线路的无线电干扰场强按下列方式计算：如果某一相的场强比其余两相至少大3dB,那么后者可以忽略，三相线路的无线电干扰场强可认为等于最大的一相的场强；否则有下式 The radio interference field strength of a three-phase single-circuit line is calculated as follows: If the field strength of a certain phase is at least 3dB greater than the other two phases, the latter can be ignored, and the radio interference field strength of the three-phase line can be considered equal to the largest one. The field strength of the phase; otherwise, the following formula

$E E. = = \frac{{E E.}_{a a} + + {E E.}_{b b}}{22} + + 1.5 1.5 - - - - - - ((1212))$

式中：Ea、Eb——指三相中两相较大的场强值，dB/(μV/m)； In the formula: Ea, Eb——refers to the larger field strength value of the two phases among the three phases, dB/(μV/m);

对于同杆架设的多回路线路，相导线产生的无线电干扰场强按上式计算，然后将同名相导线产生的场强几何相加，形成叠加后的三相Ea，Eb，Ec。 For multi-circuit lines erected on the same pole, the radio interference field strength generated by the phase conductors is calculated according to the above formula, and then the field strengths generated by the phase conductors of the same name are geometrically added to form the superimposed three-phase Ea, Eb, Ec. the

以上公式适合于导线表面场强在12-20kV/cm的高压线路，导线表面场强若小于12kV/cm，可认为导线不起电晕，也就是说该导线不产生无线电干扰，因此在计算时不考虑表面场强小于12kV/cm的导线产生的无线电干扰电平。 The above formula is suitable for high-voltage lines with a surface field strength of 12-20kV/cm. If the surface field strength of the wire is less than 12kV/cm, it can be considered that the wire does not have corona, that is to say, the wire does not generate radio interference. Therefore, when calculating The level of radio interference generated by conductors with surface field strengths less than 12kV/cm is not considered. the

最后应该说明的是:以上实施例仅用以说明本发明的技术方案而非对其限制，尽管参照上述实施例对本发明进行了详细说明，所属领域的普通技术人员应当理解：依然可以对本发明的具体实施方式进行修改或者等同替换，而未脱离本发明精神和范围的任何修改或者等同替换，其均应涵盖在本权利要求范围当中。 Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be implemented Modifications or equivalent replacements to the specific embodiments, any modification or equivalent replacement that does not depart from the spirit and scope of the present invention, shall be covered by the scope of the present claims. the

Claims

1. A method for determining radio interference in areas where AC transmission lines are crossed, is characterized in that: the method may further comprise the steps:

(1) Determine the 3D model;

(2) Determine the surface electric field intensity of each phase conductor;

(3) Determine the excitation function of each phase conductor;

(4) Determine the level of radio interference at any point within the crossover area. the

2. A method for determining radio interference in the area where AC transmission lines are crossed and erected according to claim 1, characterized in that: said step (1) is established according to the given wire type, wire-to-ground height and wire arrangement. The three-dimensional coordinate system determines the model. the

3. A method for determining radio interference in areas where alternating current transmission lines are erected according to claim 1, characterized in that: the electric field strength in the step (2) is determined by electrostatic field theory. the

4. A method for determining radio interference in areas where AC transmission lines are crossed and erected as claimed in claim 3, wherein the electric field strength at any point is determined by formula (1):

In the formula, ρl' represents the line charge density, l' is the line charge length, ε is ε _r × ε ₀ , ε _r is the relative permittivity, ε ₀ is 8.85×10 ^-12 F/m, is any point vector in space, is the line charge vector.

5. A kind of method for determining the radio interference in the cross erection area of AC transmission lines as claimed in claim 4, characterized in that: the line charge is an infinitely long straight line parallel to the Z-axis direction, represented by L, and a point on L is assumed The equation for the L1 coordinates (x', y', z') is: The coordinates of any point in space are (x, y, z);

If ρl′ is a uniformly distributed line charge, the coordinates of the line charge L1 are substituted into formula (1), and the calculation formula (2) of the electric field intensity of the uniformly distributed line charge in three-dimensional space is obtained;

Let k=(xa) ² +(yh) ² , then

According to formula (3), the electric field intensity at any point in the three-dimensional space of an infinitely long straight wire parallel to the Z-axis direction can be obtained. the

6. A method for determining radio interference in areas where AC transmission lines are crossed and erected as claimed in claim 5, wherein the equation of the coordinates (x', y', z') of the line charge L2 is:

The coordinates of any point in space are (x, y, z), then the formula (3) becomes formula (4):

make Then formula (4) becomes formula (5):

7. A method for determining radio interference in areas where AC transmission lines are crossed and erected as claimed in claim 1, characterized in that: the excitation function in the step (3) is determined by formula (6):

Γheavy _rain =70-(585/g _max )+35lg(d)-10lg(n) (6)

In the formula: g _max —— the effective value of the maximum surface potential gradient of the sub-conductor, the unit is kV/cm;

d——the diameter of the sub-conductor, in cm;

n - the number of split wires. the

8. A method for determining radio interference in areas where AC transmission lines are crossed and erected as claimed in claim 7, characterized in that: the corona pulse current in the wire is determined by formula (7):

corona pulse current

In the formula: C—— wire capacitance matrix;

Γ——excitation function;

During the corona of the first phase conductor, [Γ]=[Γ,0,0] ^T ; through mode conversion, the corona pulse current is converted into a mode current:

[i _0m ]=[N] ^-1 [i ₀ ] (8)

[N] is the mode conversion matrix, [N] ^-1 [N]=1, m=1, 2, 3, according to the calculation, the arrangement of the three-phase wires is different, and the elements of [N] are different;

When the current is injected into the wire, it propagates from the injection point to both sides, and the current propagating to the reference point is:

where L _m =α _m +jβ _m is the propagation constant, obtained from the eigenvalues of [B]=[Y][Z], [Y] and [Z] are the parallel admittance matrix and series impedance matrix of the line respectively, put The calculated mode propagating currents are inversely transformed into phase currents:

[i(x)]=[N][i _m (x)] (10)

The radio interference generated per phase is determined from the phase currents. the

9. A method for determining radio interference in areas where AC transmission lines are crossed and erected as claimed in claim 8, characterized in that: the radio interference generated by each phase is determined by formula (11):

In the formula, h - the height of the current-carrying conductor;

I - phase current;

y——the distance from the measuring point to the projection of the wire to the ground;

p——magnetic field penetration depth. the

10. A method for determining radio interference in areas where AC transmission lines are crossed as claimed in claim 9, wherein the radio interference level in step (4) is determined by formula (12):

Radio interference field strength of three-phase single-circuit lines

In the formula: Ea, Eb—refer to the larger field strength value of two phases among the three phases of the line, the unit is dB/(μV/m); when the field strength of a certain phase is at least 3dB greater than the other two phases, then ignore the other two phases Two field strengths, the radio interference field strength of the three-phase single-circuit line is the field strength of the largest phase;

The radio interference field strength of the multi-circuit line erected on the same pole is the geometric addition of the field strength generated by the phase wires of the same name to form the superimposed three-phase Ea, Eb, Ec. the