JPH07280638A - Galloping detector - Google Patents

Abstract

PURPOSE:To provide a galloping detector for dealing with the occurrence of galloping in an overhead transmission line quickly and accurately. CONSTITUTION:The galloping detector comprises a sensor group 1 for detecting the wind velocity, the air temperature and the amount of precipitation around an overhead transmission line, a computer 7 for collecting the detection results in real time through an optical fiber cable 3, and a computer 8 for calculating the profile of snow accretion based on the detection results thus collected to estimate a corresponding aerodynamic characteristics and calculating fluctuations in the frequency, amplitude and tension of the overhead transmission line while taking account of the aerodynamic characteristics thus displaying the state of estimated galloping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a galloping detecting device capable of detecting galloping occurring in an overhead power transmission line between support towers.

2. Description of the Related Art Overhead power transmission lines erected between support towers such as steel towers oscillate due to natural wind or the adhesion of ice and snow. May result in low frequency vibration. When this galloping occurs, an extremely dangerous situation such as a short-circuit accident due to contact between electric wires is caused, and therefore it is necessary to detect this early and deal with it promptly.

Conventionally, in the case of observing the galloping of such an overhead power transmission line, a method of installing a video for monitoring or attaching a tension meter or a deflection angle meter to the overhead power transmission line to record the measurement data is used. Has been taken.

[0003]

However, with the observation method using video, observation at night is impossible,
In addition, the overhead power line may become unobservable because it is covered with snow or snow clouds. Moreover, in the method using the tensiometer or the deflection angle meter, the measurement data is merely recorded, and the data is actually analyzed after one to several months, so that the situation can be grasped quickly. It wasn't. In addition, the conventional analysis method does not consider the influence of ice and snow (snow accretion) accumulated on the surface of the overhead transmission line and insulators connected to the end of the wire on the vibration, so the galloping state can be accurately determined. Could not be estimated. After all,
With the conventional method, the situation cannot be grasped quickly without being affected by external conditions such as time zone and weather, and the galloping state cannot be estimated with high accuracy. However, there was a problem that it was not possible to deal with it promptly and accurately.

The present invention has been made under such circumstances, and an object of the present invention is to provide a galloping detection device capable of promptly and appropriately coping with the occurrence of galloping of an overhead power transmission line.

[0005]

In order to solve the above-mentioned problems, the present invention is a device for detecting galloping which occurs in an overhead power transmission line between support towers, wherein the wind speed around the overhead power transmission line is Corresponding to the detection means for detecting the temperature and the precipitation amount, the first calculation means for calculating the snow accretion shape formed on the surface of the overhead transmission line based on the detection result of the detection means, and the snow accretion shape. Second calculating means for calculating aerodynamic characteristics of the overhead power transmission line, and calculating frequency, amplitude and tension fluctuations of the overhead power transmission line in consideration of the aerodynamic characteristics;
Display means for displaying an estimated galloping state based on the calculation result of the second calculating means.

[0006]

According to the present invention, the detecting means detects the wind speed, the temperature, and the amount of precipitation around the overhead power transmission line, and the first computing means detects the surface of the overhead power transmission line on the basis of the detection result of the detecting means. The second calculation means calculates the snow accretion shape to be formed,
The aerodynamic characteristics of the overhead power transmission line corresponding to this snow accretion shape are calculated, and the frequency, amplitude and tension fluctuations of the overhead power transmission line are calculated in consideration of the aerodynamic characteristics. The display means is the second
The estimated galloping state is displayed based on the calculation result of the calculation means. As a result, galloping that occurs in the overhead power transmission line can be detected quickly and accurately.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In this figure, reference numeral 1 is an overhead power transmission line (not shown) or various sensors (hereinafter referred to as a sensor group) installed in the vicinity thereof. This sensor group 1
Detects wind speed, temperature, and precipitation around overhead power lines,
Each detection result is converted into an electric signal and output.

Reference numeral 2 denotes an optical modulator installed near the overhead power transmission line, which converts an electric signal output from the sensor group 1 into an optical signal and sends it to the optical fiber cable 3. Four
Is a photoelectric converter installed in a monitoring station on the ground side, and converts an optical signal transmitted from the optical modulator 2 via the optical fiber cable 3 into an electric signal again. This electric signal is amplified by the amplifier 5 and then converted into a digital signal by the A / D (analog / digital) converter 6.

Reference numerals 7 and 8 denote computers installed in the monitoring station. The computer 7 is used for data collection and the computer 8 is used for data analysis.
The computer 7 takes in the digital signals output from the A / D converter 6 as observation data and stores them in a storage device such as an internal memory.

On the other hand, the computer 8 is the computer 7
The above-mentioned collected various observation data supplied from the company are taken in, and the analysis processing of these observation data is performed. Then, based on this analysis result, the state of galloping occurring on the overhead power transmission line is graphically displayed on a display (not shown).

Next, referring to the flow chart shown in FIG. 2, the observation data analysis processing performed by the computer 8 will be described. In the figure, first, in steps S1 to S3, each observation data is captured. Here, the captured observation data is an observation result of wind speed, temperature, and precipitation around the overhead power transmission line. Then, in step S4, the data of the line condition regarding the overhead power transmission line to be analyzed is fetched. The line condition data are data such as electric wire length, mass per unit length, moment of inertia, torsional rigidity, and distance between steel towers, which are stored in a memory or a hard disk (not shown) built in the computer 8. ing.

Next, in step S5, the snow accretion shape is calculated. The snow accretion shape means a sectional shape of ice and snow accumulated on the surface of the overhead power transmission line. Here, the steel towers are logically divided into a plurality of sections at equal intervals, and the snow accretion development process due to the twisting rotation of the overhead power transmission line is simulated for each section. As shown in FIG. 3, the snow accretion develops in such a manner that a certain amount of snow accompanies a portion facing the snowfall direction DS in parallel with the snowfall direction (S1, S2, S3 in the figure), and the electric wire EC twists and rotates. Let's go. Also, as shown,
The section of the electric wire EC in each section is equally divided in the angle direction,
Consider the development of snow accretion in each part as a vector (hereinafter referred to as a snow accretion vector) V. By connecting the ends of these snow accretion vectors V, V, ... With an arc, a snow accretion shape can be obtained. Here, the twist angle and the torque of the overhead power transmission line due to snow accretion are given by the following equations (1) and (2).

[Equation 1]

[Equation 2] However, σ is the specific gravity of snow, n ′ is the number of divisions between steel towers,
S is the distance between steel towers, ψ _i is the twist angle of the i-th segment, M _i is the rotational moment due to snow accretion of the i-th segment, nθ _i is the total number of snow accretion vectors of the i-th segment, and A _ik is the break of the snow accretion. Area, α _ik
Is the angle formed by the line connecting the vertices of two adjacent snow _accretion vectors and the center of the electric wire, and R _Gik is the center of gravity of the snow _accretion area (the snow _accretion area sandwiched between two adjacent snow _accretion vectors) from the electric wire center. The distance to the point, δ _ik is the angle of deviation of the center of gravity with respect to the reference axis (bisector of α _ik above), θ _ik is the line connecting the apex of the snow accretion vector and the center of the wire, and the initial axis SS (this rotates with respect to a horizontal axis HS in accordance with the twisting of the wire.) and angle of, GI _P is the torsional rigidity of the wire. Then, the above equations (1) and (2) are solved using the Newton-Raphson method, and the snow accretion shape for each section is calculated.

Next, in step S6, the aerodynamic characteristics corresponding to the calculated snow accretion shape are obtained. That is, the memory or hard disk of the computer 8 stores aerodynamic characteristics for some types of snow accretion, which have been obtained by experiments in advance, as aerodynamic coefficients, and the snow accretion calculated in step S5 based on these aerodynamic coefficients. Estimate the aerodynamic characteristics corresponding to the shape.

Then, in step S7, the damping constant of the vibration of the overhead power transmission line is fetched from a memory or the like. That is, the attenuation constant has been previously obtained by experiments and is stored in the memory or the hard disk of the computer 8. This damping constant is calculated as follows. First, free vibration is generated in the overhead power transmission line, and the waveform of the amplitude at that time is measured. Then, taking the logarithm of the ratio of the amplitude peaks during one cycle, and letting that value be η, the damping constant f _u
Is given by equation (3) below.

[Equation 3] Here, m is the mass of the electric wire, n is the number of vibration modes, Nc is the number of conductors (the number of elementary conductors forming one-phase electric wire), S is the distance between steel towers, and T is the wire tension. Similarly, the damping constant f _O in the torsional rotation direction is given by the following equation (4).

[Equation 4] However, J _n is the moment of inertia, and GI _Pn is the torsional rigidity of the wire.

Next, in step S8, the frequency and amplitude of the overhead power transmission line are calculated. First, the towers are logically divided into a plurality of sections at equal intervals, and equations of motion in the three directions of vertical, horizontal, and rotation are established for each section of the overhead power transmission line. In this case, in each section of the overhead power transmission line, since the line conditions are not uniform due to the snow shape and the connection of the insulators, etc., the line conditions and aerodynamic characteristics that differ for each section are taken into consideration,
The mode is estimated and the frequencies and amplitudes in the three directions are calculated in consideration of the above attenuation constant.

Next, in step S9, the phase difference between the vertical and horizontal amplitudes is calculated based on the calculation result obtained in step S8, and the tension fluctuation of the overhead power transmission line is calculated based on the phase difference. .

Then, the estimated galloping state is graphically displayed based on the analysis result obtained as described above. That is, the display of the computer 8 displays the galloping mode of the overhead power transmission line as shown in, for example, FIG. 4A, and displays the amplitude of the overhead power transmission line as shown in, for example, FIG. 4B. The trajectory is displayed.

As described above, according to this embodiment, the snow accretion shape is calculated based on the wind speed, the temperature, and the amount of precipitation around the overhead power transmission line, and the aerodynamic characteristics of the overhead power transmission line are estimated by the snow accretion shape. . Then, the frequency, amplitude, and tension fluctuations of the overhead power transmission line in the estimated mode are calculated based on the equations of motion in the three directions of up, down, horizontal, and rotation that take into account the aerodynamic characteristics and the damping constants obtained by experiments in advance. , This result is displayed graphically. As a result, it becomes possible to detect the galloping state occurring in the overhead power transmission line quickly and with high accuracy, and it is possible to deal with the galloping situation promptly and accurately.

In the present embodiment, the sag of the overhead power transmission line (the slack between the towers) and the length and weight of the insulator string installed at both ends of the power transmission line are taken into consideration to further calculate Highly accurate galloping detection can be performed. Further, in this embodiment, since the collection processing of each observation data and the analysis processing based on this can be performed in parallel by the two computers 7 and 8, the analysis processing can be advanced without interrupting the data collection processing. The observation data will not be lost. Further, in the present embodiment, the galloping that occurs in the overhead power transmission line has been described as an example, but the present invention is not limited to this, and other structures such as a fishing bridge as long as large-amplitude and low-frequency string vibration can occur It is also possible to apply to. Further, as in the present embodiment, the sensor group 1 does not detect the wind speed, the temperature, and the precipitation amount, but the galloping analysis is performed based on the predicted value of the meteorological data such as AMeDAS (regional meteorological observation system). By doing so, the state after several hours can be predicted, and it becomes possible to cope with the situation before galloping occurs.

[0020]

As described above, according to the present invention, it is possible to detect galloping that occurs in an overhead power transmission line quickly and with high accuracy, so that it is possible to take prompt and appropriate action when galloping occurs. The effect that it can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an analysis process according to the embodiment.

FIG. 3 is a diagram showing a simulation example of a snow accretion development process according to the embodiment.

4A and 4B are diagrams showing a graphic display example of a galloping state in the embodiment, FIG. 4A showing a mode display example, and FIG. 4B showing an amplitude locus display example.

[Explanation of symbols]

1 ... Sensor group, 2 ... Optical modulator, 3 ... Optical fiber cable, 4 ... Photoelectric converter, 5 ... Amplifier, 6 ... A / D converter,
7, 8 ... Computer.

Claims (1)

[Claims] 1. A device for detecting galloping occurring on an overhead power transmission line between support towers, wherein the detection means detects wind speed, temperature, and precipitation around the overhead power transmission line, and a detection result of the detection means. Based on the first calculation means for calculating the snow accretion shape formed on the surface of the overhead power transmission line, and the aerodynamic characteristics of the overhead power transmission line corresponding to the snow accretion shape are calculated, and the aerodynamic characteristics are taken into consideration. And a display unit for displaying an estimated galloping state based on the calculation result of the second calculation unit. A characteristic galloping detection device.