Portable multi-core secondary circuit wiring state detection system and detection method

Abstract

This invention discloses a portable multi-core secondary circuit cable wiring status detection system, comprising an independent signal generating device and a detection device. The signal generating device includes: a first control unit; a signal generating module; a first integrated connector; and a first isolation protection unit. The detection device includes: a second control unit; a multi-channel detection module; a second integrated connector; a human-machine interface unit; and a second isolation protection unit. The signal generating module is built based on an FPGA chip. The system is integrated into a single chassis equipped with a portable handle and a non-slip base. The control unit uses an STM32 main control chip to achieve human-machine interaction and data storage, is compatible with mainstream relay protection panel models, and can significantly reduce the number of disconnections, shorten the detection cycle, and improve the safety and convenience of on-site testing. This invention features a lightweight structure and simple operation, is suitable for on-site testing scenarios of secondary circuits in power system relay protection panels, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of power system secondary circuit detection technology, specifically to a portable multi-core secondary circuit cable wiring status detection system and method, which is suitable for simultaneous one-time detection of continuity, short circuit and insulation status of 21-core and above multi-core control cables. Background Technology

[0002] In the installation, commissioning, and maintenance of power system relay protection panels, the detection of secondary circuit wiring status is a critical step, directly affecting the reliable operation of the relay protection device. Currently, the industry commonly uses the traditional detection method of directly short-circuiting to introduce positive current, that is, directly connecting the positive power supply to the signal line under test by shorting the conductor, and judging the wiring status by observing the feedback signal of the relay protection device. However, this method has many drawbacks: First, directly introducing positive current can easily interfere with the electronic components of the original relay protection circuit, and may even lead to component damage; second, the detection process requires repeated disconnection and reconnection, which is cumbersome and inefficient, especially when used for multi-core circuits, where it is time-consuming; third, it lacks an effective isolation protection mechanism, posing a risk of electric shock to operators; fourth, it can only determine the continuity status and cannot achieve accurate detection of short circuits and insulation status, resulting in a limited detection function. Therefore, developing a portable detection device with safe isolation, multi-functional detection capabilities, and convenient operation has become an urgent need to address the pain points of existing technologies. Summary of the Invention

[0003] The purpose of this invention is to provide a portable multi-core secondary circuit cable wiring detection device. By physically separating the signal generator and the detection device, multiple sets of differentiated characteristic square wave signals are generated to achieve simultaneous detection of the continuity, short circuit, and insulation status of all cores in 21-core or higher cables. This improves detection efficiency, accuracy, and on-site deployment flexibility, while reducing safety risks.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A portable multi-core secondary circuit cable wiring status detection system includes an independent signal generating device and a detection device; the signal generating device includes: A first control unit; a signal generation module, controlled by the first control unit, for generating multiple square wave signals with different frequencies, pulse widths, or coding sequences, wherein the amplitude of each square wave signal is stable and consistent; a first integrated connector, having multiple output interfaces matching the number of core wires in the multi-core cable under test; a first isolation protection unit, connected between the signal generation module and the first integrated connector; wherein each output of the signal generation module is connected to each core wire at one end of the cable under test through an independent output interface of the first isolation protection unit and the first integrated connector, for injecting a specific set of square wave detection signals into each core wire; The detection device includes: A second control unit; a multi-channel detection module connected to the second control unit, having multiple independent detection channels matching the number of cable cores; a second integrated connector with multiple input interfaces matching the number of cores in the multi-core cable under test; a human-machine interface unit; and a second isolation protection unit connected between the second integrated connector and the multi-channel detection module. Each input interface of the second integrated connector is connected to an independent detection channel of the multi-channel detection module via the second isolation protection unit, for connecting to each core at the other end of the cable under test to synchronously acquire voltage signals on each core. The second control unit is configured to: synchronously analyze voltage signals from all detection channels; determine the continuity of the corresponding core by identifying the presence of a specific square wave characteristic in each signal; determine the short-circuit state between cores by analyzing the correlation between signals from different channels; and determine the insulation state by measuring the ground signal component of each channel.

[0005] Furthermore, the signal generation module is built based on an FPGA chip.

[0006] Furthermore, the second control unit incorporates a digital signal processing algorithm to filter, correlate, analyze the spectrum, and extract features from the acquired signal in order to identify specific square wave characteristics from the signal generator.

[0007] Furthermore, both the signal generating device and the detection device have built-in independent battery modules.

[0008] Furthermore, both the signal generating device and the detection device have built-in independent clock modules.

[0009] Furthermore, the signal generating device and the detection device are synchronized in time wirelessly or via wired means before the detection begins.

[0010] Furthermore, the human-computer interaction unit is a touch screen display.

[0011] Furthermore, the touch display screen is used to display a matrix of detection results indexed by the core wire number, and to highlight fault points such as broken wires, short circuits, and poor insulation with different colors or icons.

[0012] Furthermore, the system is integrated into a chassis equipped with a portable handle and a non-slip base.

[0013] This invention also discloses a cable wiring status detection method using the portable multi-core secondary circuit cable wiring status detection system, comprising the following steps: Step S1: At the beginning of the cable under test, connect all the output interfaces of the first integrated connector of the signal generator to all the core wires of the cable. Step S2: At the end of the cable under test, connect all the input interfaces of the second integrated connector of the testing device to all the core wires of the cable. Step S3: Start the signal generator, and its signal generation module injects a specific square wave detection signal into each core wire; Step S4: Start the detection device, and its multi-channel detection module will synchronously collect the voltage signals of all core wires at the end of the cable; Step S5: The second control unit of the detection device analyzes the signals of each channel, determines the continuity through feature recognition, determines the short circuit through signal comparison between channels, determines the insulation through signal-to-ground analysis, and outputs a complete status report of all core wires at once.

[0014] The beneficial effects of this invention are: Physically separated design, flexible deployment: The signal generating device and the detection device are completely independent and have no direct circuit connection. They can be deployed at both ends of the cable (supporting long-distance detection), adapting to complex wiring scenarios on site and solving the problem of limited wiring for integrated devices. Multi-feature signal recognition with high detection accuracy: It adopts square wave signals with different frequencies, pulse widths or coded sequences, combined with digital signal processing algorithms (filtering, correlation operation, spectrum analysis), to effectively resist the influence of cable distributed capacitance and electromagnetic interference. The false alarm rate of continuity judgment is ≤0.1%, and the accuracy of short circuit and insulation detection is industry-leading. Three-state synchronous detection with extremely high efficiency: It can simultaneously complete the continuity, short circuit and insulation status detection of all core wires at one time, without the need for core-by-core operation or equipment replacement. For a 21-core cable, the entire detection process only takes ≤3 minutes, which is more than 20 times more efficient than traditional methods. Dual isolation protection, safe and reliable: Both the signal generating device and the detection device are equipped with an isolation protection unit consisting of opto-isolation + TVS transient suppression diode combination, with a withstand voltage of ≥2500V, avoiding interference from the original circuit and high voltage surges, and completely solving the safety risks of introducing power supply in the traditional way; Portable and with ample battery life, suitable for the field: Both devices adopt a lightweight design (each unit weighs ≤5kg), are equipped with a portable handle and a non-slip base, and have a lithium battery life of ≥12 hours (signal generator) / 10 hours (detection device). They support fast charging and scenarios without external power supply, and are easy to operate without professional training. Visualized interaction and precise fault location: The touch screen displays the test results in a matrix format, with different colors highlighting fault points and clearly marking the specific core wire numbers of broken wires, short circuits, and poor insulation. Fault points can be quickly located without additional analysis. Attached Figure Description

[0015] Figure 1 This is a block diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the signal generation module of the present invention. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: like Figure 1 and 2 As shown, a portable multi-core secondary circuit cable wiring status detection system includes a physically separate signal generating device and a detection device. The two are not directly connected by circuit; signal association is achieved only through the multi-core cable under test. The specific structure is as follows: 1. Signal generating device The signal generator, as an independent excitation source, is used to inject a uniquely identified square wave detection signal into each core of the cable. It includes a first control unit, a signal generation module, a first integrated connector, a first isolation protection unit, a first battery module, and a clock module. The first control unit uses the STM32L4 series low-power main control chip as the control core of the signal generator. It communicates with the signal generator module through the SPI interface, sends square wave signal parameter configuration instructions (frequency, pulse width, encoding sequence), and achieves time synchronization through the clock module. It has built-in simple operation buttons and status indicator lights for starting signal output, parameter selection, and displaying working status (standby / working / low power / synchronization complete). Signal generation module: Based on FPGA chip, it realizes multi-channel independent signal generation through Verilog HDL programming. It can generate multiple square wave signals with different frequencies (1Hz-10kHz), pulse widths (10μs-100ms) or encoding sequences (8 bits-32 bits). The amplitude of each signal is stable and consistent (amplitude error ≤±3%), ensuring that each core wire corresponds to a unique and identifiable signal feature. After the signal is converted into an analog signal by digital-to-analog converter chip (DAC), it is output to the first isolation protection unit. The first integrated power strip is equipped with output interfaces that match the number of core wires in the cable under test (21 by default, expandable to 32). Each interface is marked with a unique core wire number (1-21). It adopts a differentiated shape design and a spring-loaded locking mechanism, which automatically locks after insertion to prevent it from falling off. Each channel inside the power strip is connected with an independent shielded wire to reduce signal crosstalk. The first isolation protection unit is composed of an opto-isolation chip (model 6N137) and a TVS transient suppression diode (model SMBJ6.5CA), connected in series between the signal generation module and the first integrated connector to achieve electrical isolation between the signal generation device and the cable under test. It has a withstand voltage rating of ≥2500V and can quickly respond to overvoltage and overcurrent impacts to prevent high voltage signals from the original circuit from entering the device. First battery module: It adopts a 12Ah lithium battery, supports 5V / 12V dual voltage output, powers all modules of the signal generator, and has a continuous working time of ≥12 hours; it has a built-in charging management chip (model TP4056) and overcharge, over-discharge and overcurrent protection circuits, supports USB-C interface fast charging, and is equipped with a power indicator light to display the remaining power. Clock module: Uses a high-precision RTC chip (model DS3231) with a timing accuracy of ≤±5ppm, used for time synchronization with the detection device to ensure the consistency of signal generation and acquisition timing. 2. Detection device The detection device serves as an independent detection and analysis terminal, used to synchronously acquire signals from each core of the cable and analyze their status. It includes a second control unit, a multi-channel detection module, a second integrated connector, a human-machine interface unit, a second isolation protection unit, a second battery module, and a clock module. The second control unit uses the STM32F407VET6 high-performance main control chip as the core of the detection device. It connects to the multi-channel detection module through the ADC interface (16-channel synchronous acquisition) to acquire signals from each detection channel. It has built-in digital signal processing algorithms (filtering, correlation operation, spectrum analysis, feature extraction) to identify square wave signal characteristics, analyze the signal correlation between channels, and calculate insulation resistance. It achieves time synchronization with the signal generator through a clock module to ensure synchronous acquisition. It has a built-in 8GB local storage module (SD card) to support the storage of more than 100,000 detection records. Multi-channel detection module: It has independent detection channels matching the number of cable cores (21 channels by default), including continuity detection submodule, short circuit detection submodule, and insulation detection submodule, and is connected to the second integrated connector through the second isolation protection unit. Continuity detection submodule: It adopts a high-speed voltage comparator (model LM311) with a response time of ≤5ms. It compares the collected voltage signal with the reference value and combines it with the feature recognition algorithm of the second control unit. If the corresponding square wave feature is detected, it is determined that the core wire is conducting; otherwise, it is determined that the wire is broken. Short circuit detection submodule: By collecting the phase difference and amplitude correlation of signals from different channels, when two or more channels detect the same square wave characteristics and the signal amplitude is abnormally attenuated (attenuation ≥ 50%), it is determined that there is a short circuit between the corresponding core wires. Insulation detection submodule: It has a built-in adjustable DC regulated power supply (model LM2596, output 0-50V) and a high-precision leakage current sensor (model CSNJ30M1, detection range 1μA-1mA). By applying DC voltage to the core wire, it measures the leakage current to ground. The second control unit calculates the insulation resistance according to the formula R=U / I (detection range 0-10MΩ, accuracy ±2%). When the insulation resistance is <1MΩ, it is judged as poor insulation. The second integrated power strip has the same structure as the first integrated power strip. It has input interfaces that match the number of cable cores, and each interface is labeled with the corresponding core number. It adopts a differentiated shape design and a spring-loaded locking mechanism to ensure quick and reliable connection with the cable end connector. Human-machine interface unit: A 7-inch capacitive touch screen, integrated with the second control unit, used to display the detection result matrix (indexed by core wire number, displaying core wire number horizontally, and displaying continuity status, short-circuit associated core wires, and insulation resistance value vertically), and highlighting fault points with different colors (red: open wire; yellow: short circuit; orange: poor insulation; green: normal); supports setting detection parameters (short circuit judgment threshold, insulation resistance threshold, signal feature matching threshold), querying / exporting detection records (USB / Bluetooth / Wi-Fi), and time synchronization. The second isolation protection unit has the same structure as the first isolation protection unit. It consists of an opto-isolation chip and a TVS transient suppression diode, which are connected in series between the second integrated connector and the multi-channel detection module to achieve electrical isolation between the detection device and the cable under test. The withstand voltage rating is ≥2500V to prevent high voltage signals from entering. Second battery module: Uses a 15Ah lithium battery, supports 5V / 12V / 24V three-voltage output, powers all modules of the detection device, and has a continuous working time of ≥10 hours; it has a built-in charging management chip and multiple protection circuits, supports USB-C interface fast charging, and is equipped with a power display screen to display the remaining power and charging status in real time. Clock module: Uses a high-precision RTC chip consistent with the signal generator for time synchronization. 3. System Coordination and Synchronization Logic The signal generator and the detection device synchronize their time via Bluetooth BLE 5.0: Before detection begins, both clock modules are activated, and time calibration is achieved through synchronization commands (synchronization error ≤ 1ms); after synchronization is completed, the signal generator outputs multiple square wave signals according to a preset timing sequence, and the detection device synchronously starts multi-channel acquisition to ensure that the acquisition and generation timing of each signal corresponds.

[0017] (III) Detection Methods A method for detecting cable wiring status using the above-mentioned detection system includes the following steps: Step S1: Cable Connection and Equipment Deployment At the beginning of the cable under test, connect all the output interfaces of the first integrated connector of the signal generator to all the core wires of the cable according to their corresponding core wire numbers; at the end of the cable under test, connect all the input interfaces of the second integrated connector of the detection device to all the core wires of the cable according to their corresponding core wire numbers, ensuring that the interfaces are securely locked. Step S2: Device Synchronization and Parameter Configuration Start the signal generator and detection device, and synchronize the time wirelessly. The status indicator light will light up after synchronization is complete. Select the preset square wave parameter scheme (or custom configuration) through the operation buttons of the signal generator, and set the detection parameters through the touch screen of the detection device: short circuit judgment amplitude attenuation threshold (default 50%), insulation resistance threshold (default 1MΩ), and signal characteristic matching threshold. Step S3: Signal Excitation and Synchronous Acquisition Press the "Start Output" button on the signal generator, and the signal generator module injects a uniquely identified square wave detection signal into each core wire according to preset parameters; the detection device automatically and synchronously starts the multi-channel detection module, and through the second integrated connector and the second isolation protection unit, it synchronously collects the voltage signal on all core wires at the end of the cable, with a collection time of ≥1 second (to ensure complete capture of square wave characteristics), and the collected data is transmitted to the second control unit in real time. Step S4: Signal Analysis and State Determination The second control unit performs synchronous analysis on all acquired channel signals: On / off status determination: Each signal is filtered and its features are extracted (frequency, pulse width, and coded sequence identification) using digital signal processing algorithms. If a specific square wave feature corresponding to the core wire of the channel is detected, the core wire is determined to be "conducting"; if no corresponding feature is detected, the core wire is determined to be "disconnected". Short circuit condition determination: Analyze the correlation of signals from all channels. If two or more channels detect the same square wave characteristics and the signal amplitude attenuation is greater than or equal to a preset threshold, then determine that the core wires corresponding to these channels are "short-circuited" and record the short-circuited core wire number combination (e.g., "core wire 2-core wire 5 short-circuited"). Insulation status determination: Apply a preset DC voltage to each core wire through the insulation detection submodule, measure the leakage current to ground, and calculate the insulation resistance value; if the insulation resistance is less than the preset threshold, the core wire is determined to be "insulation defective", otherwise it is determined to be "insulation normal".

[0018] Step S5: Result Output and Storage The touchscreen display of the testing device uses the core wire number as an index to display a matrix of testing results, highlighting fault points with different colors (red: open wire; yellow: short circuit; orange: poor insulation; green: normal), and pop-up windows display the total number of faults and specific fault information (such as "open wire 1: core wire 7; short circuit 2: core wires 2-5, core wires 11-13; poor insulation 1: core wire 15"). The testing results are automatically stored in the local storage module and can be exported to Excel format via USB / Bluetooth. Users can directly view or print the testing report.

[0019] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A portable multi-core secondary circuit cable wiring status detection system, characterized in that, The system includes independent signal generating and detection devices; The signal generating device includes: First control unit; The signal generation module, which is controlled by the first control unit, is used to generate multiple square wave signals with different frequencies, pulse widths or coding sequences, and the amplitude of each square wave signal is stable and consistent. The first integrated power strip has multiple output interfaces that match the number of cores in the multi-core cable under test; The first isolation protection unit is connected between the signal generation module and the first integrated connector. Each output of the signal generation module is connected to each core wire at one end of the cable under test through an independent output interface of the first isolation protection unit and the first integrated plug, for injecting a specific square wave detection signal into each core wire. The detection device includes: Second control unit; A multi-channel detection module, which is connected to the second control unit, has multiple independent detection channels that match the number of cable cores; The second integrated connector has multiple input interfaces that match the number of cores in the multi-core cable to be tested; Human-computer interaction unit; The second isolation protection unit is connected between the second integrated power strip and the multi-channel detection module; Each input interface of the second integrated power strip is connected to an independent detection channel of the multi-channel detection module through the second isolation protection unit, and is used to connect to each core wire at the other end of the cable under test to synchronously collect the voltage signal on each core wire. The second control unit is configured to: synchronously analyze voltage signals from all detection channels, determine the continuity status of the corresponding core wire by identifying whether there is a specific square wave characteristic in each signal; determine the short circuit status between core wires by analyzing the correlation between signals from different channels; and determine the insulation status by measuring the ground signal component of each channel.

2. The system according to claim 1, characterized in that, The signal generation module is built on an FPGA chip.

3. The system according to claim 1, characterized in that, The second control unit has a built-in digital signal processing algorithm for filtering, correlation, spectrum analysis and feature extraction of the acquired signal to identify specific square wave characteristics from the signal generator.

4. The system according to claim 1, characterized in that, Both the signal generating device and the detection device have built-in independent battery modules.

5. The system according to claim 1, characterized in that, Both the signal generating device and the detection device have built-in independent clock modules.

6. The system according to claim 1, characterized in that, The signal generating device and the detection device synchronize their time wirelessly or via wired means before the detection begins.

7. The system according to claim 1, characterized in that, The human-computer interaction unit is a touch screen display.

8. The system according to claim 7, characterized in that, The touch screen is used to display a matrix of test results indexed by the core wire number, and to highlight fault points such as broken wires, short circuits, and poor insulation with different colors or icons.

9. The system according to claim 1, characterized in that, The system is integrated into a single chassis, which is equipped with a portable handle and a non-slip base.

10. A cable wiring status detection method using the portable multi-core secondary circuit cable wiring status detection system according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step S1: At the beginning of the cable under test, connect all the output interfaces of the first integrated connector of the signal generator to all the core wires of the cable. Step S2: At the end of the cable under test, connect all the input interfaces of the second integrated connector of the testing device to all the core wires of the cable. Step S3: Start the signal generator, and its signal generation module injects a specific square wave detection signal into each core wire; Step S4: Start the detection device, and its multi-channel detection module will synchronously collect the voltage signals of all core wires at the end of the cable; Step S5: The second control unit of the detection device analyzes the signals of each channel, determines the continuity through feature recognition, determines the short circuit through signal comparison between channels, determines the insulation through signal-to-ground analysis, and outputs a complete status report of all core wires at once.

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