An overhead transmission line icing monitoring system

Abstract

The present invention relates to an ice coating monitoring system for transmission lines. 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 switching elements are arranged at intervals of a first preset distance from the transmission line downward in sequence; when the 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 for receiving the trigger signal output by the switching element and sending it to the monitoring terminal. As the ice layer of the ice coating increases, its downward pressure increases. When the second end bends downward to the position of the switching element, the switching element is triggered. When the switching element is triggered, the signal trigger circuit outputs a trigger signal to the monitoring terminal, thereby enabling simple and accurate monitoring of the ice coating.

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 are often located in complex terrains and subject to changing climates, and are prone to icing in autumn and winter. Icing on overhead transmission lines can lead to increased line weight, wire elongation, fitting deformation, 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 determine whether icing has occurred. However, this monitoring method requires changing the connection relationship between the overhead transmission line and the iron tower, resulting in greater construction difficulty and being 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 maintenance is difficult, making it difficult to operate stably for a long time.

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

[0005] Aiming at 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:

[0007] A 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 memory metal sheet and a switch assembly. 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 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 memory metal sheet accumulate ice synchronously, the second end can be bent 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 to receive the trigger signal output by the switch element and send it to the monitoring terminal.

[0008] Optionally, there is a second preset distance between the low-temperature memory metal sheet and the transmission line.

[0009] Optionally, a notch is provided on the low-temperature memory metal sheet between the first end and the second end.

[0010] Optionally, a hydrophobic ice layer is provided on the surface of the low-temperature memory metal sheet.

[0011] 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 deforms to different positions.

[0012] 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.

[0013] 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, and different analog voltage values are output by triggering the Hall sensor when the second end deforms to different positions.

[0014] 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 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 transmission module.

[0015] Optionally, the signal sending module includes a wireless communication module or a wired communication module.

[0016] Optionally, the power 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 sending module through the charge and discharge manager.

[0017] Due to the above technical solutions adopted by the present invention, it has the following advantages:

[0018] 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 for receiving the trigger signal output by the switch element and sending 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 position of 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. Description of the Drawings

[0019] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention and used together with the specification to explain the principles of the present invention.

[0020] 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, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of an ice covering monitoring system for a transmission line of the present invention;

[0022] Figure 2 It is a schematic structural diagram of a low-temperature shape memory metal sheet in an embodiment of the present invention;

[0023] Figure 3 Schematic structural diagram of the low-temperature shape memory metal sheet in another embodiment of the present invention;

[0024] Figure 4 Schematic circuit diagram of the signal processing circuit of the present invention. Detailed implementation manners

[0025] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part rather than 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 shall fall within the protection scope of the present invention.

[0026] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the art 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 "comprising" or "including" and similar words mean that the elements or items appearing before the term cover the elements or items listed after the term and their equivalents, without excluding other elements or items. The terms "connected" or "coupled" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0027] 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 shape memory metal sheet 11 and a switch assembly 12. The low-temperature shape memory metal sheet 11 is parallel to the transmission line 40. The first end 111 of the low-temperature shape 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. 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 shape 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 configured to receive the trigger signal output by the switch element 121 and send it to the monitoring terminal 30.

[0028] In this embodiment, the low-temperature shape 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 shape memory metal is enhanced. After the temperature is higher than the phase transition temperature, the low-temperature shape memory metal quickly returns to its initial shape. Therefore, based on this property, an alloy material with a phase transition temperature around or below zero degrees can be selected as the low-temperature shape memory metal sheet 11. For example, an Ni-Ti-Cu alloy can be used, and its phase transition temperature range is -50°C to 0°C. An Fe-Ni-Co-Ti alloy with better creep resistance can also be used, and its phase transition temperature range is -40°C to 0°C.

[0029] When the temperature reaches the icing temperature and the air temperature is lower than the phase transition 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. Since the temperature is lower than the phase transition temperature, the low-temperature shape memory metal sheet 11 reaches the deformability state, 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.

[0030] During the bending deformation process 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 position of 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.

[0031] 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 process 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 triggers 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.

[0032] In one embodiment, to prevent the influence of the power transmission line 40 on the low-temperature shape memory metal sheet 11 and to prevent a short circuit caused by direct contact between the low-temperature shape memory metal sheet 11 and the power transmission line 40, there is a second preset distance between the low-temperature shape memory metal sheet 11 and the power 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 power transmission line 40 or on the iron frame between the power transmission lines 40. The low-temperature shape memory metal sheet 11 can be fixed to the power transmission line 40 by a low-temperature resistant insulating buckle or an insulating bolt, or fixed to the cross arm of the iron tower of the power transmission line 40 that is in the same plane as the power transmission line 40.

[0033] In one embodiment, to ensure that the low-temperature shape memory metal sheet 11 can be reliably bent and deformed by the ice layer when icing occurs, in this embodiment, as Figure 2 and Figure 3 shown, a notch 114 can be opened in the region between the first end 111 and the second end 112 of the low-temperature shape memory metal sheet 11. Stress concentration occurs at the position with the notch 114, and it deforms preferentially when bending. Even if the ice shell covers evenly, the strain in the notch 114 area can still break through the restraint of the ice shell. Based on simulation experiments, when the low-temperature shape memory metal sheet 11 with the notch 114 is iced by 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 opened 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.

[0034] In one embodiment, as Figure 2 and Figure 3 shown, the notch 114 can be opened along the width direction of the low-temperature shape memory metal sheet 11 or along the thickness direction of the low-temperature shape memory metal sheet 11. Exemplarily, the opening depth of the notch 114 can be 10%-30% of the thickness of the low-temperature shape memory metal sheet 11. For example, when the thickness of the metal sheet is 0.5 mm, the opening 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, and when the second end 112 is iced, it can generate a bending deformation more reliably.

[0035] In one embodiment, a hydrophobic ice layer is provided on the surface of the low-temperature shape memory metal sheet 11. The hydrophobic ice layer can be a PTFE coating applied on the surface of the low-temperature shape memory metal sheet 11, or the surface of the low-temperature shape memory metal sheet 11 can be laser engraved with micron-scale grooves to reduce the actual contact area between ice and the metal. The grooves can be micron-scale 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. When the metal sheet bends, the ice layer at the grooves fractures preferentially, releasing the degree of freedom of deformation. This prevents the rigidity of the ice layer formed by icing on the low-temperature shape memory metal sheet 11 from affecting the deformation of the low-temperature shape memory metal sheet 11, ensuring that the low-temperature shape memory metal sheet 11 can smoothly generate a downward bending deformation under the condition of icing, reducing the influence of the rigidity of the ice layer.

[0036] In one embodiment, the switching element 121 in the switching 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 shape memory metal sheet 11, a plurality of contact switches can be arranged in a stepped manner below 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.

[0037] Exemplarily, a low-temperature shape 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 transmission line 40), and a width of 20-30 mm can be selected. It is pre-designed to be in a straight or slightly curved initial state. When a vertical downward load is applied due to 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:

[0038]

[0039] 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).

[0040] 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 shape memory metal sheet 11, causing it to bend and deform. Ice density (ρ ice ): about 0.9 g / cm³; therefore, the deformation sensitivity can be adjusted through the elastic coefficient k of the low-temperature shape memory metal sheet 11 so that each millimeter of ice thickness corresponds to a specific deformation amount Δ (for example, 1 mm of ice 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 ice thickness and deformation is pre-calibrated in the laboratory (for example: deformation of 0.5 mm = 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.

[0041] After obtaining the relationship between the ice thickness and the specific deformation amount Δ, the distance between the contact switches can be set according to the ice thickness grading, 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 thickness 3 mm); when it continues to bend and triggers the second-level contact switch, it sends a "second-level alarm" (ice thickness 6 mm), and so on. Thus, it is possible to monitor ice layers with different ice thicknesses.

[0042] In order to be able to output an alarm signal, in one embodiment, refer to Figure 4 As shown, 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 4 it, 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 end is provided between one end of each contact switch and the pull-up resistor, and the trigger signal output end is connected to the input end of the signal transmission module 22. When the contact switch is off, the trigger signal output disconnects and outputs a high level. When the contact switch is off, the trigger signal output end is grounded and outputs a low level, so as to be able to output a corresponding alarm signal.

[0043] Among them, the signal transmission 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 end outputs a high level, and wakes up and sends data under the trigger of the low level when the trigger signal output end 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.

[0044] The switching element 121 in the switching assembly 12 may also employ a Hall sensor to trigger an alarm signal in a non-contact manner. Exemplarily, a magnet is provided at the second end 112, and the Hall sensor is disposed below the second end 112. When the second end 112 deforms to different positions, the Hall sensor is triggered to output different analog voltage values. One Hall sensor may be provided, or multiple Hall sensors may be provided. The multiple Hall sensors may 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 switching element 121, the signal processing circuit includes: a power supply module, a signal generation module, and a signal transmission module, where,

[0045] 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. When the second end deforms to a position near 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, a window comparator may be used for the comparator, and different icing level monitoring can be achieved by setting two or more threshold voltages in the window comparator. That is, the analog voltage values output are different when the distances between the Hall sensor and the magnet are different. By comparing with the multiple threshold voltages of the window comparator, multiple digital signals are output to represent different degrees of deformation, thereby realizing multi-level icing level monitoring.

[0046] 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 ends 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 may be used to achieve power supply. At the same time, a low dropout regulator may be used in cooperation to output 3.3V or 5V voltage to continuously supply power to the signal processing circuit.

[0047] 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 perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An overhead transmission line icing monitoring system, characterized in that, Including: A monitoring device, a signal processing circuit, and a monitoring terminal, where 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 power transmission line. The first end of the low-temperature shape memory metal sheet is installed below the power transmission line through an insulating bracket or fixed on a bracket in the same plane as the power transmission line, and the second end is suspended; the switch assembly is fixedly installed on the power 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 power transmission line in sequence; when the power 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 switch element; 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 below the second end in a stepped manner, and different contact switches are triggered when the second end deforms to different positions; 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.

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

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

4. The overhead line icing monitoring system according to claim 1, wherein, A hydrophobic ice layer is provided on the surface of the low-temperature shape memory metal sheet.

5. The overhead line icing monitoring system according to claim 1, characterized in that The signal processing circuit includes: a power supply module, a signal generation module, and a signal transmission module, where in the signal generation module, one end of the contact switch is connected to the power supply through a pull-up resistor, 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.

6. The overhead line icing monitoring system according to claim 1, wherein 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, the Hall sensor is provided below the second end, and different analog voltage values are output by triggering the Hall sensor when the second end deforms to different positions.

7. The overhead transmission line icing monitoring system according to claim 6, characterized in that, The signal processing circuit includes: a power supply module, a signal generation module, and a signal transmission module, where 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.

8. The overhead line icing monitoring system according to claim 5 or 7, characterized in that, The signal transmission module includes a wireless communication module or a wired communication module.

9. The overhead line icing monitoring system according to claim 5 or 7, characterized in that 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.

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