A cable fault early warning method and system based on GIS

Abstract

The present invention relates to the field of cable fault early warning technology, and in particular, to a cable fault early warning method and system based on GIS. The present invention solves the problem of how to use a GIS system to accurately identify potential faulty cables in a stacked line and improve the accuracy of early warning. To solve the above problem, the present invention provides an early warning method, including: obtaining a location image and working information of a cable line according to a GIS system; determining a historical fluctuating voltage within a historical monitoring period according to the working information, and predicting a theoretical fluctuating voltage according to future meteorological data and the historical fluctuating voltage; recording a historical maximum voltage within a historical monitoring period as a voltage fluctuation threshold; correcting the voltage fluctuation threshold according to the operating conditions and location image of the cable line to obtain a corrected threshold; judging whether the cable line meets early warning conditions according to the rated voltage, the theoretical fluctuating voltage and the corrected threshold; and modifying the early warning conditions according to the corrected voltage and the corrected threshold.

Description

Technical Field

[0001] The present invention relates to the technical field of cable fault early warning, and in particular to a cable fault early warning method and system based on GIS. Background Art

[0002] As an important infrastructure for modern communications and power transmission, cables are increasingly used. In remote streets in urban areas or some rural areas, due to historical reasons and geographical limitations, cables are usually installed in a stacked manner. Although this method saves space and resources to a certain extent, it has great safety hazards and makes it extremely difficult to accurately locate the lines to be maintained, which increases the difficulty of maintenance work.

[0003] Related technologies usually rely on traditional monitoring methods, such as manual patrols and regular inspections. These methods are inefficient and cannot accurately locate the lines to be maintained. To solve this problem, cable fault warning methods based on GIS systems have gradually attracted attention. By introducing GIS systems, faulty cables in stacked lines can be accurately located, effectively improving the accuracy and efficiency of fault warnings, thereby ensuring the stability of the power system. Summary of the invention

[0004] The problem solved by the present invention is how to use a GIS system to accurately identify potential faulty cables in stacked lines and improve the accuracy of early warning.

[0005] To solve the above problems, an embodiment of the present invention provides a GIS-based cable fault early warning method, which includes: establishing a data management library, adding the cable lines in the target area to the data management library, and obtaining the location image and working information of the cable lines according to the GIS system; determining the historical fluctuating voltage within the historical monitoring period according to the working information, obtaining future meteorological data in the target area, and predicting the theoretical fluctuating voltage according to the future meteorological data and the historical fluctuating voltage; recording the historical maximum voltage within the historical monitoring period as the voltage fluctuation threshold; correcting the voltage fluctuation threshold according to the operation status and location image of the cable line to obtain a corrected threshold; obtaining the rated voltage of the cable line, and judging whether the cable line meets the early warning condition through the rated voltage, the theoretical fluctuating voltage and the corrected threshold; if so, recording the cable line as a line to be maintained, and marking the line to be maintained in the location image; if not, calculating the maintenance response time required for the cable line according to the location image, and setting the correction coefficient according to the maintenance response time; calculating the corrected voltage according to the correction coefficient and the theoretical fluctuating voltage, and modifying the early warning condition according to the corrected voltage and the corrected threshold.

[0006] Compared with the existing technology, the technical effects achieved by adopting this technical solution are as follows: the GIS system can analyze the location image of the cable line in the target area, so that the staff can quickly obtain the actual layout location of the cable line and the surrounding environment of the cable line. By analyzing the work information, the peak voltage change of each cable line in the historical monitoring period can be obtained, and the cable lines with higher potential fault risks can be determined in advance. The prediction of theoretical fluctuating voltage fully considers the impact of future meteorological data on the voltage change of the cable line, making the risk prediction of the cable line more accurate. The setting of voltage fluctuation threshold helps to quickly identify cable lines with abnormal voltage. The calculation of correction threshold quantifies the impact of operating conditions and location images on voltage fluctuation threshold, improves the accuracy of early warning conditions, and dynamically adjusts the correction voltage through maintenance response time, further improving the accuracy and timeliness of fault warning.

[0007] In one embodiment of the present invention, the historical fluctuating voltage within the historical monitoring period is determined according to the working information, the future meteorological data in the target area is obtained, and the theoretical fluctuating voltage is predicted according to the future meteorological data and the historical fluctuating voltage, specifically including: determining the historical voltage data within the historical monitoring period according to the working information; determining the peak power consumption period within the historical monitoring period according to the historical voltage data; obtaining the peak voltage within each peak power consumption period, calculating the average value of the peak voltage, and recording the average value as the historical fluctuating voltage; determining the future temperature data within the target time period according to the future meteorological data; determining the first correction coefficient according to the month of the target time period and the future temperature data; and predicting the theoretical fluctuating voltage according to the first correction coefficient and the historical fluctuating voltage.

[0008] Compared with the existing technology, the technical effects achieved by adopting this technical solution are as follows: historical voltage data reflects the changing trend of voltage during the historical monitoring period, and the peak power consumption period reflects the voltage fluctuation characteristics of the cable line under high load conditions, which helps to timely identify the overload risk of the cable line. The peak voltage reflects the carrying capacity of the cable line under high load conditions, and provides necessary data support for the subsequent calculation of historical fluctuating voltages. By analyzing future temperature data, changes in electricity demand within the target time period can be predicted, thereby improving the prediction accuracy of the theoretical fluctuating voltage.

[0009] In one embodiment of the present invention, a first correction coefficient is determined based on the month in which the target time period is located and future temperature data, specifically including: setting a voltage fluctuation coefficient based on the historical voltage data of each month; recording the month in which the target time period is located as the target month, and recording the month corresponding to the target month in the historical monitoring period as the comparison month; obtaining the unit average temperature of the comparison month based on the historical temperature data; determining the future minimum temperature, future maximum temperature and future average temperature of the target time period based on the future temperature data; and calculating the first correction coefficient based on the unit average temperature, the future temperature data and the voltage fluctuation coefficient.

[0010] Compared with the existing technology, the technical effects achieved by adopting this technical solution are as follows: the setting of the voltage fluctuation coefficient quantifies the relationship between temperature change and voltage fluctuation, reflects the correlation between historical power demand and climate conditions, and helps to accurately predict the theoretical fluctuating voltage under different temperature conditions. The calculation of the unit average temperature provides reliable basic data for the calculation of the first correction coefficient. The calculation of the first correction coefficient fully considers the power demand trend and temperature change characteristics of the target month and the comparison month, so that the first correction coefficient can more accurately reflect the changes in the theoretical fluctuating voltage under different future temperature conditions, thereby improving the prediction accuracy of the theoretical fluctuating voltage.

[0011] In one embodiment of the present invention, the voltage fluctuation threshold is corrected according to the operating conditions and position image of the cable line to obtain a corrected threshold, specifically including: obtaining the service life and fault records of the cable line according to the operating conditions, and setting a second correction coefficient according to the service life and the fault records; obtaining the stacking type of the cable line according to the position image, and setting a stacking effect coefficient according to the stacking type; calculating a third correction coefficient according to the second correction coefficient and the stacking effect coefficient; calculating the corrected threshold according to the third correction coefficient and the voltage fluctuation threshold.

[0012] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: the calculation of the second correction coefficient fully considers the service life and fault record of the cable line, so that the correction threshold under different operating conditions can be calculated more accurately. By introducing the stacking effect coefficient, the voltage fluctuation of the cable line under different stacking types can be evaluated more accurately. The voltage fluctuation threshold is adjusted by the third correction coefficient, which further improves the sensitivity of the voltage fluctuation threshold, thereby improving the accuracy of fault warning.

[0013] In one embodiment of the present invention, if the cable line is recorded as a line to be maintained, the line to be maintained is marked in the location image, specifically including: obtaining attribute information data of the cable line, inputting the attribute information data into the data management library, and marking the line to be maintained; within the first time period after the maintenance of the line to be maintained is completed, the location image will be updated; when the location image is updated, the location image before the update is recorded as the initial image, the updated location image is recorded as the updated image, and the cable line in the updated image is recorded as the updated circuit; the shielding rate of the updated circuit in the updated image is calculated according to the GIS system; when the shielding rate is greater than or equal to the shielding threshold, the wiring of the update circuit needs to be combed, and the location image is updated again after the wiring combing is completed; when the shielding rate is less than the shielding threshold, the initial image is compared with the update image according to the attribute information data, the changed line is identified, and according to the changed line, it is determined whether to enter the updated image into the GIS system.

[0014] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: collecting and storing attribute information data can help staff achieve efficient management of cable lines, ensure the accuracy and timeliness of maintenance work, and improve the accuracy and effectiveness of position image monitoring through updating, thereby improving the accuracy of positioning the lines to be maintained. By comparing the shielding rate and shielding threshold, staff can efficiently determine whether further measures need to be taken after the maintenance work is completed, thereby saving time and resources and reducing the difficulty of future maintenance. Identifying changed lines helps to promptly detect changes in cable lines after updates and ensure the accuracy of position image information.

[0015] In one embodiment of the present invention, if not, the maintenance response time required for the line to be maintained is calculated based on the location image, and a correction coefficient is set based on the maintenance response time, specifically including: determining the maintenance center closest to the line to be maintained based on the GIS system, and calculating the maintenance response time from the maintenance center to the line to be maintained; obtaining the theoretical waiting time of the line to be maintained based on the maintenance plan of the maintenance center within the target time period; and setting the correction coefficient based on the maintenance response time and the theoretical waiting time.

[0016] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: the calculation of the maintenance response time takes into account the distance between the maintenance center and the line to be maintained, so that the staff can more accurately evaluate the time required to reach the line to be maintained. The theoretical waiting time reflects the estimated waiting time of the line to be maintained in the maintenance plan, providing a basis for the calculation of the correction coefficient.

[0017] In one embodiment of the present invention, a correction voltage is calculated based on the correction coefficient and the theoretical fluctuating voltage, and the warning condition is modified based on the correction voltage and the correction threshold, specifically including: when the correction voltage is greater than or equal to the correction threshold, the warning condition has a first adjustment coefficient; when the correction voltage is greater than or equal to the rated voltage and less than the correction threshold, the warning condition does not need to be adjusted; when the correction voltage is less than the rated voltage, the warning condition does not need to be adjusted.

[0018] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: by correcting the theoretical fluctuating voltage through the maintenance response time, it can more accurately determine whether the cable line meets the warning conditions, and dynamically adjust the correction threshold through the first adjustment coefficient to ensure that the cable line has more scientific and accurate warning conditions when warning, preventing the risk of false alarm or missed alarm of fault warning due to improper setting of the correction threshold, and improving the accuracy and reliability of fault warning.

[0019] In one embodiment of the present invention, a GIS-based cable fault early warning system is also provided, in which the early warning method recorded in the above embodiment is applied to the early warning system, and the early warning system includes: a storage module, in which a data management library is arranged; a monitoring module, which is used to monitor the voltage fluctuation threshold within a historical monitoring period; a prediction module, which is used to predict the theoretical fluctuating voltage; and a calculation module, which is used to calculate the maintenance response time. The early warning system has all the technical features of the above early warning method, which will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is one of the flow charts of the cable fault early warning method based on GIS; Figure 2 This is the second flow chart of the cable fault early warning method based on GIS; Figure 3 This is the third flow chart of the cable fault early warning method based on GIS; Figure 4 Flow chart of the cable fault early warning method based on GIS Figure 5 This is the fifth flow chart of the cable fault early warning method based on GIS; Figure 6 This is the system diagram of the cable fault early warning system based on GIS; Description of reference numerals: 100 - prediction system; 110 - storage module; 120 - monitoring module; 130 - prediction module; 140 - calculation module. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] [First embodiment] See also Figure 1 In a specific embodiment, the present invention provides a cable fault early warning method based on GIS, the early warning method comprising: S100, establishing a data management database, adding the cable lines in the target area to the data management database, and obtaining the location image and working information of the cable lines according to the GIS system; S200, determining the historical fluctuating voltage within the historical monitoring period according to the working information, obtaining future meteorological data in the target area, and predicting the theoretical fluctuating voltage according to the future meteorological data and the historical fluctuating voltage; S300, recording the historical maximum voltage in the historical monitoring period as the voltage fluctuation threshold; S400, correcting the voltage fluctuation threshold according to the operation status of the cable line and the position image to obtain a corrected threshold; S500, obtaining the rated voltage of the cable line, and judging whether the cable line meets the early warning condition according to the rated voltage, the theoretical fluctuation voltage and the correction threshold value; S600: If yes, record the cable line as a line to be maintained, and mark the line to be maintained in the location image; S700, if not, calculating the maintenance response time required for the cable line according to the location image, and setting a correction coefficient according to the maintenance response time; S800, calculating a correction voltage according to the correction coefficient and the theoretical fluctuating voltage, and modifying the warning condition according to the correction voltage and the correction threshold.

[0023] In step S100, the target area is usually located in remote streets or some rural areas in the urban area. The cable lines in these areas are usually set up in a stacked manner. Not only is the potential risk of the cable lines high, but it is also difficult for staff to accurately locate the faulty cables in a short time, resulting in a significant increase in the time required for maintenance work. In addition, under some extreme weather conditions, cable lines in remote streets or some rural areas are more prone to failure. Therefore, the cable lines in these areas can be monitored and warned in advance through the GIS system to accurately locate the faulty cables. The data management library centrally stores various data related to the cable lines in the target area, including the load conditions of the cable lines, geographic coordinate data, fault records and maintenance records, etc., to provide basic data for the GIS system. The location image refers to a visual image of the cable line at the installation location generated by the GIS system. These images can display the specific location, direction, intersection and surrounding environmental characteristics of the cable line. The working information refers to the operating status data of the cable line, such as the load conditions of the cable line, line tension and line surface temperature.

[0024] In step S200 and step S300, the historical monitoring cycle refers to the historical time period for monitoring and recording the cable line, and this historical time period is usually 1 year. The historical fluctuating voltage refers to the peak voltage data of the cable line recorded in the historical monitoring period, which reflects the voltage fluctuation of the cable line under different loads and meteorological conditions. The future meteorological data refers to the weather data of the target area in the target time period, including temperature, humidity and wind speed, etc. The target time period is usually 1 week. The theoretical fluctuating voltage is the highest voltage that may occur in the cable line in the target time period predicted based on the historical fluctuating voltage and future meteorological data. The voltage fluctuation threshold refers to the historical highest voltage recorded in the historical monitoring period. The threshold is the safety standard for voltage fluctuation during the operation of the cable line.

[0025] In step S400, the operating status refers to the state and performance of the cable line during actual operation. For example, the service life and fault records are all part of the operating status of the cable line. The correction threshold is adjusted from the initially set voltage fluctuation threshold after analyzing the operating status and position image of the cable line to obtain a voltage fluctuation threshold that is more in line with the actual situation of the cable line.

[0026] In step S500, the rated voltage refers to the standard voltage for long-term stable operation of the cable line, which is usually 220V. The warning condition is a judgment standard set based on the rated voltage, theoretical fluctuation voltage and correction threshold. The judgment standard can be used to evaluate the potential risk of cable lines that may fail in the future.

[0027] Specifically, when the theoretical fluctuating voltage is less than or equal to the rated voltage, the cable line does not meet the warning conditions; when the theoretical fluctuating voltage is greater than the correction threshold, the cable line meets the warning conditions; when the rated voltage is less than the theoretical fluctuating voltage and the theoretical fluctuating voltage is less than or equal to the correction threshold, the cable line does not meet the warning conditions.

[0028] For example, the rated voltage is 220V, the theoretical fluctuation voltage is 238V, and the correction threshold is 260V. At this time, the cable line meets the warning conditions.

[0029] In steps S600 to S800, marking refers to adding a striking visual symbol to the line to be maintained in the location image through the GIS system, such as changing the line color, adding icons or annotations, etc., to facilitate staff to quickly identify and pay attention to it. The maintenance response time refers to the time required from the discovery of the line to be maintained to the actual start of maintenance. The correction coefficient is an adjustment parameter set according to the maintenance response time, which aims to correct the theoretical fluctuating voltage. The corrected theoretical fluctuating voltage is the corrected voltage.

[0030] The GIS system can analyze the location images of cable lines in the target area, allowing staff to quickly obtain the actual layout location of the cable lines and the surrounding environment of the cable lines. By analyzing the work information, the peak voltage changes of each cable line in the historical monitoring period can be obtained, and the cable lines with higher potential fault risks can be determined in advance. The prediction of theoretical fluctuating voltage fully considers the impact of future meteorological data on cable line voltage changes, making the risk prediction of cable lines more accurate. The setting of voltage fluctuation thresholds helps to quickly identify cable lines with abnormal voltage. The calculation of correction thresholds quantifies the impact of operating conditions and location images on voltage fluctuation thresholds, improves the accuracy of early warning conditions, and dynamically adjusts the correction voltage through maintenance response time, further improving the accuracy and timeliness of fault warnings.

[0031] [Second embodiment] See also Figure 2 In a specific embodiment, the historical fluctuating voltage within the historical monitoring period is determined according to the working information, the future meteorological data in the target area is obtained, and the theoretical fluctuating voltage is predicted according to the future meteorological data and the historical fluctuating voltage, specifically including: S210, determining historical voltage data within a historical monitoring period according to the working information; S220, determining the peak power consumption period within the historical monitoring period according to the historical voltage data; S230, obtaining the peak voltage in each peak power consumption period, calculating the average value of the peak voltage, and recording the average value as the historical fluctuation voltage; S240, determining future temperature data within a target time period according to future meteorological data; S250, determining a first correction coefficient according to the month of the target time period and future temperature data; S260: predicting a theoretical fluctuating voltage according to the first correction coefficient and the historical fluctuating voltage.

[0032] In step S210 to step S230, the historical voltage data refers to the characteristic voltage data of the cable line recorded in the historical monitoring period, including the lowest voltage, the highest voltage and the duration of the highest voltage at each voltage change. The peak power consumption period refers to the time period when the power demand reaches the highest level in the historical monitoring period. The peak power consumption period of the target area in the historical monitoring period is usually from 7 to 9 in the morning and from 6 to 10 in the evening. The peak voltage refers to the maximum voltage value recorded in each peak power consumption period. The historical fluctuation voltage U h is the peak voltage U p The average value is calculated as: .

[0033] In steps S240 to S260, the future temperature data refers to the specific temperature values ​​of all natural days in the target time period, and the first correction coefficient k1 is an adjustment coefficient calculated based on the month of the target time period and the future temperature data, which is used to correct the historical fluctuating voltage to more accurately predict the theoretical fluctuating voltage U t , theoretical ripple voltage U t The calculation formula is as follows: U t =k1×U h .

[0034] The historical voltage data reflects the changing trend of voltage during the historical monitoring period. The peak electricity consumption period reflects the voltage fluctuation characteristics of the cable line under high load conditions, which helps to timely identify the overload risk of the cable line. The peak voltage reflects the carrying capacity of the cable line under high load conditions, and provides necessary data support for the subsequent calculation of historical fluctuating voltage. By analyzing future temperature data, the changes in electricity demand within the target time period can be predicted, thereby improving the prediction accuracy of the theoretical fluctuating voltage.

[0035] [Third embodiment] See also Figure 2 In a specific embodiment, the first correction coefficient is determined according to the month of the target time period and future temperature data, specifically including: S251. Setting a voltage fluctuation coefficient according to the historical voltage data of each month; S252, recording the month in which the target time period falls as the target month, and recording the month corresponding to the target month in the historical monitoring period as the comparison month; S253, obtaining the unit average temperature of the comparison month according to the historical temperature data; S254, determining the future minimum temperature, the future maximum temperature, and the future average temperature of the target time period according to the future temperature data; S255. Calculate a first correction coefficient according to the unit average temperature, future temperature data and voltage fluctuation coefficient.

[0036] In step S251 to step S255, the voltage fluctuation coefficient refers to the degree of influence of each degree change in temperature on the voltage fluctuation, and the voltage fluctuation coefficient is usually between 0.1% and 1%, preferably 0.1%, 0.3% and 0.5%. The comparison month is a historical month with a different year but the same month as the target month. The unit average temperature refers to the monthly average temperature of the comparison month. The future minimum temperature refers to the average value of the daily minimum temperatures of all natural days in the target time period. The future maximum temperature refers to the average value of the daily maximum temperatures of all natural days in the target time period. The future average temperature refers to the average value of the daily average temperatures of all natural days in the target time period. It should be noted that when the target months are from June to August, the voltage fluctuation coefficient is large, and at this time the voltage fluctuation coefficient is mainly affected by the future maximum temperature. Under normal circumstances, the temperature from June to August is higher. When the outside temperature is higher, the frequency of use of the refrigeration equipment will be higher. At the same time, the set temperature of the refrigeration equipment will also be lower, resulting in a large voltage fluctuation. Therefore, the future temperature data used to calculate the first correction coefficient refers to the future maximum temperature. When the target months are from December to February, the voltage fluctuation coefficient is large, and at this time the voltage fluctuation coefficient is mainly affected by the future minimum temperature. Therefore, the future temperature data used to calculate the first correction coefficient refers to the future minimum temperature. When the target months are from March to May or September to November, the voltage fluctuation coefficient is small, and at this time the future temperature data used to calculate the first correction coefficient refers to the future average temperature. The calculation formula of the first correction coefficient k1 is as follows: k1=1+c×(T f -T a ).

[0037] Among them, T f is the future temperature data, in °C, T a is the unit average temperature in °C, and c is the voltage fluctuation coefficient.

[0038] For example, when the target month is July, the reference temperature of the comparison month is 26°C, the future maximum temperature in the target time period is 31°C, the future temperature data at this time is also 31°C, and the voltage fluctuation coefficient is 0.3%, then the first correction coefficient is 1.015.

[0039] The setting of the voltage fluctuation coefficient quantifies the relationship between temperature changes and voltage fluctuations, reflects the correlation between historical electricity demand and climate conditions, and helps to accurately predict the theoretical fluctuating voltage under different temperature conditions. The calculation of the unit average temperature provides reliable basic data for the calculation of the first correction coefficient. The calculation of the first correction coefficient fully considers the electricity demand trend and temperature change characteristics of the target month and comparison month, so that the first correction coefficient can more accurately reflect the changes in the theoretical fluctuating voltage under different future temperature conditions, thereby improving the prediction accuracy of the theoretical fluctuating voltage.

[0040] [Fourth embodiment] See also Figure 3 In a specific embodiment, the voltage fluctuation threshold is corrected according to the operation status and position image of the cable line to obtain a corrected threshold, which specifically includes: S410, obtaining the service life and fault record of the cable line according to the operation situation, and setting a second correction coefficient according to the service life and fault record; S420, acquiring a stacking type of the cable line according to the position image, and setting a stacking effect coefficient according to the stacking type; S430, calculating a third correction coefficient according to the second correction coefficient and the stacking effect coefficient; S440: Calculate a correction threshold according to the third correction coefficient and the voltage fluctuation threshold.

[0041] In step S410, the second correction coefficient is a correction factor set based on the service life N of the cable line and the historical fault record R. The calculation formula of the second correction coefficient k2 is as follows: When N≤3 years, R≤3 times, k2=1.0; When 3<N≤5 years, R≤3 times, k2=1.1; When 3<N≤5 years, R>3 times, k2=1.2; When N>5 years and R>3 times, k2=1.3.

[0042] In step S420, the stacking type refers to the laying method and arrangement of the cable line during installation. The stacking effect coefficient is a coefficient set according to the stacking type of the cable, which is used to quantify the impact of the stacking method on the voltage of the cable line. It should be noted that the stacking type of cable lines in the target area is usually buried horizontal stacking or overhead stacking, and the number of stacking layers is generally multiple layers. Buried horizontal stacking will lead to reduced cable spacing and limited heat dissipation. When the surface temperature of the cable line increases, the voltage resistance characteristics of the cable surface insulation material may decrease, which will make the cable line more prone to voltage overload under high load, resulting in a corresponding decrease in the voltage fluctuation threshold; when the overhead stacked cable lines are subjected to external forces, such as wind and ice and snow loads, mechanical stress will be generated, causing the insulation material of the cable line to deform, thereby increasing resistance and affecting the voltage load. When the connection points of the overhead stacked cable lines are subjected to mechanical stress, poor contact or short circuit may occur, affecting the overall voltage stability. Therefore, the stacking utility coefficient k can be calculated by temperature and mechanical stress. s , k s The calculation formula is as follows: When the stacking type is buried horizontal stacking, ; When the stack type is overhead stack, .

[0043] Among them, α is the first empirical coefficient, which reflects the influence of temperature on the withstand voltage characteristics of the cable line, T s is the cable surface temperature, T e is the real-time ambient temperature in °C. The value of α is usually between 0.05 and 0.15. s The larger the value of α is, the larger the value of β is. β is the second empirical coefficient, which reflects the influence of external force on the withstand voltage characteristics of the cable line. w is the force exerted by the wind on the cable, F i It is the force exerted on the cable by the ice and snow load. F0 is the reference value of external force resistance when designing the cable line. The unit is N / m. The value of β is usually between 0.1 and 0.5. The greater the external force, the greater the value of β.

[0044] For example, when the stacking type is buried horizontal stacking, T s At 50°C, T e is 20℃ and α is 0.1, then the calculated stacking utility coefficient is 0.15.

[0045] In step S430 and step S440, the third correction coefficient k3 is a comprehensive coefficient calculated by combining the second correction coefficient and the stacking effect coefficient. c The calculation formula is as follows: k3=k2×k s ; U c =k3×U f .

[0046] Among them, Uf is the voltage fluctuation threshold, in V.

[0047] The calculation of the second correction coefficient fully considers the service life and fault record of the cable line, so that the correction threshold under different operating conditions can be calculated more accurately. By introducing the stacking effect coefficient, the voltage fluctuation of the cable line under different stacking types can be evaluated more accurately. The voltage fluctuation threshold is adjusted by the third correction coefficient, which further improves the sensitivity of the voltage fluctuation threshold, thereby improving the accuracy of fault warning.

[0048] [Fifth embodiment] See also Figure 4 In a specific embodiment, if the cable line is marked as a line to be maintained, the line to be maintained is marked in the location image, specifically including: S610, acquiring attribute information data of the cable line, inputting the attribute information data into a data management library, and marking the line to be maintained; S620, within the first time period after the maintenance of the line to be maintained is completed, the location image will be updated; S630, when the position image is updated, the position image before the update is recorded as the initial image, the position image after the update is recorded as the updated image, and the cable line in the updated image is recorded as the updated circuit; S640, calculating the shielding rate of the update circuit in the update image according to the GIS system; S650, when the shielding rate is greater than or equal to the shielding threshold, it is necessary to perform wiring combing on the update circuit, and update the position image again after the wiring combing is completed; S660. When the masking rate is less than the masking threshold, the initial image is compared with the updated image according to the attribute information data to identify the changed line, and according to the changed line, it is determined whether to enter the updated image into the GIS system.

[0049] In step S610 to step S660, the attribute information data refers to various information related to the cable line, including the model, installation time and rated load of the cable line. The first time period refers to the location image update stage immediately after the maintenance work is completed. The first time period is usually 5 to 15 minutes, preferably 8 minutes, 10 minutes and 12 minutes. Update refers to the process of using the image as the initial image for the next update after each updated image is entered into the GIS system. The obscuration rate refers to the degree to which the cable line is obscured by other objects or other lines in the updated image, usually expressed as a percentage. The obscuration threshold is a preset standard value used to determine whether the cable line needs to be re-wired. The obscuration threshold is usually less than 20%. The changed line refers to the cable line that has changed in the updated image compared with the initial image, usually including the cable line that has been increased, decreased and the attribute information data changed in the updated image after maintenance.

[0050] It should be noted that after each maintenance work is completed, the staff must enter the main tasks of this maintenance in the maintenance management system according to the fault conditions of the line to be maintained, including line installation, line integration and line replacement operations. Then, through the maintenance management system, the GIS system will update the location image of the cable line after maintenance. If the obscuration rate of the updated image is greater than or equal to the obscuration threshold due to bad weather such as rain, snow or fog, the staff can change the length of the first time period in the maintenance management system and update the location image after the bad weather ends. When the obscuration rate of the updated image is less than the obscuration threshold, it will be compared with the initial image. When the maintenance management system recognizes that the task is completed, the updated image can be entered into the GIS system.

[0051] For example, when the maintenance task is line installation, after completing the maintenance work, the staff needs to enter the line installation on the maintenance management system. Through the maintenance management system, the GIS system updates the location image of the cable line after maintenance. When the masking rate of the updated image is less than the masking threshold, the updated image is compared with the initial image to determine whether a new cable line has been added. If so, the maintenance management system will determine that the task is completed and enter the updated image into the GIS system.

[0052] Collecting and storing attribute information data can help staff achieve efficient management of cable lines and ensure the accuracy and timeliness of maintenance work. By updating, the accuracy and effectiveness of location image monitoring are improved, thereby improving the accuracy of positioning the lines to be maintained. Comparing the shielding rate and shielding threshold can enable staff to efficiently determine whether further measures need to be taken after the maintenance work is completed, thereby saving time and resources and reducing the difficulty of future maintenance. Identifying changed lines helps to promptly detect changes in cable lines after updates and ensure the accuracy of location image information.

[0053] [Sixth embodiment] See also Figure 5 In a specific embodiment, if not, the maintenance response time required for the line to be maintained is calculated according to the location image, and a correction coefficient is set according to the maintenance response time, specifically including: S710, determining the maintenance center closest to the line to be maintained according to the GIS system, and calculating the maintenance response time from the maintenance center to the line to be maintained; S720, obtaining the theoretical waiting time of the line to be maintained according to the maintenance plan of the maintenance center within the target time period; S730. Set a correction coefficient according to the maintenance response time and the theoretical waiting time.

[0054] In step S710 to step S730, the maintenance center is the place responsible for the maintenance and repair of the cable line, which is usually equipped with professional staff and necessary equipment. The maintenance response time is the time required from the maintenance center receiving the maintenance task of the line to be maintained to the staff arriving at the line to be maintained. The maintenance plan is the work arrangement made by the maintenance center according to the demand and resource conditions, such as the maintenance and inspection activities to be carried out within the target time period. The theoretical waiting time refers to the estimated time between the issuance of the maintenance request and the start of the actual maintenance of the line to be maintained under a given maintenance plan. The correction coefficient is a correction parameter set according to the maintenance response time T1 and the theoretical waiting time T2. The calculation formula of the correction coefficient e is as follows: e=(T2-T1)÷T0.

[0055] Among them, T0 is the historical average response time of the target area calculated based on historical maintenance data.

[0056] It should be noted that when the maintenance response time is less than or equal to the theoretical waiting time, it means that the maintenance work of the line to be maintained is facing delays. At this time, it is necessary to calculate the correction coefficient and correct the theoretical fluctuating voltage so that the early warning of the line to be maintained can be advanced and the line to be maintained has sufficient maintenance response time. When the maintenance response time is greater than the theoretical waiting time, the staff of the maintenance center can maintain the line to be maintained according to the original work plan without calculating the correction coefficient.

[0057] For example, when the maintenance response time is 9 hours and the theoretical waiting time is 18 hours, a correction factor needs to be calculated. When the historical average response time is 10 hours, the calculated correction factor is 0.9.

[0058] The calculation of maintenance response time takes into account the distance between the maintenance center and the line to be maintained, allowing staff to more accurately assess the time required to reach the line to be maintained. The theoretical waiting time reflects the estimated waiting time of the line to be maintained in the maintenance plan, providing a basis for the calculation of the correction factor.

[0059] [Seventh embodiment] See also Figure 5 In a specific embodiment, the correction voltage is calculated according to the correction coefficient and the theoretical fluctuation voltage, and the warning condition is modified according to the correction voltage and the correction threshold, specifically including: S810, when the correction voltage is greater than or equal to the correction threshold, the warning condition has a first adjustment coefficient; S820: When the correction voltage is greater than or equal to the rated voltage and less than the correction threshold, the warning condition does not need to be adjusted; S830: When the corrected voltage is less than the rated voltage, the warning condition does not need to be adjusted.

[0060] In step S810 to step S830, the voltage U is corrected. r It is based on the correction coefficient e and the theoretical ripple voltage U t The first adjustment coefficient a1 is calculated to be a coefficient used to adjust the correction threshold in the early warning condition. The early warning condition refers to step S500. The correction voltage U r And the calculation formula of the first adjustment coefficient a1 is as follows: U r =e×U t ; a1=(U r -U t )÷U r .

[0061] The rated voltage is U z , the judgment conditions for modifying the warning conditions are as follows: When U r ≥U c When , the warning condition needs to be adjusted by the first adjustment coefficient; When U z ≤U r <U c When the warning condition is set, no adjustment is required; When U r <U z No adjustment is required for the warning conditions.

[0062] For example, when the rated voltage is 200V, the correction threshold is 280V, and the theoretical fluctuating voltage is 270V, at this time, the rated voltage < theoretical fluctuating voltage ≤ correction threshold, and the cable line does not meet the warning conditions. After the theoretical fluctuating voltage is corrected, the corrected voltage is 285V, then the corrected voltage ≥ correction threshold, indicating that the cable line meets the warning conditions. Therefore, it is necessary to adjust the correction threshold. When the first adjustment coefficient is 0.053, the correction threshold is lowered by 5.3% according to the first adjustment coefficient, and the lowered correction threshold is 265.16V.

[0063] By correcting the theoretical fluctuating voltage through the maintenance response time, it is possible to more accurately determine whether the cable line meets the warning conditions. The correction threshold is dynamically adjusted through the first adjustment coefficient to ensure that the cable line has more scientific and accurate warning conditions when issuing warnings, thereby preventing the risk of false alarms or missed alarms of fault warnings due to improper setting of the correction threshold, and improving the accuracy and reliability of fault warnings.

[0064] [Eighth embodiment] See also Figure 6 In one embodiment of the present invention, a GIS-based cable fault early warning system 100 is also provided. The early warning method recorded in the above embodiment is applied to the early warning system 100. The early warning system 100 includes: a storage module 110, in which a data management library is arranged; a monitoring module 120, in which the monitoring module 120 is used to monitor the voltage fluctuation threshold within a historical monitoring period; a prediction module 130, in which the prediction module 130 is used to predict the theoretical fluctuation voltage; a calculation module 140, in which the calculation module 140 is used to calculate the maintenance response time. The early warning system has all the technical features of the above early warning method, which will not be described one by one here.

[0065] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A cable fault early warning method based on GIS, characterized in that: The early warning method comprises: Establish a data management database, add the cable lines in the target area to the data management database, and obtain the location image and working information of the cable lines according to the GIS system; Determine the historical fluctuating voltage within the historical monitoring period according to the working information, obtain future meteorological data in the target area, and predict the theoretical fluctuating voltage according to the future meteorological data and the historical fluctuating voltage; Recording the historical maximum voltage within the historical monitoring period as the voltage fluctuation threshold; Correcting the voltage fluctuation threshold according to the operation status of the cable line and the position image to obtain a corrected threshold; Obtaining the rated voltage of the cable line, and judging whether the cable line meets the early warning condition according to the rated voltage, the theoretical fluctuation voltage and the correction threshold; If so, the cable line is recorded as a line to be maintained, and the line to be maintained is marked in the location image; If not, calculating the maintenance response time required for the line to be maintained according to the position image, and setting a correction coefficient according to the maintenance response time; A correction voltage is calculated according to the correction coefficient and the theoretical fluctuating voltage, and the warning condition is modified according to the correction voltage and the correction threshold.

2. The early warning method according to claim 1, characterized in that: The determining of the historical fluctuating voltage within the historical monitoring period according to the working information, acquiring the future meteorological data in the target area, and predicting the theoretical fluctuating voltage according to the future meteorological data and the historical fluctuating voltage specifically includes: Determine the historical voltage data within the historical monitoring period according to the working information; Determining the peak power consumption period within the historical monitoring period according to the historical voltage data; Obtaining the peak voltage in each of the peak power consumption periods, calculating the average value of the peak voltage, and recording the average value as the historical fluctuating voltage; Determining future temperature data within a target time period according to the future meteorological data; Determine a first correction coefficient according to the month in which the target time period is located and the future temperature data; The theoretical fluctuating voltage is predicted according to the first correction coefficient and the historical fluctuating voltage.

3. The early warning method according to claim 2, characterized in that: The determining of the first correction coefficient according to the month of the target time period and the future temperature data specifically includes: According to the historical voltage data of each month, a voltage fluctuation coefficient is set; The month in which the target time period falls is recorded as the target month, and the month corresponding to the target month in the historical monitoring period is recorded as the comparison month; Obtaining the unit average temperature of the comparison month according to the historical temperature data; Determine the future minimum temperature, future maximum temperature and future average temperature of the target time period according to the future temperature data; The first correction coefficient is calculated according to the unit average temperature, the future temperature data and the voltage fluctuation coefficient.

4. The early warning method according to claim 3, characterized in that: The step of correcting the voltage fluctuation threshold according to the operation status of the cable line and the position image to obtain a corrected threshold specifically includes: Obtaining the service life and fault records of the cable line according to the operation status, and setting a second correction coefficient according to the service life and the fault records; Acquire the stacking type of the cable line according to the position image, and set the stacking effect coefficient according to the stacking type; Calculate a third correction coefficient according to the second correction coefficient and the stacking effect coefficient; The correction threshold is calculated according to the third correction coefficient and the voltage fluctuation threshold.

5. The early warning method according to claim 4, characterized in that: If so, marking the cable line as a line to be maintained, and marking the line to be maintained in the location image specifically includes: Acquire the attribute information data of the cable line, input the attribute information data into the data management library, and mark the line to be maintained; The location image is updated within a first time period after the maintenance of the line to be maintained is completed; When the position image is updated, the position image before the update is recorded as the initial image, the position image after the update is recorded as the updated image, and the cable line in the updated image is recorded as the updated circuit; Calculating a shielding rate of the update circuit in the update image according to the GIS system; When the shielding rate is greater than or equal to the shielding threshold, it is necessary to perform wiring combing on the update circuit, and after the wiring combing is completed, the position image is updated again; When the masking rate is less than the masking threshold, the initial image is compared with the updated image according to the attribute information data to identify the changed line; According to the changed line, it is determined whether to enter the updated image into the GIS system.

6. The early warning method according to claim 5, characterized in that: If not, calculating the maintenance response time required for the line to be maintained according to the position image, and setting a correction coefficient according to the maintenance response time specifically includes: Determine the maintenance center closest to the line to be maintained according to the GIS system, and calculate the maintenance response time from the maintenance center to the line to be maintained; Obtaining the theoretical waiting time of the line to be maintained according to the maintenance plan of the maintenance center within the target time period; A correction coefficient is set according to the maintenance response time and the theoretical waiting time.

7. The early warning method according to claim 6, characterized in that: The calculating of the correction voltage according to the correction coefficient and the theoretical fluctuation voltage, and modifying the warning condition according to the correction voltage and the correction threshold value specifically include: When the correction voltage is greater than or equal to the correction threshold, the warning condition has a first adjustment coefficient; When the corrected voltage is greater than or equal to the rated voltage and less than the corrected threshold, the warning condition does not need to be adjusted; When the corrected voltage is less than the rated voltage, the warning condition does not need to be adjusted.

8. A cable fault early warning system based on GIS, characterized in that: The early warning method according to any one of claims 1 to 7 is applied to the early warning system, wherein the early warning system comprises: A storage module, wherein the data management library is arranged in the storage module; A monitoring module, the monitoring module is used to monitor the voltage fluctuation threshold within the historical monitoring period; A prediction module, the prediction module is used to predict the theoretical fluctuating voltage; A calculation module is used to calculate the maintenance response time.

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