An old low-voltage cable multi-fault intelligent identification and positioning system

Abstract

The application discloses an old low-voltage cable multi-fault intelligent identification and positioning system, and belongs to the technical field of cable fault identification and positioning. The system comprises a mobile terminal, a signal collector, a current collection assembly, a voltage collection assembly and an intelligent cable fault tester. The signal collector is in wireless communication connection with the mobile terminal. The current collection assembly and the voltage collection assembly are electrically connected with the signal collector and used for collecting electric parameter signals of the cable. The intelligent cable fault tester is in a split structure independent of the mobile terminal and is used for off-line ranging and positioning of cable faults. The application provides an intelligent identification and positioning system with a split portable design and off-line accurate ranging and positioning.

Description

Technical Field

[0001] This invention relates to the field of cable fault identification and location technology, and in particular to an intelligent identification and location system for multiple faults in old low-voltage cables. Background Technology

[0002] In the daily operation and maintenance of power systems and distribution networks, monitoring cable status and troubleshooting, especially in older transformer substations, are crucial for ensuring power supply reliability and safety. With the continuous expansion of the power grid and the improvement of its intelligence level, the requirements for portability, accuracy of fault identification, and system response efficiency of cable fault detection equipment are also constantly increasing.

[0003] Most current monitoring systems adopt a centralized processing and wired communication architecture. However, in actual operation, this approach has many problems, such as cumbersome wiring process. When performing live-line repairs on old transformer substations, the complex wiring connections not only increase the difficulty of operation but also bring significant safety hazards.

[0004] At the same time, because a large amount of raw data is directly transmitted to the host for centralized processing, the host's computing pressure is often too high, and the system's anti-interference ability is weak in complex electromagnetic environments.

[0005] Meanwhile, traditional cable fault testing instruments are often bulky and integrated, making them inconvenient for on-site operators to carry or move flexibly. In actual testing, existing equipment struggles to accurately locate and efficiently identify complex faults such as open circuits, short circuits, and low-resistance grounding in cables. It also suffers from problems such as large test blind zones and insufficient signal resolution, which fall far short of meeting the actual needs of rapid emergency repairs in modern power grids. Summary of the Invention

[0006] The purpose of this invention is to provide an intelligent identification and positioning system with a split, portable design and accurate offline ranging and positioning.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an intelligent identification and location system for multiple faults in old low-voltage cables, including a mobile terminal, a signal acquisition unit, a current acquisition component, a voltage acquisition component, and an intelligent cable fault tester; The signal acquisition device establishes a wireless communication connection with the mobile terminal. The current acquisition component and the voltage acquisition component are both electrically connected to the signal acquisition device and are used to acquire the electrical parameter signals of the cable. The intelligent cable fault tester is a separate structure independent of the mobile terminal, used for offline ranging and location of cable faults.

[0008] As a further description of the above technical solution: the mobile terminal integrates a data processing module, a touch screen, a network communication module, and a terminal power supply module; The data processing module is used to carry the time-series fluctuation correlation algorithm and the multi-fault state machine logic for intelligent fault identification, and the network communication module is used to conduct wireless communication and data synchronization with the signal acquisition device through an ad hoc network.

[0009] As a further description of the above technical solution: the signal acquisition device, as a local edge computing node, includes a data processing controller, and analog sampling and signal synthesis modules, a storage system, a clock system, a WIFI module, and indicator lights, which are respectively connected to the data processing controller; In addition, it includes a power supply module for the data acquisition unit, a step-down module, a charging module, and a lithium battery to power each module.

[0010] As a further description of the above technical solution: the current acquisition component includes a phase current sensor and a zero-sequence current sensor; The phase current sensor adopts an open-type clamp-on current transformer design, and the zero-sequence current sensor adopts a large-aperture flexible Rogowski coil or a large-aperture current transformer design.

[0011] As a further description of the above technical solution: the voltage acquisition component includes a puncture clamp and an alligator clamp; The piercing clip is equipped with an insulated piercing needle and a spring mechanism to pierce the insulation layer on the surface of old cables to form a power extraction port and to synchronously collect voltage signals.

[0012] As a further description of the above technical solution: the intelligent cable fault tester is designed based on the principle of low-voltage pulse reflection method. Its hardware system includes a core main control unit, as well as a pulse transmission unit, a signal receiving and conditioning unit, a high-speed acquisition unit, a power supply unit, a human-machine interaction unit, a storage and communication unit, and a protection interface unit connected to the core main control unit.

[0013] As a further description of the above technical solution: the data processing module has a set of zero drift and dead zone calibration parameters designed in the firmware, which can independently set the compensation value and dead zone shielding threshold for phase voltage, zero sequence voltage, phase current, neutral current, zero sequence current and leakage current.

[0014] As a further description of the above technical solution: the system adopts a hierarchical distributed architecture design. The mobile terminal, as the core host computer, can connect to multiple lower-level signal acquisition devices simultaneously. Each signal acquisition device can connect multiple current acquisition components and voltage acquisition components in parallel.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The system adopts a hierarchical distributed wireless architecture, using the data collector as an edge computing node to complete preliminary analysis and judgment. No on-site wiring is required, which effectively reduces the computing power pressure on the host computer, while enhancing anti-interference performance and significantly reducing the operational complexity of live-line emergency repairs in old transformer substations.

[0016] 2. The data acquisition unit has a high-frequency synchronous sampling function, and combined with the internal zero drift and dead zone calibration algorithm, it effectively eliminates hardware noise interference; by using phase current and large-aperture flexible zero-sequence sensor to directly perform physical measurement, it avoids synthesis error, thereby significantly improving the accuracy of fault identification.

[0017] 3. The intelligent cable fault tester adopts a split design, making it lightweight and portable. Based on the low-voltage pulse reflection method and dual-core hardware architecture, it can accurately measure the distance of faults such as open circuit, short circuit, and low-resistance grounding, and can quickly determine the fault type. It features a small blind zone and high resolution. Attached Figure Description

[0018] Figure 1 A hardware architecture diagram of the signal acquisition device according to the present invention is shown; Figure 2 A schematic diagram of a mobile terminal according to the present invention is shown; Figure 3 A schematic diagram of a single independent working scheme according to the present invention is shown; Figure 4 A schematic diagram of a multi-host collaborative working scheme according to the present invention is shown; Figure 5 A schematic diagram of the phase current sensor according to the present invention is shown; Figure 6 A schematic diagram of a zero-sequence current sensor according to the present invention is shown; Figure 7 A schematic diagram of the puncture clip according to the present invention is shown; Figure 8 A schematic diagram of the alligator clip according to the present invention is shown; Figure 9 A schematic diagram of the intelligent cable fault tester according to the present invention is shown; Legend: 100. Mobile terminal; 11. Data processing module; 12. Touch screen; 13. Network communication module; 14. Terminal power supply module; 200. Signal Acquisition Unit; 21. Step-down Module; 22. Charging Module; 23. Lithium Battery; 24. Acquisition Unit Power Supply Module; 25. Data Processing Controller; 26. Storage System; 27. Clock System; 28. WIFI Module; 29. ​​Indicator Light; 300. Current acquisition component; 31. Phase current sensor; 32. Zero-sequence current sensor; 400. Voltage acquisition component; 41. Puncture clip; 42. Alligator clip; 500. Intelligent cable fault tester; 51. Core main control unit; 52. Pulse transmission unit; 53. Signal receiving and conditioning unit; 54. High-speed acquisition unit; 55. Power supply unit; 56. Human-machine interaction unit; 57. Storage and communication unit; 58. Protection interface unit. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figures 1-9 The present invention provides a technical solution: an intelligent identification and location system for multiple faults in old low-voltage cables. The system mainly includes a mobile terminal 100, at least one signal acquisition unit 200, a current acquisition component 300 and a voltage acquisition component 400 connected to the signal acquisition unit 200, and a split-type intelligent cable fault tester 500 for offline precise distance measurement.

[0021] The system adopts a hierarchical distributed architecture design, highlighting high flexibility and strong anti-interference capability. With the mobile terminal 100 as the core host computer, it can simultaneously achieve wireless communication and data synchronization with up to 8 lower-level signal acquisition devices 200 through self-organizing networks (such as based on Wi-Fi Ad-Hoc mode or dedicated radio frequency bands). The system has a built-in microsecond-level time synchronization mechanism to ensure that multiple sampling points collect voltage and current waveforms under a unified time reference, providing accurate time stamps for subsequent waveform correlation analysis.

[0022] Each signal acquisition unit 200, acting as a local edge computing node, can connect multiple current acquisition components 300 and voltage acquisition components 400 in parallel, thereby establishing a multi-level data sensing network. By introducing edge computing technology, not only is the computing load on the host significantly reduced, but the acquisition unit is also able to perform preliminary filtering of data, RMS calculation, and preliminary judgment of fault transient triggering on-site.

[0023] This architecture eliminates the need for on-site communication cabling, reducing the complexity of wiring and related safety hazards, and greatly meets the practical needs of emergency repair operations in old low-voltage distribution areas for "live testing and plug-and-play".

[0024] As the command and interaction core of the entire system, the mobile terminal 100 prioritizes industrial-grade rugged tablet devices, such as a 12.1-inch terminal with IP65 or higher protection standards, featuring drop resistance, dustproof, and waterproof characteristics.

[0025] The mobile terminal 100 integrates a data processing module 11, a touch screen 12, a network communication module 13, and a terminal power supply module 14, making it fully functional and reliable.

[0026] Thanks to the high-brightness touchscreen 12 that supports multi-touch (and operation with gloves), maintenance personnel can clearly and intuitively view real-time electrical parameters, equipment waveforms (supporting waveform scaling and translation measurement operations), and the final fault location and analysis results.

[0027] The interface design uses a graphical topology display format, with fault locations highlighted in red for easy and quick location.

[0028] The data processing module 11 is equipped with a high-frequency multi-core processor and runs a deeply optimized, highly anti-interference customized Android system to carry timing fluctuation correlation algorithms and multi-fault state machine logic. Through the algorithm layer, it analyzes the transient high-frequency waveforms synchronously uploaded by each node and can intelligently identify complex faults such as cable arcing short circuits and intermittent grounding based on the Pearson correlation coefficient or waveform morphology differences.

[0029] The network communication module 13 has a built-in 5G communication module and WiFi hotspot generator, enabling flexible and reliable connections. On the one hand, the module can establish high-frequency local communication with the field signal acquisition device 200 through the UDP / TCP protocol, ensuring efficient and lossless transmission of large transient waveform files. On the other hand, the module uploads the analysis results to the cloud power management platform through the MQTT or HTTP protocol, supporting cloud data archiving and remote expert consultation.

[0030] Each mobile terminal 100 is equipped with a high-performance WiFi hotspot (such as supporting the Wi-Fi 6 standard), which can connect to up to 8 signal collectors 200 at the same time to achieve high-density data transmission and control command interaction.

[0031] The system supports flexible operating modes, enabling it to run independently on a single machine or to collaborate with multiple hosts in a cross-regional environment.

[0032] For work scenarios in remote areas or without 5G network coverage, the device can autonomously collect and store transient data, and the built-in solid-state storage space (at least 128GB or more) can meet the local data storage needs.

[0033] Once the device re-enters network coverage, it will automatically resume transmitting cached data to the backend cloud server for centralized analysis and processing.

[0034] The terminal power supply module 14 adopts a dual power supply redundancy design and integrates a smart power management IC (PMIC), supporting two power supply methods: one is continuous power supply via an external Type-C adapter that supports fast charging protocol; the other is independent power supply through a built-in high-capacity lithium battery.

[0035] Under full-load operation with joint optimization of software and hardware, the system power consumption is stably controlled within 200VA; the built-in lithium battery pack (typical capacity of 10000mAh to 20000mAh) can still provide more than 2 hours of independent battery life after the device is disconnected from the external power source, which can ensure the smooth completion of tasks such as on-site mobile troubleshooting and emergency repair.

[0036] The signal acquisition unit 200 is equipped with a data processing controller 25, which can adopt a DSP+MCU or high-performance FPGA architecture and is responsible for core functions such as task scheduling, data calculation, network management and human-computer interaction within the system.

[0037] The data processing controller 25 is directly connected to each functional module through two parallel data buses for non-blocking transmission: the first high-speed data sampling bus (such as SPI or parallel bus) mainly interfaces with the analog front end for real-time extraction and push of raw waveform data and calculation results, thereby ensuring high-frequency waveform recording data throughput; the second local control bus (such as I2C or UART) connects to the peripheral system for storage, clock management and communication control, while enhancing system stability through physical isolation of control and data signals.

[0038] The left side of the architecture has five analog input ports, all equipped with overvoltage / overcurrent protection circuits and low-pass filters, for receiving raw signals from external sensors. These signals include three-phase voltage inputs (Ua, Ub, Uc), three-phase current and neutral point current inputs (Ia, Ib, Ic, In), as well as the I0 signal dedicated to zero-sequence current input.

[0039] The received analog signal will be input into a highly integrated analog circuit and digital signal processing module, which is equipped with a 16-bit to 24-bit high-precision ADC. It performs high-precision AD conversion through multiplexing and synchronous sampling, and supports sampling rates from 10kHz to 100kHz to capture transient high-frequency components.

[0040] In addition, the module calculates and synthesizes key power grid parameters in real time, thereby providing a synthetic current vector to help identify asymmetrical faults or single-phase grounding faults in the power grid.

[0041] The preprocessed data is transmitted to the data processing controller 25 via an internal centralized data bus that includes signal lines (e.g., Ua, Ub, Uc, U0, Ia, Ib, Ic, In, I0) and the device’s unique physical ID.

[0042] The signal acquisition unit 200 also integrates a solid-state storage system 26 (such as an eMMC chip) for caching local waveform data, which works in conjunction with a high-precision clock system 27 (including an RTC real-time clock) to generate accurate timing stamps.

[0043] The clock system 27 is also connected to the system status indicator 29, which makes it easy to intuitively see whether the device is online, sampling, or fault-triggered.

[0044] In addition, the data processing controller 25 is connected to the WIFI module 28, which communicates through a high-gain WIFI antenna, thereby providing stable wireless signal penetration capability in complex transformer substation environments.

[0045] The power system at the top of the architecture adopts a modular design, supports multiple power inputs, and is particularly outstanding in its ability to smoothly switch from passive to active power supply.

[0046] The core data acquisition power supply module 24 achieves wide voltage input through the three-phase voltage data lines (Ua, Ub, Uc) of the internal data bus, and uses the switching power supply module to supply power from the phase-to-phase voltage of the power grid, which is also the main power supply method of the system.

[0047] Meanwhile, the data acquisition unit is connected to a high-rate lithium battery 23 and a supercapacitor / high-speed seamless switching circuit. When the power grid environment is interrupted (such as a fault trip), the system can smoothly switch to battery power within <10ms, ensuring that the key waveform data recorded at the moment of the fault is not lost.

[0048] The lithium battery 23 is also equipped with an intelligent charging module 22 with temperature monitoring capabilities. The charging module 22 is connected to a standard Type-C interface through a step-down module 21 to support external charging input and equipment maintenance and debugging.

[0049] The current acquisition component 300 is divided into a phase current sensor 31 and a zero-sequence current sensor 32. It uses high magnetic permeability materials, such as permalloy or nanocrystalline iron core, to ensure excellent wideband response performance.

[0050] The phase current sensor 31 uses an open-type clamp-on current transformer (CT) design with an aperture of not less than 35mm and is equipped with anti-slip gear pads, which facilitates quick one-handed installation without cutting old cables; the sensor can collect real-time signals of Ia, Ib, Ic and In respectively.

[0051] The zero-sequence current sensor 32 adopts a design with a large aperture flexible Rogowski coil or a large opening current transformer (such as an aperture greater than 150mm) to cover the three-phase four-wire cable bundle. It accurately detects the zero-sequence current I0 generated by the three-phase imbalance through physical measurement, thereby effectively avoiding interference from calculation synthesis errors.

[0052] The voltage acquisition component 400 includes a piercing clip 41 and an alligator clip 42. The piercing clip 41 adopts a flame-retardant high-insulation PC (polycarbonate) shell and is equipped with a high-hardness insulating piercing needle and a constant torque spring mechanism inside. It can safely pierce the insulation layer on the surface of low-voltage cable with aging insulation to form a power extraction port without damaging the conductor cross-sectional area, and at the same time realize the synchronous acquisition of Ua, Ub and Uc voltage signals.

[0053] The alligator clip 42 is designed for exposed busbars or terminal blocks, facilitating quick clamping and measurement; all voltage circuits have built-in high-voltage current-limiting fuses, providing maximum personal and equipment safety protection in the event of a short circuit.

[0054] To meet the design requirements of reducing the size and weight of the main unit, the Intelligent Cable Fault Tester 500 is designed as a separate structure independent of the main unit, which can be used independently so that engineers can easily carry it and apply it flexibly in narrow or complex working conditions.

[0055] This device is specifically designed for detecting faults in low-voltage power cables, control cables, and signal cables with voltages of 0.4kV and below. Based on the principle of low-voltage pulse reflection, the device can accurately detect common faults in cables such as open circuits, short circuits, low-resistance grounding, and insulation aging. At the same time, it can quickly locate the fault point and measure the total length of the cable by using the product formula of waveform propagation time and wave velocity (L=v×t / 2).

[0056] The device operates based on an internal FPGA, which can generate low-voltage probe pulses with controllable width and frequency (pulse width adjustable from tens of nanoseconds to several microseconds, square wave with amplitude of tens of volts), and inject the pulses into the cable under test through a coupling circuit with impedance matching function.

[0057] When a pulse encounters an impedance mismatch point (i.e., a fault point or termination) in a cable, it generates a reflected echo. These signals are captured by a high-speed acquisition circuit with variable gain amplification.

[0058] The main control unit calculates the time difference between pulse transmission and echo reception by using extreme point or inflection point algorithms, and accurately calculates the fault distance by combining the cable wave velocity parameters.

[0059] Furthermore, by analyzing the polarity characteristics (positive polarity reflection indicates open circuit / high resistance, and reverse polarity reflection indicates short circuit / low resistance) and distortion characteristics of the reflected signal waveform, the fault type can be further determined.

[0060] The device adopts a dual-core hardware architecture of FPGA and STM32. The FPGA is responsible for nanosecond-level timing control and high-speed data throughput, while the STM32 is responsible for floating-point operations and state management, thereby realizing efficient collaboration between high-speed pulse signal processing and low-speed human-computer interaction.

[0061] The hardware system of the intelligent cable fault tester 500 includes a core main control unit 51, a pulse transmission unit 52, a signal receiving and conditioning unit 53, a high-speed acquisition unit 54 (with a built-in high-speed ADC with a sampling rate of up to 100MS / s to 200MS / s), a power supply unit 55 (equipped with a filter to provide clean analog power), a human-machine interaction unit 56 (including an LCD screen and physical buttons), a storage and communication unit 57, and a protection interface unit 58 (supporting opto-isolation to protect against pulse overvoltage impacts).

[0062] The overall design adopts a layered modular layout, with strict separation between digital and analog circuits. Copper-plated grounding shielding reduces the interference of digital high-frequency signals on analog echo signals. This tester not only has high sampling accuracy (blind zone less than 0.5 meters, ranging resolution up to 0.1 meters), high ranging accuracy and strong anti-interference capability, but also features portability and durability. It has a shockproof shell design and is suitable for outdoor and harsh working environments such as construction sites, residential areas, and industrial and mining enterprises, meeting the needs of various complex application scenarios.

[0063] To further achieve high-precision, adaptive, and stable operation of this system under complex conditions in old low-voltage distribution areas, the following section elaborates on the signal processing, parameter configuration, and communication mechanism of this application, based on specific equipment configurations and underlying data protocols.

[0064] The mobile terminal 100 (i.e., the low-voltage cable fault identification system) and the signal collector 200 (i.e., the low-voltage cable fault signal collector) adopt a strict "one master and multiple slaves" binding mechanism.

[0065] In a preferred embodiment, the product model of the mobile terminal 100 is designated as KLET-27MT, and its standard power supply specification is DC5V / 2A; the product model of each signal collector 200 is designated as KLET-27SC, and its power supply specification is DC5V / 1A.

[0066] The system is hard-bound using physical numbers during deployment. When the mobile terminal 100 is numbered 2601001, the physical numbers of its eight signal collectors 200 will be strictly assigned from 26010011 to 26010018.

[0067] When establishing a wireless local area network, the mobile terminal 100 will automatically generate a corresponding WiFi name (such as a 32-byte string, in the format DYDL-2601001) based on its own serial number, and configure the corresponding factory default password (such as 12345678).

[0068] This ensures rapid "plug-and-play" networking on-site and eliminates signal crosstalk issues during concurrent troubleshooting of multiple stations.

[0069] At the data acquisition level, the analog front end of the signal acquisition unit 200 and the data processing controller 25 perform high-precision floating-point operations (float type, single precision 4 bytes) on all input electrical quantities, and retain three decimal places of sampling precision throughout the entire range.

[0070] The telemetry signals collected comprehensively cover phase voltage (Ua, Ub, Uc), zero-sequence voltage (U0), phase current (Ia, Ib, Ic), neutral current (In), zero-sequence current (I0), and leakage current (Id).

[0071] In order to eliminate the interference of zero drift and environmental noise caused by long-term operation of hardware circuits on the identification of fault transient waveforms, the data processing module 11 has designed a set of "zero drift and dead zone" calibration parameters based on point number (HEX address) mapping in the firmware.

[0072] In "Expert Mode" or "Development Mode", maintenance personnel can set compensation values ​​for phase voltage zero drift (address 8000), zero-sequence voltage U0 zero drift (address 8001), phase current zero drift (address 8002), neutral current In zero drift (address 8003), zero-sequence current I0 zero drift (address 8004), and leakage current Id zero drift (address 8005).

[0073] For the dead zone shielding thresholds (addresses 8006 to 800B) configured for the above signals, the effective setting range is uniformly specified as 0 to 2000.

[0074] When the dead zone setting is equal to 0, it means that it is not enabled. When it is greater than 0, the corresponding dead zone filtering algorithm is automatically activated. Phase voltage, zero-sequence voltage, and various current signals can be independently controlled to enable or disable through specific Boolean type registers (such as addresses 800D to 8012, where a setting of 0 means disable and 1 means enable).

[0075] In addition, the system's data upload cycle supports wideband stepless adjustment from a minimum of 1 power frequency cycle to a maximum of 360 seconds, with a default value of 1 second, enabling the algorithm to adaptively control the computation timeliness under different load scenarios.

[0076] In terms of the underlying state machine and fault identification logic design, the signal acquisition unit 200 condenses massive waveform analysis information into concise state bytes (uchar type, length 1 byte), achieving multi-dimensional fault location and safety alarm with extremely low bandwidth usage.

[0077] For the "voltage identification state" of three-phase voltage (corresponding to addresses 0001 to 0003), the system can distinguish and output "0: invalid", "1: voltage state" and "2: voltage loss state" in real time.

[0078] For specific abnormalities in each phase of the line, the equipment can output the short circuit fault alarm status of the three phases A, B, and C through point numbers 000A to 000C (1: normal state, 2: short circuit fault status), and at the same time, it can output the leakage fault alarm status separately through point number 0014 (1: normal state, 2: leakage fault status).

[0079] More advancedly, this system integrates fine-grained identification of the operation and disconnection location of the disconnectors at the test points in the transformer area: point number 001E is specifically used to characterize the status of the disconnectors at the upper and lower levels of the test point (1: normal state, 2: upper level disconnector is open, 3: lower level disconnector is open).

[0080] Point numbers 001F to 0021 provide detailed disconnection fault status for phases A, B, and C, accurately distinguishing between "2: upper-level disconnection status" and "3: lower-level disconnection status".

[0081] The aforementioned status information is sent up cyclically according to a set period under normal operation. Once the background and lower-level machines detect any sudden change in fault characteristics, they will immediately exceed the normal periodic mechanism and trigger the sudden change over-limit sending mechanism to ensure the real-time alarm needs of on-site emergency repair and dispatch to the greatest extent.

[0082] At the network communication and data protocol level, a strict handshake rule is established between the mobile terminal 100 and the signal collector 200. The communication content is refined to cover four categories of messages: heartbeat, basic information, working status, and fault information, so as to achieve comprehensive life cycle management of the equipment.

[0083] Among them, the heartbeat message is initiated by the collector, and the mobile terminal 100 receives and returns it to form a closed-loop heartbeat, which is used to maintain the online keep-alive status of both devices.

[0084] When the device is first connected, the data collector must send a registration message to the backend terminal to register its basic information. This information strictly includes the device name, device model, information version number which is fixed at 1.00, manufacturer abbreviation, production date represented by a 4-byte integer timestamp, and unique serial number.

[0085] Only after basic information registration and successful verification can the system begin normal data sampling and protocol interaction. During the subsequent steady-state operation period, the data collector strictly sends working status messages cyclically at a frequency of once per minute; when a disturbance occurs in the distribution area, it immediately extracts the fault data acquisition slice and sends up a fault information message.

[0086] The underlying network communication not only supports both TCP and UDP communication modes, but also defaults to port 9527 to achieve bidirectional throughput of high-speed transient waveforms and protocol data with the server backend.

[0087] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-fault intelligent identification and location system for old low-voltage cables, characterized in that: Includes a mobile terminal (100), a signal acquisition unit (200), a current acquisition component (300), a voltage acquisition component (400), and an intelligent cable fault tester (500); The signal acquisition unit (200) establishes a wireless communication connection with the mobile terminal (100). The current acquisition component (300) and the voltage acquisition component (400) are both electrically connected to the signal acquisition unit (200) and are used to acquire the electrical parameter signals of the cable. The intelligent cable fault tester (500) is a separate structure independent of the mobile terminal (100) and is used for offline ranging and location of cable faults.

2. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 1, characterized in that: The mobile terminal (100) integrates a data processing module (11), a touch screen (12), a network communication module (13), and a terminal power supply module (14). The data processing module (11) is used to carry the time-series fluctuation correlation algorithm and the multi-fault state machine logic for intelligent fault identification. The network communication module (13) is used to conduct wireless communication and data synchronization with the signal acquisition unit (200) through the self-organizing network.

3. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 1, characterized in that: The signal acquisition unit (200) serves as a local edge computing node, and includes a data processing controller (25), an analog sampling and signal synthesis module, a storage system (26), a clock system (27), a WIFI module (28), and an indicator light (29) connected to the data processing controller (25). In addition, it also includes a data acquisition power supply module (24), a step-down module (21), a charging module (22), and a lithium battery (23) to power each module.

4. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 1, characterized in that: The current acquisition component (300) includes a phase current sensor (31) and a zero-sequence current sensor (32). The phase current sensor (31) adopts an open-type clamp-on current transformer design, and the zero-sequence current sensor (32) adopts a large-aperture flexible Rogowski coil or a large-aperture current transformer design.

5. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 1, characterized in that: The voltage acquisition component (400) includes a puncture clip (41) and an alligator clip (42). The piercing clip (41) is equipped with an insulating piercing needle and a spring mechanism inside, which is used to pierce the insulation layer on the surface of old cables to form a power outlet and to synchronously collect voltage signals.

6. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 1, characterized in that: The intelligent cable fault tester (500) is designed based on the principle of low-voltage pulse reflection method. Its hardware system includes a core main control unit (51), and a pulse transmission unit (52), a signal receiving and conditioning unit (53), a high-speed acquisition unit (54), a power supply unit (55), a human-machine interaction unit (56), a storage and communication unit (57), and a protection interface unit (58) connected to the core main control unit (51).

7. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 2, characterized in that: The data processing module (11) has a set of zero drift and dead zone calibration parameters designed in the firmware, which can independently set the compensation value and dead zone shielding threshold for phase voltage, zero sequence voltage, phase current, neutral current, zero sequence current and leakage current.

8. The intelligent identification and location system for multiple faults in old low-voltage cables according to claim 1, characterized in that: The system adopts a hierarchical distributed architecture design. The mobile terminal (100) serves as the core host computer and can connect to multiple lower-level signal acquisition units (200) simultaneously. Each signal acquisition unit (200) can connect multiple current acquisition components (300) and voltage acquisition components (400) in parallel.

Images