RU2314616C1 - Method for detecting a precursor of conductor galloping in intermediate run of aerial electric power line and device for realization of the method - Google Patents

Abstract

FIELD: power engineering, possible use for remote detection in real time scale of a precursor of conductor galloping during monitoring of aerial electric power lines to perform timely melting of ice coating and snow precipitations on wires, preventing breakdowns of aerial electric power line due to mechanical overloads of its elements during conductor galloping; device may be used also to gather information during preparation of zoning maps of ice and wind loads and conductor galloping.

SUBSTANCE: device for detecting a precursor of conductor galloping of intermediate run of aerial electric power line, containing two force measuring sensors, to lower ends of which, interconnected jointly, conductor is connected, and upper ends of sensors through corresponding insulator strings are fastened to beam of support at a distance from each other equal to length of insulator string with sensor, thus forming an equilateral triangle with V-like suspension of conductor, longitudinal acceleration sensor, mounted in place of attachment of conductor to force measuring sensors, three television transmission channels, three functional transformers, three threshold generators, three threshold elements, three-input logical element AND.

EFFECT: development of device for automatic detection of conductor galloping precursor in intermediate run of an aerial electric power line.

2 cl, 6 dwg

Description

The invention relates to the electric power industry and can be used for real-time remote detection of a precursor of a wire dance (phase wire or lightning cable) of an intermediate span when monitoring overhead power lines to conduct timely melting of ice-frost and snow deposits on wires, preventing accident of overhead power lines from -for mechanical overload of its elements when dancing wires. The device can also be used to collect information when compiling regionalization maps for ice, wind loads and wire dancing.

The level of technology.

A known visual method for detecting and evaluating the parameters of dancing wires or ground wires of overhead power lines. The main disadvantage of the visual method is that it requires the direct presence of an observer in a controlled section of an overhead power line, in addition, it has low accuracy in measuring dance parameters and is practically impossible in conditions of poor visibility.

Known methods and corresponding devices for detecting the dancing of wires of overhead power lines and measuring its parameters, based on measuring the parameters of the electromagnetic field of the wire using antennas (electromagnetic sensors) located near the controlled span at an electrically safe distance from the wires, and having a higher compared to the visual method accuracy. When dancing the wires, the amplitudes and phases of the industrial frequency signals induced in the sensors change. With appropriate processing by the frequency and amplitude of the induced signals, the presence of mechanical dance and its parameters are judged [1-6].

There is a method of detecting dancing wires, based on the detection of changes in the intensity of the laser beam passing from the transmitter to the receiver, due to its overlapping dancing wire [7]. According to the parameters of the frequency of changes in the intensity of the laser beam, it is proposed to measure the dance parameters.

There is also a method for determining the dance of wires and its parameters according to signals from electromechanical accelerometers with a sensitivity axis perpendicular to the axis of the wire, installed respectively on a quarter of the length of the wire to the right and left of the suspension points of the intermediate span wire. By changing the amplitude and phase of the signals from the outputs of the accelerometers, the wavelength of the dance is calculated [8].

The main disadvantage of all the above methods and devices is that they are used to detect and register an already established mode of wire dancing, characterized by the moment when the dance phenomenon has reached its development and is accompanied by maximum force effects on the elements of the overhead power line, therefore, in the practical application of these methods and devices for organizing and conducting timely melting of deposits in order to prevent the destruction of structural elements inii principle will always be enough time to build the circuit and melting of the most heat. In addition, the known devices are not actually functionally complete detectors of wire dancing, as they do not contain threshold elements and threshold shapers.

A device is known that implements an aerodynamic method for detecting deposits on a wire of an intermediate span of an overhead power transmission line [9], from which a V-shaped wire suspension can be used as an integral element in the technical implementation of the inventive method for detecting a harbinger of dancing wire (ground wire) of an intermediate span of an overhead power line . This V-shaped suspension contains two force measuring sensors, each of which is suspended movably between the support beam (cable-resistant) and the corresponding insulator string, the lower ends of both insulator strings are pivotally connected to each other, the upper ends of the sensors are attached to the support beam at a distance from each other equal to the length of the string of insulators with a sensor, forming an equilateral triangle with a V-shaped suspension.

The authors do not know the methods and corresponding devices for detecting a harbinger of wire dancing.

SUMMARY OF THE INVENTION

The objectives of the invention is to develop a method for automatically detecting a harbinger of dancing wire intermediate span overhead power lines, allowing you to use it remotely in real time, and developing a device for its implementation.

The goals are achieved by the fact that in accordance with the claimed method, in the place of attachment of the intermediate span wire to a string of insulators, the values of ice and wind loads on the wire and the longitudinal acceleration of the wire are simultaneously measured, these values are compared with the corresponding threshold values, and if they exceed them or are equal him, then they decide on the presence of a harbinger of dancing wire intermediate span overhead power lines, and if the measured values are less than the corresponding their threshold values, then decide on the absence of a harbinger of dancing wire.

A device for implementing the inventive method for detecting a harbinger of a dancing wire of an intermediate span of an overhead power transmission line contains two load-sensing sensors, a wire is attached to the lower ends of which are interconnected, and the upper ends of the sensors are fixed to the support beam at a distance from each other through the corresponding insulator strings from each other, equal to the length of the string of insulators with a sensor, thus forming an equilateral triangle with a V-shaped wire suspension, the sensor native acceleration installed in the place of attachment of the wire to the load sensors, three television transmission channels, three functional converters, three threshold shapers, three threshold elements, a three-input logic element AND, in accordance with this, the first and second force sensors, as well as the longitudinal acceleration sensor, are respectively connected to the inputs of the first, second and third television channels, the outputs of the first and second television channels are connected in parallel to the corresponding inputs of the first and second functional converters, the first input of the third functional converter is connected to the output of the first functional converter, the output of the third functional converter is connected to the first input of the first threshold element, the first threshold driver is connected to the second input of the first threshold element, the output of the first threshold element is connected to the first input of the AND gate, the second input of the third functional converter is connected to the output of the second functional converter and the first input of the second threshold element, the output of the second threshold element is connected to the second input of the AND logic element, the output of the second threshold driver is connected to the second input of the second threshold element, the output of the third TV channel is connected to the first input of the third threshold element, the output of the third driver is connected to the second input of it threshold, the output of the third threshold element is connected to the third input of the logical element AND, the output of the logical element And is the output of the device.

The inventive device, implementing a method for detecting a precursor of a dance of wire of an intermediate span of an overhead power line, provides continuous automatic real-time detection of a precursor of a dance of wire or a lightning cable (the first moment of excitation of dynamic vibrations of a dance that occurs when a combination of conditions conducive to the appearance of a dance occurs) of an intermediate span of an overhead line power transmission with any operating voltage on any type of support.

Disclosure of the invention.

The subject of the invention is a method for detecting a harbinger of a dancing wire of an intermediate span of an overhead power line and a device for its implementation.

A method for detecting a harbinger of a dancing wire of an intermediate span of an overhead power transmission line, which consists in the fact that at the point of attachment of the wire to a string of insulators, the values of ice and wind loads on the wire and the longitudinal acceleration of the wire are simultaneously measured, these values are compared with the corresponding threshold values, and if they exceed them or equal to them, then decide on the presence of a harbinger of dancing wire intermediate span overhead power lines, and if the measured values If they are less than the corresponding threshold values, then they decide on the absence of a harbinger of wire dancing.

The device for detecting a harbinger of a dancing wire of an intermediate span of an overhead power transmission line implementing the inventive method comprises two load-sensing sensors, the wire is attached to the lower ends of which are interconnected, and the upper ends of the sensors are fixed to the support beam at a distance from each other through the corresponding string of insulators equal to the length of the string of insulators with a sensor, thus forming an equilateral triangle with a V-shaped wire suspension, the device also contains a longitudinal acceleration sensor installed in the place of attachment of the wire to the load sensors, three television transmission channels, three functional converters, three threshold shapers, three threshold elements, a three-input logic element And, in accordance with this, the first and second load sensors are respectively connected to the inputs of the first and second TV channels, the longitudinal acceleration sensor is connected to the input of the third TV channel, the outputs of the first and second television channels are connected in parallel to the corresponding inputs of the first and second functional converters, the first input of the third functional converter is connected to the output of the first functional converter, the output of the third functional converter is connected to the first input of the first threshold element, the first threshold former is connected to its second input, the output of the first threshold element is connected to the first input of the logical element And, the output of the second functional converter is connected to the second input of the third functional the converter and the first input of the second threshold element, the output of which is connected to the second input of the AND logic element, the output of the second threshold driver is connected to the second input of the second threshold element, the output of the third television transmission channel is connected to the first input of the third threshold element, the output of the third driver is connected to the second input of it threshold, the output of the third threshold element is connected to the third input of the logical element AND, the output of the logical element And is the output of the device.

The specified set of features makes it possible to achieve the objectives of the invention - in accordance with the claimed method for detecting a precursor of dancing an intermediate wire span of an overhead power transmission line, a device for its implementation automatically, simultaneously and continuously, in real time, in the place where the intermediate span wire is attached to a string of insulators, measures the values of ice and wind loads on the wire and the longitudinal acceleration of the wire, these values are compared with the corresponding threshold beginnings, and if they exceed them or are equal to them, then he makes a decision on the presence of a harbinger of a wire dance of an intermediate span of an overhead power line, and if the measured values turn out to be less than the corresponding threshold values, he makes a decision on the absence of a harbinger of a wire dance.

From the theory and practical observations of the conditions of the emergence and existence of dancing, it follows that in addition to the presence of crest-like deposits of a certain mass on the wire, the influence of wind of a certain speed and a certain direction, the emergence, development and steady state of dancing of wires or lightning cables is the appearance of a longitudinal jerk (acceleration) of the wire along axis due to the lifting of the center of mass of the wire under the influence of lifting force [10-12]. The lifting force occurs when the wind flow reaches the optimum size and angle of attack on the wing of the ridge-shaped deposits located in the center of mass of the wire (in the middle of the span). Subsequently, this primary oscillation creates in the wire the appearance of such a distribution of the angles of attack of the wind relative to the crest-like deposits, in which the oscillations begin to amplify and become steady due to the absorption of wind energy.

It should be noted that the inventive method for detecting a harbinger of dancing an intermediate wire span of an overhead power line, which consists in simultaneous and continuous measurement at the point of attachment of the intermediate span wire to a string of insulators of the value of ice and wind loads on the wire and the longitudinal acceleration of the wire, comparing these values with the corresponding threshold values, making a decision on the presence of a harbinger of dancing wire intermediate span overhead power lines, e if they exceed them or equal them, and making a decision about the absence of a precursor wire dancing, if the measured values are less than the respective threshold values, the applicants are not known.

The applicants are also not aware of the devices that detect the harbinger of dancing wire intermediate span overhead power lines.

Description of the device for implementing the method.

The description of the device for detecting the harbinger of the dance of the wire of the intermediate span of the overhead power transmission line is illustrated by five drawings, presented in figure 1 - figure 5. Figure 1 shows a functional diagram of the device; figure 2 is a vector diagram of the work of load sensors in a V-shaped suspension of the wire with ice-wind load on the wire of the intermediate span; figure 3 - figure 5 shows, respectively, the circuit of the first, second, and third functional converters that implement calculations by the magnitude of the loads N ₁ and N ₂ for each of the two load cells, ice-wind N _sum (figure 3), total ice with the weight of the wire and mounting hardware V (figure 4), the wind load P _in (figure 5).

In FIG. 1 shows the layout of the longitudinal acceleration sensor 3 of the wire at the point of attachment of the phase wire 21 to the load cells 1 and 2 attached to the garlands of insulators 19 and 20 on the lower crosshead 17 of the overhead power line support 18, and a functional diagram of the actual device for detecting a harbinger of wire dancing. The device contains two load sensors 1 and 2, a longitudinal acceleration sensor for wire 3, three television transmission channels 4, 5 and 6, three functional converters 7, 8 and 11, three threshold formers 9, 10 and 12, three threshold elements 13, 14 and 15 , three-input logic element AND 16.

Figure 3 presents a diagram of a first functional converter 7 having two inputs N ₁ and N ₂ and including four multipliers 22, a shaper 23 of constant value 2cosγ, two adders 24 and an element of square root extraction 25.

Figure 4 shows a diagram of a second functional converter 8, having two inputs N ₁ and N ₂ and consisting of an adder 23, a shaper 26 of constant value sinγ and a multiplier 22.

Figure 5 shows a diagram of a third functional Converter 11 and a vector diagram of its operation. This converter has two inputs N _sum and V and consists of two multipliers 22, an adder 24 and a square root 25 extraction element. On the vector diagram of FIG. 5, as on other sheets of the application description and FIG. 2, V ₀ is indicated - the weight of the wire intermediate span and fasteners, V 'is the weight of deposits on this wire, V is the total weight of the intermediate span wire with deposits on it and fasteners, R _B is the wind load and N _sum is the total ice-wind load on the wire with the weight of the intermediate wire span and mounting hardware.

The device operates as follows.

Power loading is carried on the intermediate passage and, consequently, V-shaped suspension generally consists of three components: V _0, V 'and F _B. These three components act independently of each other and V ₀ cannot be equal to zero. Therefore, there are basically six possible power loads on the V-shaped wire suspension, two of which differ only in the opposite direction of the wind. Thus, there are four main options for the power load on the V-shaped suspension of the wire.

The first option - there is no deposits on the wire V '= 0, there is no wind Р _B = 0 and, therefore, sensors 1 and 2 perceive the weight of the fastening fittings together with the weight of the wire 21 of the intermediate span V ₀ , the output signals of sensors 1 and 2 are equal to each other N ₁ = N ₂ , V = V ₀ , N _sum = V ₀ . In the second option - deposits on the wire are V '> 0, there is no wind Р _В = 0, the weight of deposits V' is added to V ₀ , the signals from sensors 1 and 2 are equal to each other and larger in magnitude than in the first version of the load N ' ₁ = N ' ₂ > N ₁ = N ₂ , V = V ₀ + V', N _sum = V ₀ + V '. In the third version - there is no deposit on the wire V '= 0, there is wind, for example, from left to right Р _В > 0, wind load Р _{В is} added perpendicularly to V ₀ , the output signals of sensors 1 and 2 are not equal N ₁ > N ₂ , V = V ₀ ,

.

.

Consider the fourth option, presented in figure 2 and figure 5, in which two of the three necessary conditions for the appearance of a harbinger of wire dancing (ground wire) are combined - the presence of comb-like deposits and wind, and the load (weight) of the deposits and the effect of the wind are such that the condition for the occurrence of dancing and, accordingly, the measured values of these loads of sediments and wind exceed the threshold values generated by the corresponding threshold devices.

In the embodiment illustrated in Figure 2, there is deposition on the wire V '> 0 is the wind, for example, left, _P> 0, V ₀ is added to the weight of deposits on the wire V' and perpendicular glaze wind load F _B signals sensors 1 and 2 are not equal to each other N ₁ > N ₂ , V = V ₀ + V ',

.

.

If the wind blows from right to left, the vector diagram will be a mirror image of figure 2 and on it only the vectors N ₁ and N ₂ will change places.

The signals of the sensors are N ₁ > N ₂ (and vice versa, if the wind blows from right to left, then N ₁ <N ₂ ) in the form of voltages or currents, respectively, through separate first 4 and second 5 TV transmission channels are fed in parallel to the corresponding inputs of functional converters 7 and 8. The first functional Converter 7 (figure 3) on the input signals N ₁ and N ₂ calculates the value of the ice-wind load N _sum by the expression

.

.

In it, the angle γ = 180 ° -α, and the angle α is the angle between the axes of the sensors 1 and 2 at the place of their connection and the wires attached to them. The second functional Converter 8 (figure 4) on the input signals N ₁ and N ₂ calculates the value of V by the expression V = (N ₁ + N ₂ ) × sinγ. The signal of ice-wind load N _sum from the output of the first functional converter 7 (Fig. 1) is supplied to the first input of the third functional converter 11. The signal V = V '+ V ₀ from the output of the second functional converter 8 is fed to the second input of the third functional converter 11 and at the first input of the second threshold element 13, the second input of which receives a signal V ₀ (threshold value of the load deposits) from the output of the second shaper threshold 9. The third functional Converter 11 (Fig.5) calculates the value of the wind new wire load by expression

,

,

which, from the output of the third functional converter 11 (FIG. 1), enters the first input of the first threshold element 15. The second input of the first threshold element 15 receives a signal P _{B (0)} (threshold value of the wind load) from the output of the first shaper of threshold 12. Threshold elements 15 and 13 will generate signals at their outputs - logical units P 'and V', since the values of P _B and V exceeded the set thresholds P _{B (0)} and V ₀ . Under the influence of wind, the wire will deviate in the direction of the wind and, having reached the maximum deviation under the influence of gravity, will begin to return to its original state in the direction of the wind and increase the angle of attack of the crest-like deposits due to the stiffness of the wire. In this case, the speed of the return movement is summed with the wind speed and when the middle of the wire with deposits reaches the optimum angle of attack, there will be a sharp increase in the lifting force of this section of the wire with deposits, and accordingly, the center of the wire will bend up, and its ends will get additional acceleration due to the pulling of the wire to the center w, which will be measured by the longitudinal acceleration sensor 3. The increased signal from the longitudinal longitudinal acceleration sensor 3 through the third channel of the telecast 6 is fed to the first input its threshold element 14, the second input of which receives the signal w ₀ (threshold value of the longitudinal acceleration of the wire) from the output of the third threshold device 10. Since the signal of longitudinal acceleration w from the sensor 3 has increased, it will exceed the value of the threshold value w ₀ and the threshold element 14 will form a signal at its output - a logical unit w '.

The signals of the logical units P ', V' and w 'from the outputs of the threshold elements are simultaneously fed to the corresponding inputs of the logical element And 16, and it forms the logical unit of the signal "There is a harbinger of dancing" at the output. If at least one of the conditions for the occurrence of a harbinger of a wire dance (ground wire) is missing, then at least one logical unit will be absent and the signal "There is a harbinger of a dance" will be absent at the output of logic element 16. In particular, this signal will be absent in the absence of deposits and wind, as in the first version of the power load on the V-shaped suspension, in the absence of wind and the presence of deposits - in the second version and the absence of deposits in the presence of wind - in the third version.

If the inventive device is used to detect the harbinger of dancing of a lightning protection cable of an intermediate span of an overhead power transmission line, then in the device itself it is only necessary to change the threshold values of V ₀ , P _{B (0)} and w ₀ and fix the lightning cable to a V-shaped suspension with force measuring sensors similar to that considered for the phase wire, as shown in figure 1 at the top left.

Since all other climatic influences (temperature, pressure, humidity, etc.) and changes in the operating modes of the overhead power transmission line have almost the same effect on force sensors and longitudinal acceleration sensors, and a common TV transmission device is used, the listed effects practically do not affect the accuracy measurements and device for all types of overhead power transmission line supports remotely automatically continuously in real time on an intermediate span of production t precursor dancing detection wires (ground wires) intermediate span the overhead power line.

Information sources

1. Auth. testimonial. USSR No. 556528, IPC Н02G 7/14, 1974.

2. Auth. testimonial. USSR No. 1647728, IPC Н02G 7/14, 1989.

3. Auth. testimonial. USSR No. 1721685, IPC Н02G 7/14, 1990.

4. Auth. testimonial. USSR No. 1742923, IPC Н02G 7/14, 1990.

5. Patent for the invention of the Russian Federation No. 2016450, IPC Н02G 7/14, 1994.

6. Patent for the invention of the Russian Federation No. 2016451, IPC Н02G 7/14, 1994.

7. Patent for the invention of the Russian Federation No. 2023336, IPC Н02G 7/14, 1991.

8. Patent for the invention of the Russian Federation No. 2017297, IPC Н02G 7/14, 1991.

9. Patent for the invention of the Russian Federation No. 2273933, IPC Н02G 7/16, 2004.

10. Kuznetsov P.A. The influence of the form of deposits on the wire of an overhead power line on its state in the wind flow / P.A. Kuznetsov, V.Ya. Bashkevich // Problems of electric power industry: Interuniversity. scientific Sat / Saratov. state tech. un-t - Saratov: SSTU, 2006 .-- S. 50-55.

11. Kuznetsov P.A. Analysis of the dynamic effects of dancing wires and lightning cables on the structural elements of intermediate spans of overhead power transmission lines 110, 500 kV / P.A. Kuznetsov, S.V. Averyanov, G.G. Ugarov, V.Ya. Bashkevich // Electronic Journal "New in the Russian Electric Power Industry". - 2006. - No. 2. - S. 29-36.

12. Yakovlev L.V. Vibration on overhead power lines and methods for protecting wires and lightning protection cables / L.V. Yakovlev // Library of Electrical Engineering, supplement to the journal "Energy". - 2000. - No. 8.- P.76.

Claims (3)

1. A method for detecting a harbinger of a dancing wire of an intermediate span of an overhead power transmission line, which consists in the fact that in the intermediate span in the place of attachment of the wire to a string of insulators, the values of ice and wind loads on the wire and the longitudinal acceleration of the wire are simultaneously measured, these values are compared with the corresponding threshold values , and if they exceed them or are equal to them, then they decide on the presence of a harbinger of wire dancing, and if the measured values are less than the corresponding x threshold values, then decide on the absence of a harbinger of dancing wire. 2. A device for detecting a harbinger of a dancing wire of an intermediate span of an overhead power transmission line, containing two load-sensing sensors, the wire is attached to the lower ends of which are interconnected, and the upper ends of the sensors are fixed to the support beam at a distance from each other, equal to each other, equal to the length of the string of insulators with a sensor, thus forming an equilateral triangle with a V-shaped wire suspension, the longitudinal acceleration sensor installed in place is mounted wires to the load sensors, three television transmission channels, three functional converters, three threshold shapers, three threshold elements, a three-input logic element "I", while the first and second force sensors and the longitudinal acceleration sensor are respectively connected to the inputs of the first, second and third channels TV shows, the outputs of the first and second channels of TV shows are connected in parallel to the corresponding inputs of the first and second functional converters, to the output of the first functional the first input of the third functional converter is connected, the output of the third functional converter is connected to the first input of the first threshold element, to the second input of which the first threshold driver is connected, the output of the first threshold element is connected to the first input of the AND gate, the second functional converter is connected to the output the input of the third functional converter and the first input of the second threshold element, the output of which is connected to the second input of the “And” element, the output of the second threshold driver is connected to the second input of the second threshold element, the output of the third TV channel is connected to the first input of the third threshold element, the output of the third threshold driver is connected to the second input, the output of the third threshold element is connected to the third input of the logic element And, the output of the AND gate is the output of the device. 3. The device according to claim 2, characterized in that the upper ends of the sensors through the corresponding garlands of insulators are mounted on the support beam at a distance from each other, not equal to the length of the string of insulators with the sensor, thus forming an isosceles triangle with a V-shaped wire suspension.

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