A geodetic network online monitoring system

Abstract

This utility model relates to an online monitoring system for a geogrid, comprising a back-end control device and several sets of front-end acquisition devices. Each set of front-end acquisition devices is installed at a measured point and includes a current-electrode grounding rod, a voltage-electrode grounding rod, and a cable coil. The current-electrode grounding rod and the voltage-electrode grounding rod are respectively connected to the cable coil, and the distance between the current-electrode grounding rod and the measured geogrid is 10-30m. The back-end control device includes a communication interface and a human-machine interface unit. The front-end acquisition devices communicate with the back-end control device through the cable coil to transmit the acquired data to the back-end control device, which then displays the data through the human-machine interface unit. This utility model not only ensures the reliability of geogrid monitoring but also improves detection efficiency, reduces the impact of soil resistivity inhomogeneity, minimizes environmental interference, and enhances measurement stability.

Description

Technical Field

[0001] This utility model relates to the field of power grid technology, and in particular to an online monitoring system for a geogrid. Background Technology

[0002] Grounding grids are one of the most widely used safety technologies today. A reliable and effective connection between the grounding down conductor of traction power equipment and the grounding grid is fundamental to the safe operation of power equipment and the personal safety of operators. However, connection points located in the soil are subject to long-term exposure to moisture and other factors, leading to corrosion, breakage, and loosening of the connections. This increases the resistance at the contact point between the grounding down conductor and the grounding grid, failing to meet the requirements of railway power regulations. This creates safety hazards during the operation of traction power equipment, and in severe cases, causes the equipment to detach from the grounding grid. Utility Model Content

[0003] The purpose of this invention is to improve the safety hazards caused by the disconnection of traction power equipment from the grounding grid in the existing technology, and to provide an online monitoring system for the grounding grid to ensure the safe operation of traction power equipment.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions:

[0005] An online monitoring system for a ground grid includes a back-end control device and several sets of front-end acquisition devices. Each set of front-end acquisition devices is installed at a measured point and includes a current-electrode grounding rod, a voltage-electrode grounding rod, and a cable coil. The current-electrode grounding rod and the voltage-electrode grounding rod are respectively connected to the cable coil, and the distance between the current-electrode grounding rod and the ground grid under test is 10-30m. The back-end control device includes a communication interface and a human-machine interaction unit. The front-end acquisition devices communicate with the back-end control device through the communication interface of the cable coil to transmit the acquired data to the back-end control device, and the data is displayed through the human-machine interaction unit.

[0006] In the above scheme, by deploying front-end acquisition equipment at the measured point, current and voltage data can be collected, and impedance data can be calculated. By analyzing impedance changes, it is possible to determine whether there are any safety hazards in the traction power equipment. Therefore, this system can effectively monitor the grounding grid. Furthermore, by installing the current electrode grounding rod within 30m of the grounding grid being measured, a short-distance measurement method is used, which improves detection efficiency.

[0007] In a more optimized implementation, the human-computer interaction unit includes a display screen, a keyboard, and an industrial control computer, with the display screen and keyboard electrically connected to the industrial control computer.

[0008] In the above scheme, the keyboard facilitates user input operations, and the industrial control computer generates relevant instructions based on user operations, enabling the front-end data acquisition devices at the specified measurement points to perform corresponding operations. The display screen shows the collected data in real time, allowing for timely monitoring of the current status of the grounding network. Therefore, this structure of the human-machine interface unit makes the entire system more flexible, enabling both automated and manual monitoring.

[0009] In a more optimized implementation, the back-end control device further includes a variable frequency power unit connected to an industrial control computer for outputting power at different frequencies.

[0010] In the above scheme, by setting up a different frequency power unit to output power at different frequencies, the needs of different monitoring projects can be met. Therefore, the above system can be used to monitor multiple projects, which solves the problem of how to monitor multiple grounding parameter projects.

[0011] In a more optimized implementation, the back-end control device further includes a voltage transformer and a current transformer, which are connected to a linear circuit consisting of the grounding grid under test, the current electrode grounding rod, and the earth.

[0012] In the above scheme, by arranging voltage transformers and current transformers, it is possible to monitor step voltage, contact voltage, and grounding impedance, that is, to monitor multiple items.

[0013] In a more optimized implementation, the back-end control device further includes a resistance tester electrically connected to an industrial computer.

[0014] In the above scheme, by deploying resistance testers, data such as electrical integrity, distributed potential, and grounding return current can be monitored in real time, thus enabling the monitoring of multiple items.

[0015] In a more optimized implementation, the back-end control device further includes a power supply and surge protection unit connected to the industrial control computer.

[0016] In the above solution, by arranging power supply and surge protection units, the back-end control equipment can be protected to operate safely and normally, thereby protecting the normal operation of the entire system. Therefore, the above system can solve the problem of how to ensure the reliability of the entire system operation.

[0017] In a more optimized implementation, the keyboard is a soft keyboard integrated with the display screen. In this solution, by integrating the keyboard and display screen, the overall size of the human-computer interaction unit can be reduced, thereby miniaturizing the back-end control device as much as possible.

[0018] In a more optimized implementation scheme, the front-end data acquisition device also includes a GPS module for collecting location information. In this scheme, by setting up a GPS module to collect location information, after obtaining the measurement items, a corresponding distribution map can be generated based on the location information, facilitating a more intuitive understanding and prediction of the overall distribution and changing trends of the measurement items.

[0019] Compared with existing technologies, the geodetic network online monitoring system of this invention has the following technical advantages:

[0020] 1) It can be used to monitor the continuity resistance between the grounding down conductor and the grounding grid of power equipment, as well as the grounding impedance, soil resistivity, and return system integrity, thus completing the monitoring of the entire grounding system and enabling timely and comprehensive understanding of the safety performance of the grounding grid.

[0021] 2) By setting the distance between the current electrode grounding rod and the grounding grid under test to 10-30m, short-distance measurement can be achieved, which can shorten the measurement path, reduce wiring time, and thus improve detection efficiency; it can also reduce the influence of soil resistivity non-uniformity; and it can also reduce environmental interference and improve measurement stability.

[0022] Other advantages of this invention will be explained in the specific embodiments. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of an online monitoring system for a geodetic grid provided in the embodiment.

[0025] In the diagram, the markings are: 11-grounding grid under test; 12-voltage electrode grounding rod; 13-current electrode grounding rod; 14-cable coil; 15-back-end control equipment. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] See also Figure 1 The Earth Network Online Monitoring System provided in this embodiment includes a back-end control device 15 and a front-end acquisition device. The front-end acquisition device is installed outdoors and is mainly used to actively or passively collect data under the control of the back-end control device 15, and then transmit the collected data to the back-end control device 15 for display.

[0028] Since the grounding network in a substation typically covers a large area, monitoring only one point is insufficient to assess the reliability of the entire network's operation. Therefore, it is preferable to deploy multiple test points at different locations within the grounding network, with each test point equipped with a set of front-end acquisition devices.

[0029] See also Figure 1 Each set of front-end acquisition equipment includes a current electrode grounding rod 13, a voltage electrode grounding rod 12, and a cable coil 14. Both the current electrode grounding rod 13 and the voltage electrode grounding rod 12 are equipped with connection points, which are connected to the cable coil 14 respectively. The distance between the current electrode grounding rod 13 and the ground grid 11 under test is 10-30m, which means short-distance measurement is implemented, the measurement path is shortened, the time for setting up the cable coil is reduced, and the detection efficiency can be improved.

[0030] Conventional methods (such as the potential drop method and the three-electrode method) require laying long test lines (usually 3-5 times the diagonal length of the grounding grid) at the edge of the grounding grid to form a stable current field and potential gradient. However, substation sites are complex, and long-distance wiring is easily hindered by terrain, equipment, cable trenches, etc., resulting in time-consuming and error-prone wiring. In this embodiment, by arranging the test points in reverse, for example, placing the current electrode grounding rod 13 and the voltage electrode grounding rod 12 close to the edge of the grounding grid under test, the measurement path is shortened to 1-2 times the diagonal length of the grounding grid under test. For example, in a large grounding grid, the traditional method requires 500 meters of test lines, while this solution only requires about 200 meters, significantly reducing wiring time.

[0031] Furthermore, short-distance measurements can reduce the impact of soil resistivity inhomogeneity. Long-distance test lines may cross soil layers with different resistivities (such as the interface between rock and soil), leading to current field distortion and requiring multiple adjustments to the test point positions to eliminate errors. By shortening the test distance, the current field is mainly distributed in the vicinity of the ground grid being measured, reducing dependence on the soil resistivity at a distance. Even with soil inhomogeneity, the actual impedance of the ground grid can be more accurately reflected through local current field analysis (such as using the four-electrode method).

[0032] Furthermore, short-distance measurements can reduce environmental interference and improve measurement stability. Long-distance test lines are susceptible to electromagnetic interference (such as from nearby operating equipment), temperature changes (causing fluctuations in soil resistivity), and human activities (such as vehicles running over the test lines), leading to fluctuations in measurement data. Short-distance measurements, by reducing the length of the test line, can reduce the coupling area of ​​electromagnetic interference and decrease signal attenuation. If combined with the injection of high-frequency current (such as above 1kHz), separating the measurement signal from power frequency interference (50Hz) and improving the signal-to-noise ratio, the impact of interference can be further reduced.

[0033] See also Figure 1 The back-end control device 15 includes a communication interface and a human-machine interaction unit. The cable coil 14 of the front-end acquisition device is connected to the communication interface of the back-end control device 15 to transmit the acquired data to the back-end control device 15 and display it through the human-machine interaction unit.

[0034] In this embodiment, the human-machine interface unit includes a display screen, a keyboard, and an industrial control computer. The display screen and keyboard are electrically connected to the industrial control computer. Preferably, the keyboard is a soft keyboard, integrated with the display screen. This design facilitates user operation and saves installation space, enabling a miniaturized human-machine interface unit. The user performs input operations via the keyboard, and the industrial control computer converts the user's input into control commands, driving all or some of the front-end data acquisition devices to collect data and displaying the returned data on the display screen, allowing the user to know the current operating status of the grounding network at any time.

[0035] Monitoring the normal operation of the grounding grid includes not only operating current and voltage, but also step voltage, grounding impedance, and other parameters. Since different parameters require different power frequencies, the back-end control equipment 15 can also include a variable-frequency power unit to meet the needs of multi-parameter monitoring. This unit is electrically connected to an industrial control computer (ICC) and outputs power at different frequencies under the ICC's control to meet the requirements of different monitoring parameters. For example, step voltage testing requires 5AKW, and grounding impedance testing requires 8KW. The variable-frequency power unit can be, for example, an E3350 model device.

[0036] Based on this, the back-end control device 15 may further include a voltage transformer and a current transformer, which are connected to a linear circuit consisting of the grounding grid 11, the current electrode grounding rod 13, and the earth. The voltage transformer and current transformer can be used to monitor step voltage, contact voltage, grounding impedance, and soil resistivity. For example, a DY650 model voltage transformer and a DL740 model current transformer can be used.

[0037] For example, when measuring grounding impedance, a 40-70Hz variable frequency current (I) is injected into the grounding grid under test to form a test current field. The potential difference (U) is measured between the edge of the grounding grid under test and the current electrode grounding rod. The grounding impedance Z = U / I.

[0038] For example, when measuring step voltage, the potential difference between the current electrode grounding rod and the voltage electrode grounding rod is measured, and the step voltage distribution at different locations is calculated by combining the soil resistivity model.

[0039] For example, when measuring soil resistivity, a quadrupole probe is arranged at equal intervals (a). Current (I) is injected through the outer electrode, and the potential difference (U) between the inner electrodes is measured. The soil resistivity ρ = 2πa * U / I. The front-end acquisition device can also include a GPS module, which, combined with positioning, can generate a three-dimensional distribution map of soil resistivity.

[0040] The back-end control device 15 may also include a resistance tester connected to the industrial control computer, which enables real-time monitoring of data such as electrical integrity, distributed potential, and grounding return current. For example, the resistance tester can be an FJ62456 model device.

[0041] For example, when measuring electrical integrity, a low-frequency pulse signal is injected through one end of the grounding grid being tested. The pulse signal propagates along the conductor and is reflected when it encounters a fault point (such as a break). The time difference of the reflected signal is measured to calculate the location of the fault point.

[0042] For example, when measuring the return current of the grounding grid, a high-frequency current (I) is injected into the grounding grid to form a test current field. Then, the potential difference (Umn) is measured at different locations of the grounding grid. The resistance distribution of the grounding grid is calculated according to Ohm's law (R=Umn / I). Combined with the soil resistivity model, the return current path and loss of the grounding grid are inverted.

[0043] It is easy to understand that the back-end control device 15 also includes a power management unit and a housing. The components such as the frequency conversion power unit, voltage transformer, current transformer, and resistance tester are arranged inside the housing. The power management unit is connected to 220V AC power to provide the power required for the operation of each component.

[0044] The normal operation of the back-end control device 15 is crucial to ensuring the normal operation of the entire system. Therefore, in order to ensure the normal operation of the back-end control device 15, a power supply and surge protection unit can be set up. The power supply and surge protection unit is connected to the industrial control computer and provides power supply protection and surge protection.

[0045] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An online monitoring system for a geodetic grid, characterized in that, The system includes a back-end control device and several sets of front-end acquisition devices. Each set of front-end acquisition devices is installed at a test point and includes a current electrode grounding rod, a voltage electrode grounding rod, and a cable coil. The current electrode grounding rod and the voltage electrode grounding rod are respectively connected to the cable coil, and the distance between the current electrode grounding rod and the grounding grid under test is 10-30m. The back-end control device includes a communication interface and a human-machine interaction unit. The front-end acquisition devices communicate with the back-end control device through the communication interface of the cable coil to transmit the acquired data to the back-end control device, and display it through the human-machine interaction unit.

2. The online monitoring system for a geodetic grid according to claim 1, characterized in that, The human-computer interaction unit includes a display screen, a keyboard, and an industrial control computer, with the display screen and keyboard electrically connected to the industrial control computer.

3. The online monitoring system for a geodetic grid according to claim 2, characterized in that, The back-end control equipment also includes a variable frequency power unit connected to the industrial control computer, used to output power at different frequencies.

4. The online monitoring system for a geodetic grid according to claim 3, characterized in that, The back-end control equipment also includes a voltage transformer and a current transformer, which are connected to a linear circuit consisting of the grounding grid under test, the current electrode grounding rod, and the earth.

5. The online monitoring system for a geodetic grid according to claim 3, characterized in that, The back-end control equipment also includes a resistance tester that is electrically connected to the industrial control computer.

6. The online monitoring system for a geodetic grid according to claim 2, characterized in that, The back-end control equipment also includes a power supply and surge protection unit connected to the industrial control computer.

7. The online monitoring system for a geodetic grid according to claim 2, characterized in that, The keyboard is a soft keyboard integrated with the display screen.

8. The online monitoring system for a geodetic grid according to claim 2, characterized in that, The front-end data acquisition device also includes a GPS module for collecting location information.

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