CN-122017473-A - Intelligent chip-assisted cable fault accurate positioning system and cable

CN122017473ACN 122017473 ACN122017473 ACN 122017473ACN-122017473-A

Abstract

The invention relates to the field of power cable fault monitoring, and discloses an intelligent chip-assisted cable fault accurate positioning system and a cable, wherein the system comprises a test host and micro control nodes distributed along the cable, and is provided with a pulse transceiver module, a reference acquisition module, a centroid extraction module, a wave speed calibration module, a dynamic windowing module and a positioning resolving module, wherein the micro control nodes are pre-implanted in the cable; the system is used for constructing a local physical base line to acquire a centroid time stamp, resolving real-time local wave velocity, intercepting reflected wave characteristics by combining a dynamic integration time window, and synthesizing target absolute position coordinates. The absolute time synchronization error among the distributed nodes is eliminated by constructing a local physical base line, the wave speed change and the wave dispersion caused by the aging of the cable medium are self-adaptive by utilizing a dynamic windowing mechanism, the problem of feature extraction instability caused by a fixed window is solved, and the absolute precision of fault positioning is improved.

Inventors

ZONG XUAN
Shang Chaonan
XU GUANGYU
CHEN XILIANG
CHEN PENG
WU MEILING

Assignees

江苏宇久电缆科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The utility model provides an intelligent chip-assisted cable fault accurate positioning system, includes test host computer and distributes at the little control node of cable along the line that awaits measuring, its characterized in that, the system includes: the pulse receiving and transmitting module is used for injecting high-frequency pulses into the cable to be tested and establishing a communication link; the reference acquisition module is connected with a first high-frequency signal coupling end and a second high-frequency signal coupling end with fixed intervals to form a local physical base line, and acquires waveforms to generate a background discrete voltage sequence; The centroid extraction module integrates the background discrete voltage sequence to output a first centroid time stamp and a second centroid time stamp, and calls a dynamic integration time window parameter interception sequence to output a reflected wave centroid time stamp; The wave speed calibration module calculates real-time local wave speed by using the time difference between the local physical baseline value and the first centroid time stamp and the second centroid time stamp; the dynamic windowing module generates dynamic integration time window parameters according to the real-time local wave speed for the centroid extraction module to call; And the positioning calculation module calculates the relative distance by utilizing the real-time local wave speed and the difference value between the barycenter timestamp of the reflected wave and the first barycenter timestamp, and synthesizes the absolute position coordinates of the target feature points with the absolute physical coordinates of the micro control nodes.
2. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the pulse transceiver module comprises a pulse generating circuit, a low-frequency carrier modem, a broadband impedance matching network and a high-voltage isolation coupling device, wherein when a cable to be tested is in an electrified operation period, the pulse transceiver module injects high-frequency patrol pulses into the cable to be tested by utilizing a frequency domain passive frequency division network and a time division multiplexing logic and performs channel avoidance control, blocks low-frequency communication and performs suspension control in a time window for issuing the high-frequency patrol pulses, and resumes low-frequency carrier communication signals to be issued after passing an end boundary of the suspension time window.
3. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein a high-low-pass frequency division network is integrated in a front-end circuit of the reference acquisition module, the high-low-pass frequency division network separates a low-frequency communication branch and a high-frequency measurement branch, the reference acquisition module wakes a two-channel analog-to-digital converter after receiving a synchronization instruction issued by the low-frequency communication branch, performs multi-period synchronous accumulation average logic, and utilizes in-phase superposition of a plurality of high-frequency inspection pulses to offset background noise to extract waveform envelopes of the high-frequency inspection pulses and generate a background discrete voltage sequence.
4. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the centroid extraction module is provided with a background noise wake-up threshold, and opens an initial integration time window when the voltage amplitude in the background discrete voltage sequence rises and crosses the background noise wake-up threshold, and performs weighted average calculation on discrete time points in the initial integration time window by taking the absolute value of the discrete voltage amplitude in the background discrete voltage sequence as a weight parameter, so as to respectively obtain a first centroid time stamp and a second centroid time stamp corresponding to the forward propagation electromagnetic wave passing through the first high-frequency signal coupling end and the second high-frequency signal coupling end at two ends of the local physical base line.
5. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the wave speed calibration module extracts real-time local wave speed sequences acquired in at least two routing inspection periods set by history, synthesizes a medium state baseline through a weighted moving average algorithm, calculates a downward offset amplitude proportion of the real-time local wave speed relative to the medium state baseline, generates a local insulation damage early warning label when the downward offset amplitude proportion is greater than or equal to a preset baseline tolerance threshold, and packages the local insulation damage early warning label into a ranging data packet to be uploaded to a test host.
6. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the dynamic windowing module performs dispersion adaptive mapping according to real-time local wave speed, and when the real-time local wave speed is reduced, the dynamic windowing module performs scaling according to a pre-stored reference time window width, reference wave speed and dispersion adjustment factor, and increases the value of the dynamic integration time window parameter to enable the time window to cover a reflected wave energy envelope in which energy distribution is dispersed.
7. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the dynamic windowing module executes anti-divergence locking logic, and when the wave speed calibration module outputs the local insulation damage early warning label, the dynamic windowing module judges that the real-time local wave speed enters an unreliable interval and starts an anti-divergence locking mechanism, pauses a dispersion adaptive mapping calculation process, and locks a dynamic integral time window parameter backed up in a period of not generating the local insulation damage early warning label as a current output value to be issued to the centroid extraction module.
8. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the centroid extraction module presets a reflected wave search interval according to the total length value of the cable to be detected and the real-time local wave velocity value; when the background discrete voltage sequence voltage amplitude in the reflected wave searching interval crosses the background discrete voltage sequence voltage amplitude crossing the background discrete voltage sequence wake-up threshold again, the centroid extraction module takes the moment crossing the background discrete voltage sequence voltage amplitude crossing the background discrete voltage sequence as the reflected wave wake-up threshold as a reflected wave integration starting boundary, and the dynamic integration time window parameter output by the dynamic windowing module is called to execute waveform discrete integration operation on the reflected wave signal so as to obtain a reflected wave centroid time stamp.
9. The intelligent chip-assisted cable fault accurate positioning system according to claim 1, wherein the positioning resolving module invokes absolute physical coordinates of the installation position of the micro control node pre-stored in the nonvolatile memory of the micro control node, and performs linear superposition on the absolute physical coordinates of the installation position of the micro control node and a relative distance calculated by a reflected wave centroid timestamp, a first centroid timestamp and a real-time local wave velocity to obtain and output absolute position coordinates of a target feature point carrying an early warning tag in an early warning mode.
10. The cable is applied to the intelligent chip-assisted cable fault accurate positioning system according to any one of claims 1-9, and is characterized by comprising a conductor wire core, a crosslinked polyethylene insulating layer, an insulating shielding layer, a water blocking buffer layer, a metal armor layer and an anti-corrosion outer sheath which are sequentially coated from inside to outside, wherein a micro control node is implanted in the water blocking buffer layer in advance at a fixed physical interval along the axial direction of the cable, the micro control node is embedded between the outer side of the insulating shielding layer and the inner side of the metal armor layer, the micro control node is encapsulated in a conformal way by adopting epoxy resin or polyimide material, and a reference acquisition module, a centroid extraction module, a wave speed calibration module, a dynamic windowing module and a positioning calculation module are integrated inside the micro control node.

Description

Intelligent chip-assisted cable fault accurate positioning system and cable Technical Field The invention relates to the field of power cable fault monitoring, in particular to an intelligent chip-assisted cable fault accurate positioning system and a cable. Background Power cables are widely used in modern power grids, and in order to achieve rapid troubleshooting of cable faults, the industry generally adopts a time domain reflectometry or a technical scheme of deploying distributed monitoring nodes along the line. The prior art injects high-frequency test pulse into the cable end, monitors the reflected waveform generated by the impedance mutation point when the pulse signal propagates in the cable, records the time difference between the transmitted pulse and the reflected wave, and calculates the relative distance of the fault point by combining the theoretical wave velocity of the cable medium, thereby realizing the physical positioning of the fault position. The existing distributed monitoring scheme faces the error limit of physical time synchronization in practical application. Each distributed monitoring node typically employs an independent local clock source, limited by the inherent nature of hardware, with frequency offset and absolute time synchronization errors between nodes, which results in a shift in the recorded reference of the pulse time stamps. Meanwhile, background electromagnetic noise and power frequency harmonic interference exist in a cable environment in a live running state, signals of high-frequency test pulses are attenuated after long-distance transmission, reflection waveforms of the high-frequency test pulses are easy to be interfered by the environmental noise, and therefore the system is difficult to accurately extract transient voltage amplitude values and pulse arrival moments of the waveforms. The prior positioning technology mostly depends on a fixed waveform interception window and a theoretical wave speed reference value in the waveform characteristic extraction and distance dissociation calculation link. During the service of the cable, the aging or wetting of the medium causes dynamic changes in the propagation speed of the internal electromagnetic wave and causes dispersion and energy dispersion of the reflected waveform. The fixed waveform clipping window cannot accommodate the waveform stretching phenomenon, resulting in incomplete clipping of the reflected wave energy envelope. The truncation error in the characteristic extraction process can cause instability of the calculated reflected wave time stamp, and finally, the error caused by the change of the local wave velocity is superimposed and converted into absolute positioning deviation in the process of physical coordinate calculation. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an intelligent chip-assisted cable fault accurate positioning system and a cable, which solve the problems that the existing cable fault positioning technology has absolute time synchronization errors caused by independent clock source frequency deviation between distributed nodes, is easy to be interfered by background noise and power frequency harmonic waves in an electrified operation environment, and in addition, the aging or damp of a cable medium can cause dynamic change of internal wave velocity and dispersion of reflected waveforms, so that a fixed waveform interception window generates reflected wave characteristic extraction instability, and further generates absolute positioning deviation in the process of physical coordinate calculation. In order to achieve the above purpose, the invention is realized by the following technical scheme that the first aspect of the invention provides an intelligent chip-assisted cable fault accurate positioning system, which comprises a test host and micro control nodes distributed along a cable to be tested, wherein the system comprises: The pulse receiving and transmitting module is configured at the test host end, and is used for injecting high-frequency test pulses or high-frequency inspection pulses into the cable to be tested and establishing a carrier communication link; The reference acquisition module is configured in the micro control node, and is connected with a first high-frequency signal coupling end and a second high-frequency signal coupling end with fixed physical spacing based on a single local clock source to construct a local physical baseline, so as to acquire a waveform sequence and generate a background discrete voltage sequence; the centroid extraction module is used for carrying out waveform discrete integration on the background discrete voltage sequence, outputting a first centroid time stamp and a second centroid time stamp, calling a dynamic integration time window parameter interception sequence when receiving the reflected wave, and outputting a reflected wave centroid time stamp; The wave speed calibration module ca