Power transmission line icing monitoring system

Abstract

The invention relates to a power transmission line icing monitoring system, a monitoring device comprises a low-temperature memory metal sheet and a switch assembly, the low-temperature memory metal sheet is parallel to a power transmission line, a first end of the low-temperature memory metal sheet is installed below the power transmission line through an insulating frame or fixed on a support on the same plane with the power transmission line, and a second end is suspended; the switch elements are sequentially arranged downwards from the power transmission line at a first preset distance; when the power transmission line and the low-temperature memory metal sheet accumulate ice layers synchronously, the second end can be bent and deformed downwards under the gravity action of the ice layers to trigger the switch element; and the signal processing circuit is connected with the switch element and is used for receiving the trigger signal output by the switch element and sending the trigger signal to a monitoring terminal. When the second end is bent downwards to the switch element, the switch element is triggered along with the increase of the ice layer of the icing, and when the switch element is triggered, the signal trigger circuit outputs a trigger signal to the monitoring terminal, so that the icing can be simply and accurately monitored.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment monitoring, and particularly relates to an overhead transmission line icing monitoring system. Background Art

[0002] With the rapid development of China's economy, the demand for electricity is increasing continuously. As an important carrier for power transmission, the safe and stable operation of overhead transmission lines is of crucial importance. Overhead transmission lines often have complex terrains and changeable climates, and icing is likely to occur in autumn and winter. Icing on overhead transmission lines causes an increase in line weight, elongation of conductors, deformation of fittings, and even accidents such as conductor galloping, wire breakage, tower collapse, flashover, and tripping, seriously threatening the safe and stable operation of the power system.

[0003] In related technologies, various sensors are often used to monitor the icing of overhead transmission lines. For example, in some related technologies, a tension sensor is installed between the fitting and the overhead transmission line to detect changes in the weight of the overhead transmission line to detect whether icing occurs. However, this monitoring method requires changing the connection relationship between the overhead transmission line and the iron tower, with a relatively high construction difficulty, and is easily affected by weather conditions such as strong winds. When the wind is strong and the overhead transmission line gallops, false alarms may occur in the tension sensor, affecting the monitoring accuracy. In other related technologies, such as using multi-sensor fusion algorithms or visual monitoring algorithms, not only is the cost high, it is easily interfered with, but also the maintenance is difficult, and it is difficult to operate stably for a long time.

[0004] Therefore, how to simply and reliably monitor the icing of overhead transmission lines has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides an overhead transmission line icing monitoring system to solve the technical problem of how to simply and reliably monitor the icing of overhead transmission lines in the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solutions: An overhead transmission line icing monitoring system includes: a monitoring device, a signal processing circuit, and a monitoring terminal. Among them, the monitoring device includes a low-temperature shape memory metal sheet and a switch assembly. The low-temperature shape memory metal sheet is parallel to the overhead transmission line. The first end of the low-temperature shape memory metal sheet is installed below the overhead transmission line through an insulating bracket or fixed on a bracket in the same plane as the overhead transmission line, and the second end is suspended; the switch assembly is fixedly installed on the overhead transmission line and has at least one switching element, and the switching elements are arranged at intervals of a first preset distance downward from the overhead transmission line in sequence; when the overhead transmission line and the low-temperature shape memory metal sheet accumulate ice layers synchronously, the second end can be bent downward under the action of the gravity of the ice layer to trigger the switching element; the signal processing circuit is connected to the switching element and is used to receive the trigger signal output by the switching element and send it to the monitoring terminal.

[0007] Optionally, there is a second preset distance between the low-temperature memory metal sheet and the power transmission line.

[0008] Optionally, a notch is provided on the low-temperature memory metal sheet between the first end and the second end.

[0009] Optionally, a hydrophobic ice layer is provided on the surface of the low-temperature memory metal sheet.

[0010] Optionally, the switch assembly includes a plurality of switch elements, and the switch element includes a contact switch; a plurality of the contact switches are arranged in a stepped manner below the second end, and different contact switches are triggered when the second end is deformed to different positions.

[0011] Optionally, the signal processing circuit includes: a power supply module, a signal generation module, and a signal transmission module. Among them, in the signal generation module, one end of the contact switch is connected to the power supply through a pull-up resistor, and the other end is grounded. The output end of the signal generation module is connected between the pull-up resistor and one end of the contact switch and is connected to the input end of the signal transmission module.

[0012] Optionally, the switch assembly includes at least one switch element, and the switch element includes a Hall sensor; a magnet is provided at the second end, and the Hall sensor is provided below the second end. Different analog voltage values are output by triggering the Hall sensor when the second end is deformed to different positions.

[0013] Optionally, the signal processing circuit includes: a power supply module, a signal generation module, and a signal transmission module. Among them, in the signal generation module, the output end of the Hall sensor is connected to the input end of an amplifier, the output end of the amplifier is connected to the input end of a voltage comparator, and the output end of the voltage comparator is connected to the input end of the signal transmission module.

[0014] Optionally, the signal transmission module includes a wireless communication module or a wired communication module.

[0015] Optionally, the power supply module includes: a power storage unit, a solar panel, and a charge and discharge manager. The solar panel is connected to the power storage unit through the charge and discharge manager, and the power storage unit is respectively connected to the power supply ends of the signal generation module and the signal transmission module through the charge and discharge manager.

[0016] Due to the adoption of the above technical solutions, the present invention has the following advantages: The monitoring device includes a low-temperature shape memory metal sheet and a switch assembly. The low-temperature shape memory metal sheet is parallel to the transmission line. The first end of the low-temperature shape memory metal sheet is installed below the transmission line through an insulating bracket or fixed on a bracket in the same plane as the transmission line, and the second end is suspended; the switch assembly is fixedly installed on the transmission line and has at least one switch element, and the switch elements are arranged at intervals of a first preset distance downward from the transmission line in sequence; when the transmission line and the low-temperature shape memory metal sheet accumulate ice synchronously, the second end can be bent downward under the action of the gravity of the ice layer to trigger the switch element; the signal processing circuit is connected to the switch element and is used to receive the trigger signal output by the switch element and send it to the monitoring terminal. During the bending deformation of the low-temperature shape memory metal sheet, as the ice layer covering the ice increases, its downward pressure increases. There is at least one switch element arranged below the second end of the low-temperature shape memory metal sheet. When the second end bends downward to the switch element, the switch element is triggered. When the switch element is triggered, the signal trigger circuit outputs a trigger signal to the monitoring terminal, and thus the ice covering can be monitored simply and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings herein are incorporated into and constitute a part of this specification, showing embodiments in accordance with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of an ice covering monitoring system for a transmission line of the present invention; Figure 2 It is a schematic structural diagram of a low-temperature shape memory metal sheet in an embodiment of the present invention; Figure 3 It is a schematic structural diagram of a low-temperature shape memory metal sheet in another embodiment of the present invention; Figure 4 It is a schematic circuit diagram of the signal processing circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the following clearly and completely describes the technical solutions in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0021] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings as understood by those of ordinary skill in the field to which the present invention pertains. The terms "first", "second", "third" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0022] Referring to Figures 1 to 4 As shown, a transmission line icing monitoring system according to the present invention, as Figure 1 shown, includes: a monitoring device 10, a signal processing circuit 20, and a monitoring terminal 30. The monitoring device 10 includes a low-temperature memory metal sheet 11 and a switch assembly 12. The low-temperature memory metal sheet 11 is parallel to the transmission line 40. The first end 111 of the low-temperature memory metal sheet 11 is installed below the transmission line 40 through an insulating bracket 113 or fixed on a bracket in the same plane as the transmission line 40, and the second end 112 is suspended; the switch assembly 12 is fixedly installed on the transmission line 40 and has at least one switch element 121, and the switch elements 121 are arranged at intervals of a first preset distance downward from the transmission line 40 in sequence; when the transmission line 40 and the low-temperature memory metal sheet 11 accumulate ice layers synchronously, the second end 112 can be bent downward under the action of the gravity of the ice layer to trigger the switch element 121; the signal processing circuit 20 is connected to the switch element 121 and is used for receiving the trigger signal output by the switch element 121 and sending it to the monitoring terminal 30.

[0023] In this embodiment, the low-temperature memory metal has a relatively low phase transition temperature. When the temperature is lower than the phase transition temperature, the deformability of the low-temperature memory metal is enhanced. After the temperature is higher than the phase transition temperature, the low-temperature memory metal quickly returns to its initial shape. Therefore, based on this characteristic, an alloy material with a phase transition temperature around or below zero degrees can be selected as the low-temperature memory metal sheet 11. For example, Ni-Ti-Cu alloy can be used, and its phase transition temperature range is -50°C to 0°C. Alternatively, Fe-Ni-Co-Ti alloy with better creep resistance can be used, and its phase transition temperature range is -40°C to 0°C.

[0024] When the temperature reaches the icing temperature and the air temperature is lower than the phase change temperature of the low-temperature shape memory metal sheet 11, the low-temperature shape memory metal sheet 11 exhibits deformation performance. At the same time, the low-temperature shape memory metal sheet 11 is arranged on the transmission line 40 or on a bracket in the same plane as the transmission line 40. As the transmission line 40 reaches the icing state and ice layers gradually accumulate, the low-temperature shape memory metal sheet 11 also accumulates ice layers. Due to the temperature being lower than the phase change temperature, the low-temperature shape memory metal sheet 11 reaches deformability, and the gravity of the ice layer generates a downward pressure on the metal sheet, causing the second end 112 in the suspended state of the low-temperature shape memory metal sheet 11 to bend downward.

[0025] During the bending deformation of the low-temperature shape memory metal sheet 11, as the ice layer of the icing increases, the downward pressure increases. Therefore, in this embodiment, at least one switch element 121 is arranged below the second end 112 of the low-temperature shape memory metal sheet 11. When the second end 112 bends downward to the switch element 121, the switch element 121 is triggered. When the switch element 121 is triggered, the signal trigger circuit outputs a trigger signal to the monitoring terminal 30, and thus the icing can be monitored simply and accurately.

[0026] In one embodiment, the switch assembly 12 may include a plurality of switch elements 121, and the plurality of switch elements 121 may be arranged in a stepped manner on the path passed by the second end 112 during the bending deformation of the low-temperature shape memory metal sheet 11. When deformed to the first degree, the second end 112 contacts the first switch element 121 to trigger the output of the first trigger signal. When deformed to the second degree, the second end 112 departs from the second switch element 121 to trigger the output of the second trigger signal, and so on. A plurality of switch elements 121 can be triggered, and then a multi-level alarm signal is output to realize the monitoring of the multi-level icing degree.

[0027] In one embodiment, in order to prevent the influence of the transmission line 40 on the low-temperature shape memory metal sheet 11 and prevent short circuit caused by direct contact between the low-temperature shape memory metal sheet 11 and the transmission line 40, therefore, there is a second preset distance between the low-temperature shape memory metal sheet 11 and the transmission line 40, and the second preset distance can be 1 - 10 mm. The low-temperature shape memory metal sheet 11 can be installed on the transmission line 40 or on the iron frame between the transmission lines 40. The low-temperature shape memory metal sheet 11 can be fixed on the transmission line 40 through a low-temperature-resistant insulating buckle or an insulating bolt, or fixed on the cross arm of the iron tower of the transmission line 40 in the same plane as the transmission line 40.

[0028] In one embodiment, in order to ensure that the low-temperature shape memory metal sheet 11 can be reliably bent and deformed by the ice layer during icing, in this embodiment, as Figure 2 and Figure 3As shown, a notch 114 can be formed in the region between the first end 111 and the second end 112 of the low-temperature memory metal sheet 11. Stress concentration occurs at the position with the notch 114, and it deforms preferentially during bending. Even when the ice shell uniformly covers it, the strain in the region of the notch 114 can still break through the restraint of the ice shell. Based on simulation experiments, when the ice thickness on the low-temperature memory metal sheet 11 with the notch 114 is 10 mm, the strain at the notch 114 increases by 3 times, and the trigger force threshold decreases by 45%. Therefore, it can reliably generate a bending deformation. Optionally, the notch 114 can be formed at a position close to the first end 111, for example, at the transition position between the first end 111 and the second end 112.

[0029] In one embodiment, as Figure 2 and Figure 3 shown, the notch 114 can be formed along the width direction of the low-temperature memory metal sheet 11, or can also be formed along the thickness direction of the low-temperature memory metal sheet 11. Exemplarily, the depth of the notch 114 can be 10% - 30% of the thickness of the low-temperature memory metal sheet 11. For example, when the thickness of the metal sheet is 0.5 mm, the depth of the notch 114 is 0.05 - 0.15 mm, so as to concentrate the stress at the connection between the first end 111 and the second end 112. When ice accumulates on the second end 112, a bending deformation can be generated more reliably.

[0030] In one embodiment, a hydrophobic ice layer is provided on the surface of the low-temperature memory metal sheet 11. The hydrophobic ice layer can be a PTFE coating applied on the surface of the low-temperature memory metal sheet 11, or the surface of the low-temperature memory metal sheet 11 can be laser engraved with micron-level grooves to reduce the actual contact area between ice and the metal. The grooves can be micron-level wavy grooves with a depth of 50 - 100 μm and a pitch of 0.5 - 1 mm to form an uneven contact surface. Microcracks are generated at the grooves due to stress concentration in the ice layer, reducing the overall rigidity of the ice shell; and when the metal sheet bends, the ice layer at the grooves fractures preferentially, releasing the degree of freedom of deformation. Prevent the rigidity of the ice layer formed by icing on the low-temperature memory metal sheet 11 from affecting the deformation of the low-temperature memory metal sheet 11, ensure that the influence of the ice layer rigidity on the low-temperature memory metal sheet 11 is reduced in the icing state, and enable the low-temperature memory metal sheet 11 to smoothly generate a downward bending deformation.

[0031] In one embodiment, the switch element 121 in the switch assembly 12 can adopt a contact switch, that is, a mechanical switch. Since the deformation path of the end of the second end 112 is circular during the bending deformation of the low-temperature memory metal sheet 11, a plurality of contact switches can be arranged in a stepped manner under the second end 112 according to the deformation path of the end of the second end 112, and different contact switches are triggered when the second end 112 deforms to different positions.

[0032] Exemplarily, a low-temperature memory metal sheet 11 with a thickness of 0.5 - 1 mm, a length of 200 - 300 mm (adjusted according to the diameter of the power transmission line 40), and a width of 20 - 30 mm can be selected. When it is pre-designed to be in a straight or slightly curved initial state and a vertical downward load is applied by the weight of the ice layer, the metal sheet bends downward, and the deformation amount Δ and the ice layer weight F satisfy the formula:

[0033] where L is the effective length of the metal sheet; E is the elastic modulus; I is the moment of inertia of the cross-section (related to the width and thickness).

[0034] When ice accumulates on the surface of the metal sheet, the weight of the ice layer (F = ρ ice × g × V) generates a downward pressure on the low-temperature memory metal sheet 11, causing it to bend and deform. Ice density (ρ ice ): approximately 0.9 g / cm³; therefore, the deformation sensitivity can be adjusted through the elastic coefficient k of the low-temperature memory metal sheet 11, so that each millimeter of ice-covered thickness corresponds to a specific deformation amount Δ (for example, 1 mm of ice coverage corresponds to 0.5 mm of deformation). The specific relationship between the ice layer weight (thickness) and the deformation amount can be calibrated through experiments. The relationship between the ice thickness and the deformation is pre-calibrated in the laboratory (for example: 0.5 mm of deformation = 1 mm of ice thickness, 1.0 mm of deformation = 2 mm of ice thickness), and a look-up table or scaled output is established.

[0035] After obtaining the relationship between the ice-covered thickness and the specific deformation amount Δ, the distance between the contact switches can be set according to the ice thickness classification, for example, 3 mm / level. Exemplarily, when the metal sheet bends to contact the first-level contact switch, the circuit closes and sends a "first-level alarm" (ice coverage of 3 mm); when it continues to bend and triggers the second-level contact switch, a "second-level alarm" (ice coverage of 6 mm) is sent, and so on. Thus, ice layers with different ice-covered thicknesses can be monitored.

[0036] In order to be able to output an alarm signal, in one embodiment, as shown in Figure 4 the signal processing circuit 20 includes: a power supply module, a signal generation module 21, and a signal transmission module 22. Among them, in the signal generation module 21, one end of the contact switch is connected to the power supply through a pull-up resistor, and the other end is grounded. The output end of the signal generation module 21 is connected between the pull-up resistor and one end of the contact switch, and is connected to the input end of the signal transmission module 22. In Figure 4In this case, taking three contact switches as an example, one end of the first contact switch K1 is connected to the power supply through the first pull-up resistor R1, and the other end is grounded; one end of the second contact switch K2 is connected to the power supply through the second pull-up resistor R2, and the other end is grounded; one end of the third contact switch K3 is connected to the power supply through the third pull-up resistor R3, and the other end is grounded. Among them, a corresponding trigger signal output terminal is provided between one end of each contact switch and the pull-up resistor, and the trigger signal output terminal is connected to the input terminal of the signal sending module 22. When the contact switch is disconnected, the trigger signal output terminal outputs a high level. When the contact switch is closed, the trigger signal output terminal is grounded and outputs a low level, so that a corresponding alarm signal can be output.

[0037] Among them, the signal sending module 22 can be a wireless communication module or a wired communication module. Exemplarily, taking the wireless communication module as an example, a low-power LoRa module can be used. It is in a sleep state when the trigger signal output terminal outputs a high level, and wakes up and sends data under the trigger of the low level when the trigger signal output terminal outputs a low level. Of course, the wireless communication module can also use an NB-IoT module to transmit the alarm signal using the operator network.

[0038] The switch element 121 in the switch assembly 12 can also use a Hall sensor to trigger the alarm signal in a non-contact manner. Exemplarily, a magnet is provided at the second end 112, and the Hall sensor is arranged below the second end 112. Different analog voltage values are triggered when the second end 112 deforms to different positions. One Hall sensor can be provided, or multiple Hall sensors can be provided. The multiple Hall sensors can also be arranged in a stepped manner according to the deformation route of the second end 112. When the Hall sensor is used as the switch element 121, the signal processing circuit includes: a power supply module, a signal generation module, and a signal sending module, among which, In the signal generation module, the output terminal of the Hall sensor is connected to the input terminal of the amplifier, the output terminal of the amplifier is connected to the input terminal of the voltage comparator, and the output terminal of the voltage comparator is connected to the input terminal of the signal sending module. When the second end deforms to the vicinity of a certain Hall sensor, the Hall sensor outputs an analog voltage (positively correlated with the magnetic field strength). The signal output by the Hall sensor is amplified by the amplifier, and then converted into a digital signal by the comparator. When one Hall sensor is provided, the comparator can use a window comparator, and different icing level monitoring can be realized by setting two or more threshold voltages in the window comparator. That is, the different distances between the Hall sensor and the magnet result in different output analog voltage values. By comparing with multiple threshold voltages of the window comparator, multiple digital signals are output to characterize different degrees of deformation, thereby realizing multi-level icing level monitoring.

[0039] In one embodiment, the power supply module includes: a power storage unit, a solar panel, and a charge and discharge manager. The solar panel is connected to the power storage unit through the charge and discharge manager, and the power storage unit is respectively connected to the power supply terminals of the signal generation module and the signal transmission module through the charge and discharge manager. In this embodiment, a 3.7V lithium battery, a 5W solar panel, and a charge and discharge management chip can be used to achieve power supply. At the same time, a low dropout regulator can be used to output 3.3V or 5V voltage to continuously supply power to the signal processing circuit.

[0040] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transmission line icing monitoring system, characterized in that: include: Monitoring device, signal processing circuit and monitoring terminal, wherein: The monitoring device comprises a low-temperature memory metal sheet and a switch assembly, wherein the low-temperature memory metal sheet is parallel to the transmission line, the first end of the low-temperature memory metal sheet is installed below the transmission line through an insulating frame or fixed on a bracket in the same plane as the transmission line, and the second end is suspended; the switch assembly is fixedly installed on the transmission line, and has at least one switch element, and the switch elements are arranged in sequence at a first preset distance downward from the transmission line; when the transmission line and the low-temperature memory metal sheet accumulate ice layers synchronously, the second end can be bent and deformed downward under the gravity of the ice layer to trigger the switch element; The signal processing circuit is connected to the switch element, and is used for receiving the trigger signal output by the switch element, and sending the trigger signal to the monitoring terminal.

2. The transmission line icing monitoring system according to claim 1, characterized in that: There is a second preset distance between the low-temperature memory metal sheet and the power transmission line.

3. The transmission line icing monitoring system according to claim 1, characterized in that: A notch is provided on the low-temperature memory metal sheet between the first end and the second end.

4. The transmission line icing monitoring system according to claim 1, characterized in that: An ice-repellent layer is arranged on the surface of the low-temperature memory metal sheet.

5. The transmission line icing monitoring system according to claim 1, characterized in that: The switch assembly includes a plurality of switch elements, and the switch elements include contact switches; The plurality of contact switches are arranged below the second end in a stepped manner, and different contact switches are triggered when the second end is deformed to different positions.

6. The transmission line icing monitoring system according to claim 5, characterized in that: The signal processing circuit includes: a power supply module, a signal generating module and a signal sending module, wherein: In the signal generating module, one end of the contact switch is connected to the power supply through a pull-up resistor, and the other end is grounded. The output end of the signal generating module is linked between the pull-up resistor and one end of the contact switch, and is connected to the input end of the signal sending module.

7. The transmission line icing monitoring system according to claim 1, characterized in that: The switch assembly includes at least one switch element, and the switch element includes a Hall sensor; The second end is provided with a magnet, and the Hall sensor is provided below the second end. When the second end is deformed to different positions, the Hall sensor is triggered to output different analog voltage values.

8. The transmission line icing monitoring system according to claim 7, characterized in that: The signal processing circuit includes: a power supply module, a signal generating module and a signal sending module, wherein: In the signal generating module, the output end of the Hall sensor is connected to the input end of the amplifier, the output end of the amplifier is connected to the input end of the voltage comparator, and the output end of the voltage comparator is connected to the input end of the signal sending module.

9. The transmission line icing monitoring system according to claim 6 or 8, characterized in that: The signal sending module includes a wireless communication module or a wired communication module.

10. The transmission line icing monitoring system according to claim 6 or 8, characterized in that: The power module comprises: A power storage unit, a solar panel and a charge and discharge manager, wherein the solar panel is connected to the power storage unit through the charge and discharge manager, and the power storage unit is respectively connected to the power supply ends of the signal generating module and the signal sending module through the charge and discharge manager.

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