DC grounding electrode drainage cable monitoring device

Abstract

The utility model discloses a direct current grounding electrode drainage cable monitoring device, which is characterized in that a grounding end current detection interface of a grounding end current detection device is connected with the grounding end of a drainage cable, and the grounding end current detection device is used for detecting current signals of the grounding end of the drainage cable; the current signal output end of the grounding end current detection device is connected with the current signal input end of the data storage device; a feed end current detection interface of the feed end current detection device is connected with a drainage cable feed end of the drainage cable buried underground, and the feed end current detection device is used for detecting a current signal of the drainage cable feed end of the drainage cable buried underground; and the current signal output end of the feed end current detection device is connected with the current signal input end of the data storage device. According to the utility model, the operation condition of each drainage cable of the direct current grounding electrode can be monitored online in real time, and the condition of non-uniform polar ring current distribution caused by damage and electric leakage of the drainage cable can be found in time.

Description

Technical Field

[0001] This utility model relates to the field of high voltage direct current transmission, specifically to a monitoring device for a DC grounding electrode current-carrying cable. Background Technology

[0002] As an important component of DC power transmission, one of the main functions of the DC grounding electrode is to discharge thousands of amperes of DC current into the ground in a designed proportion through dozens of current-carrying cables connected to the electrode during monopolar operation. When designing the grounding electrode, the current distribution area is planned according to the actual terrain. If the current-carrying cables are damaged, uneven current distribution will lead to problems such as increased local current density and increased ground step voltage.

[0003] Current technology only detects the current on the above-ground portion of each cable, and only detects whether the current has entered the ground. It does not detect the leakage of current in the underground portion of the diversion cable. When there is damage to the underground portion of the diversion cable, it will cause leakage. If the leakage of the underground portion of each cable is not detected, it is impossible to determine whether the current enters the ground normally at the end of the diversion cable or abnormally at the damaged part in the middle of the diversion cable.

[0004] Therefore, it is necessary to design a DC grounding electrode current-carrying cable monitoring device to monitor the leakage status of each current-carrying cable, and to promptly receive alarm information and handle any faults in the current-carrying cables, thereby ensuring the normal operation of the UHVDC grounding electrode. Summary of the Invention

[0005] The purpose of this invention is to provide a DC grounding electrode current-leading cable monitoring device, which is suitable for online monitoring of faults in high voltage DC transmission grounding electrode current-leading cables and can monitor and alarm grounding faults caused by cable damage, etc.

[0006] To achieve this objective, the present invention provides a DC grounding electrode current-guiding cable monitoring device, which includes a grounding end current detection device, a feeder end current detection device, and a data storage device.

[0007] The grounding current detection device is installed at the grounding end of the current-carrying cable in the center area of ​​the pole address. The grounding current detection interface of the grounding current detection device is connected to the grounding end of the current-carrying cable. The grounding current detection device is used to detect the current signal at the grounding end of the current-carrying cable. The current signal output terminal of the grounding current detection device is connected to the current signal input terminal of the data storage device.

[0008] The feeder current detection device is installed at the feeder end of the underground feeder cable. The feeder current detection interface of the feeder current detection device is connected to the feeder end of the underground feeder cable. The feeder current detection device is used to detect the current signal at the feeder end of the underground feeder cable. The current signal output terminal of the feeder current detection device is connected to the current signal input terminal of the data storage device.

[0009] Furthermore, the feed end of the underground drain cable is connected to the feed electrode.

[0010] Furthermore, the drain cable is formed by twisting together cables of multiple feed electrodes.

[0011] Furthermore, the current signal output terminal of the grounding current detection device is connected to the current signal input terminal of the data storage device via a signal cable.

[0012] Furthermore, the current signal output terminal of the power supply current detection device is connected to the current signal input terminal of the data storage device via a signal cable.

[0013] Furthermore, the grounding end of the drain cable is used to connect to the busbar cable.

[0014] Furthermore, the feed-end current detection device is directly buried underground, and the outer shell of the feed-end current detection device is an insulating layer.

[0015] Furthermore, the data storage device has a display section and a data transmission interface.

[0016] Furthermore, the data storage device is also connected to the converter station or monitoring center via wired or wireless communication.

[0017] Furthermore, the grounding current detection device is installed at the grounding end of the current-carrying cable in the center area of ​​the pole site via a fixed bracket.

[0018] The beneficial effects of this utility model are: it can detect grounding faults in the current-carrying cable that cannot be detected by existing current-carrying cable detection devices; it can monitor the current at the grounding end and the feeder end of the current-carrying cable in real time; it can display the current-carrying cable fault in real time in the central area of ​​the electrode site or the equipment compartment; it can send the current-carrying cable fault information to the converter station or other monitoring center through wired or wireless means; and it improves the safety of unattended grounding electrode operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the DC grounding electrode current-leading cable monitoring device of this utility model;

[0020] Figure 2 This is a schematic diagram of the data processing unit of this utility model;

[0021] Figure 3 This is a schematic diagram of the data processing unit panel of this utility model;

[0022] Among them, 1—grounding current detection device, 2—feeder current detection device, 3—data storage device, 4—current-driving cable, 5—signal cable, and 6—feeder electrode. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0024] like Figure 1 —3 shows a DC grounding electrode current-feeding cable monitoring device, which includes a grounding end current detection device 1, a feeder end current detection device 2 and a data storage device 3;

[0025] The grounding current detection device 1 is installed at the grounding end of the current-carrying cable 4 in the center area of ​​the pole address. The grounding current detection interface of the grounding current detection device 1 is connected to the grounding end of the current-carrying cable 4. The grounding current detection device 1 is used to detect the current signal at the grounding end of the current-carrying cable 4. The current signal output terminal of the grounding current detection device 1 is connected to the current signal input terminal of the data storage device 3.

[0026] The feeder current detection device 2 is installed at the feeder end of the underground feeder cable 4. The feeder current detection interface of the feeder current detection device 2 is connected to the feeder end of the underground feeder cable 4. The feeder current detection device 2 is used to detect the current signal at the feeder end of the underground feeder cable 4. The current signal output terminal of the feeder current detection device 2 is connected to the current signal input terminal of the data storage device 3.

[0027] The grounding current detection device 1 and the feeder current detection device 2 use the same current detection device. The grounding current detection device and the feeder current detection device are selected with a range of ±50A to ±900A based on the actual current of the DC grounding electrode. In a specific embodiment, the JLK80I model current detection device from Wuhan Jingliang Electronics Co., Ltd. is used.

[0028] The grounding electrode ring has a diameter of several hundred meters, but the outer perimeter of the grounding electrode is buried underground, with fields or trees covering the ground, making it inconvenient to install detection devices. The central area of ​​the grounding electrode is enclosed by a wall to form a square area with sides of more than ten meters, which is specifically used to store equipment and is not open to non-staff members. This square area is the central area of ​​the electrode site.

[0029] The feeder end of the underground drain cable 4 is connected to the feeder electrode 6. The feeder electrode 6 is a metal rod that conducts electricity. It is typically made by calcining petroleum coke with a conductive material and bringing it into contact with the soil, allowing the current from the drain cable 4 to be conducted into the ground through the feeder electrode. A single drain cable is generally connected to eight feeder electrodes 6 to more effectively utilize the cable's transmission capacity, reduce the current density on individual electrodes, thereby reducing losses and heat generation. This contributes to improved conductivity efficiency and stability.

[0030] The feed electrode 6 is generally buried three to four meters underground. The feed end current detection device 2 can be kept at the same depth as the feed electrode 6, or it can be kept at a depth of two to three meters underground, just like the diversion cable. The depth will be adjusted according to different projects. The main purpose is to prevent the ground potential from rising and affecting people's activities on the ground, and to avoid digging up the diversion cable during activities such as planting on the ground.

[0031] The current-draining cable 4 is made by twisting together the cables of multiple feed electrodes 6.

[0032] The current signal output terminal of the ground current detection device 1 is connected to the current signal input terminal of the data storage device 3 via the signal cable 5.

[0033] The current signal output terminal of the power supply end current detection device 2 is connected to the current signal input terminal of the data storage device 3 via signal cable 5. To ensure the stability and accuracy of data transmission, signal cable 5 is used as a dedicated cable for power supply and data transmission for both the grounding end current detection device 1 and the power supply end current detection device 2.

[0034] The grounding end of the current-carrying cable 4 is used to connect to the busbar cable. The current-carrying cable 4 is used to conduct the current from the busbar cable into the ground.

[0035] The feeder current detection device 2 is directly buried underground, and the outer shell of the feeder current detection device 2 is an insulating layer.

[0036] The data storage device 3 has a display section and a data transmission interface. The display section is used to display multiple sets of current data detected by the grounding current detection device 1 and the power supply current detection device 2, and to display fault information. The data transmission section is used to receive current information transmitted by the signal cable 5.

[0037] The data storage device 3 is also connected to the converter station or monitoring center via wired or wireless communication. The converter station or monitoring center is used to monitor and store the leakage status of the drain cable.

[0038] The grounding current detection device 1 is installed at the grounding end of the current-carrying cable 4 in the center area of ​​the pole site via a fixed bracket.

[0039] The working principle of this DC grounding electrode current-feeding cable monitoring device is as follows: the grounding end current detection device 1 detects the current value at the grounding end of the current-feeding cable 4, and the feeder end current detection device 2 detects the current value at the feeder end of the current-feeding cable 4. The detected current values ​​are displayed and processed by the data storage device 3: the current value at the grounding end of the current-feeding cable 4 is compared with the current value at the feeder end of the current-feeding cable 4. When the current value at the grounding end of the current-feeding cable 4 is greater than the current value at the feeder end of the current-feeding cable 4, it indicates that the current-feeding cable 4 has a fault such as damage or leakage; when the current value at the grounding end of the current-feeding cable 4 is less than the current value at the feeder end of the current-feeding cable 4, it indicates that the current detection device is faulty. When both the current-feeding cable 4 and the current detection device malfunction, the data storage device displays the fault information; when the current value at the grounding end of the current-feeding cable 4 is equal to the current value at the feeder end of the current-feeding cable 4, it indicates that the current-feeding cable and the current detection device are operating normally.

[0040] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A monitoring device for DC grounding electrode current-carrying cable, characterized in that: It includes a ground current detection device (1), a feed current detection device (2), and a data storage device (3); The grounding current detection device (1) is installed at the grounding end of the current-carrying cable (4) in the center area of ​​the pole address. The grounding current detection interface of the grounding current detection device (1) is connected to the grounding end of the current-carrying cable (4). The grounding current detection device (1) is used to detect the current signal at the grounding end of the current-carrying cable (4). The current signal output terminal of the grounding current detection device (1) is connected to the current signal input terminal of the data storage device (3). The feed end current detection device (2) is installed at the feed end of the underground feed cable of the diverting cable (4). The feed end current detection interface of the feed end current detection device (2) is connected to the feed end of the underground feed cable of the diverting cable (4). The feed end current detection device (2) is used to detect the current signal of the feed end of the underground feed cable of the diverting cable (4). The current signal output terminal of the feed end current detection device (2) is connected to the current signal input terminal of the data storage device (3).

2. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The feed cable (4) is buried underground and its feed end is connected to the feed electrode (6).

3. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The drain cable (4) is formed by twisting together the cables of multiple feed electrodes (6).

4. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The current signal output terminal of the grounding current detection device (1) is connected to the current signal input terminal of the data storage device (3) via a signal cable (5).

5. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The current signal output terminal of the power supply current detection device (2) is connected to the current signal input terminal of the data storage device (3) via a signal cable (5).

6. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The grounding end of the diversion cable (4) is used to connect to the busbar cable.

7. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The current detection device (2) at the power supply end is directly buried underground, and the outer shell of the current detection device (2) at the power supply end is an insulating layer.

8. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The data storage device (3) has a display section and a data transmission interface.

9. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The data storage device (3) is also connected to the converter station or monitoring center via wired or wireless communication.

10. The DC grounding electrode current-leading cable monitoring device according to claim 1, characterized in that: The grounding current detection device (1) is installed at the grounding end of the current-carrying cable (4) in the center area of ​​the pole site via a fixed bracket.

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