Method for calculating phase-to-phase distance of current overhead transmission line

Abstract

The invention discloses a current overhead transmission line phase-to-phase distance calculation method. The method comprises the steps of measuring the tower head size of each base of iron tower in a certain continuous gear of a current overhead line, the coordinate of a wire hanging point in a certain gear, the coordinate of any point of each phase of wire in the gear and the temperature of the wire, calculating a k value coefficient of a wire curve under a measurement working condition, and obtaining a curvilinear equation of any gear of the wire in the continuous gear; and calculating the space distance between any two points of the three-phase conductor through the curve equation of the three-phase conductor. The method solves the phase-to-phase distance of any two points through a small number of measurement point data, has the advantages of being simple in calculation method, high in precision, capable of reducing field workload and the like, and can be effectively used for calculation of the structural height of the phase-to-phase spacer of the overhead line at present.

Description

Technical Field

[0001] The present invention relates to a method for calculating the phase distance of an existing overhead transmission line, belonging to the technical field of conductor mechanics calculation. Background Art

[0002] According to the requirements of galloping control of overhead transmission lines, it is necessary to install phase spacers on the existing overhead lines, so it is necessary to calculate the phase distance at the installation position. Due to various factors such as construction errors in the existing overhead transmission lines, the tension of the three-phase conductors during stringing is generally different, and some even differ greatly. There is a large error in the theoretical calculation of the phase distance according to the original design conditions of the line. And directly measuring the phase distance at the installation position on site with a total station is a huge workload and consumes a large amount of human and material resources. Summary of the Invention

[0003] In order to solve the problems of high difficulty in measuring the phase distance and large workload when installing phase spacers on existing overhead transmission lines, the present invention provides a method for calculating the phase distance of an existing overhead transmission line.

[0004] A method for calculating the phase distance of an existing overhead transmission line according to the present invention includes the following steps:

[0005] Step (1): For a certain span of conductors, establish a space rectangular coordinate system, specifically including: taking the ground tower center of the tower on the smaller side as the coordinate origin, taking the direction of the tower cross arm as the X-axis, taking the direction of the larger side of the line as the Y-axis, and taking the upward direction as the Z-axis to establish a space rectangular coordinate system;

[0006] Step (2): Measure the coordinates of the conductors in the strain section, the length of the conductor cross arm of the tower, the hanging height of each phase conductor, and the span of each span on site;

[0007] Step (3): Calculate the sag f of this span of conductors, and further calculate the curve coefficient k, and this k value is applicable to other spans of conductors in the strain section; specifically including: according to the measured coordinates of the hanging points of the conductors on both sides of a certain span in the span X1(x1, y1, z1), X2(x2, y2, z2) and the coordinates of a certain point X(x, y, z) in the middle of the span, obtain the sag f of the conductor at y in the span y , from the conductor sag formula f y =ky(l - y) deduce Calculate the k value of the conductors in this strain section;

[0008] Step (4): Through the measured length of the conductor cross arm of each tower in the strain section, the hanging height of each phase conductor, the span of each span, and the calculated k value of the conductors in the strain section, calculate the sag of the installation point of the phase spacer for each span, and calculate the sag of the conductor at the installation point of the phase spacer from the conductor sag calculation equation f y =ky(l - y);

[0009] Step (5): Based on the established spatial rectangular coordinate system, calculate the phase distance at the installation position of the phase spacer according to the measured conductor cross-arm length, conductor suspension point height, span, and the calculated sag at the installation point of the phase spacer between phases.

[0010] The on-site measurement of the conductor coordinates, conductor temperature, conductor cross-arm length of the tower, the suspension point height of each phase conductor, and the span of each span specifically includes: setting up a base station once with a total station to ensure the relative position relationship of the measurement points, measuring the coordinates of the suspension points on both sides of each phase conductor in a certain span within the strain section and the coordinates of a certain point on each phase conductor within the span, and measuring the conductor cross-arm length of each tower, the suspension point height of each phase conductor, and the span of each span within the strain section.

[0011] The present invention has the following beneficial effects:

[0012] The present invention discloses a method for calculating the phase distance of an existing overhead transmission line. Based on the on-site measurement of the suspension points of the upper, middle, and lower phase conductors and a certain point in the span, taking the center of the tower at the smaller side tower as the coordinate origin, the cross-arm direction of the tower as the X-axis, the line direction as the Y-axis, and the upward direction as the Z-axis, a spatial coordinate system of the conductors in this span is established, and the sag of the conductors in each span within the strain section is inversely deduced, so as to simply, efficiently, and accurately calculate the spatial distance at the installation position of the phase spacer. Brief Description of the Drawings

[0013] Figure 1 It is a schematic diagram of the installation position of the phase spacer of the present invention;

[0014] Figure 2 It is a conductor curve diagram of the present invention. Detailed Embodiment

[0015] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0016] As Figure 1 shown in the figure: the lower conductor 1, the middle conductor 2, the upper conductor 3, and the phase spacer 4 installed between the upper conductor - middle conductor and the middle conductor - lower conductor. When installing the phase spacer on the existing overhead line, it is necessary to calculate the phase distance of the conductors at the installation position.

[0017] The present invention provides a method for calculating the phase distance of an existing overhead transmission line. The specific steps include:

[0018] Step 1: For a certain span of conductors, taking the center of the tower ground at the smaller side tower as the coordinate origin, the cross-arm direction of the tower as the X-axis, the direction of the larger side of the line as the Y-axis, and the upward direction as the Z-axis, establish a spatial rectangular coordinate system, as Figure 2, the coordinates of the hanging points on both sides of a certain span are X1(x1, y1, z1) and X2(x2, y2, z2) respectively, the coordinates of the measuring point in the span are X0(x0, y0, z0), and the sag at the measuring point is f0. The hanging point, measuring point coordinates and sag of phase A are represented by X A1 , X A2 , X A0 , f A0 respectively. The hanging point, measuring point coordinates and sag of phase B are represented by X B1 , X B2 , X B0 , f B0 respectively. The hanging point, measuring point coordinates and sag of phase C are represented by X C1 , X C2 , X C0 , f C0 respectively;

[0019] Step 2: Set up the total station as a base station once to ensure the relative position relationship of the measuring points. Measure the coordinates of the hanging points on both sides of each phase of the conductor in a certain span and the coordinates of the measuring point in the middle of each phase of the conductor in the span,

[0020] Coordinates of the hanging point and the measuring point in the middle of phase A: X A1 (x A1 , y A1 , z A1 ), X A2 (x A2 , y A2 , z A2 ), X A0 (x A0 , y A0 , z A0 );

[0021] Coordinates of the hanging point and the measuring point in the middle of phase B: X B1 (x B1 , y B1 , z B1 ), X B2 (x B2 , y B2 , z B2 ), X B0 (x B0 , y B0 , z B0 );

[0022] Coordinates of the hanging point and the measuring point in the middle of phase C: X C1 (x C1 , y C1 , z C1 ), X C2 (x C2 , y C2 , z C2 ), X C0(x C0 , y C0 , z C0 )

[0023] Step 3: Calculate the sag of the measuring conductor at the measuring point in the span:

[0024]

[0025]

[0026]

[0027] Step 4: Calculate the curve coefficient k of each phase conductor in the measuring span:

[0028] Where: l A0 = y A0 - y A1 , l A = y A2 - y A1 ;

[0029] Where: l B0 = y B0 - y B1 , l B = y B2 - y B1 ;

[0030] Where: l A0 = y A0 - y A1 , l A = y A2 - y A1 ;

[0031] Step 5: Measure the cross-arm length, conductor suspension point height, and span parameters of each tower in the strain section. Taking a certain calculation span as an example, it is measured that the cross-arm length of phase A of the tower on the lower side of the span is x A小 , the conductor suspension point height of phase A is z A小 , the cross-arm length of phase B is x B小 , the conductor suspension point height of phase B is z B小 , the cross-arm length of phase C is x C小 , the conductor suspension point height of phase C is z C小 . The cross-arm length of phase A of the tower on the upper side of the span is x A大 , the conductor suspension point height of phase A is z A大 , the cross-arm length of phase B is x B大 , the conductor suspension point height of phase B is z B大 , the cross-arm length of phase C is x C大 , the conductor suspension point height of phase C is zC大 The span is l A计算 .

[0032] Step 6: Based on the spatial rectangular coordinate system established in Step 1, with the center of the smaller-side tower as the coordinate origin, the direction of the tower cross-arm as the X-axis, the line direction as the Y-axis, and the upward direction as the Z-axis. According to the measurement values in Step 5, the sag calculation formulas for each phase of the calculated span are obtained:

[0033] f Ay = k A * y A *(y A2 - y A ),

[0034] f By = k B * y B *(y B2 - y B ),

[0035] f Cy = k C * y C *(y C2 - y C ),

[0036] In the formula, y A , y B , y C are the y coordinates of the installation points of the phase spacers for phases A, B, and C.

[0037] Step 7: Calculate the phase distance at the installation position of the phase spacers. For example, the phase distance D1 at the installation position of the phase spacer between phase A and phase B conductors at the 1 / 3 position within the span, and the phase distance D2 at the installation position of the phase spacer between phase B and phase C conductors at the 2 / 3 position within the span. The calculation formulas for the above two phase distances are as follows:

[0038]

[0039]

[0040] Among them,

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] wherein:

[0058] x1, y1, z1: the coordinates of the conductor suspension points on the small-side tower;

[0059] x2, y2, z2: the coordinates of the conductor suspension points on the large-side tower;

[0060] x 1 / 3 , y 1 / 3 , z 1 / 3 : the coordinates of the conductor at the span from the small side to the large side; x , y 2 / 3 , z 2 / 3 : the coordinates of the conductor at the span from the small side to the large side; 2 / 3 : the coordinates of the conductor at the span from the small side to the large side; ;

[0061] f 1 / 3 : the sag of the conductor at the span from the small side to the large side; ;

[0062] f 2 / 3 : the sag of the conductor at the span from the small side to the large side; ;

Claims

1. A calculation method for the phase distance of an existing overhead transmission line, characterized in that, Including the following steps: Step (1): For a certain conductor section, establish a space rectangular coordinate system, specifically including: taking the ground tower center of the tower on the smaller side as the coordinate origin, taking the direction of the tower cross-arm as the X-axis, taking the direction of the larger side of the line as the Y-axis, and taking the upward direction as the Z-axis to establish a space rectangular coordinate system; Step (2): On-site measure the coordinates of the conductors in the strain section, the conductor cross-arm length of the tower, the hanging point height of each phase conductor, and the span of each span; Step (3): Calculate the sag f of the conductor in this span, and further calculate the curve coefficient k, which is applicable to the conductors in other spans within the strain section. Specifically, it includes: Based on the coordinates X1(x1, y1, z1) and X2(x2, y2, z2) of the hanging points of the conductors on both sides of a certain span obtained by measurement, and the coordinates X(x, y, z) of a certain point in the span, obtain the sag f of the conductor at y in the span y , from the conductor sag formula f y =ky(l - y) deduce Calculate the k value of the conductors in this strain section; Step (4): Calculate the sag at the installation point of the phase spacer for each span by measuring the cross-arm length of the conductor of each tower in the strain section, the suspension point height of each phase conductor, the span of each span, and the calculated k value of the strain section conductor, and calculate the sag of the conductor at the installation point of the phase spacer from the conductor sag calculation equation f y = k * y * (l - y) to calculate the sag of the conductor at the installation point of the phase spacer; Step (5): Based on the established space rectangular coordinate system, calculate the phase-to-phase distance at the installation position of the phase spacer according to the measured conductor cross-arm length, conductor hanging point height, span, and the calculated sag at the installation point of the phase spacer.

2. The calculation method for the phase-to-phase distance of an existing overhead transmission line according to claim 1, characterized in that, The on-site measurement of the coordinates of the conductors in the strain section, the conductor temperature, the conductor cross-arm length of the tower, the hanging point height of each phase conductor, and the span of each span specifically includes: setting up a base station once with a total station to ensure the relative position relationship of the measurement points, measuring the coordinates of the hanging points on both sides of each phase conductor in a certain span within the strain section and the coordinate of a certain point on each phase conductor within the span, measuring the conductor cross-arm length of each tower within the strain section, the hanging point height of each phase conductor, and the span of each span.

Images