CN118311369A - State identification and target cable positioning method for secondary cable - Google Patents

State identification and target cable positioning method for secondary cable Download PDF

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Publication number
CN118311369A
CN118311369A CN202410241336.0A CN202410241336A CN118311369A CN 118311369 A CN118311369 A CN 118311369A CN 202410241336 A CN202410241336 A CN 202410241336A CN 118311369 A CN118311369 A CN 118311369A
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China
Prior art keywords
cable
target
frequency
target cable
signal
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Pending
Application number
CN202410241336.0A
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Chinese (zh)
Inventor
杜鹏飞
张开普
邢毅川
程一凡
史雷敏
张宏涛
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Xuchang Power Supply Co of Henan Electric Power Co
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Xuchang Power Supply Co of Henan Electric Power Co
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Priority to CN202410241336.0A priority Critical patent/CN118311369A/en
Publication of CN118311369A publication Critical patent/CN118311369A/en
Pending legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/10—Complex mathematical operations
    • G06F17/14—Fourier, Walsh or analogous domain transformations, e.g. Laplace, Hilbert, Karhunen-Loeve, transforms
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Pure & Applied Mathematics (AREA)
  • Mathematical Optimization (AREA)
  • Mathematical Analysis (AREA)
  • Data Mining & Analysis (AREA)
  • Computational Mathematics (AREA)
  • Algebra (AREA)
  • Databases & Information Systems (AREA)
  • Software Systems (AREA)
  • General Engineering & Computer Science (AREA)
  • Locating Faults (AREA)

Abstract

The invention discloses a state identification and target cable positioning method for a secondary cable, which comprises the following steps: data acquisition, data processing, amplitude deviation calculation, correlation coefficient calculation, target cable head end identification, target cable head end input high-frequency signals and acquisition of high-frequency signals in a cable channel to determine a target cable; the invention can judge the running state of the cable, accurately and effectively identify and position the target cable, and protect the safety of personnel and equipment.

Description

State identification and target cable positioning method for secondary cable
Technical Field
The invention belongs to the technical field of cable detection and positioning, and particularly relates to a state identification and target cable positioning method for a secondary cable.
Background
The transformer substation is internally provided with a plurality of secondary cables, the head end and the tail end of the secondary cables are respectively connected into a screen cabinet of the transformer substation, the middle part of the secondary cables is usually laid in a cable trench, and the running state of the cables cannot be timely distinguished due to the fact that the number of the cables is large and the length of the cables is long, for example, the secondary cables are inevitably or touched in the overhaul process, loose connection is easy to cause virtual connection, and if the secondary cables are not timely found, secondary short circuit or open circuit of a transformer is caused in serious cases.
In addition, when a secondary cable for transmitting voltage in a set of protection, measurement and control or metering device needs to be replaced, the number of secondary cables with the same number in the voltage switching cabinet is large, so that a target secondary cable is difficult to find, the traditional method for positioning the target cable is that the target secondary cable to be removed is removed from the protection, measurement or metering device and is subjected to insulation wrapping, then the target cable is electrified to be removed to the voltage switching cabinet, one person visually observes the position of the target cable in the switching cabinet by shaking the cable to be removed, in the operation process of the electrified violent cable removing mode, once insulation wrapping is not firm, a secondary short circuit of a voltage transformer is caused, primary equipment is burnt, even personal safety is threatened, and for the cable to be removed, the method for manually observing the target cable is adopted, so that the accuracy is not high, time and labor are wasted, protection misoperation can be caused once errors occur, and human eyes of the secondary cable with virtual connection hidden danger can not be distinguished.
Therefore, to solve the above-mentioned problems, it is necessary to develop a state recognition and target cable positioning method for the secondary cable.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a state identification and target cable positioning method for a secondary cable, which can judge the running state of the cable, accurately and effectively identify and position the target cable and protect the safety of personnel and equipment.
The purpose of the invention is realized in the following way: a state identification and target cable positioning method for a secondary cable comprises the following steps:
S1, data acquisition; collecting a cable signal u n (t) which normally runs in a screen cabinet of a transformer substation as a reference signal, and sequentially collecting other cable signals u m (t) outside a reference signal cable, wherein m epsilon N + is the number of cable cores in the screen cabinet, the sampling frequency is 1kHz, and t is the sampling time;
S2, data processing; calculating characteristic components of the acquired cable signals:
Δun(t)＝un(t)-un(t-T)
Δum(t)＝um(t)-um(t-T)；
Wherein T represents an alternating current power frequency period; the fundamental frequency magnitudes U m and U n of U m (t) and U n (t) are then calculated using a fast fourier transform;
s3, calculating amplitude deviation; calculating the fundamental frequency amplitude deviation delta of the reference signal and the signal to be measured by the following steps:
S4, calculating a correlation coefficient; the correlation coefficients R mn of the reference signals Δu n (t) and Δu m (t) are calculated by:
Wherein k is the total number of sampling points;
S5, identifying the head end of the target cable; judging whether R mn·δ<pset is met, if yes, judging that the cable is the head end of the target cable, and performing the work of the step S6, if not, judging that the cable is a normal operation cable, and returning to the step S1, wherein p set is a correlation coefficient threshold;
s6, inputting a high-frequency signal; inputting a high-frequency signal at the head end of a target cable, and determining that a target is in a grounding range before inputting;
and S7, collecting high-frequency signals in the cable channel, and determining the target cable.
Further, the target cable comprises a standby cable and a hidden danger cable.
Further, in the step S5, the correlation coefficient threshold p set takes a value of 0.97.
Further, in the step S6, a high-frequency signal generator is used to input a high-frequency signal to the head end of the target cable.
Further, the high-frequency signal in the step S6 is a signal having a frequency of 200Hz or more.
Further, in step S7, a measuring instrument consisting of a measuring coil and a handheld oscilloscope is adopted to screen the cables in the cable channel one by one, and the cable with the high-frequency signal is the target cable.
Due to the adoption of the technical scheme, the invention has the beneficial effects that: through the cable signal in the collection transformer substation screen cabinet to normal operating's cable signal is the benchmark, whether is waiting to move back or the target cable of hidden danger state judges the discernment, then through the head end injection high frequency signal at this target cable, through the position of this high frequency signal in order to confirm target cable of collection in the cable pit, realize quick accurate location target cable, need not the manual visual inspection, reduce violent damage cable and to the influence of operation cable, improve fortune dimension personnel work efficiency, reduce intensity of labour, the safety of protection personnel and equipment.
Drawings
Fig. 1 is a flow chart of the present invention.
Detailed Description
The technical scheme of the invention is further specifically described below through examples and with reference to the accompanying drawings.
As shown in fig. 1, a method for identifying the state of a secondary cable and positioning a target cable includes the following steps:
S1, data acquisition; and acquiring a cable signal u n (t) of normal operation in a screen cabinet of the transformer substation as a reference signal, and sequentially acquiring other cable signals u m (t) outside a reference signal cable, wherein m epsilon N + is the number of cable cores in the screen cabinet, the sampling frequency is 1kHz, and t is the sampling time.
S2, data processing; calculating characteristic components of the acquired cable signals:
Δun(t)＝un(t)-un(t-T)，
Δum(t)＝um(t)-um(t-T)；
Wherein T represents an alternating current power frequency period; the fundamental frequency magnitudes U m and U n of U m (t) and U n (t) are then calculated using a fast fourier transform.
S3, calculating amplitude deviation; calculating the fundamental frequency amplitude deviation delta of the reference signal and the signal to be measured by the following steps:
S4, calculating a correlation coefficient; the correlation coefficients R mn of the reference signals Δu n (t) and Δu m (t) are calculated by:
Where k is the total number of sampling points.
S5, identifying the head end of the target cable; and judging whether R mn·δ<pset is met, if yes, judging that the cable is a target cable, namely the head end of the cable to be backed off or the hidden danger cable, performing the work of the step S6, if not, judging that the cable is a normal operation cable, and returning to the step S1, wherein p set is a correlation coefficient threshold value, and specifically, the value of the correlation coefficient threshold value p set is 0.97.
S6, inputting a high-frequency signal; the method comprises the steps of inputting a high-frequency signal into the head end of a target cable, namely a cable to be backed off or a hidden danger cable, determining that a target is in a grounding range before inputting, and inputting the high-frequency signal into the head end of the target cable by using a high-frequency signal generator, wherein the high-frequency signal is a signal with the frequency of more than 200 Hz.
S7, collecting high-frequency signals in a cable channel, and determining a target cable; specifically, a measuring instrument consisting of a measuring coil and a handheld oscilloscope is adopted to screen cables in a cable channel one by one, and the cable with high-frequency signals is the target cable.
Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same, and although the present invention has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention, and any modifications and equivalents are intended to be encompassed in the scope of the claims of the present invention.

Claims (6)

1. A state identification and target cable positioning method for a secondary cable is characterized by comprising the following steps of: the method comprises the following steps:
S1, data acquisition; collecting a cable signal u n (t) which normally runs in a screen cabinet of a transformer substation as a reference signal, and sequentially collecting other cable signals u m (t) outside a reference signal cable, wherein m epsilon N + is the number of cable cores in the screen cabinet, the sampling frequency is 1kHz, and t is the sampling time;
S2, data processing; calculating characteristic components of the acquired cable signals:
Δun(t)＝un(t)-un(t-T)
Δum(t)＝um(t)-um(t-T)；
Wherein T represents an alternating current power frequency period; the fundamental frequency magnitudes U m and U n of U m (t) and U n (t) are then calculated using a fast fourier transform;
s3, calculating amplitude deviation; calculating the fundamental frequency amplitude deviation delta of the reference signal and the signal to be measured by the following steps:
S4, calculating a correlation coefficient; the correlation coefficients R mn of the reference signals Δu n (t) and Δu m (t) are calculated by:
Wherein k is the total number of sampling points;
S5, identifying the head end of the target cable; judging whether R mn·δ<pset is met, if yes, judging that the cable is the head end of the target cable, and performing the work of the step S6, if not, judging that the cable is a normal operation cable, and returning to the step S1, wherein p set is a correlation coefficient threshold;
S6, inputting a high-frequency signal; inputting a high-frequency signal at the head end of the target cable, and determining that the target cable is in a grounding range before inputting;
and S7, collecting high-frequency signals in the cable channel, and determining the target cable.
2. The method for identifying the state of a secondary cable and locating a target cable according to claim 1, wherein: the target cable comprises a cable to be backed and a hidden danger cable.
3. The method for identifying the state of a secondary cable and locating a target cable according to claim 1, wherein: in the step S5, the correlation coefficient threshold p set takes a value of 0.97.
4. The method for identifying the state of a secondary cable and locating a target cable according to claim 1, wherein: in the step S6, a high-frequency signal generator is used to input a high-frequency signal to the head end of the target cable.
5. The method for identifying the state of a secondary cable and locating a target cable according to claim 1, wherein: the high-frequency signal in the step S6 is a signal with a frequency of 200Hz or more.
6. The method for identifying the state of a secondary cable and locating a target cable according to claim 1, wherein: in the step S7, a measuring instrument consisting of a measuring coil and a handheld oscilloscope is adopted to screen the cables in the cable channel one by one, and the cable with the high-frequency signal is the target cable.
CN202410241336.0A 2024-03-04 2024-03-04 State identification and target cable positioning method for secondary cable Pending CN118311369A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202410241336.0A CN118311369A (en) 2024-03-04 2024-03-04 State identification and target cable positioning method for secondary cable

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202410241336.0A CN118311369A (en) 2024-03-04 2024-03-04 State identification and target cable positioning method for secondary cable

Publications (1)

Publication Number Publication Date
CN118311369A true CN118311369A (en) 2024-07-09

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ID=91721254

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202410241336.0A Pending CN118311369A (en) 2024-03-04 2024-03-04 State identification and target cable positioning method for secondary cable

Country Status (1)

Country Link
CN (1) CN118311369A (en)

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