Simultaneous Measurement Method of Four-Degree-of-Freedom Vibration of Continuous Ice-Covered Splitting Conductor

Abstract

This invention discloses a method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor, belonging to the field of transmission line conductor measurement technology. Addressing the problems of high cost and incomplete testing in continuous ice-covered split conductor model galloping experiments, this invention provides a method that can simultaneously measure the axial, in-plane, out-of-plane, and torsional vibration of a continuous ice-covered split conductor model galloping, thus meeting the research needs of continuous ice-covered split conductors under various conditions.

Description

Technical Field

[0001] This invention belongs to the field of transmission line conductor measurement technology, specifically relating to a method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor. Background Technology

[0002] During the construction of power transmission lines, projects inevitably cross areas with complex terrain and weather conditions. In winter and early spring, transmission lines are highly susceptible to icing, which can lead to conductor galloping. Galloping refers to a low-frequency (approximately 0.08-3Hz), high-amplitude (5-300 times the conductor diameter) vibration induced by ice covering the transmission line, causing its cross-sectional shape to change from circular to non-circular. This vibration can be induced by wind speeds and includes axial, in-plane, out-of-plane, and torsional movements. The duration of icing galloping on transmission lines can typically last for several hours, easily causing damage to towers, conductor breakage, insulator breakage / damage, wear and tear on hardware and components, and phase-to-phase flashover, leading to line tripping, power outages, and even complete shutdowns. my country is one of the countries most prone to galloping, with over 1320 recorded galloping incidents (accidents) to date, involving voltage levels from 35 to 1000 kV. Compared to single conductors, split conductors, due to the influence of spacers, have significantly higher torsional stiffness in their sub-conductors compared to single conductors of the same cross-section. This leads to increased eccentric icing on split conductors, resulting in stronger aerodynamic loads and making them more susceptible to galloping. Therefore, it is crucial to continue in-depth research on galloping of iced split conductors, encompassing axial, in-plane, out-of-plane, and torsional motions.

[0003] Experimental research is an effective means of studying the galloping of transmission lines. Some scholars have conducted galloping experiments on full-scale transmission lines using iced conductor cross-sections made of different materials, but this presents challenges due to the difficulty in determining and controlling wind field conditions. Furthermore, many scholars have conducted extensive work on wind tunnel experiments to measure the aerodynamic coefficients of segmental models of iced conductors and their influencing factors; however, segmental model experiments cannot analyze the overall galloping behavior and nonlinear characteristics of continuous iced conductors. To address these issues, some scholars have used scaled-down models of continuous iced conductors to conduct galloping experiments in wind tunnels, playing a crucial role in exploring galloping laws and studying nonlinear characteristics. The methods and means for measuring galloping data in these experiments mainly focus on video recording and sensor methods.

[0004] During the galloping process, the camera method requires continuous shooting with a high-resolution, high-frame-rate high-speed camera, and a high-performance workstation with large memory for data storage and processing, resulting in high costs. Furthermore, while this method can measure vibrations in the in-plane and out-of-plane directions, it cannot measure axial and torsional vibrations, and it can only obtain the galloping pattern of a portion of the conductor within the visible range, not the entire span of the conductor. Currently, the sensor method mainly focuses on in-plane vibration measurement, and there is no corresponding detection method for the torsional vibration of conductor galloping. Similarly, this method cannot currently guarantee the completeness of the measurement results. Therefore, there is an urgent need for a method that can simultaneously measure the axial, in-plane, out-of-plane, and torsional vibrations of a continuous ice-covered split conductor model. Summary of the Invention

[0005] To address the issues of high testing costs and incomplete testing of galloping experiments on continuous ice-covered split conductor models, this invention provides a method for simultaneously measuring the axial, in-plane, out-of-plane, and torsional vibrations of galloping continuous ice-covered split conductor models, thereby meeting the research needs of galloping continuous ice-covered split conductor models under various conditions.

[0006] To achieve the above objectives, the present invention employs the following technical solutions:

[0007] A method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor includes the following steps:

[0008] Step 1: Determine the test system. Based on the dimensions of the continuous ice-covered split conductor model, determine the sensor models used for vibration measurement, including force sensors, laser displacement sensors, wireless attitude sensors, spacers, signal acquisition and analysis systems, and signal processing software.

[0009] Step 2, Install the test system: Install the force sensor at one end of the continuous ice-covered splitting conductor, fix the wireless attitude sensor at the center of the spacer bar, and then install it on the splitting conductor through the spacer bar. Install the laser displacement sensor in the in-plane direction of the continuous ice-covered splitting conductor, and then connect each sensor to the same signal acquisition and analysis system.

[0010] Step 3, Data Acquisition: When the continuous ice-covered split conductor gallops, the force sensor, laser displacement sensor, and wireless attitude sensor simultaneously acquire data. The force sensor directly measures the axial dynamic tension signal; the wireless attitude sensor directly measures the in-plane acceleration signal, out-of-plane acceleration signal, and torsional angular displacement signal of the split conductor; the laser displacement sensor directly measures the in-plane displacement signal in a non-contact measurement manner.

[0011] Step 4, Data Correction: Based on the signals collected by each sensor, select the measurement point signal with the largest amplitude. First, convert the in-plane acceleration signal obtained by the wireless attitude sensor into an in-plane displacement signal through filtering and frequency domain integration. Then, calculate the signal correction parameters for the same measurement point signal. Finally, correct the converted out-of-plane displacement signal using the correction parameters.

[0012] Step 5, Data Processing:

[0013] 1) Axial dynamic tension: The time history curve is obtained directly from the signal obtained by the force sensor test, and then the axial galloping spectrum curve is obtained through spectrum analysis;

[0014] 2) In-plane vibration: The time history curve is directly obtained from the signal measured by the laser displacement sensor, and then the in-plane galloping spectrum curve is obtained through spectrum analysis; at the same time, the in-plane galloping mode shape is plotted based on the displacement signal of the conductor at different positions at the same time, and the in-plane galloping trajectory is plotted based on the displacement signal of the conductor at different positions at different times.

[0015] 3) Out-of-plane vibration: The acceleration signal obtained by the wireless attitude sensor is converted into a displacement signal by filtering and frequency domain integration. After being corrected by the signal correction parameter, the out-of-plane galloping time history curve is obtained. Then, the out-of-plane galloping spectrum curve is obtained by spectrum analysis. The out-of-plane galloping mode shape is drawn according to the displacement signal of the conductor at different positions at the same time. The out-of-plane galloping trajectory is drawn according to the displacement signal of the conductor at different positions at different times.

[0016] 4) Torsional vibration: The torsional angular displacement time history curve is obtained directly from the torsional angular displacement signal of the wireless attitude sensor, and further obtained through spectrum analysis to obtain the torsional galloping spectrum curve; at the same time, the two-way coupled galloping trajectory is obtained based on the in-plane and out-of-plane galloping displacements.

[0017] Furthermore, the signal correction parameter is calculated as: maximum in-plane displacement obtained from the laser displacement sensor / maximum in-plane displacement obtained from the wireless attitude sensor.

[0018] Furthermore, the four-degree-of-freedom vibration quantities include axial dynamic tension, displacement-time history curves, frequency spectrum curves, mode shapes, and trajectories of in-plane, out-of-plane, and torsional galloping.

[0019] Furthermore, the continuous icing split conductor is applicable to split conductors with two, four, six, eight, ten, and twelve split numbers.

[0020] Furthermore, the continuous ice-covered split conductor model is a laboratory-scaled model.

[0021] Furthermore, the wireless attitude sensor is to be placed and fixed at the center of the spacer bar.

[0022] Furthermore, the number and location of the laser displacement sensor and wireless attitude sensor used determine the modal order that the system can measure.

[0023] A measuring device for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor as described above, the measuring device comprising a force sensor, several laser displacement sensors, several wireless attitude sensors, several spacers, a signal acquisition and analysis system, and signal processing software.

[0024] The force sensor is installed at one end of the continuum split wire model;

[0025] The wireless attitude sensor is fixedly installed at the center of the spacer bar;

[0026] The laser displacement sensor is installed directly below the continuum split wire model, corresponding to the positions of each wireless attitude sensor.

[0027] The force sensor, wireless attitude sensor, and laser displacement sensor are sequentially connected to the same data acquisition and analysis system.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] This invention solves the problems of high cost and incomplete testing in existing continuous ice-covered split conductor model galloping experiments. By combining various common sensors (force sensors, wireless attitude sensors, laser displacement sensors) with the structure of the split conductor itself, it can simultaneously measure and accurately correct the axial, in-plane, out-of-plane, and torsional vibrations of continuous ice-covered split conductors. It is low-cost and provides comprehensive testing, which can provide technical support for related research on the galloping of split conductor transmission lines. Attached Figure Description

[0030] Figure 1 A diagram of the testing system for measuring the galloping of an ice-covered four-split conductor using this method;

[0031] Figure 2 This is a flowchart of the testing process using this determination method;

[0032] Figure 3 This is a graph showing the axial dynamic tension of the conductor.

[0033] Figure 4 Comparison of in-plane first-order vibration displacement after integration by laser displacement sensor and wireless attitude sensor;

[0034] Figure 5 Comparison of in-plane first-order vibration displacement after integral correction by laser displacement sensor and wireless attitude sensor;

[0035] Figure 6The time history curve, frequency spectrum curve, and mode shape curve of the first-order galloping within the conductor plane;

[0036] Figure 7 The time history curve, frequency spectrum curve, and mode shape curve of the first-order out-of-plane galloping of the conductor;

[0037] Figure 8 The time history curve, frequency spectrum curve, and trajectory diagram of the first-order torsional galloping of the conductor;

[0038] Figure 9 A diagram of the testing system for measuring the galloping of ice-covered bifurcated conductors using this method;

[0039] Figure 10 A diagram of the testing system for measuring the galloping of an ice-covered six-split conductor using this method;

[0040] Figure 11 A diagram of the testing system for testing the galloping of ice-covered eight-split conductors using this measurement method;

[0041] Figure 12 A diagram of the testing system for measuring the galloping of ice-covered, cracked conductors using this measurement method;

[0042] Figure 13 This diagram shows the test system for testing the galloping of an ice-covered twelve-split conductor using this measurement method. Detailed Implementation

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0044] Force sensor: TecsisF28073210067, Beijing Haibohua Technology Co., Ltd.;

[0045] Laser displacement sensor: Panasonic HL-G112-A-C5, Panasonic Electric Works (China) Co., Ltd.;

[0046] Wireless attitude sensor: ALUBILPMS-B2, Guangzhou Arubi Electronic Technology Co., Ltd.;

[0047] Signal acquisition and analysis system: Donghua DH5922, Jiangsu Donghua Test Technology Co., Ltd.;

[0048] Signal processing software: Matlab 2016.

[0049] Example 1

[0050] like Figures 1-2 The present invention provides a method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor model, taking the measurement and correction of the first-order mode of a scaled-down continuous ice-covered four-split conductor model as an example, comprising the following steps:

[0051] (1) Based on the continuous four-split conductor model, select the force sensor, laser displacement sensor, wireless attitude sensor, spacer, signal acquisition and analysis system, and signal processing software used in the experiment.

[0052] (2) Install the force sensor at one end of the continuous four-split conductor model, install and fix five wireless attitude sensors at the center of the four-split spacer, and place them at 1 / 4, 1 / 3, 1 / 2, 2 / 3 and 3 / 4 distances from one end of the conductor, respectively. Install the laser displacement sensor at the corresponding positions below the conductor, and then connect each sensor to the same data acquisition and analysis system in sequence.

[0053] (3) When the continuous ice-covered split conductor model dances under the action of wind excitation, the signals of each sensor are collected and saved at the same time.

[0054] (4) Figure 3 As shown, the axial dynamic tension time history curve of the conductor can be directly obtained from the signal of the force sensor.

[0055] (5) Further, such as Figure 4 As shown, displacement signals from five laser displacement sensors were extracted, and the time history curve at the measuring point with the largest amplitude was analyzed to obtain the spectral curve, whose vibration frequency was 3.516 Hz. The galloping mode of the entire conductor can be obtained by taking the displacement signals of each measuring point at the same time. The galloping trajectory of the entire conductor within one cycle can be obtained by taking the displacement signals of each measuring point at the same time within one cycle (t = 29.59s, t = 29.64s, t = 29.66s, t = 29.69s, t = 29.71s, t = 29.74s).

[0056] (6) Extract the in-plane displacement signal from the laser displacement sensor and the in-plane acceleration signal from the wireless attitude sensor at the midpoint of the conductor. First, filter and perform frequency domain integration transformation on the in-plane acceleration signal from the wireless attitude sensor to obtain the displacement signal. Compare the two displacement signals as follows: Figure 5 As shown, the maximum displacement signal from the wireless attitude sensor after conversion is 4.22 mm, while the maximum displacement signal directly measured by the laser displacement sensor is 4.93 mm. Further, the signal correction parameter ε = 4.93 / 4.22 ≈ 1.17 is calculated. The displacement signal from the wireless attitude sensor is corrected using this parameter, and the result is as follows. Figure 6 As shown, all data are multiplied by 1.17, and the corrected signal matches the signal obtained directly from the test very well.

[0057] (7) Further, the out-of-plane acceleration signals of each wireless attitude sensor are extracted, and the signals are sequentially converted and corrected using the correction parameter ε. For example... Figure 7As shown, the frequency spectrum curve is obtained by performing spectral analysis on the time history curve at the measuring point with the maximum amplitude. The vibration frequency is 3.516Hz. The galloping mode of the entire conductor can be obtained by taking the displacement signals of each measuring point at the same time. The galloping trajectory of the entire conductor within one cycle can be obtained by taking the displacement signals of each measuring point at the same time (t=29.69s, t=29.72s, t=29.75s, t=29.77s, t=29.79s, t=29.82s) within one cycle.

[0058] (8) Further, extract the torsion angle signals of each wireless attitude sensor, such as... Figure 8 As shown, the frequency spectrum curve can be obtained by performing spectral analysis on the time history curve at the measurement point with the maximum amplitude. The vibration frequency is 3.516Hz. Combined with the in-plane and out-of-plane displacement curves, the gyratory trajectory diagram in the axial direction can be obtained.

[0059] Example 2

[0060] like Figure 9 The method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor of the present invention can be used to measure and correct the vibration of a scaled model of a continuous ice-covered two-split conductor. The specific process is the same as in Example 1.

[0061] Example 3

[0062] like Figure 10 The method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor of the present invention can be used to measure and correct the vibration of a scaled model of a continuous ice-covered six-split conductor. The specific process is the same as in Example 1.

[0063] Example 4

[0064] like Figure 11 The method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor of the present invention can be used to measure and correct the vibration of a scaled model of an eight-split continuous ice-covered conductor. The specific process is the same as in Example 1.

[0065] Example 5

[0066] like Figure 12 The method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor of the present invention can be used to measure and correct the vibration of a scaled model of a continuous ice-covered split conductor. The specific process is the same as in Example 1.

[0067] Example 6

[0068] like Figure 13 The method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor of the present invention can be used to measure and correct the vibration of a scaled model of a continuous ice-covered twelve-split conductor. The specific process is the same as in Example 1.

[0069] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A method for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor, characterized in that: Includes the following steps: Step 1: Determine the test system. Based on the dimensions of the continuous ice-covered split conductor model, determine the sensor models used for vibration measurement, including force sensors, laser displacement sensors, wireless attitude sensors, spacers, signal acquisition and analysis systems, and signal processing software. Step 2, Install the test system: Install the force sensor at one end of the continuous ice-covered split conductor, fix the wireless attitude sensor at the center of the spacer bar, and then install it on the split conductor through the spacer bar. Install the laser displacement sensor in the in-plane direction of the continuous ice-covered split conductor. The positions of the laser displacement sensor and the wireless attitude sensor are directly below the continuous split conductor model. Then connect each sensor to the same signal acquisition and analysis system. Step 3, Data Acquisition: When the continuous ice-covered split conductor gallops, the force sensor, laser displacement sensor, and wireless attitude sensor simultaneously acquire data. The force sensor directly measures the axial dynamic tension signal; the wireless attitude sensor directly measures the in-plane acceleration signal, out-of-plane acceleration signal, and torsional angular displacement signal of the split conductor; the laser displacement sensor directly measures the in-plane displacement signal in a non-contact measurement manner. Step 4, Data Correction: Based on the signals collected by each sensor, select the measurement point signal with the largest amplitude. First, convert the in-plane acceleration signal obtained by the wireless attitude sensor into an in-plane displacement signal through filtering and frequency domain integration. Then, calculate the signal correction parameters for the same measurement point signal. Finally, correct the converted out-of-plane displacement signal using the correction parameters. Step 5, Data Processing: 1) Axial dynamic tension: The time history curve is directly obtained by testing the signal from the force sensor, and then the axial galloping spectrum curve is obtained by spectrum analysis; 2) In-plane vibration: The time history curve is directly obtained from the signal measured by the laser displacement sensor, and then the in-plane galloping spectrum curve is obtained through spectrum analysis; at the same time, the in-plane galloping mode shape is plotted based on the displacement signal of the conductor at different positions at the same time, and the in-plane galloping trajectory is plotted based on the displacement signal of the conductor at different positions at different times. 3) Out-of-plane vibration: The acceleration signal obtained by the wireless attitude sensor is converted into a displacement signal by filtering and frequency domain integration. After being corrected by the signal correction parameter, the out-of-plane galloping time history curve is obtained. Then, the out-of-plane galloping spectrum curve is obtained by spectrum analysis. The out-of-plane galloping mode shape is drawn according to the displacement signal of the conductor at different positions at the same time. The out-of-plane galloping trajectory is drawn according to the displacement signal of the conductor at different positions at different times. 4) Torsional vibration: The torsional angular displacement time history curve is obtained directly from the torsional angular displacement signal of the wireless attitude sensor, and further obtained by spectrum analysis to obtain the torsional galloping spectrum curve; at the same time, the two-way coupled galloping trajectory is obtained based on the in-plane and out-of-plane galloping displacements. The signal correction parameter = the maximum in-plane displacement obtained by the laser displacement sensor / the maximum in-plane displacement obtained by the wireless attitude sensor.

2. The method for simultaneous measurement of four-degree-of-freedom vibration of a continuous ice-covered split conductor according to claim 1, characterized in that: The four-degree-of-freedom vibration quantities include axial dynamic tension, displacement-time history curves, frequency spectrum curves, mode shapes, and trajectories of in-plane, out-of-plane, and torsional galloping.

3. The method for simultaneous measurement of four-degree-of-freedom vibration of a continuous ice-covered split conductor according to claim 1, characterized in that: The continuous icing split conductor is applicable to split conductors with two, four, six, eight, ten, and twelve splits.

4. The method for simultaneous measurement of four-degree-of-freedom vibration of a continuous ice-covered split conductor according to claim 1, characterized in that: The continuous ice-covered split conductor model is a laboratory-scaled model.

5. The method for simultaneous measurement of four-degree-of-freedom vibration of a continuous ice-covered split conductor according to claim 1, characterized in that: The wireless attitude sensor is to be placed and fixed at the center of the spacer bar.

6. The method for simultaneous measurement of four-degree-of-freedom vibration of a continuous ice-covered split conductor according to claim 1, characterized in that: The number and location of the laser displacement sensor and wireless attitude sensor used determine the modal order that the system can measure.

7. A measuring device for simultaneously measuring the four-degree-of-freedom vibration of a continuous ice-covered split conductor as described in claim 1, characterized in that: The measuring device includes a force sensor, several laser displacement sensors, several wireless attitude sensors, several spacers, a signal acquisition and analysis system, and signal processing software; The force sensor is installed at one end of the continuum split wire model; The wireless attitude sensor is fixedly installed at the center of the spacer bar; The laser displacement sensor is installed directly below the continuum split wire model, corresponding to the positions of each wireless attitude sensor. The force sensor, wireless attitude sensor, and laser displacement sensor are sequentially connected to the same data acquisition and analysis system.

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