Power system secondary circuit detection system and method based on high-frequency current detection

Abstract

The invention discloses a power system secondary circuit detection system and method based on high-frequency current detection, and relates to the technical field of power system test tools. The invention aims to solve the problems that the traditional secondary circuit line inspection method is time-consuming and labor-consuming, easy to be interfered and single in function. The system comprises a source end device and a detection end device. The source end device comprises a high-frequency current source, a direct-current voltage source, a first switch matrix, a first intelligent control module, a first communication module and a plurality of groups of test lines; the detection end device comprises a high-frequency current detection module, a second switch matrix, a second intelligent control module, a second communication module and a plurality of groups of test lines; according to the technical scheme, the first intelligent control module controls two-end synchronous operation through the communication module, the high-frequency current source outputs high-frequency current to be injected into a loop, and wiring correctness is automatically judged after detection and analysis of the detection end; automation and integration of secondary circuit wiring correctness detection and insulation test are realized, and detection efficiency and accuracy are improved.

Description

Technical Field

[0001] This invention relates to the field of power system testing tools, and in particular to a power system secondary circuit testing system and method based on high-frequency current detection. Background Technology

[0002] The secondary circuit of a power system refers to the electrical circuits used for monitoring, controlling, regulating, and protecting primary equipment. It includes all low-voltage circuits such as measurement circuits, relay protection circuits, switch control and signaling circuits, and electrical interlocking circuits. The correctness of the secondary circuit wiring directly affects the safe and stable operation of a substation. Incorrect wiring refers to incorrect secondary circuit wiring, which prevents protection devices from correctly identifying system faults or from correctly controlling the outputs, and is one of the main causes of relay protection accidents.

[0003] The wiring of secondary circuits is currently done manually, and the accuracy of the wiring is highly dependent on the skill level of the wiring personnel. In order to ensure the correctness of the secondary circuits, the test personnel need to check the secondary circuits.

[0004] Currently, secondary circuit wiring is mainly performed by testing personnel using wiring tools such as wiring lights, wiring pens, and multimeters. They check each core by core by forming a closed loop with the substation's grounding grid. One testing personnel grounds one core of the cable via a grounding wire, while another personnel use wiring tools to test all cores of the cable against ground to determine if the wiring on both sides is correct. This testing method is time-consuming and labor-intensive, and may result in missed or incorrect connections. If the testing personnel touch the wrong terminals or come into contact with a live cable during wiring, it can cause AC or DC grounding, which in severe cases may lead to switch malfunction, load loss, and disruption of the power grid's stable operation.

[0005] Meanwhile, during on-site wiring, it is common to encounter situations where one cable core on one side is simultaneously conductive with multiple cable cores on the opposite side (due to internal circuit connections, such as normally closed contacts, low-resistance components, voltage transformers, etc.). For example, due to normally closed contacts, cores 1 and 2 of the opposite terminal block may be interconnected. In this case, when using traditional methods to check cores 1 and 2, both cores 1 and 2 on the opposite terminal block will be conductive, making it impossible to determine whether the wiring of cores 1 and 2 is correct. At this point, all conductive cable cores must be removed and rewired to confirm the correct core wires. This method is not only time-consuming, but also prone to incorrect or loose terminal connections during the rewiring process, thus affecting the safe and stable operation of the power system. Summary of the Invention

[0006] The technical problem to be solved and the technical task proposed by this invention is to improve and refine existing technical solutions, and to provide a power system secondary circuit detection system and method based on high-frequency current detection. This aims to overcome the shortcomings of existing secondary circuit tracing methods, such as low efficiency, high safety risks, and poor adaptability to complex scenarios. The invention achieves automatic secondary circuit detection, simplifies wiring operations, provides intuitive output of results and error correction schemes, and also has insulation detection capabilities, thereby improving detection efficiency and safety. To this end, this invention adopts the following technical solution.

[0007] A power system secondary circuit detection system based on high-frequency current detection includes a source-end device and a detection-end device; The source-end device includes: A high-frequency current source is used to output high-frequency current to distinguish it from the power frequency current of the power system and avoid power frequency induced electrical interference. A DC voltage source used to output an adjustable DC voltage for insulation testing; The first switching matrix contains multiple sets of high-speed switches, used to control the output paths of the high-frequency current source and the DC voltage source; The first intelligent control module is used to execute the test control program and control the switching state of the first switch matrix; The first communication module is used for long-distance ultra-low latency communication with the detection terminal device; Multiple sets of telescopic hovering test leads are used to connect the source device to the terminal block on the secondary circuit side; The detection terminal device includes: A high-frequency current detection module is used to detect high-frequency current and filter out power frequency induced electrical interference. The second switch matrix contains multiple sets of high-speed switches, which are used to control the input path of the high-frequency current detection module. The second intelligent control module is used to control the switching state of the second switch matrix and analyze the detection results; The second communication module is used to communicate with the source device to achieve synchronous control. Multiple sets of telescopic hovering test leads are used to connect the testing device to the terminal block on the other side of the secondary circuit; The first intelligent control module sends control commands to the detection device through the first communication module, enabling the source device and the detection device to operate synchronously. The high-frequency current output from the high-frequency current source is injected into the secondary circuit through the first switch matrix and the telescopic hovering test line. The high-frequency current is detected by the second switch matrix and the high-frequency current detection module of the detection device to automatically determine the correctness of the secondary circuit wiring. The DC voltage source applies DC voltage through the first switch matrix and the telescopic hovering test line to perform insulation testing.

[0008] This technical solution integrates anti-interference detection, automatic synchronous control, and insulation testing, fundamentally solving the problems of low efficiency, susceptibility to interference, limited functionality, and inability to handle complex circuits associated with traditional manual wiring methods. Specifically, this solution uses a first intelligent control module and a first communication module to send control commands to the detection end, achieving synchronous operation and automatic judgment between the source and detection ends. The entire detection process (such as sequential current injection, scanning detection, and result analysis) is automatically completed by the device, greatly reducing manual intervention, significantly improving detection efficiency, and lowering the risk of human error. Using a high-frequency current, distinct from the power system's power frequency, as the detection signal allows the high-frequency current detection module to effectively filter out the ubiquitous power frequency induced electrical interference in the field environment, ensuring the purity of the signal acquisition. Compared to traditional multimeters and other tools that are susceptible to interference and prone to misjudgment, this fundamentally improves the accuracy and reliability of the detection. This device, based on high-frequency current detection to ensure wiring correctness, integrates a DC voltage source, enabling direct insulation testing of secondary circuits. This achieves seamless integration of the two major functions of "wiring inspection" and "insulation testing" on the same platform, avoiding the inconvenience of testers carrying multiple devices, improving work efficiency, and reducing equipment costs. Multiple sets of telescopic hovering test leads are used for connection, avoiding the problems of messy, tangled, and easily detached traditional test leads. They can be quickly and reliably connected to the terminal blocks, providing a stable and convenient physical connection foundation for the aforementioned automated testing process, ensuring the smooth operation of the entire system.

[0009] As a preferred technical means: the telescopic hovering test lead includes a test pin, a test flexible wire, and a telescopic hovering reel; the test pin adopts a 2mm banana male head and includes a 2mm female to 4mm male adapter for direct insertion into the test socket of the terminal block.

[0010] This technical solution integrates a telescopic cable reel and modular adapters, achieving rapid and reliable test lead connections and simplified on-site management, directly improving the preparation efficiency and user experience of testing work. Specifically, the "telescopic cable reel" allows the test cable to be freely stretched to the required length and automatically locked, eliminating the need for manual fixing or winding. After testing, it can be automatically retracted with a simple pull, avoiding the problems of traditional test leads being long, messy, and prone to tangling, making the testing site cleaner and more orderly, and significantly improving the efficiency of connection and cable retraction. The test pins use "2mm banana male" connectors and are equipped with "2mm female to 4mm male adapters," forming a standardized and modular interface solution. This allows a set of test leads to be directly and reliably inserted into the test sockets of the two most common terminal block sizes (2mm and 4mm) in substations without additional tools or temporary modifications, ensuring the stability and convenience of electrical connections. By integrating the "test pin (interface)," "test flexible wire (conductor)," and "telescopic hovering reel (winding mechanism)" into one complete component, the hassle of temporary assembly is eliminated, providing testers with an integrated, plug-and-play testing experience. This reduces the possibility of component loss or misconfiguration and reflects strong ergonomic considerations.

[0011] As a preferred technical means, the source device also includes an intelligent image analysis module, which is used to convert the secondary circuit wiring diagram into a simplified secondary circuit diagram and display the terminal number, circuit number and cable number information to guide the test personnel to connect the telescopic hover test line.

[0012] This technical solution transforms complex professional drawings into concise operation guides through intelligent and visual means, fundamentally solving the problems of low efficiency and high error rates caused by the reliance on manual drawing interpretation in traditional methods. This ensures that subsequent testing work can be carried out accurately and efficiently. Specifically, the intelligent image analysis module uses image recognition technology to automatically extract and intuitively display key information such as "terminal numbers, circuit numbers, and cable numbers," generating clear secondary circuit diagrams. This allows even less experienced testers to operate accurately based on the concise diagrams, significantly reducing the risk of wiring errors caused by misinterpreting the drawings. The intelligent image analysis module achieves automatic parsing and visualization of drawing information. Testers no longer need to manually search for targets in lengthy drawings and complex codes; they can quickly and directly obtain all the connection information required for the current testing task, greatly shortening pre-test preparation time and improving overall work efficiency. This technical solution transforms abstract, symbolic wiring diagrams into easily understandable visual diagrams, enhancing the intuitiveness of operation. Testers can directly and clearly connect the telescopic hovering test leads to the corresponding terminal blocks based on the information on the simplified diagram, avoiding errors that may be caused by a change in thinking, and making the operation process smoother and more reliable.

[0013] As a preferred technical means: the source end device is equipped with a first touch screen, and the detection end device is equipped with a second touch screen; the first touch screen is used to set control options, display a simplified diagram of the secondary circuit and the detection results, and display a diagram of the error correction scheme when there is a wiring error; the second touch screen is used to simultaneously display the detection results and the diagram of the error correction scheme so that the testers on both sides can operate together.

[0014] This technical solution constructs a highly efficient collaborative work platform through information synchronization and functional division of labor on both sides of the touchscreen, solving the fundamental problems of information asymmetry, high communication costs, and low collaborative efficiency in traditional secondary circuit testing. Specifically, the second touchscreen synchronously displays the test results and error correction schemes, allowing the testing operator to obtain completely consistent key information in real time without relying on the source operator's relay, eliminating communication barriers and transforming the loose collaboration between the two sides into a closely linked whole, greatly improving the efficiency and accuracy of teamwork. When a wiring error is detected, both touchscreens synchronously display the error correction scheme diagram, ensuring that regardless of which operator is responsible for modifying the wiring, they can obtain the most intuitive graphical guidance at their work point, avoiding secondary wiring errors caused by unclear verbal descriptions or memory errors, greatly improving the accuracy and first-time success rate of the error correction process, and effectively shortening troubleshooting time. The source end, as the "control center," is responsible for task initiation and global information display; the testing end, as the "information synchronization terminal," focuses on receiving and confirming the test status, making the responsibilities of the operators on both sides clear and the human-machine interaction path well-defined, reducing operational confusion and improving the smoothness of the entire testing process.

[0015] As a preferred technical means: the first intelligent control module and the second intelligent control module control the corresponding switch states in the first switch matrix and the second switch matrix, use the current shunting principle to detect the continuity of multiple cable cores, and determine whether the wiring is correct by the direction of high-frequency current.

[0016] This technical solution overcomes the long-standing technical challenge of multi-core continuity detection in secondary circuits by combining the principle of current shunting with high-frequency current direction determination. It achieves a leap from simple continuity assessment to intelligent diagnosis of path correctness. Specifically, for multi-core continuity scenarios, it eliminates the need to remove normally closed contacts, low-resistance components, or other components causing continuity. By actively controlling the synchronous closing of corresponding switches in the first and second switch matrices, a measurement circuit containing multiple cores is constructed. This allows for direct analysis of the current direction in each branch, pinpointing the location of misconnections. The use of high-frequency current not only provides interference immunity but also enables instantaneous current direction detection due to its rapid dynamic characteristics. By determining the flow direction of the high-frequency current in each cable core constituting the circuit, the source and path of the signal are traced, thereby locating the point of cross-connection.

[0017] As a preferred technical means: the source-end device and the detection-end device each include 26 sets of telescopic hovering test lines, arranged in two rows, with 13 sets in each row, respectively labeled with the letter A. The Z mark is used to accommodate secondary cables with up to 24 cores.

[0018] This technical solution, through a combination of capacity redundancy design, compact layout, and clear labeling, provides the testing system with a standardized interface array that offers ample capacity, convenient operation, and strong error prevention, laying a solid physical foundation for subsequent efficient and accurate automated testing. Specifically, the 26 test leads can completely cover all cores of a 24-core cable, with an additional 2 sets of spare leads. This avoids the predicament of not being able to complete the entire cable test at once due to insufficient test leads. The redundancy design also provides flexibility for special operating conditions (such as testing spare cores or simultaneously monitoring multiple signals). The double-row arrangement (13 groups per row) significantly reduces the width of the device panel compared to a single-row long column layout, making the equipment more compact and portable, and better suited to the human eye's field of vision and hand operating range. This facilitates quick and accurate insertion and removal of test leads by testing personnel, reduces the risk of accidental contact with adjacent terminals, and improves operational efficiency and safety. Compared to purely numerical numbering, letter markings are more easily recognizable. Testers can quickly and accurately match test leads with device ports and target terminals based on the letter markings on diagrams or drawings, fundamentally avoiding test errors or equipment risks caused by incorrect port identification and ensuring the accuracy of the wiring process.

[0019] As a preferred technical means, the first intelligent control module and the second intelligent control module are configured to: when the high-frequency current detection module detects high-frequency current at multiple ports, control the corresponding switches in the first switch matrix and the second switch matrix to close synchronously to form a loop, and determine whether there is cross-connection of the cable core by analyzing the direction of the high-frequency current.

[0020] This technical solution constructs a specific measurement loop by actively controlling the synchronous closing of the switch matrix, and analyzes the direction of high-frequency current on each cable core in this loop. It can accurately determine the actual flow direction and path of the current, thus solving the technical blind spot of traditional methods that cannot distinguish whether there is cross-connection or misconnection in multi-core conduction.

[0021] Another objective of this invention is to provide a power system secondary circuit detection method based on high-frequency current detection, which employs the aforementioned power system secondary circuit detection system based on high-frequency current detection. The method includes the following steps: 1) Wiring steps: Connect the source device to the terminal block on one side of the secondary circuit through multiple sets of telescopic hover test leads, and connect the detection device to the terminal block on the other side of the secondary circuit through multiple sets of telescopic hover test leads. 2) Image conversion step: The intelligent image analysis module of the source device converts the imported secondary circuit wiring diagram into a simplified secondary circuit diagram containing terminal numbers, circuit numbers and cable numbers. 3) Selection and Startup Steps: Select the cable under test through the first touchscreen of the source device and issue a test command; 4) High-frequency current detection step: The source device and the detection device are synchronously controlled through the first communication module and the second communication module to perform secondary circuit wiring correctness detection, specifically including: The first intelligent control module of the source device controls the high-frequency current source and the first switch matrix to inject high-frequency current into each core of the cable to be tested through the selected telescopic hovering test line in sequence. For each core wire, the second intelligent control module of the detection end device controls the second switch matrix to detect the high-frequency current signal of each cable core in sequence; Based on the detection results of the high-frequency current detection module, the correctness of the cable core connection is judged by logic. When multi-core conduction is detected, the corresponding switches in the first switch matrix and the second switch matrix are controlled to close synchronously to form a loop. The wiring is judged to be correct by the current shunting principle and the direction of high-frequency current. 5) Result output steps: The first touch screen of the source device and the second touch screen of the detection device simultaneously display the detection results; if there is a wiring error, a diagram of the error correction scheme is provided.

[0022] The wiring process uses multiple sets of telescopic hovering test leads to connect the device to the secondary circuit terminal block. The test leads can be locked to the required length through the hovering function, avoiding the problems of knots and tangles caused by the uncontrollable length of traditional test leads. This eliminates the need for testers to repeatedly tidy up the leads, reducing auxiliary operation time during the wiring process and improving wiring efficiency. At the same time, no additional adapter tools are required to connect the test leads to the terminal block, further simplifying the wiring process.

[0023] The image conversion step uses an intelligent image analysis module to transform traditional complex secondary circuit wiring diagrams into simplified secondary circuit diagrams containing terminal numbers, circuit numbers, and cable numbers. Compared to the traditional method of manually interpreting complex diagrams page by page and manually recording terminal correspondences, the simplified diagrams can intuitively present core wiring information. Testers do not need to spend a lot of time interpreting the details of the diagrams and can quickly locate the correspondence between "test wires and terminal blocks," significantly reducing the wiring error rate caused by diagram interpretation errors and improving the overall efficiency of the wiring preparation stage.

[0024] The selection and activation process is integrated through the first touchscreen of the source device, enabling the selection of the cable to be tested and the issuance of test commands. This eliminates the need for testers to manually adjust multiple physical knobs or switches, and also eliminates the need for separate activation settings at the source and testing ends. The testing process can be triggered simply by completing a visual operation at the source end, reducing reliance on the skill level of the testers and avoiding asynchronous activation issues caused by independent activation on both sides, thus laying the foundation for subsequent synchronous testing.

[0025] The high-frequency current detection step is a core advantage, specifically reflected in three aspects: Strong synchronization reduces detection errors: Synchronous control between the source and detection ends is achieved through the first and second communication modules, avoiding the delay problem of traditional manual coordination between the two sides, ensuring the timing of high-frequency current injection and current signal detection, and reducing misjudgments caused by synchronization deviation.

[0026] Excellent anti-interference capability and reliable test results: Using high-frequency current as the detection signal (different from the power frequency current of the power system), it can naturally filter out the interference of the power frequency induced current on the detection signal, and improve the detection accuracy compared with traditional power frequency current detection or multimeter measurement.

[0027] Excellent adaptability to complex scenarios, no need to disconnect wires: For multi-core conduction scenarios (such as multi-core connections caused by normally closed contacts or low-resistance components), there is no need to remove the conducting core wires for re-testing as in traditional methods. Instead, it directly determines whether the wiring is correct by controlling the corresponding switches in the first and second switch matrices to close synchronously to form a loop, using the current shunting principle and high-frequency current direction judgment, and locating the error point. This reduces the time cost of disconnecting wires and avoids secondary wiring errors that may occur during the disconnection process, significantly improving the detection efficiency and accuracy under complex working conditions.

[0028] No risk of missed detection: By sequentially injecting high-frequency current and scanning each core of the cable to be tested, every core of the cable can be covered, avoiding the problem of missed detection caused by negligence when manually checking each core, and ensuring comprehensive detection coverage.

[0029] The results output steps are synchronized through the touch screens at both the source and testing ends, displaying the results and error correction scheme diagrams. This avoids the information lag or transmission deviation issues that occur in traditional testing where results are recorded on one side and manually transmitted to the other. Testers on both sides can see consistent test results in real time, reducing communication costs. For wiring error scenarios, error correction scheme diagrams are provided directly—eliminating the need for testers to deduce the cause of the error or adjust the wiring direction based on the test data. Error points can be intuitively located (such as incorrectly connected core wire numbers or cross-connection positions), quickly clarifying the error correction operation and shortening the interval between error discovery and error correction.

[0030] As a preferred technical means, after the high-frequency current detection step, an insulation test step is also included: After confirming that the secondary circuit wiring is correct, select the insulation test function and test voltage through the first touch screen of the source device; The first intelligent control module of the source device controls its DC voltage source and first switch matrix, and sequentially applies the set DC voltage to each core of the cable to be tested through the telescopic hovering test line. The insulation resistance data of each cable core is displayed on the first touch screen of the source device.

[0031] This technical solution allows for complete insulation testing entirely through the first touchscreen of the source device, enabling all core operations from selecting insulation test functions and setting test voltages to viewing insulation resistance data. No switching between the source and testing devices is required, nor are additional auxiliary devices connected or operated. Compared to traditional insulation testing, which involves separate deployment of insulation equipment, manual wiring, and manual data recording, this solution integrates function selection, parameter setting, and result viewing into a single, visual interface, significantly reducing operational complexity and minimizing operator steps and cross-device collaboration costs. Furthermore, this solution eliminates the need for operators to remove existing wiring and reconnect test leads. This saves time and shortens the time required for rewiring, shortening the transition from wiring correctness testing to insulation testing. It also avoids secondary errors such as wiring misalignment and loose terminal connections that may occur during rewiring, ensuring the wiring basis for insulation testing remains consistent with previous correctness checks and reducing test deviations caused by wiring changes. The first intelligent control module controls the switch matrix to sequentially apply a set voltage to each core of the cable under test, enabling independent insulation testing of each core. Compared to the traditional method of applying voltage to multiple cores simultaneously, core-by-core testing ensures that the insulation resistance data of each core is independent and accurate, avoiding false pass or false abnormality judgments caused by mutual interference between cores. The insulation test results are directly displayed on the first touch screen of the source device, eliminating the need for testers to manually transcribe data from individual instruments. On the one hand, the data presentation is intuitive and real-time, allowing testers to quickly locate cores with abnormal insulation resistance without having to check the data one by one. On the other hand, the visualized data format facilitates direct recording or export, reducing errors and time costs associated with manual recording.

[0032] As a preferred technical method: when determining the correctness of wiring... If multiple conductors are detected, cross-connection is determined by the following steps: the source device and the detection device operate synchronously to close the switch corresponding to the multiple conductors to form a circuit; the direction of the high-frequency current in each conductor core is detected; and based on the direction of the high-frequency current, it is determined whether cross-connection exists. If a high-frequency current is detected at the only port, the correctness or incorrectness of the core wire connection is determined by checking whether the port number matches the target cable core number currently output from the source.

[0033] This technical solution achieves wire-free testing by synchronously closing corresponding switches at the source and detection ends to form a circuit. It eliminates the need for testers to remove normally closed contacts, low-resistance components, or cable cores that could cause continuity. This saves time and avoids secondary errors such as terminal damage, incorrect rewiring, and loose connections that may occur during wire removal. It fundamentally solves the problems of low testing efficiency and high risk in traditional multi-core continuity scenarios. By employing synchronous operation of the source and detection devices and synchronously closing the switch matrices on both sides, it ensures a stable circuit formation of high-frequency current, avoiding problems such as circuit failure and current signal disorder caused by timing deviations in the switch actions. This provides a stable testing environment for subsequent current direction detection and reduces misjudgments caused by synchronization errors. This technical solution achieves accurate judgment by detecting the direction of high-frequency current—different wiring states correspond to different current directions. Testers can directly locate cross-connection problems based on the directional differences, significantly improving the accuracy of misjudgments in multi-core continuity scenarios. By comparing port numbers with the target cable core numbers at the source end, this method eliminates the need for testers to perform complex current calculations and loop impedance analyses. A simple check of matching numbers quickly determines whether the wiring is correct or incorrect, reducing reliance on testers' specialized skills and avoiding misjudgments caused by complex manual calculations and experience-based assessments. This ensures the accuracy and efficiency of single-core testing results. This technical solution addresses the two most common scenarios in secondary circuit wiring testing: multi-core continuity and single-port high-frequency current detection. It designs clear and independent judgment processes for each, forming a complete closed-loop judgment logic. This prevents situations where judgment is impossible due to missed scenarios or confusion between the two scenarios. Testers do not need to distinguish scenarios or perform additional operations; the device automatically triggers the corresponding judgment process based on the number of detected ports, ensuring clear and unambiguous judgment results under different wiring conditions, eliminating any ambiguity.

[0034] Beneficial effects: 1. Convenient testing: The secondary circuit verification is carried out automatically, and the verification and error correction of this cable can be completed automatically with a single wiring. 2. Simple wiring: The telescopic hovering test leads are used to avoid messy and tangled test leads. Combined with the intuitive display of wiring information in the secondary circuit diagram, testers can quickly complete the connection of test leads to terminal blocks. 3. Convenient and intelligent testing: After wiring is completed, the test items can be selected via the touch screen to automatically complete the wiring test and output the results; if there are errors, the error points and correction methods are intuitively fed back; if the wiring is correct, insulation testing can be performed directly. 4. Excellent adaptability to complex scenarios: It can accurately identify scenarios such as cable core crossing errors and multi-core continuity, locate errors without disconnecting the wiring, and support retesting after modification; 5. Facilitates subsequent maintenance: It generates a visual document of the substation's secondary circuits, recording information such as cable number, circuit number, wiring terminals, and circuit purpose, providing a convenient reference for the inspection and maintenance of secondary equipment, and improving work efficiency and safety. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the source device structure of the present invention; Figure 2 This is a schematic diagram of the detection end device of the present invention; Figure 3 This is a schematic diagram of the working principle of the source device of the present invention; Figure 4 This is a schematic diagram of the working principle of the detection end device of the present invention; Figure 5 This is the detection logic diagram.

[0036] In the diagram: 1. Source end device; 2. Detection end device; 3. Secondary circuit terminal block; 4. Secondary circuit terminal block; 5. Cable under test; 101. First touch screen; 102. Telescopic hovering test lead (source end); 1021. Test pin (source end); 1022. Test flexible cord (source end); 1023. Telescopic hovering reel (source end); 103. USB interface; 104. TF card slot; 105. Power supply module (source end); 1051. Power indicator light (source end); 1052. Charging port (source end); 1053. Sleep button (source end); 1054. Power switch (source end); 106. First intelligent control module; 107. High-frequency current source; 108. DC power supply. 109. Pressure source; 110. First switch matrix; 111. First communication module; 111. Intelligent image analysis module; 201. Second touch screen; 202. Telescopic hover test line (detection end); 2021. Test pin (detection end); 2022. Test flexible wire (detection end); 2023. Telescopic hover reel (detection end); 203. Power supply module (detection end); 2031. Power indicator light (detection end); 2032. Charging port (detection end); 2033. Sleep button (detection end); 2034. Power switch (detection end); 204. Second intelligent control module; 205. High-frequency current detection module; 206. Second switch matrix; 207. Second communication module. Detailed Implementation

[0037] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] Example 1: Power System Secondary Circuit Detection System Based on High-Frequency Current Detection This embodiment provides a power system secondary circuit detection system based on high-frequency current detection, including a source-end device 1 and a detection-end device 2.

[0039] Figure 1 This is a schematic diagram of the source device 1. Figure 3 The diagram shows the working principle of the source device 1. The source device 1 includes a first touch screen 101, a telescopic hover test line (source end) 102, a USB interface 103, a TF card slot 104, a power supply module (source end) 105, a first intelligent control module 106, a high-frequency current source 107, a DC voltage source 108, a first switch matrix 109, a first communication module 110, and an intelligent image analysis module 111.

[0040] The power supply module (source end) 105 of the source end device 1 includes a power indicator light (source end) 1051, a charging port (source end) 1052, a sleep button (source end) 1053, and a power switch (source end) 1054.

[0041] The telescopic hover test line (source end) 102 of the source end device 1 includes a test pin (source end) 1021, a test flexible wire (source end) 1022, and a telescopic hover reel (source end) 1023.

[0042] Figure 2 A schematic diagram of the structure of the detection end device 2. Figure 4 The diagram shows the working principle of the detection device 2. The detection device 2 is equipped with a second touch screen 201, a telescopic hovering test line (detection end) 202, a power supply module (detection end) 203, a second intelligent control module 204, a high-frequency current detection module 205, a second switch matrix 206, and a second communication module 207.

[0043] The power supply module (detection terminal) 203 of the detection terminal device 2 includes a power indicator light (detection terminal) 2031, a charging port (detection terminal) 2032, a sleep button (detection terminal) 2033, and a power switch (detection terminal) 2034.

[0044] The telescopic hover test line (test end) 202 of the test end device 2 includes a test pin (test end) 2021, a test flexible wire (test end) 2022, and a telescopic hover reel (test end) 2023.

[0045] The telescopic hover test lead (source end) 102 on the source end device 1 is connected to the secondary circuit terminal block 3 on the secondary circuit side. The tester imports the substation secondary circuit wiring diagram through the USB interface 103 or TF card slot 104, and the intelligent image analysis module 111 converts it into a simplified secondary circuit diagram. The tester selects the cable under test 5 through the first touch screen 101, and connects the telescopic hover test lead (source end) 102 and the telescopic hover test lead (detection end) 202 to the secondary circuit terminal block 3 and the secondary circuit terminal block 4 respectively according to the order of the simplified secondary circuit diagram, and then issues a test command.

[0046] The first intelligent control module 106 converts the test command into control signals and sends them to the high-frequency current source 107, the DC voltage source 108, and the first switch matrix 109 respectively. By controlling the closing or opening of different switch groups inside the first switch matrix 109, as well as the output or stop of the high-frequency current source 107 and the DC voltage source 108, the high-frequency current or DC voltage is transmitted to the secondary circuit terminal block 3 through different ports of the telescopic hovering test line (source end) 102.

[0047] Meanwhile, the control commands of the source device 1 are sent to the detection device 2 through the first communication module 110. After being received by the second communication module 207 of the detection device 2, the second intelligent control module 204 controls the closing or opening of different switch groups inside the second switch matrix 206 to realize the synchronous operation of the source and the detection.

[0048] The telescopic hovering test line (detection end) 202 on the detection end device 2 is connected to the secondary circuit terminal block 4 on the other side of the secondary circuit. After receiving the control command from the source end device 1, the second communication module 207 controls the closing or opening of different switch groups inside the second switch matrix 206 by the second intelligent control module 204. The high-frequency current emitted by the source end device 1 is transmitted to the secondary circuit terminal block 4 through the test cable 5, and then the high-frequency current is transmitted to the high-frequency current detection module 205 through the second switch matrix 206. After analysis by the second intelligent control module 204, the test results are displayed through the second touch screen 201.

[0049] Example 2: A power system secondary circuit detection method based on high-frequency current detection This embodiment provides a power system secondary circuit detection method based on high-frequency current detection, using the detection system of Embodiment 1. The specific execution process is as follows (refer to...). Figure 5 Detection logic diagram): After the tester selects the cable under test (assuming the cable has n cores and cores 1 and 2 are connected through an external normally closed contact) via the first touch screen 101 and executes the test command, switch 1 of the first switch matrix 109 of the source device 1 closes, connecting the high-frequency current source 107 to cable core 1; the second switch matrix 206 of the detection device 2 closes switches 1 to n in sequence, connecting the high-frequency current detection module 205 to cable cores 1 to n respectively.

[0050] If the detection device 2 detects high-frequency current on only one port, it further determines whether the port is the port corresponding to core 1: if yes, it proves that the wiring of core 1 of the cable under test is correct; if no, it means that core 1 is incorrectly connected to this position and needs to be modified.

[0051] If multiple ports of the detection device 2 detect high-frequency current (such as ports 1 and 2), it is determined that core 1 and core 2 are connected. At this time, switches 1 and 2 of the first switch matrix 109 of the source device 1 and the second switch matrix 206 of the detection device 2 are closed synchronously, forming a circuit between the high-frequency current source 107 and the high-frequency current detection module 205 through the cables of core 1 and core 2. Through the current shunting principle, the high-frequency current detection module 205 can obtain a portion of the high-frequency current. By detecting the direction of this portion of the high-frequency current, it is determined whether there is a cross-connection between core 1 and core 2.

[0052] After the test of core 1 is completed, switch 2 of the first switch matrix 109 of the source device 1 is closed, connecting the high-frequency current source 107 to cable core 2, and the correctness of the wiring of core 2 is tested according to the same logic as above.

[0053] After all the core wires of the cable under test have been tested, if there is a wiring error, the error correction scheme will be displayed simultaneously on the first touch screen 101 and the second touch screen 201. The tester can then modify the secondary wiring and retest. If all wiring is correct, "wiring correct" will be displayed and the wiring correctness test will end. The tester can then choose whether to continue the insulation test on this cable.

[0054] Secondary circuit insulation testing only requires the use of source-end device 1: The tester selects the cable under test via the first touchscreen 101 and connects the telescopic hover test lead (source end) 102 to the secondary circuit terminal block 3 in the order of the secondary circuit diagram (if the wiring correctness check has been completed, the test can be performed directly without repeating the wiring); select the test voltage (0... After issuing a test command (2500V optional), the first intelligent control module 106 converts the test command into a control signal and sends it to the DC voltage source 108 and the first switch matrix 109 respectively. It controls the first switch matrix 109 to close the cores 1 to n in sequence, and applies a set DC voltage to the cable under test 5 through the telescopic hovering test line (source end) 102. The insulation data of each cable core is displayed through the first touch screen 101.

[0055] The above-described power system secondary circuit detection system and method based on high-frequency current detection is a specific embodiment of the present invention, which embodies the substantial features and progress of the present invention. According to actual use needs, equivalent modifications in shape, structure, etc. can be made to it under the guidance of the present invention, all of which are within the protection scope of this solution.

Claims

1. A power system secondary circuit detection system based on high-frequency current detection, characterized in that: Includes source-end devices and detection-end devices; The source-end device includes: A high-frequency current source is used to output high-frequency current to distinguish it from the power frequency current of the power system and avoid power frequency induced electrical interference. A DC voltage source used to output an adjustable DC voltage for insulation testing; The first switching matrix contains multiple sets of high-speed switches, used to control the output paths of the high-frequency current source and the DC voltage source; The first intelligent control module is used to execute the test control program and control the switching state of the first switch matrix; The first communication module is used for long-distance ultra-low latency communication with the detection terminal device; Multiple sets of telescopic hovering test leads are used to connect the source device to the terminal block on the secondary circuit side; The detection terminal device includes: A high-frequency current detection module is used to detect high-frequency current and filter out power frequency induced electrical interference. The second switch matrix contains multiple sets of high-speed switches, which are used to control the input path of the high-frequency current detection module. The second intelligent control module is used to control the switching state of the second switch matrix and analyze the detection results; The second communication module is used to communicate with the source device to achieve synchronous control. Multiple sets of telescopic hovering test leads are used to connect the testing device to the terminal block on the other side of the secondary circuit; The first intelligent control module sends control commands to the detection device through the first communication module, enabling the source device and the detection device to operate synchronously. The high-frequency current output from the high-frequency current source is injected into the secondary circuit through the first switch matrix and the telescopic hovering test line. The high-frequency current is detected by the second switch matrix and the high-frequency current detection module of the detection device to automatically determine the correctness of the secondary circuit wiring. The DC voltage source applies DC voltage through the first switch matrix and the telescopic hovering test line to perform insulation testing.

2. The power system secondary circuit detection system based on high-frequency current detection according to claim 1, characterized in that: The telescopic hover test lead includes a test pin, a test cord, and a telescopic hover reel; the test pin uses a 2mm banana-shaped male connector and includes a 2mm female to 4mm male adapter for direct insertion into the test socket of the terminal block.

3. The power system secondary circuit detection system based on high-frequency current detection according to claim 1, characterized in that: The source device also includes an intelligent image analysis module, which converts the secondary circuit wiring diagram into a simplified secondary circuit diagram, displaying the terminal numbers, circuit numbers, and cable numbers to guide testers in connecting the telescopic hover test leads.

4. The power system secondary circuit detection system based on high-frequency current detection according to claim 3, characterized in that: The source device is equipped with a first touch screen, and the detection device is equipped with a second touch screen. The first touch screen is used to set control options, display a simplified diagram of the secondary circuit and the detection results, and display a diagram of the error correction scheme when there is a wiring error. The second touch screen is used to simultaneously display the detection results and the diagram of the error correction scheme so that the testers on both sides can operate together.

5. A power system secondary circuit detection system based on high-frequency current detection according to claim 1, characterized in that: The first and second intelligent control modules control the corresponding switch states in the first and second switch matrices, use the current shunting principle to detect the continuity of multiple cable cores, and determine whether the wiring is correct by the direction of the high-frequency current.

6. The power system secondary circuit detection system based on high-frequency current detection according to claim 1, characterized in that: The source-end device and the detection-end device each contain 26 sets of telescopic hovering test leads, arranged in two rows of 13 sets each, labeled with the letter A. The Z mark is used to accommodate secondary cables with up to 24 cores.

7. The power system secondary circuit detection system based on high-frequency current detection according to claim 1, characterized in that: The first and second intelligent control modules are configured to: when the high-frequency current detection module detects high-frequency current at multiple ports, control the corresponding switches in the first and second switch matrices to close synchronously to form a loop, and determine whether there is cross-connection of the cable core by analyzing the direction of the high-frequency current.

8. A method for detecting secondary circuits in a power system based on high-frequency current detection, characterized in that: The power system secondary circuit detection system based on high-frequency current detection according to any one of claims 1-7, the method comprising the following steps: 1) Wiring steps: Connect the source device to the terminal block on one side of the secondary circuit through multiple sets of telescopic hover test leads, and connect the detection device to the terminal block on the other side of the secondary circuit through multiple sets of telescopic hover test leads. 2) Image conversion step: The intelligent image analysis module of the source device converts the imported secondary circuit wiring diagram into a simplified secondary circuit diagram containing terminal numbers, circuit numbers and cable numbers. 3) Selection and Startup Steps: Select the cable under test through the first touchscreen of the source device and issue a test command; 4) High-frequency current detection step: The source device and the detection device are synchronously controlled through the first communication module and the second communication module to perform secondary circuit wiring correctness detection, specifically including: The first intelligent control module of the source device controls the high-frequency current source and the first switch matrix to inject high-frequency current into each core of the cable to be tested through the selected telescopic hovering test line in sequence. For each core wire, the second intelligent control module of the detection end device controls the second switch matrix to detect the high-frequency current signal of each cable core in sequence; Based on the detection results of the high-frequency current detection module, the correctness of the cable core connection is judged by logic. When multi-core conduction is detected, the corresponding switches in the first switch matrix and the second switch matrix are controlled to close synchronously to form a loop. The wiring is judged to be correct by the current shunting principle and the direction of high-frequency current. 5) Result output steps: The first touch screen of the source device and the second touch screen of the detection device simultaneously display the detection results; if there is a wiring error, a diagram of the error correction scheme is provided.

9. A power system secondary circuit detection method based on high-frequency current detection according to claim 8, characterized in that: Following the high-frequency current detection step, an insulation test step is also included: After confirming that the secondary circuit wiring is correct, select the insulation test function and test voltage through the first touch screen of the source device; The first intelligent control module of the source device controls its DC voltage source and first switch matrix, and sequentially applies the set DC voltage to each core of the cable to be tested through the telescopic hovering test line. The insulation resistance data of each cable core is displayed on the first touch screen of the source device.

10. A power system secondary circuit detection method based on high-frequency current detection according to claim 8, characterized in that: When determining the correctness of the wiring, If multiple conductors are detected, cross-connection is determined by the following steps: the source device and the detection device operate synchronously to close the switch corresponding to the multiple conductors to form a circuit; the direction of the high-frequency current in each conductor core is detected; and based on the direction of the high-frequency current, it is determined whether cross-connection exists. If a high-frequency current is detected at only one port, the correctness or error of the core wire wiring is determined by checking whether the port number matches the target cable core number currently output from the source.

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