Cable icing detection system and detection method and preparation method of ultrasonic phased array transducer

Abstract

The invention discloses a cable icing detection system and method and a preparation method of an ultrasonic phased array transducer. The detection system comprises a power supply module, a signal acquisition module, a signal processing module and a wireless transmission module. Wherein the signal acquisition module adopts a flexible detection device and is arranged at a detection point position of a cable, and the detection device is provided with an ultrasonic phased array transducer formed by an array formed by a plurality of independent flexible transducers; a power supply module and a wireless transmission module are arranged on the detection system; signals are sent to the signal processing module through the wireless transmission module, and the signal processing module analyzes the collected signals to obtain cable icing condition data. On the basis of an ultrasonic detection method, the ultrasonic transducers are arranged and fixed on the outer surface of a real cable in an array mode, the icing state of the cable can be directly detected while the shape is maintained, the method is not affected by weather, and real-time accurate measurement can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of icing detection technology, specifically relating to a method for detecting cable icing based on ultrasonic phased array. Background Technology

[0002] Ice accumulation on power lines can easily cause conductor galloping, line breakage, and tower collapse, leading to power outages. Rain, snow, and ice storms have become a significant factor affecting the safe operation of the power grid. Therefore, it is urgent to further strengthen ice accumulation monitoring to guide the orderly implementation of line de-icing, load switching, and anti-icing work, ensuring power supply safety. Currently, high-voltage cables are assessed for ice accumulation using methods such as weather forecasting, visual observation, and drone inspections. Ice thickness detection typically employs image processing analysis, capacitance measurement, and water collection coefficient calculation.

[0003] Currently, high-voltage cables are assessed for icing using methods such as weather forecasting, visual observation, and drone inspections. Ice thickness detection typically employs image processing analysis, capacitance measurement, and water collection coefficient calculation. This method relies excessively on worker experience to determine whether icing poses a threat to power transmission safety. Furthermore, it lacks the capability for remote, online quantitative measurement of ice thickness and identification of icing types. Mechanical monitoring methods calculate ice thickness by measuring the load caused by icing, but installation is cumbersome, and the conductor icing model is inaccurate. Microwave methods analyze the feedback from different substances like ice, water, and air using microwave signals to establish a conductor icing thickness calculation model based on microwave signal intensity and sensor icing distribution, enabling icing thickness monitoring via microwave probes. However, due to varying surface morphologies, this method cannot accurately represent the actual icing condition of conductors and is susceptible to errors caused by water / ice identification. Image monitoring methods can obtain icing information through human vision or image processing technology, directly reflecting the true ice shape of the line. However, video monitoring terminal lenses installed on towers are easily covered by ice, and clear images are difficult to capture in foggy or high-humidity conditions.

[0004] Currently, a method for detecting ice thickness on 10kV overhead transmission lines based on ultrasonic detection technology, in which the distance from the ultrasonic sensor to the line changes due to icing, and the difference in distance before and after icing is detected by ultrasonic waves, is not yet in practical use. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, the present invention aims to provide a method for detecting cable icing based on ultrasonic phased array. Based on ultrasonic detection, ultrasonic transducers are arranged and fixed in an array on the outer surface of the actual cable. While maintaining the cable's shape, the icing status can be directly detected, and the method is unaffected by weather conditions, enabling real-time and accurate measurement.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention relates to an ultrasonic phased array cable icing detection system, wherein the detection system comprises a power supply module, a signal acquisition module, a signal processing module, and a wireless transmission module; wherein, The detection system employs flexible detection devices, which are positioned at the detection points on the cable. The flexible transducer is equipped with an ultrasonic phased array transducer consisting of an array of multiple independent flexible transducers. The detection system is equipped with a power supply module and a wireless transmission module; The signal is transmitted to the signal processing module via the wireless transmission module. The signal processing module analyzes the collected signal to obtain data on the cable icing situation.

[0007] Furthermore, the detection system is disposed on the outer surface of the cable, which covers the circumferential surface of the cable at the detection point. At the detection point, the outer surface of the cable is provided with an insulation layer, and a transducer mounting base is provided on the insulation layer. Multiple flexible transducers are embedded in the mounting base, and the flexible transducers are slightly higher than the surface of the mounting base.

[0008] Furthermore, the detection system includes an ultrasonic measurement board, which includes a pulse generation and receiving unit.

[0009] Furthermore, at the same detection point, 32 or 64 flexible transducers are selected and installed according to the cable diameter and the size of the flexible transducer. By controlling the time when each flexible transducer in each group emits sound waves, a time delay effect is achieved.

[0010] Secondly, based on the aforementioned ultrasonic phased array cable icing detection system, this application also provides a detection method, which includes the following: The beam propagation direction is deflected by the excitation time difference, i.e., the phase difference, of different array elements in the ultrasonic phased array transducer. By setting different excitation time differences for array elements, the beam can be focused at a specified depth or distance, thereby enhancing the signal strength at the focal point and improving the lateral resolution. The area of ​​the cross-section at a set position on the cable surface is obtained based on the depth data of the focal point; The area of ​​each cross section is accumulated to obtain the ice shape at the detection point on the cable surface.

[0011] Furthermore, the focal point is adjusted by controlling the phase, amplitude, and frequency of the array elements. Based on the position of the target focal point, the required phase delay for each array element is calculated. The center of a set of array elements is excited last, the two outer elements are excited first, and then the middle array elements are excited symmetrically in sequence.

[0012] Thirdly, this application also provides a method for fabricating an ultrasonic phased array transducer, wherein the ultrasonic phased array transducer is applied to the above-mentioned ultrasonic phased array cable icing detection system, and the fabrication method includes the following: Step 1: Apply conductive adhesive to the adhesive film at equal intervals to attach the signal lines. Step 1: Adhere the flexible piezoelectric sheet with electrode layers on both sides to the surface of the adhesive film; Step 3: The piezoelectric sheet is divided into transducers by laser cutting. Each transducer is connected to a signal line to obtain a thin film that completely covers the ultrasonic phased array transducer. Step four: The thin film covering the ultrasonic phased array transducer is adhered to the detection point for use in measuring the icing condition on the object surface.

[0013] Furthermore, if the thin film covering the ultrasonic phased array transducer is attached to a non-metallic surface, a layer of conductive adhesive is first applied to the non-metallic mounting substrate before a ground wire is led out.

[0014] The beneficial effects of this invention are: It can promptly detect ice formation on cable and tower surfaces in the early stages of icing, outputting early warning signals to improve safety. It can measure cable surface thickness in real time and accurately, outputting ice thickness signals; when the ice thickness reaches a certain level, de-icing is performed, reducing energy consumption and improving transmission efficiency. An array-based scanning output of multi-point ice thickness signals at the transducer's location allows for de-icing when the ice thickness reaches a certain level, reducing energy consumption and improving efficiency. Simultaneously, it can approximate the area covered by ice at that cross-section, thereby estimating the ice mass per unit length of the conductor. It can also identify ice patterns and output ice pattern information, selecting the optimal mechanical de-icing method to improve de-icing efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the icing detection system of the present invention. Figure 2 This is a schematic diagram of the installation method for an ultrasonic icing detection probe; Figure 3 Design drawing for an ultrasonic phased array transducer; Figure 4 This is a schematic diagram of the flexible transducer installation scheme provided in the embodiment; Figure 5 This is a schematic diagram of the flexible transducer installation scheme provided in the embodiment. Detailed Implementation

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0017] Example 1:

[0018] The present invention relates to an ultrasonic phased array cable icing detection system, wherein the detection system comprises a power supply module, a signal acquisition module, a signal processing module, and a wireless transmission module; wherein, The detection system employs flexible detection devices, which are positioned at the detection points on the cable. The flexible transducer is equipped with an ultrasonic phased array transducer consisting of an array of multiple independent flexible transducers. The detection system is equipped with a power supply module and a wireless transmission module; The signal is transmitted to the signal processing module via the wireless transmission module. The signal processing module analyzes the collected signal to obtain data on the cable icing situation.

[0019] Furthermore, the detection system is disposed on the outer surface of the cable, which covers the circumferential surface of the cable at the detection point. At the detection point, the outer surface of the cable is provided with an insulation layer, and a transducer mounting base is provided on the insulation layer. Multiple flexible transducers are embedded in the mounting base, and the flexible transducers are slightly higher than the surface of the mounting base.

[0020] Furthermore, the detection system includes an ultrasonic measurement board, which includes a pulse generation and receiving unit.

[0021] Furthermore, at the same detection point, 32 or 64 flexible transducers are selected and installed according to the cable diameter and the size of the flexible transducer. By controlling the time when each flexible transducer in each group emits sound waves, a time delay effect is achieved.

[0022] This application utilizes ultrasonic phased array technology to detect icing on power transmission cables, enabling early warning of surface icing, thickness monitoring, and ice type identification. The overall working principle is as follows: Figure 1 As shown, a power supply module, signal acquisition module, signal processing module, and wireless module are required. The ultrasonic equipment is installed at monitoring points along the route. A single ultrasonic measurement board connects to multiple icing detection sensors. The board is powered by a button battery and equipped with a small solar panel for charging. A wireless transmission module is also included to transmit the data acquisition signals from the monitoring points to a ground server. Because the surface morphology is basically consistent, it can replace the actual icing state of a real conductor.

[0023] The specific installation scheme for the transducer provided in this application is as follows: Figure 2As shown. Statistics show that the outer diameter of conductors of different voltage levels ranges from 15.07mm to 40mm. An insulation layer is first added to the outside of the conductor, and then a substrate with multiple flexible transducers embedded in it is placed over the insulation layer, slightly higher than the cable surface. To reduce the impact of the height difference on cable icing, a curved transition zone is designed at the edge to connect the two surfaces. Because the transducers are flexible, they have a certain curvature, making them fit the cable surface better. Depending on the cable diameter and the size of the flexible transducers, 32 or 64 transducers can be installed in the same cross-section. By controlling the different emission times of each crystal in each group, a time delay effect is achieved. Based on different emission and reception rules and time gain compensation, various phased array effects such as beam focusing, deflection, deflection focusing, dynamic apodization, and dynamic aperture can be achieved. Currently, it is recommended to use multi-element scanning deflection and phased array focusing excitation effects. The scanning beam deflection function allows for real-time adjustment of the excitation delay time of different array elements, from low to high, enabling the ultrasonic beam to propagate in different directions without moving the probe. This achieves "electronic scanning" measurement of the detection area, cyclically measuring the ice thickness at various locations along the cable cross-section to obtain the ice cross-sectional area. Focusing adjustment allows the beam to be focused at different depths or positions, increasing the acoustic energy density in specific areas and enhancing the detection sensitivity for minute defects. Adjusting the focus point of each array element allows for multi-beam synthesis, simultaneously generating multiple beams with different directions or focus points, achieving rapid, full-coverage detection of cable ice.

[0024] Example 2:

[0025] Secondly, based on the aforementioned ultrasonic phased array cable icing detection system, this application also provides a detection method, which includes the following: The beam propagation direction is deflected by the excitation time difference, i.e., the phase difference, of different array elements in the ultrasonic phased array transducer. By setting different excitation time differences for array elements, the beam can be focused at a specified depth or distance, thereby enhancing the signal strength at the focal point and improving the lateral resolution. The area of ​​the cross-section at a set position on the cable surface is obtained based on the depth data of the focal point; The area of ​​each cross section is accumulated to obtain the ice shape at the detection point on the cable surface.

[0026] Furthermore, the focal point is adjusted by controlling the phase, amplitude, and frequency of the array elements. Based on the position of the target focal point, the required phase delay for each array element is calculated. The center of a set of array elements is excited last, the two outer elements are excited first, and then the middle array elements are excited symmetrically in sequence.

[0027] Based on different transmission and reception rules and time gain compensation, the phase control effects of beam focusing, deflection, deflection focusing, dynamic apodization, and dynamic aperture are achieved. The excitation effect utilizes multi-element scanning deflection and phased array focusing. Scanning beam deflection, by adjusting the excitation delay time of different elements from low to high, allows the ultrasonic beam to propagate in different directions without moving the probe, achieving "electronic scanning" measurement of the detection area. The ice thickness at various locations along the cable cross-section is measured cyclically to obtain the ice cross-sectional area. Focusing adjustment allows the beam to be focused to different depths or positions, increasing the acoustic energy density in specific areas and enhancing the detection sensitivity for minute defects. Adjusting the focus point of each element group allows for multi-beam synthesis, simultaneously generating multiple beams with different directions or focus points, enabling rapid, full-coverage detection of cable ice.

[0028] The principle of beam steering in this embodiment is as follows: by controlling the excitation time difference (phase difference) of different array elements in the array, the propagation direction of the beam is deflected. For example, for a linear array, if the left array element is excited before the right array element, the beam will deflect to the right, and vice versa. Mathematical basis: Let the element spacing be d, and the phase difference between adjacent array elements be Δϕ, then the beam deflection angle θ satisfies Δϕ = 2πdsinθ / λ (where λ is the wavelength). By adjusting Δϕ, θ can be continuously varied within a certain range (typically ±30° to ±60°).

[0029] Phased array focusing principle: By setting the excitation delay of different array elements, the beam is focused at a specified depth (or distance), enhancing the signal strength at that point and improving lateral resolution. For example, when focusing at depth z, the excitation delay of the central array element is minimal, while the delay of the elements on both sides increases with distance, ensuring that the acoustic waves of all array elements are synchronously superimposed at z. Dynamic focusing: During detection, the focusing depth can be adjusted in real time, allowing targets at different depths to be clearly imaged.

[0030] In this embodiment, this can be achieved by controlling the phase, amplitude, and frequency of the array elements. Currently, we mainly adjust the focal point by controlling the phase of the array elements. Based on the position of the target focal point, we calculate the required phase delay for each array element. The center of a group of array elements is excited last, the two outer elements are excited first, and then the middle array elements are excited symmetrically in sequence.

[0031] Based on ultrasonic detection, ultrasonic transducers are arranged in an array and fixed on the outer surface of the actual cable. While preserving cable shape, this method directly detects the cable's icing status, unaffected by weather conditions. It provides real-time, accurate measurements, including icing / free-of-ice detection, ice shape detection, and ice thickness monitoring. This allows for timely assessment of cable and tower surface icing in the early stages, providing early warning signals and improving safety. It can measure cable surface thickness in real-time and accurately, outputting multi-point ice thickness signals at the transducer's location via array scanning. When the ice thickness reaches a certain level, de-icing is performed, reducing energy consumption and improving efficiency. Simultaneously, it can approximate the area covered by ice at that cross-section, thus estimating the ice mass per unit length of the conductor. It can also identify ice patterns and output ice pattern information, selecting the optimal mechanical de-icing method to improve de-icing efficiency.

[0032] Example 3:

[0033] Thirdly, this application also provides a method for fabricating an ultrasonic phased array transducer, wherein the ultrasonic phased array transducer is applied to the above-mentioned ultrasonic phased array cable icing detection system, and the fabrication method includes the following: Step 1: Apply conductive adhesive to the adhesive film at equal intervals to attach the signal lines. Step 1: Adhere the flexible piezoelectric sheet with electrode layers on both sides to the surface of the adhesive film; Step 3: The piezoelectric sheet is divided into transducers by laser cutting. Each transducer is connected to a signal line to obtain a thin film that completely covers the ultrasonic phased array transducer. Step four involves attaching the thin film covering the ultrasonic phased array transducer to the detection point for use in measuring the icing condition of the object's surface. In this embodiment, the icing condition is mainly measured by ice physical properties, such as thickness, ice density, and ice surface roughness.

[0034] Furthermore, if the thin film covering the ultrasonic phased array transducer is attached to a non-metallic surface, a layer of conductive adhesive is first applied to the non-metallic mounting substrate before a ground wire is led out.

[0035] After completing the above steps, a thin film covering the entire flexible array transducer is obtained. This film can be adhered to any model for use, such as the interior of an airfoil, ducts, or wind turbine blades in testing scenarios. If the substrate is a conductive material such as metal, only a ground wire needs to be led out. If the substrate is non-metallic, a layer of conductive adhesive needs to be applied to the non-metallic mounting base before leading out the ground wire. See the schematic diagram below. Figure 4 .

[0036] This patent is used in environments where the wires have uneven surfaces, so a clamp-type installation is adopted, as shown in Figure 5. The boundary can adopt a snap-on design to facilitate wire installation.

[0037] This invention has many specific applications. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. An ultrasonic phased array cable icing detection system, characterized in that, The detection system includes a power supply module, a signal acquisition module, a signal processing module, and a wireless transmission module; wherein, The detection system uses flexible detection devices and is set at the detection point of the cable. The flexible transducer is equipped with an ultrasonic phased array transducer composed of multiple independent flexible transducers. The detection system is equipped with a power supply module and a wireless transmission module; The signal is transmitted to the signal processing module via the wireless transmission module. The signal processing module analyzes the collected signal to obtain data on the cable icing situation.

2. The ultrasonic phased array cable icing detection system according to claim 1, characterized in that, The detection system is installed on the outer surface of the cable, covering the circumferential surface of the cable at the detection point. At the detection point, the outer surface of the cable is provided with an insulation layer, and a transducer mounting base is provided on the insulation layer. Multiple flexible transducers are embedded in the mounting base, and the flexible transducers are slightly higher than the surface of the mounting base.

3. The ultrasonic phased array cable icing detection system according to claim 2, characterized in that, The detection system includes an ultrasonic measurement board, which contains a pulse generation and receiving unit.

4. The ultrasonic phased array cable icing detection system according to claim 1, characterized in that, At the same detection point, 32 or 64 flexible transducers are selected and installed according to the cable diameter and the size of the flexible transducer. By controlling the time when each flexible transducer in each group emits sound waves, a time delay effect is achieved.

5. The detection method based on the ultrasonic phased array cable icing detection system according to claim 1, characterized in that, The detection method includes the following: The beam propagation direction is deflected by the excitation time difference, i.e., the phase difference, of different array elements in the ultrasonic phased array transducer. By setting different excitation time differences for array elements, the beam can be focused at a specified depth or distance, thereby enhancing the signal strength at the focal point and improving the lateral resolution. The area of ​​the cross-section at a set position on the cable surface is obtained based on the depth data of the focal point; The area of ​​each cross section is accumulated to obtain the ice shape at the detection point on the cable surface.

6. The detection method according to claim 5, characterized in that, The focal point is adjusted by controlling the phase, amplitude, and frequency of the array elements. The phase delay required for each array element is calculated based on the position of the target focal point. The center of a set of array elements is excited last, the two outer elements are excited first, and then the middle array elements are excited symmetrically in sequence.

7. A method for fabricating an ultrasonic phased array transducer, characterized in that, The ultrasonic phased array transducer is applied to the ultrasonic phased array cable icing detection system as described in any one of claims 1 to 4, and the preparation method comprises the following: Step 1: Apply conductive adhesive to the adhesive film at equal intervals to attach the signal lines. Step 1: Adhere the flexible piezoelectric sheet with electrode layers on both sides to the surface of the adhesive film; Step 3: The piezoelectric sheet is divided into transducers by laser cutting. Each transducer is connected to a signal line to obtain a thin film that completely covers the ultrasonic phased array transducer. Step four: The thin film covering the ultrasonic phased array transducer is adhered to the detection point for use in measuring the icing condition on the object surface.

8. The method for fabricating an ultrasonic phased array transducer according to claim 7, characterized in that, If the thin film covering the ultrasonic phased array transducer is attached to a non-metallic surface, a layer of conductive adhesive is first applied to the non-metallic mounting substrate before a ground wire is led out.

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