A method and device for monitoring wind deviation of transmission line conductors

Abstract

The present application relates to the technical field of windage monitoring of electric wires, and specifically to a method and device for monitoring windage of transmission line conductors, the method comprising: obtaining in real time the acceleration and voltage of the conductor at each moment when the transmission line conductor is swinging; obtaining the maximum value point of the acceleration at all moments; taking two adjacent maximum value points as a group of swing pairs; determining the local trend factor of each group of swing pairs; determining the local fluctuation factor of each group of swing pairs; determining the swing stability of each group of swing pairs; determining the volatility estimate of each group of swing pairs; determining the voltage disorder of each group of swing pairs; determining the voltage fluctuation index of each group of swing pairs; determining the windage influence of the transmission line, and monitoring the transmission line conductors. The present application monitors and warns of conductor swings and voltage fluctuations in real time, improves the reliability and safety of the power grid, and reduces power outages and equipment damage caused by windage.

Description

Technical Field

[0001] The present application relates to the technical field of windage monitoring of electric wires, and in particular to a method and device for monitoring windage of transmission line conductors. Background Art

[0002] With rapid economic development and growing electricity demand, transmission lines, as the main arteries of power transmission, are crucial for their safe and stable operation. However, wind in the natural environment poses a potential threat to transmission line safety. Wind deflection of conductors can cause changes in the mechanical tension of the lines. This increase or decrease in tension affects the vibration frequency and amplitude of the conductors, which in turn causes changes in the line's inductance and capacitance parameters. Due to changes in the relative position and distance between conductors, the inductance and capacitance of the lines may vary. These changes in parameters affect the transmission characteristics of the lines, causing voltage fluctuations across the conductors, thereby affecting the stability and transmission efficiency of the power system.

[0003] When analyzing problems such as the stability and transmission efficiency of the power system caused by conductor wind deviation, the existing technology finds it difficult to monitor the impact of conductor wind deviation on conductor voltage in real time, and thus it is difficult to accurately feedback the stability fluctuations of voltage caused by conductor wind deviation, causing the voltage to exceed the safe operating range of the power grid equipment, causing voltage instability and affecting the power supply quality. Summary of the Invention

[0004] In order to solve the above technical problems, a method and device for monitoring windage of transmission line conductors are provided to solve the existing problems.

[0005] The solution to the technical problem of this application is to provide a method and device for monitoring windage of transmission line conductors, comprising the following steps:

[0006] In a first aspect, an embodiment of the present application provides a method for monitoring windage of a transmission line conductor, the method comprising the following steps:

[0007] Real-time acquisition of the acceleration and voltage of the transmission line conductor at each moment when the conductor swings;

[0008] Obtain the maximum value points of acceleration at all times; take two adjacent maximum value points as a set of swing pairs;

[0009] Analyze the trend change of acceleration at all times between each swing pair to determine the local trend factor of each swing pair; determine the local fluctuation factor of each swing pair based on the dispersion degree and fluctuation range of acceleration at all times between each swing pair; and determine the swing stability of each swing pair based on the local trend factor and the local fluctuation factor;

[0010] Determine an estimated fluctuation rate for each swing pair based on the voltage fluctuations at each moment between each swing pair; analyze the voltage fluctuation range at all moments between each swing pair to determine the voltage disorder degree for each swing pair; and determine a voltage fluctuation index for each swing pair based on the estimated fluctuation rate and the voltage disorder degree.

[0011] Based on the swing stability and the voltage fluctuation index, the windage influence of the transmission line is determined, and the transmission line conductor is monitored.

[0012] Preferably, the determining of the local trend factor of each swing pair includes: using a trend test algorithm to obtain the absolute value of the Z statistic of the acceleration at all moments between each swing pair as the local trend factor of each swing pair.

[0013] Preferably, the local fluctuation factor is the product of the dispersion and the range of acceleration at all times between each set of swing pairs.

[0014] Preferably, the swing stability is the ratio of the local trend factor to the local fluctuation factor.

[0015] Preferably, determining the volatility estimate of each swing pair includes: using a GARCH algorithm to obtain the volatility estimate of the voltage at all moments between each swing pair.

[0016] Preferably, the voltage disorder degree is the product of the range and the mean of the voltage at all times between each set of swing pairs.

[0017] Preferably, the voltage fluctuation index is a normalized result of the product of the fluctuation rate estimate and the voltage disorder degree.

[0018] Preferably, determining the windage influence of the transmission line includes:

[0019] Performing negative mapping on the swing stability, and forming a two-dimensional array with the negative mapping result of each swing pair and the voltage fluctuation index;

[0020] Linear fitting is performed on the two-dimensional arrays of all pairs of swing groups, and the slope of the fitting line is used as the wind deflection influence of the transmission line.

[0021] Preferably, the monitoring of the transmission line conductor includes: when the wind deviation impact is greater than a preset warning threshold, the voltage fluctuation of the transmission line conductor exceeds the safe operation range of the power grid equipment; otherwise, the voltage fluctuation of the transmission line conductor is within the safe operation range of the power grid equipment.

[0022] In the second aspect, an embodiment of the present application also provides a transmission line conductor wind deviation monitoring device, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-mentioned transmission line conductor wind deviation monitoring methods.

[0023] This application has at least the following beneficial effects:

[0024] The present application obtains the maximum value points of acceleration at all times; takes two adjacent maximum value points as a group of swing pairs; analyzes the trend change of acceleration at all times between each group of swing pairs, as well as the discrete degree of acceleration at all times between each group of swing pairs and the extreme degree of change, and determines the swing stability of each group of swing pairs. Its beneficial effect is that it takes into account the trend change and fluctuation degree of the wire during the swing process to reflect whether the wire swing has an obvious trend, to judge the randomness of the wire swing, and then to judge whether the wire swing is caused by specific factors; according to the voltage fluctuation at each moment between each group of swing pairs and The extreme degree of change is determined to determine the voltage fluctuation index of each swing pair. Its beneficial effect is that it analyzes the fluctuation of the corresponding voltage when the conductor swings, and then reflects the stability of the voltage change; the influence of wind deviation on the transmission line is determined, and the transmission line conductor is monitored. Its beneficial effect is that it takes into account the influence of the instability of conductor swing on the fluctuation of conductor voltage, and reflects the degree of influence of conductor wind deviation on voltage stability, and then conducts real-time monitoring and early warning of conductor swing and voltage fluctuation, so as to ensure the smooth operation of power grid equipment, improve the reliability and safety of the power grid, and reduce power outages and equipment damage caused by wind deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following is a detailed description of a method for monitoring windage deviation of a transmission line conductor according to the present application with reference to the accompanying drawings.

[0026] Figure 1 A flowchart of the steps of a method for monitoring windage deviation of a transmission line conductor provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the swing position of the conductor when it is deflected by wind provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of acceleration changes at various moments provided in an embodiment of the present application;

[0029] Figure 4 A flowchart of the steps of the method for obtaining the swing stability of each swing pair provided in an embodiment of the present application;

[0030] Figure 5A flowchart of the steps of the method for obtaining the voltage fluctuation index of each swing pair provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of this application more clearly understood, the following describes in further detail a method and device for monitoring windage deviation of a transmission line conductor proposed in this application, in conjunction with the accompanying drawings and implementation examples. It should be understood that the specific embodiments described herein are merely intended to explain this application and are not intended to limit this application.

[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0033] See also Figure 1 , which shows a flowchart of a method for monitoring windage deviation of a transmission line conductor provided by an embodiment of the present application, the method comprising the following steps:

[0034] Step 1: Obtain the acceleration and voltage of the transmission line conductor at each moment when the transmission line conductor swings in real time.

[0035] Conductor windage refers to the phenomenon in which a conductor deflects under the action of wind. A location on a transmission line conductor that is susceptible to windage is selected, and a monitoring sensor group is fixedly installed at the predetermined location on the transmission line conductor. The monitoring sensor group includes an acceleration sensor and a voltage transformer. The acceleration sensor is used to collect in real time the acceleration of the conductor at the sensor group installation location when it swings due to windage. The voltage transformer is used to collect in real time the voltage of the conductor at the sensor group installation location during power transmission. The collection time interval is t. The collected acceleration and voltage are normalized to eliminate the dimension, and then arranged according to the collection time to obtain the acceleration and voltage at each moment.

[0036] Preferably, in this embodiment, the collection time interval is 0.1s. As other implementation methods, the implementer can set it according to the actual situation and use the maximum and minimum value normalization method for processing, wherein the maximum and minimum value normalization method is a well-known technology and will not be repeated here; as other implementation methods, the implementer can use other methods of the existing technology, such as Z-Score normalization, etc., and this embodiment does not impose any special restrictions on this.

[0037] At this point, the acceleration and voltage of the transmission line conductor at each moment when the transmission line conductor is deflected by wind are obtained.

[0038] Step 2: Analyze the trend change of acceleration at all times between each group of swing pairs to determine the local trend factor of each group of swing pairs; determine the local fluctuation factor of each group of swing pairs based on the discrete degree and fluctuation range of acceleration at all times between each group of swing pairs; determine the swing stability of each group of swing pairs based on the local trend factor and the local fluctuation factor.

[0039] Changes in the physical shape and position of a wire will affect its inductance. Inductance is the resistance of current changes to magnetic field changes. When the shape of a wire changes, its inductance will also change, causing voltage changes. Vibration or deviation of the wire may change the distribution of its electromagnetic field, thereby generating electromagnetic interference to surrounding electronic equipment and affecting voltage stability.

[0040] When the absolute value of the acceleration of the wire's wind deviation is the largest, it means that the change in the speed of the wire in unit time is the largest. At this time, the swing amplitude of the wire is the largest. When the acceleration of the wire's wind deviation is 0, it means that the speed of the wire has not changed, that is, the wire is in a uniform motion state. At this time, the wire is in the middle position of the swing. The schematic diagram of the swing position of the wire when it is wind deflected is as follows: Figure 2 As shown, x represents the conductor in the middle swing position, and y and z represent the conductor in the maximum swing position on both sides.

[0041] Furthermore, the flowchart of the steps of the method for obtaining the swing stability of each swing pair provided in the embodiment of the present application is as follows: Figure 4 shown.

[0042] Based on the above analysis, the acceleration change of the wire is analyzed, the acceleration trend change of the wire between two adjacent maximum swing amplitudes is judged, and the local trend factor is determined, which is specifically:

[0043] Obtain the maximum value points of acceleration at all times; take two adjacent maximum value points as a set of swing pairs;

[0044] Preferably, in this embodiment, the difference method is used to obtain the maximum point. As other implementation methods, the implementer can use other methods in the existing technology, such as the derivative method, local extreme points, etc. This embodiment does not impose any special restrictions on this.

[0045] Furthermore, the schematic diagram of acceleration changes at each moment provided in this embodiment is as follows: Figure 3 As shown, the horizontal axis is time, the vertical axis is normalized acceleration, and the small circles in the figure represent the maximum points.

[0046] The trend test algorithm is used to obtain the absolute value of the Z statistic of the acceleration at all moments between each swing pair as the local trend factor of each swing pair;

[0047] Preferably, in this embodiment, the Mann-Kendall trend test algorithm is used to obtain the Z statistic, wherein the Mann-Kendall trend test algorithm is a well-known technology and is not described here in detail. When calculating the Z statistic of the acceleration at all times between each group of swing pairs, the acceleration corresponding to the two maximum points is included.

[0048] It should be noted that each swing pair reflects the change in acceleration of the wire when it swings from the maximum deviation position to another maximum deviation position. Secondly, the size of the Z statistic reflects the intensity of the change trend of acceleration within each swing pair. The larger the Z statistic, the higher the significance trend of the acceleration within each swing pair, that is, the more uniform the swing speed of the wire when it swings from the maximum deviation position to another maximum deviation position, and unstable swing will not occur.

[0049] Furthermore, the discreteness and range of acceleration changes within each swing pair are analyzed to determine the local fluctuation factor to reflect the randomness of the wire swing and the frequency of extreme swings. Specifically, it is:

[0050] Calculating the dispersion and range of acceleration at all times between each set of swing pairs; and taking the product of the dispersion and range as the local fluctuation factor of each set of swing pairs;

[0051] Preferably, in this embodiment, the degree of discreteness is measured by calculating the standard deviation of the acceleration at all moments between each group of swing pairs. As other implementation methods, the implementer can use other methods of the prior art to measure the degree of discreteness, such as variance, coefficient of variation, information entropy, etc. This embodiment does not impose any special restrictions on this.

[0052] It should be noted that the local fluctuation factor reflects the volatility of acceleration changes and the frequency of extreme changes, reflects the randomness of wire swing and the frequency of extreme swing events. The larger the local fluctuation factor, the stronger the randomness of wire swing, the more frequent the extreme swing events, and the more unstable the swing.

[0053] Furthermore, based on the local trend factor and the local fluctuation factor, the swing stability is determined, specifically:

[0054] The ratio of the local trend factor to the local volatility factor is used as the swing stability of each swing pair;

[0055] It should be noted that, in this embodiment, in order to avoid the denominator being 0, a value greater than 0 is added to the denominator when calculating the ratio, and the value is 0.01; secondly, the swing stability reflects a comprehensive evaluation of the swing stability of the wire. The greater the swing stability, the more obvious the swing trend of the wire. The smaller the swing stability, the more frequent the swing of the wire but without obvious trend, indicating that the swing of the wire is more random rather than caused by specific factors.

[0056] At this point, the swing stability of each swing pair is obtained.

[0057] Step 3: Determine the estimated fluctuation rate of each swing pair based on the voltage fluctuation at each moment between each swing pair; analyze the voltage fluctuation range at all moments between each swing pair to determine the voltage disorder degree of each swing pair; and determine the voltage fluctuation index of each swing pair based on the estimated fluctuation rate and the voltage disorder degree.

[0058] When wind causes conductors to deflect, it increases or decreases the distance between them, causing changes in inductance and capacitance. If the distance between conductors increases, the inductance increases, reducing the voltage. Conversely, if the distance between conductors decreases, the inductance decreases, increasing the voltage. Furthermore, excessive wind deflection can cause significant voltage fluctuations, impacting power supply quality and, in extreme cases, triggering protective devices and causing line tripping.

[0059] Based on the above analysis, the voltage fluctuation when the conductor is deflected by wind is analyzed, and the voltage fluctuation index is determined, which is:

[0060] Based on the corresponding moments of acceleration between each set of swing pairs, the voltages at the same moments between each set of swing pairs are obtained;

[0061] The GARCH (Generalized Autoregressive Conditional Heteroskedasticity) algorithm is used to obtain the voltage volatility estimate at all times between each pair of swings.

[0062] It should be noted that the GARCH algorithm is a well-known technology and will not be described in detail here.

[0063] Calculate the product of the voltage range and mean at all times between each swing pair as the voltage disorder degree of each swing pair;

[0064] A normalized result of the product of the fluctuation rate estimate and the voltage disorder degree is used as the voltage fluctuation index of each swing pair;

[0065] It should be noted that the volatility estimator is obtained through the GARCH algorithm, which reflects the magnitude of voltage volatility over time. A higher volatility indicates that the voltage level will change significantly within a local time period. A larger volatility estimator indicates greater voltage volatility and a larger voltage fluctuation index is obtained. Secondly, the voltage disorder reflects the extreme nature of voltage changes within a local time period. A larger voltage disorder indicates more extreme voltage changes and a larger voltage fluctuation index is obtained, indicating that there is a large voltage fluctuation problem in the corresponding swing group of the conductor and that the voltage stability change is poor.

[0066] Furthermore, the flowchart of the method for obtaining the voltage fluctuation index of each swing pair provided in the embodiment of the present application is as follows: Figure 5 shown.

[0067] At this point, the voltage fluctuation index of each swing pair is obtained.

[0068] Step 4: Based on the swing stability and the voltage fluctuation index, determine the windage influence of the transmission line and monitor the transmission line conductors.

[0069] Furthermore, based on the swing stability and the voltage fluctuation index, the influence of the conductor swing caused by wind deviation on the conductor voltage fluctuation is analyzed, specifically:

[0070] Performing negative mapping on the swing stability; forming a two-dimensional array with the negative mapping result of each swing pair and the voltage fluctuation index;

[0071] In this embodiment, the specific process of negative mapping is: negative mapping is performed through an exponential function, assuming that the swing stability is recorded as ,Will The result of the negative mapping is as follows, where is an exponential function with a natural constant as its base.

[0072] Perform linear fitting on the two-dimensional arrays of all pairs of swing groups, and use the slope of the fitted line as the wind deflection influence of the transmission line;

[0073] It is understandable that in this embodiment, the least squares method is used for linear fitting. As other implementations, the implementer may adopt other methods in the prior art, such as the maximum likelihood estimation method, etc. This embodiment does not impose any special restrictions on this.

[0074] It should be noted that the windage effect of the transmission line reflects the degree of influence of the instability of the conductor swing caused by wind on the voltage fluctuation. If the windage effect is large, it means that the instability of the conductor swing has a significant impact on the voltage fluctuation; if the windage effect is small or close to zero, it means that the conductor has little influence on the voltage fluctuation when it is not swinging.

[0075] The acceleration and voltage of the conductors at each moment are collected in real time. Based on the real-time data, the swing instability and voltage fluctuation index are calculated to determine the windage impact. Based on the windage impact, the conductors of the transmission line are monitored to determine whether the current swing and voltage fluctuations are within a safe range to ensure the smooth operation of the power grid equipment. Specifically:

[0076] When the wind deviation impact is greater than the preset warning threshold, the voltage fluctuation of the transmission line conductor exceeds the safe operation range of the power grid equipment; when the wind deviation impact is less than or equal to the preset warning threshold, the voltage fluctuation of the transmission line conductor is within the safe operation range of the power grid equipment;

[0077] Preferably, in this embodiment, the preset warning threshold value is 2.5. As other implementation methods, the implementer can set it according to actual conditions.

[0078] It should be noted that when the wind deviation impact is greater than the preset warning threshold, the amplitude and frequency of the wire swing cause the distance between the wires to change significantly, causing large changes in inductance and capacitance, resulting in voltage instability and affecting power supply quality.

[0079] Based on the same inventive concept as the above-mentioned method, an embodiment of the present application also provides a transmission line conductor wind deviation monitoring device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-mentioned transmission line conductor wind deviation monitoring methods.

[0080] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0081] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the present application. It should be noted that a person skilled in the art can make various modifications and improvements without departing from the spirit of the present application. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiments made in accordance with the technical essence of the present application without departing from the content of the present application's technical solution fall within the scope of protection of the present application's technical solution.

Claims

1. A method for monitoring windage of transmission line conductors, characterized in that: The method comprises the following steps: Real-time acquisition of the acceleration and voltage of the transmission line conductor at each moment when the conductor swings; Obtain the maximum value points of acceleration at all times; take two adjacent maximum value points as a set of swing pairs; Analyze the trend change of acceleration at all times between each swing pair to determine the local trend factor of each swing pair; determine the local fluctuation factor of each swing pair based on the dispersion degree and fluctuation range of acceleration at all times between each swing pair; and determine the swing stability of each swing pair based on the local trend factor and the local fluctuation factor; Determine an estimated fluctuation rate for each swing pair based on the voltage fluctuations at each moment between each swing pair; analyze the voltage fluctuation range at all moments between each swing pair to determine the voltage disorder degree for each swing pair; and determine a voltage fluctuation index for each swing pair based on the estimated fluctuation rate and the voltage disorder degree. Based on the swing stability and the voltage fluctuation index, the windage influence of the transmission line is determined, and the transmission line conductor is monitored.

2. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: The determining of the local trend factor of each swing pair includes: using a trend test algorithm to obtain the absolute value of the Z statistic of the acceleration at all moments between each swing pair as the local trend factor of each swing pair.

3. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: The local fluctuation factor is the product of the dispersion and the range of acceleration at all times between each set of swing pairs.

4. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: The swing stability is the ratio of the local trend factor to the local fluctuation factor.

5. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: Determining the volatility estimate of each swing pair includes: using a GARCH algorithm to obtain the volatility estimate of the voltage at all moments between each swing pair.

6. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: The voltage disorder degree is the product of the range and the mean of the voltage at all times between each swing pair.

7. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: The voltage fluctuation index is a normalized result of the product of the fluctuation rate estimate and the voltage disorder degree.

8. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: Determining the windage influence of the transmission line includes: Performing negative mapping on the swing stability, and forming a two-dimensional array with the negative mapping result of each swing pair and the voltage fluctuation index; Linear fitting is performed on the two-dimensional arrays of all pairs of swing groups, and the slope of the fitting line is used as the wind deflection influence of the transmission line.

9. A method for monitoring windage of a transmission line conductor according to claim 1, characterized in that: The monitoring of the transmission line conductor includes: when the wind deviation influence is greater than a preset warning threshold, the voltage fluctuation of the transmission line conductor exceeds the safe operation range of the power grid equipment; otherwise, the voltage fluctuation of the transmission line conductor is within the safe operation range of the power grid equipment.

10. A transmission line conductor windage monitoring device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method for monitoring windage deviation of a transmission line conductor as described in any one of claims 1 to 9 are implemented.

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