A line impedance tester
Patent Information
- Application Number
- CN202522210781.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-20
- Publication Date
- 2026-10-13
- Estimated Expiration
- 2035-10-20
AI Technical Summary
[0002]现有的低压配电网故障诊断技术主要通过现有电力监测仪表获取数据来源才能实现，通常仅能定位到故障所在的一段线路区间，而无法精准确定具体的故障点位置，故障定位精度上存在明显不足，仍然需要现场运维人员对该段线路进行全面的人工排查
[0015]本实用新型的有益效果在于：提供一种线路阻抗测试仪，包括主控模块、模数转换器、取电负载、电流转换模块、线路头部采样件以及线路尾部采样件，在使用时，将线路头部采样件连接待测线路的头部，线路尾部采样件和取电端用于连接待测线路的尾部，借助取电负载处的电流反馈实现头尾电流同步，利用线路头部采样件和线路尾部获取件采集待测线路头尾间的压差，结合取电负载和电流转换模块转换得到线路电流参数以及欧姆定律，计算得到线路阻抗，适用于近距离的待测线路，能够快速且准确采样线路阻抗测试所需的数据，显著降低现场故障排查时间，提升故障处理效率，保障配电网的安全稳定运行。
Smart Images
Figure CN224851355U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electronic circuit technology, and in particular to a line impedance tester. Background Technology
[0002] Existing low-voltage distribution network fault diagnosis technologies primarily rely on data from existing power monitoring instruments. These technologies typically only pinpoint the fault location to a section of the line, failing to pinpoint the exact fault location. This lack of accuracy necessitates a comprehensive manual inspection of the affected section by on-site maintenance personnel. This reliance on manual fault location has several drawbacks: firstly, it requires significant manpower and time, especially in long-distance lines across complex terrains (such as mountainous areas or densely populated urban areas), where manual inspection is extremely inefficient; secondly, prolonged fault inspections extend power outage times, impacting users' electricity experience and potentially causing substantial economic losses to industrial production.
[0003] Therefore, the challenge of accurately locating fault points in current low-voltage distribution network fault diagnosis technologies has become a key bottleneck restricting the improvement of work efficiency for grassroots maintenance personnel and affecting the reliability of power supply in the distribution network. To solve these technical problems, it is urgent to develop a testing device capable of accurately locating potential faults caused by abnormal line impedance, thereby significantly reducing on-site fault investigation time, improving fault handling efficiency, and ensuring the safe and stable operation of the distribution network. Utility Model Content
[0004] The technical problem to be solved by this utility model is to provide a line impedance tester that can quickly and accurately sample the data required for line impedance testing, significantly reduce the time for on-site fault diagnosis, improve fault handling efficiency, and ensure the safe and stable operation of the power distribution network.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A line impedance tester includes a main control module, an analog-to-digital converter, a power supply load, a current conversion module, a line head sampling device, and a line tail sampling device; The main control module is connected to the output terminal of the analog-to-digital converter. The analog-to-digital converter has three input terminals, two of which are connected to the line head sampling device and the line tail sampling device respectively, and the other input terminal is connected to the output terminal of the current conversion module. The input terminal of the current conversion module is connected to one end of the power-collecting load, and the other end of the power-collecting load is set as the power-collecting terminal. The line head sampling device is used to connect to the head of the line under test, and the line tail sampling device and the power-collecting terminal are used to connect to the tail of the line under test.
[0006] Furthermore, it also includes load access control components; One end of the load access control device is connected to the end of the power-consuming load that is away from the power-consuming end, and the other end of the load access control device is grounded; The control terminal of the load access control device is connected to the main control module.
[0007] Furthermore, the load access control device includes a power switching transistor; The drain of the power switch is connected to the end of the power-taking load furthest from the power-taking terminal, and the source of the power switch is grounded. The gate of the power switch is connected to the main control module.
[0008] Furthermore, it also includes a pre-stage protection circuit; The line head sampling device and the line tail sampling device are respectively connected to the two input terminals of the front-stage protection circuit, and the two output terminals of the front-stage protection circuit are connected one-to-one with the two input terminals of the analog-to-digital converter.
[0009] Furthermore, it also includes AC / DC conversion power supplies; The AC input terminal of the AC-DC converter is connected to the power supply terminal, and the DC power supply terminal of the AC-DC converter is connected to the main control module, the analog-to-digital converter, and the current conversion module, respectively.
[0010] Furthermore, it also includes a display, and the main control module is connected to the display.
[0011] Furthermore, the current conversion module includes a through-hole current transformer; One end of the power-taking load is grounded through the window via the current-carrying conductor of the through-hole transformer; The output terminal of the through-core transformer is connected to the input terminal of the analog-to-digital converter.
[0012] Furthermore, it also includes a memory, and the main control module is connected to the memory.
[0013] Furthermore, it also includes a maintenance communication port, to which the main control module is connected.
[0014] Furthermore, both the head sampling component and the tail sampling component of the line are alligator clips.
[0015] The beneficial effects of this utility model are as follows: It provides a line impedance tester, including a main control module, an analog-to-digital converter, a power-collecting load, a current conversion module, a line head sampling device, and a line tail sampling device. In use, the line head sampling device is connected to the head of the line under test, and the line tail sampling device and the power-collecting terminal are used to connect to the tail of the line under test. The current at the head and tail is synchronized by the current feedback at the power-collecting load. The voltage difference between the head and tail of the line under test is collected by the line head sampling device and the line tail sampling device. The line current parameters and Ohm's law are converted by the power-collecting load and the current conversion module, and the line impedance is calculated. It is suitable for lines under test at close range, and can quickly and accurately sample the data required for line impedance testing, significantly reducing the time for on-site fault diagnosis, improving fault handling efficiency, and ensuring the safe and stable operation of the distribution network. Attached Figure Description
[0016] Figure 1 This is a schematic diagram showing the composition and wiring of a line impedance tester according to the present invention. Figure 2 This is a system block diagram of the current conversion module of a line impedance tester of this utility model after adopting a power switching transistor; Figure 3 The system block diagram of the line impedance tester of this utility model after adding an AC-DC conversion power supply.
[0017] Label Explanation: 1. Main control module; 2. Analog-to-digital converter; 3. Power supply load; 4. Current conversion module; 5. Line head sampling device; 6. Line tail sampling device; 7. Load access control device; 8. Pre-stage protection circuit; 9. AC / DC power supply; 10. Display; 11. Memory; 12. Maintenance communication port; 13. Line under test. Detailed Implementation
[0018] To explain in detail the technical content, objectives, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.
[0019] Please refer to Figures 1 to 3 A line impedance tester includes a main control module 1, an analog-to-digital converter 2, a power-consuming load 3, a current conversion module 4, a line head sampling component 5, and a line tail sampling component 6. The main control module 1 is connected to the output terminal of the analog-to-digital converter 2. The analog-to-digital converter 2 has three input terminals, two of which are connected to the line head sampling device 5 and the line tail sampling device 6 respectively, and the other input terminal is connected to the output terminal of the current conversion module 4. The input terminal of the current conversion module 4 is connected to one end of the power-taking load 3, and the other end of the power-taking load 3 is set as the power-taking terminal. The line head sampling component 5 is used to connect to the head of the line under test 13, and the line tail sampling component 6 and the power-taking terminal are used to connect to the tail of the line under test 13.
[0020] As can be seen from the above description, the beneficial effects of this utility model are as follows: In use, the line head sampling component 5 is connected to the head of the line under test 13, and the line tail sampling component 6 and the power taking end are used to connect to the tail of the line under test 13. The current at the head and tail is synchronized by the current feedback at the power taking load 3. The voltage difference between the head and tail of the line under test 13 is collected by the line head sampling component 5 and the line tail sampling component. The line current parameters and Ohm's law are obtained by combining the power taking load 3 and the current conversion module 4, and the line impedance is calculated. It is suitable for the line under test 13 at close range. It can quickly and accurately sample the data required for line impedance testing, significantly reduce the on-site fault diagnosis time, improve fault handling efficiency, and ensure the safe and stable operation of the distribution network.
[0021] Furthermore, it also includes a load access control component 7; One end of the load access control unit 7 is connected to the end of the power-consuming load 3 away from the power-consuming end, and the other end of the load access control unit 7 is grounded; The control terminal of the load access control component 7 is connected to the main control module 1.
[0022] As described above, by setting the load access control component 7, the main control module 1 can flexibly control whether the power-consuming load 3 is connected to the test circuit, thus realizing the on / off control of the test circuit. When no test is needed, the power-consuming load 3 can be disconnected to avoid unnecessary power consumption; when test is required, its connection can be controlled, improving the flexibility and energy efficiency of the equipment, while also facilitating flexible adjustment of the test status according to different test requirements.
[0023] Furthermore, the load access control unit 7 includes a power switching transistor; The drain of the power switch is connected to the end of the power-taking load 3 that is furthest from the power-taking terminal, and the source of the power switch is grounded. The gate of the power switch is connected to the main control module 1.
[0024] As described above, using a power switching transistor as the load connection control device 7 offers advantages such as fast response speed, high control precision, and low on-resistance. The main control module 1 can quickly turn the power switching transistor on and off by controlling the gate voltage, thereby accurately controlling the connection and disconnection of the power-supplying load 3, ensuring timely and reliable control. Furthermore, the low power consumption of the power switching transistor helps reduce the overall energy consumption of the equipment.
[0025] Furthermore, it also includes a pre-stage protection circuit 8; The line head sampling component 5 and the line tail sampling component 6 are respectively connected to the two input terminals of the front-stage protection circuit 8, and the two output terminals of the front-stage protection circuit 8 are connected to the two input terminals of the analog-to-digital converter 2 in a one-to-one correspondence.
[0026] As described above, the pre-amplifier protection circuit 8 can preprocess and protect the signals collected by the line head sampling unit 5 and the line tail sampling unit 6. When abnormal conditions such as overvoltage or overcurrent occur in the line under test 13, the pre-amplifier protection circuit 8 can effectively suppress these abnormal signals, preventing them from damaging subsequent precision circuits such as the analog-to-digital converter 2, improving the anti-interference capability and service life of the equipment, and ensuring the accuracy of the sampling data.
[0027] Furthermore, it also includes an AC / DC converter 9; The AC input terminal of the AC-DC converter 9 is connected to the power supply terminal, and the DC power supply terminal of the AC-DC converter 9 is connected to the main control module 1, the analog-to-digital converter 2, and the current conversion module 4, respectively.
[0028] As described above, the AC / DC converter 9 can directly draw power from the power input terminal and convert it into the DC power required by each module, eliminating the need for an additional independent power supply. This simplifies the overall structure of the equipment and lowers the barrier to entry for its use. Simultaneously, it ensures the stability and consistency of power supply to each module, avoiding test errors caused by power supply issues and improving the reliability of the equipment.
[0029] Furthermore, it also includes a display 10, and the main control module 1 is connected to the display 10.
[0030] As described above, the display 10 can intuitively present the test results, such as the line impedance calculated by the main control module 1, to the user, enabling the user to quickly understand the test data and improving the readability and ease of use of the test results. Users do not need to access the data through other devices, simplifying the operation process and enhancing the human-computer interaction of the device.
[0031] Furthermore, the current conversion module 4 includes a through-hole current transformer; One end of the power-taking load 3 is grounded through the window via the current-carrying conductor of the through-hole transformer; The output terminal of the through-core transformer is connected to the input terminal of the analog-to-digital converter 2.
[0032] As described above, the through-core current transformer features high measurement accuracy, good linearity, and excellent isolation performance. Through the through-core current transformer, the large current in the power-receiving load 3 can be converted into a small signal suitable for acquisition by the analog-to-digital converter 2, achieving safe and accurate conversion of the current signal. Simultaneously, it avoids interference from strong current signals to weak current circuits, ensuring the accuracy of current parameter acquisition and providing a reliable basis for precise calculation of line impedance.
[0033] Furthermore, it also includes a memory 11, and the main control module 1 is connected to the memory 11.
[0034] As described above, the memory 11 can store the test data processed by the main control module 1, facilitating users to query, analyze, and compare historical test data later. Even after a power outage, the data will not be lost, ensuring data integrity and continuity, and providing data support for long-term line monitoring and fault analysis.
[0035] Furthermore, it also includes a maintenance communication port 12, to which the main control module 1 is connected.
[0036] As described above, the maintenance communication port 12 provides a convenient channel for equipment maintenance and upgrades. Through this interface, staff can perform operations such as program updates, parameter configuration, and fault diagnosis, reducing the difficulty and cost of equipment maintenance, facilitating later management and functional expansion, and extending the equipment's service life.
[0037] Furthermore, both the line head sampling component 5 and the line tail sampling component 6 are alligator clips.
[0038] As described above, the alligator clip features a secure grip and easy operation, enabling quick and stable connection to the head and tail of the circuit under test 13, ensuring reliable contact at the sampling point and reducing the impact of poor contact on test results. Furthermore, the alligator clip has a wide range of applications, adaptable to different specifications of the circuit under test 13, improving the versatility and practicality of the equipment.
[0039] Please refer to Figure 1 and Figure 2 Embodiment 1 of this utility model is as follows: A line impedance tester includes a main control module 1, an analog-to-digital converter 2, a power-supplying load 3, a current conversion module 4, a line head sampling component 5, and a line tail sampling component 6. The main control module 1 is connected to the output of the analog-to-digital converter 2, which has three inputs. Two inputs are connected to the line head sampling component 5 and the line tail sampling component 6, respectively, and the other input is connected to the output of the current conversion module 4. The input of the current conversion module 4 is connected to one end of the power-supplying load 3, and the other end of the power-supplying load 3 is used as a power-supplying end. The line head sampling component 5 is used to connect to the head of the line under test 13, and the line tail sampling component 6 and the power-supplying end are used to connect to the tail of the line under test 13. The line head sampling component 5, the line tail sampling component 6, and the power-supplying end are all alligator clips, which can be easily clamped onto the line under test 13.
[0040] In this embodiment, the usage process of a line impedance tester is as follows: First, such as Figure 1 As shown, the line head sampling component 5 is connected to the head of the line under test 13, and the line tail sampling component 6 and the power take-off terminal are connected to the tail of the line under test 13. Next, the power-taking load 3 is activated, allowing the current of the circuit under test 13 to flow through the power-taking load 3, and the current is converted by the current conversion module 4 to obtain a first current value, defined as I1. The current conversion module 4 includes a current transformer. One end of the power-taking load 3 is grounded through the current-carrying conductor of the through-hole transformer through the window; the conversion output terminal of the through-hole transformer is connected to the input terminal of the analog-to-digital converter 2.
[0041] When the power load 3 is connected to the line under test 13 and the first current value is collected, the head voltage U1 is sampled through the line head sampling device 5 and the tail voltage U2 is sampled through the line tail sampling device 6. The first voltage difference is calculated and defined as ΔU1=U1-U2. As shown in the figure, the analog-to-digital converter 2 adopts a three-channel ADC converter, which is connected to the line head sampling device 5, the line tail sampling device 6 and the conversion output terminal of the through-core transformer respectively.
[0042] Then, disconnect the power-consuming load 3 from the connection state, sample the head voltage U3 again through the line head sampling device 5, and sample the tail voltage U4 through the line tail sampling device 6, and calculate the second voltage difference, which is defined as ΔU2=U3-U4.
[0043] Finally, the impedance value R of the circuit under test 13 is calculated as R = {△U1 - △U2} ÷ I1. During the above test process, voltages U1 and U2, as well as U3 and U4, can be determined by sampling multiple waveform signals. For example, each signal can be sampled for a complete 5-cycle to determine the final value. Furthermore, multiple impedance values R can be obtained by repeatedly executing the above process; for example, testing 10 impedance values consecutively is required to complete the test. The maximum value of the multiple impedance values R can be initially determined to eliminate the invalid impedance caused by the voltage drop due to changes in the existing load current in the circuit under test 13. The remaining impedance values can then be averaged to obtain the final impedance value.
[0044] Regarding the connection status control of the power-consuming load 3 mentioned above, the line impedance tester also includes a load connection control component 7. One end of the load connection control component 7 is connected to the end of the power-consuming load 3 furthest from the power-consuming end, and the other end of the load connection control component 7 is grounded. The control terminal of the load connection control component 7 is connected to the main control module 1. The main control module 1 adjusts the grounding line of the power-consuming load 3 by controlling the load connection control component 7, thereby correspondingly controlling whether the power-consuming load 3 is connected to the line 13 under test. Figure 2 As shown, in a preferred design, the load access control unit 7 includes a power switch transistor; the drain of the power switch transistor is connected to the end of the power-drawing load 3 away from the power-drawing end, and the source of the power switch transistor is grounded. The gate of the power switch is connected to the main control module 1.
[0045] In this embodiment, the line head sampling device 5 and the line tail sampling device 6 are respectively connected to the two input terminals of the front-end protection circuit 8, and the two output terminals of the front-end protection circuit 8 are connected to the two input terminals of the analog-to-digital converter 2 in a one-to-one correspondence.
[0046] In addition, the line impedance tester is equipped with internal functional components such as a memory 11, a maintenance communication port 12, and a display 10. The memory 11 can be used to save test records for later retrieval and export. The maintenance communication port 12 provides a convenient channel for equipment maintenance and upgrades. The display 10 provides data display and human-machine interaction functions, simplifying the operation process and enhancing the equipment's interactivity.
[0047] Please refer to Figure 3 Embodiment two of this utility model is as follows: A line impedance tester, based on the above embodiment 1, further includes an AC / DC conversion power supply 9; The AC input terminal of the AC-DC converter 9 is connected to the power supply terminal, and the DC power supply terminal of the AC-DC converter 9 is connected to the main control module 1, the analog-to-digital converter 2 and the current conversion module 4 respectively.
[0048] Combination Figure 3As can be seen, the AC / DC converter 9 draws power directly from the circuit under test 13 through the power input terminal, and then converts it into DC power suitable for use by the main control module 1, etc.
[0049] In summary, this utility model provides a line impedance tester, including a main control module, an analog-to-digital converter, a power supply load, a current conversion module, a line head sampling component, and a line tail sampling component. In use, the line head sampling component is connected to the head of the line under test, and the line tail sampling component and the power supply end are connected to the tail of the line under test. Current feedback from the power supply load achieves synchronization between the head and tail currents. The line head sampling component and the line tail sampling component collect the voltage difference between the head and tail of the line under test. Combined with the power supply load and the current conversion module, the line current parameters and Ohm's law are obtained, and the line impedance is calculated. This device is suitable for short-distance lines under test, enabling rapid and accurate sampling of the data required for line impedance testing, ensuring reliable subsequent fault diagnosis results. A maintenance communication port provides a convenient channel for equipment maintenance and upgrades. Staff can perform operations such as program updates, parameter configuration, and fault diagnosis. The line impedance tester also has a display that visually presents the test results, such as the line impedance calculated by the main control module, to the user, allowing for quick understanding of the test data and improving the readability and usability of the test results. The sampling section uses alligator clips, which can quickly and stably connect to the head and tail of the line under test, significantly reducing on-site fault diagnosis time, improving fault handling efficiency, and ensuring the safe and stable operation of the power distribution network.
[0050] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.
Claims
1. A line impedance tester, characterized in that, It includes a main control module (1), an analog-to-digital converter (2), a power supply load (3), a current conversion module (4), a line head sampling device (5), and a line tail sampling device (6). The main control module (1) is connected to the output terminal of the analog-to-digital converter (2). The analog-to-digital converter (2) has three input terminals, two of which are connected to the line head sampling device (5) and the line tail sampling device (6) respectively, and the other input terminal is connected to the output terminal of the current conversion module (4). The input terminal of the current conversion module (4) is connected to one end of the power-taking load (3), and the other end of the power-taking load (3) is set as the power-taking terminal. The line head sampling component (5) is used to connect to the head of the line under test (13), and the line tail sampling component (6) and the power-taking terminal are used to connect to the tail of the line under test (13).
2. The line impedance tester according to claim 1, characterized in that, It also includes a load access control component (7); One end of the load access control unit (7) is connected to the end of the power-taking load (3) away from the power-taking end, and the other end of the load access control unit (7) is grounded; The control terminal of the load access control unit (7) is connected to the main control module (1).
3. A line impedance tester according to claim 2, characterized in that, The load access control unit (7) includes a power switching transistor; The drain of the power switch is connected to the end of the power-taking load (3) away from the power-taking terminal, and the source of the power switch is grounded. The gate of the power switch is connected to the main control module (1).
4. A line impedance tester according to claim 1, characterized in that, It also includes a pre-stage protection circuit (8); The line head sampling component (5) and the line tail sampling component (6) are respectively connected to the two input terminals of the front-end protection circuit (8), and the two output terminals of the front-end protection circuit (8) are connected to the two input terminals of the analog-to-digital converter (2) in a one-to-one correspondence.
5. A line impedance tester according to claim 1, characterized in that, It also includes AC / DC converter (9); The AC input terminal of the AC-DC converter (9) is connected to the power supply terminal, and the DC power supply terminal of the AC-DC converter (9) is connected to the main control module (1), the analog-to-digital converter (2) and the current conversion module (4) respectively.
6. A line impedance tester according to claim 1, characterized in that, It also includes a display (10), and the main control module (1) is connected to the display (10).
7. A line impedance tester according to claim 1, characterized in that, The current conversion module (4) includes a through-core transformer; One end of the power-taking load (3) is grounded through the current-carrying conductor of the through-hole transformer via a window; The output terminal of the through-core transformer is connected to the input terminal of the analog-to-digital converter (2).
8. A line impedance tester according to claim 1, characterized in that, It also includes a memory (11), and the main control module (1) is connected to the memory (11).
9. A line impedance tester according to claim 1, characterized in that, It also includes a maintenance communication port (12), and the main control module (1) is connected to the maintenance communication port (12).
10. A line impedance tester according to claim 1, characterized in that, Both the head sampling component (5) and the tail sampling component (6) of the line are alligator clips.