Distribution network low-voltage cable fault studying and judging device based on electricity testing grounding ring

Abstract

The utility model discloses a distribution network low-voltage cable fault studying and judging device based on an electricity testing grounding ring, and the device is characterized in that the device comprises a transmission assembly, an electricity taking CT, and an installation assembly; the mounting assembly comprises a connecting conductor, a current sampling piece and an electricity testing grounding ring; the current sampling piece is arranged on the connecting conductor, the connecting conductor is provided with a mounting hole, the electricity testing grounding ring is provided with a mounting part matched with the mounting hole, the mounting part is in threaded connection with the mounting hole, the connecting conductor comprises a first end head, a conductive block and a second end head, and the first end head is connected with the second end head through the conductive block; the conductive block is connected in series with the low-voltage cable through the first end and the second end; the transmission assembly is electrically connected with the power-taking CT and the current sampling piece, and the transmission assembly is in communication connection with the remote fault studying and judging platform. Current signals of a low-voltage cable are collected and uploaded to a remote fault studying and judging platform for processing, an electricity testing grounding ring is installed for grounding wire work, deployment is convenient, and line power supply reliability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, and particularly relates to a distribution network low-voltage cable fault judgment device based on a voltage and earth connection ring. Background Art

[0002] The existing fault judgment devices for distribution network overhead lines are mostly used for 10KV high-voltage lines. By installing fault traveling wave acquisition devices on the 10kV distribution network overhead lines, large traveling wave signals during fault occurrence are collected. The distribution network lines are decomposed into several short-distance intervals, and the fault interval is determined first, and the traveling wave is located within the interval to improve the reliability and accuracy of positioning.

[0003] However, due to reasons such as differences in cable gaps, the fault judgment devices for 10KV high-voltage lines cannot be applied to low-voltage cables below 400V. Moreover, in the distribution network, the number of low-voltage cables below 400V is huge and the distribution range is wide. Even if an adaptation design is made for the fault judgment devices of 10KV high-voltage lines, the cost required for batch installation of positioning devices is high, the deployment period is long, and they cannot be quickly put into use; when the low-voltage cables below 400V are faulty or under maintenance, it is also easy to cause an expansion of the power outage range due to the inability to install grounding wires, the line operation mode is not flexible, and the power supply reliability is poor. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a distribution network low-voltage cable fault judgment device based on a voltage and earth connection ring, which is suitable for rapid deployment on low-voltage cables and improves the power supply reliability of the line.

[0005] To solve the above technical problem, the technical solution adopted by the utility model is as follows:

[0006] A distribution network low-voltage cable fault judgment device based on a voltage and earth connection ring includes a transmission component, a power-taking CT, and an installation component;

[0007] The installation component includes a connecting conductor, a current sampling piece, and a voltage and earth connection ring;

[0008] The current sampling piece is arranged on the connecting conductor. The connecting conductor is provided with an installation hole, and the voltage and earth connection ring is provided with an installation part adapted to the installation hole. The installation part is threadedly connected to the installation hole. The connecting conductor includes a first end, a conductive block, and a second end. The first end is connected to the second end through the conductive block, and the conductive block is connected in series on the low-voltage cable through the first end and the second end;

[0009] The transmission component is electrically connected to the power-taking CT and the current sampling piece respectively, and the transmission component is communicatively connected to a remote fault judgment platform.

[0010] Further, the current sampling component is a Rogowski coil;

[0011] The current sampling component is sleeved on the connecting conductor.

[0012] Further, a connection socket is provided on the current sampling component;

[0013] The data sampling end of the transmission component is plugged into the connection socket.

[0014] Further, both the first end and the second end are copper lugs, and the copper lugs are electrically connected to the low-voltage cable.

[0015] Further, an insulating sheath is provided on the side circumferential surface of the conductive block.

[0016] Further, an installation buckle is provided on the power-taking CT;

[0017] The power-taking CT is fixed on the low-voltage cable through the installation buckle.

[0018] The beneficial effects of the present utility model are as follows: A distribution network low-voltage cable fault judgment device based on a voltage and ground checking ring is provided, which is composed of a transmission component, a power-taking CT, and an installation component; the connecting conductor carrying the current sampling component is pre-installed on the actually operating low-voltage cable; the power-taking CT is used to collect the electric energy of the low-voltage cable to supply power to the transmission component; when a fault occurs, the current sampling component is used to collect the fault current signal on the low-voltage cable, and the transmission component uploads the collected result to a remote fault judgment platform for processing. When grounding inspection and repair are required, a voltage and ground checking ring can be installed on the connecting conductor for grounding wire work, without the need to arrange the grounding wire in the upper-level line, avoiding the expansion of the power outage range, thereby reducing the impact on user power outage, avoiding the possible insulation aging, poor contact, or even accidental electrification of the voltage and ground checking ring due to long-term exposure to the outdoor environment, increasing the risk of electric shock to personnel, significantly improving safety and fault handling efficiency, greatly enhancing power supply reliability, providing an auxiliary means for line operation and maintenance, greatly reducing operation and maintenance costs, and can be quickly deployed on low-voltage cables to improve operation and maintenance efficiency. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the installation component of a distribution network low-voltage cable fault judgment device based on a voltage and ground checking ring of the present utility model;

[0020] Figure 2 It is a cross-sectional view of the installation component of a distribution network low-voltage cable fault judgment device based on a voltage and ground checking ring of the present utility model;

[0021] Figure 3Structural schematic diagram of the voltage and ground connection ring of a low-voltage distribution network cable fault judgment device based on a voltage and ground connection ring of the present utility model;

[0022] Figure 4 Structural schematic diagram of the power-taking CT of a low-voltage distribution network cable fault judgment device based on a voltage and ground connection ring of the present utility model;

[0023] Figure 5 Connection schematic diagram of a low-voltage distribution network cable fault judgment device based on a voltage and ground connection ring of the present utility model.

[0024] Label description:

[0025] 1. Transmission component; 2. Power-taking CT; 3. Connection conductor; 4. Current sampling component; 5. Voltage and ground connection ring; 6. Mounting hole; 7. Mounting part; 8. Connection socket; 9. Buckle ring; 10. Battery; 11. Remote fault judgment platform;

[0026] 31. First end; 32. Conductive block; 33. Second end. Detailed implementation method

[0027] To describe in detail the technical content, achieved purpose and effects of the present utility model, the following is described in conjunction with the implementation method and accompanied by the drawings.

[0028] Please refer to Figures 1 to 5 , a low-voltage distribution network cable fault judgment device based on a voltage and ground connection ring, including a transmission component 1, a power-taking CT 2 and a mounting component;

[0029] The mounting component includes a connection conductor 3, a current sampling component 4 and a voltage and ground connection ring 5;

[0030] The current sampling component 4 is arranged on the connection conductor 3. The connection conductor 3 is provided with a mounting hole 6. The voltage and ground connection ring is provided with a mounting part 7 adapted to the mounting hole 6. The mounting part 7 is threadedly connected to the mounting hole 6. The connection conductor 3 includes a first end 31, a conductive block 32 and a second end 33. The first end 31 is connected to the second end 33 through the conductive block 32. The conductive block 32 is connected in series to the low-voltage cable through the first end 31 and the second end 33;

[0031] The transmission component 1 is electrically connected to the power-taking CT 2 and the current sampling component 4 respectively. The transmission component 1 is communicatively connected to the remote fault judgment platform 11.

[0032] As can be seen from the above description, the beneficial effects of the present utility model are as follows: It consists of a transmission component 1, a power-taking CT 2, and a mounting component; the connecting conductor 3 carrying the current sampling component 4 is pre-installed on the actually operating low-voltage cable; the power-taking CT 2 is used to collect the current of the low-voltage cable; when a fault occurs, the current sampling component 4 is used to collect the fault current signal on the low-voltage cable, and the transmission component 1 uploads the collection result to the remote fault judgment platform 11 for processing. When it is necessary to check and ground, the voltage testing and grounding ring 5 can be installed on the connecting conductor 3 for grounding work, without the need to arrange the grounding wire in the upper-level line, avoiding expanding the power outage range, thereby reducing the impact on user power outage; avoiding the voltage testing and grounding ring 5 may cause insulation aging, poor contact, or even accidental electrification due to long-term exposure to the outdoor environment, increasing the risk of electric shock to personnel, significantly improving safety and fault handling efficiency, greatly enhancing power supply reliability, providing an auxiliary means for line operation and maintenance, greatly reducing operation and maintenance costs, and can be quickly deployed on low-voltage cables to improve operation and maintenance efficiency.

[0033] Further, the current sampling component 4 is a Rogowski coil;

[0034] The current sampling component 4 is sleeved on the connecting conductor 3.

[0035] As can be seen from the above description, the Rogowski coil has good linearity and broadband response characteristics, can accurately capture transient and high-frequency fault current signals on the low-voltage cable, ensure the integrity and accuracy of the acquisition of fault characteristic information, provide reliable data support for the remote fault judgment platform 11, and effectively improve the accuracy of fault location and analysis.

[0036] Further, a connection socket 8 is provided on the current sampling component 4;

[0037] The data sampling end of the transmission component 1 is plugged into the connection socket 8.

[0038] As can be seen from the above description, the plug-in connection structure is compact and stable, can effectively resist common working conditions such as vibration and shaking in the operation of the distribution network, avoid connection loosening or data transmission interruption caused by line jitter, ensure that the fault current signal can be stably and efficiently transmitted to the transmission component 1, and provide a reliable data basis for fault judgment; improve the maintenance convenience of the device. When it is necessary to repair or replace the current sampling component 4 or the transmission component 1, the staff does not need to use complex tools or cumbersome operations, and only needs to plug and unplug the interface to complete the disassembly and installation of the components, significantly shortening the equipment maintenance time and reducing operation and maintenance costs.

[0039] Further, both the first end 31 and the second end 33 are copper lugs, and the copper lugs are electrically connected to the low-voltage cable.

[0040] As can be seen from the above description, the copper nose can be closely attached to the cable by means of a bolt lock to form a firm mechanical connection, withstanding vibrations and external pulling forces during line operation; at the same time, the standardized copper nose specifications are suitable for a variety of cable models, and the staff can quickly complete the installation without special tools, significantly improving the on-site construction efficiency.

[0041] Further, an insulating sheath is provided on the side circumferential surface of the conductive block 32.

[0042] As can be seen from the above description, the insulating sheath can effectively isolate the direct contact between the conductive block 32 and the external environment, preventing the staff from accidentally touching the conductive block 32 during installation and maintenance, thus avoiding electric shock accidents, and greatly improving the safety of on-site operations; at the same time, the insulating sheath can resist the erosion of environmental factors such as rain, moisture, and corrosive gases, preventing the surface of the conductive block 32 from being oxidized and corroded, reducing the conductive performance, ensuring the stable transmission of current signals, and maintaining the accuracy and reliability of device fault judgment.

[0043] Further, an installation buckle is provided on the power-taking CT 2;

[0044] The power-taking CT 2 is fixed to the low-voltage cable through the installation buckle.

[0045] As can be seen from the above description, the application of the installation buckle greatly simplifies the installation process. The staff does not need to use complex tools or perform cumbersome wiring operations. Only by aligning the buckle with the low-voltage cable and snapping it can the installation be completed, greatly shortening the on-site deployment time and significantly improving the construction efficiency.

[0046] Please refer to Figures 1 to 5 , the first embodiment of the present utility model is:

[0047] A distribution network low-voltage cable fault judgment device based on an electric inspection grounding ring 5, including a transmission component 1, a power-taking CT 2, and an installation component; the installation component includes a connection conductor 3, a current sampling component 4, and an electric inspection grounding ring 5; the current sampling component 4 is arranged on the connection conductor 3, the connection conductor 3 is detachably connected to the electric inspection grounding ring 5, and the connection conductor 3 is used to be connected in series on the low-voltage cable; the transmission component 1 is electrically connected to the power-taking CT 2 and the current sampling component 4 respectively, and the transmission component 1 is communicatively connected to the remote fault judgment platform 11.

[0048] In this embodiment, the usage process of a distribution network low-voltage cable fault judgment device based on an electric inspection grounding ring 5 is as follows:

[0049] First, install the installation component on the low-voltage cable; during installation, connect the connection conductor 3 in series on the low-voltage cable, and the electric inspection grounding ring 5 can not be installed first;

[0050] Secondly, the power-taking CT2 is installed on the low-voltage cable; the power-taking CT2 can be selected as a current transformer to induce electric energy from the low-voltage cable and supply power to the transmission component 1. Specifically, when an alternating current passes through the primary coil of the power-taking CT2, an alternating magnetic flux will be generated in the iron core. This alternating magnetic flux is transmitted to the secondary winding through the closed iron core. According to Faraday's law of electromagnetic induction, an induced electromotive force will be generated in the secondary winding. When a load is connected across the two ends of the secondary winding, an induced current will flow through, thus realizing the extraction of energy from the main circuit. Moreover, it is worth noting that the power verification and grounding ring 5 of this embodiment does not need to be continuously installed on the low-voltage cable through the connecting conductor 3, but only needs to be installed during the grounding and maintenance operation, avoiding the possible insulation aging, poor contact, and even accidental electrification of the power verification and grounding ring 5 due to long-term exposure to the outdoor environment (such as wind, rain, corrosion, external collision, etc.), increasing the risk of electric shock to personnel.

[0051] Then, the transmission component 1 is respectively connected to the current sampling component 4 and the power-taking CT2, collects current signals and uploads them to the remote fault judgment platform 11; the remote fault judgment platform 11 has a power quality detection function and can give early warnings about line overload and three-phase imbalance. Among them, the transmission component 1 can adopt a hybrid networking technology of short-distance wireless communication and GPRS, support various complex line topologies, and ensure that the state of the low-voltage cable can be grasped at any time.

[0052] Finally, the remote fault judgment platform 11 analyzes the data to obtain the fault judgment result. It can be understood that the software processing procedures for fault judgment are all implemented by existing algorithms. For example: receiving the zero-sequence current data of the low-voltage cable and extracting its transient component and power frequency component, using a variety of algorithms to compare the similarity of transient currents of adjacent acquisition units to determine the fault section, etc., which will not be elaborated here.

[0053] In this embodiment, the current sampling component 4 is equipped with an indicator light, and it can be determined that the low-voltage switch has been operated in place by judging the mechanical indication of the low-voltage switch and the indicator light of two non-same principle indications, ensuring that the safety measures meet the maintenance requirements.

[0054] Such as Figure 2 and Figure 3As shown in the figure, when grounding maintenance is required, the voltage detector grounding ring 5 can be directly connected to the connecting conductor 3. Specifically, the connecting conductor 3 is provided with a mounting hole 6; the voltage detector grounding ring 5 is provided with a mounting portion 7 adapted to the mounting hole 6, and the mounting portion 7 is threadedly connected to the mounting hole 6. Before grounding maintenance, it is necessary to first determine whether the line is energized. The voltage detector grounding ring 5 provides a reliable contact point for voltage detection. Maintenance personnel can use a special voltage detector to contact the voltage detector grounding ring 5, and accurately judge whether there is voltage on the line through the indication of the voltage detector, so as to avoid maintenance operations on energized lines and ensure the personal safety of maintenance personnel. Moreover, the voltage detector grounding ring 5 provides a fixed connection point for the grounding wire. After confirming that the line is de-energized, connecting the grounding wire to the voltage detector grounding ring 5 can form an equipotential body between the line and the ground, conduct the remaining charge into the ground, and prevent the induced electricity on the line or the charge generated by other reasons from harming the maintenance personnel. This grounding position is added to the low-voltage branch cable. During maintenance, there is no need to arrange the grounding wire in the upper-level line, avoiding expanding the power outage range, and thus reducing the impact on user power outage.

[0055] In this embodiment, as Figure 4 shown, the power-taking CT 2 is provided with mounting buckles; the power-taking CT 2 is fixed to the low-voltage cable through the mounting buckles. The power-taking CT 2 can be applied to 400V cables of different specifications through the mounting buckles.

[0056] In this embodiment, the current sampling component 4 is a Rogowski coil; the current sampling component 4 is sleeved on the connecting conductor 3. The current sampling component 4 is provided with a connecting socket 8; the data sampling end of the transmission component 1 is inserted into the connecting socket 8. Based on the principle of electromagnetic induction and Ampere's circuital law, when the measured current passes through the central axis of the Rogowski coil, an alternating magnetic field will be generated in the Rogowski coil. According to Faraday's law of electromagnetic induction, the alternating magnetic field will generate an induced electromotive force in the coil, and this induced electromotive force is proportional to the rate of change of the measured current. By integrating the induced electromotive force through an integration circuit, an output signal proportional to the measured current can be obtained, thus realizing the measurement of the current.

[0057] In this embodiment, it further includes a storage battery 10 built in the transmission component 1. The storage battery 10 can be powered by a supercapacitor. By applying new materials and innovative power technologies, power can be continuously taken in the range of line current 0 - 650A. A line current of 2.5A can meet the full-function operation of the device. The supercapacitor can continuously operate for 4 hours when fully charged, without relying on a battery, thus effectively extending the life of the device.

[0058] Please refer to Figure 1 and Figure 2 , the second embodiment of the present utility model is:

[0059] A distribution network low-voltage cable fault judgment device based on an electroscope grounding ring 5. On the basis of the above-mentioned Embodiment 1, the connecting conductor 3 includes a first end 31, a conductive block 32 and a second end 33; the first end 31 is connected to the second end 33 through the conductive block 32. Both the first end 31 and the second end 33 are copper lugs. The side surface of the conductive block 32 is provided with an insulating sheath.

[0060] In summary, a distribution network low-voltage cable fault judgment device provided by the present utility model is composed of a transmission component, a power-taking CT and an installation component; a connecting conductor carrying a current sampling component is pre-installed on an actually operating low-voltage cable; the current of the low-voltage cable is collected by the power-taking CT; when a fault occurs, the fault current signal on the low-voltage cable is collected by the current sampling component, and the collection result is uploaded to a remote fault judgment platform by the transmission component for processing. When grounding needs to be repaired, an electroscope grounding ring can be installed on the connecting conductor for grounding wire work, without arranging the grounding wire in the upper-level line, avoiding expanding the power outage range, thereby reducing the impact on user power outage, significantly improving safety and fault handling efficiency, and greatly enhancing power supply reliability; moreover, the combination method between the electroscope grounding ring and the connecting conductor is flexible, and it can be installed or disassembled at any time according to actual maintenance needs, which can not only meet the monitoring requirements of the low-voltage cable during fault judgment, but also provide reliable grounding protection during maintenance, effectively improving the comprehensive utilization rate and adaptability of the device. This device integrates the latest wireless radio frequency communication technology, high-precision Rogowski coil sampling technology, small-current power-taking technology, and high-precision wave recording technology, and integrates functions such as fault judgment, operation monitoring, communication, and electroscope grounding. It has the characteristics of high integration, small and flexible, easy to install, and low operation and maintenance costs, provides an auxiliary means for line operation and maintenance, greatly reduces the operation and maintenance costs, can be quickly deployed on low-voltage cables, and improves the operation and maintenance efficiency.

[0061] The above are only the embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. All equivalent transformations made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in related technical fields, are equally included in the patent protection scope of the present utility model.

Claims

1. A low-voltage distribution network cable fault judgment device based on a voltage and ground connection ring, characterized in that It includes a transmission component, a power-taking CT, and a mounting component; The mounting component includes a connecting conductor, a current sampling component, and a voltage-testing and grounding ring; The current sampling component is arranged on the connecting conductor. The connecting conductor is provided with a mounting hole. The voltage-testing and grounding ring is provided with a mounting part adapted to the mounting hole. The mounting part is threadedly connected to the mounting hole. The connecting conductor includes a first end, a conductive block, and a second end. The first end is connected to the second end through the conductive block. The conductive block is connected in series to the low-voltage cable through the first end and the second end; The transmission component is electrically connected to the power-taking CT and the current sampling component respectively, and the transmission component is communicatively connected to a remote fault judgment platform.

2. The fault judgment device for low-voltage distribution network cables based on a voltage and ground checking loop according to claim 1, wherein The current sampling component is a Rogowski coil; The current sampling component is sleeved on the connecting conductor.

3. The low-voltage cable fault judgment device for a distribution network based on a voltage and ground checking loop according to claim 2, wherein The current sampling component is provided with a connecting socket; The data sampling end of the transmission component is plugged into the connecting socket.

4. The fault judgment device for low-voltage distribution network cables based on an electrification verification grounding ring according to claim 1, wherein, The connecting conductor includes a first end, a conductive block, and a second end; The first end is connected to the second end through the conductive block.

5. The fault judgment device for low-voltage distribution network cables based on a voltage and ground checking loop according to claim 4, wherein, Both the first end and the second end are copper lugs, and the copper lugs are electrically connected to the low-voltage cable.

6. The fault judgment device for low-voltage distribution network cables based on a voltage and ground checking loop according to claim 1, characterized in that, The side surface of the conductive block is provided with an insulating sheath.

7. The fault judgment device for low-voltage distribution network cables based on a voltage and ground checking loop according to claim 1, wherein, The power-taking CT is provided with a mounting buckle; The power-taking CT is fixed to the low-voltage cable through the mounting buckle.

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