Mechanical protection device capable of quickly responding to arc short circuit

Abstract

The invention discloses a mechanical protection device capable of quickly responding to arc light short circuit, which is mounted in a ring main unit and comprises an arc light sensor, a grounding structure and a switch structure for driving the grounding structure to rotate, the arc light sensor is arranged on the inner wall of the ring main unit, the grounding structure is rotatably arranged in the ring main unit, and three grounding contacts are further arranged in the ring main unit. The switch structure is in communication connection with the arc light sensor and drives the grounding structure to rotate to be connected with the grounding contact. The beneficial effects of the invention are that the arc light sensor is matched with the switch structure, so that tripping can be started within 35MS, tiny abnormal current can be detected, and the protection of an electrical system is improved; the structure is simple, fault sources are few, reliability is high, the service life is long, opening and closing phases are controlled at the same time, synchronous control is achieved, impact of overvoltage and inrush current on an electrical system is reduced, input of electrical system protection is reduced, and the overall service life of the electrical system is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of transformer fire prevention and control, and in particular to a fast-response arc short-circuit mechanical protection device. Background Art

[0002] In the case of medium and low voltage busbar short circuit faults, damage to key equipment and personnel is mainly caused by arc light. However, most medium and low voltage busbars do not have fast busbar protection, but only use simple arc extinguishing devices and transformer backup protection. These protections are less intelligent and slow to operate, which often prolongs the fault removal time, further expanding the degree of equipment damage, impacting transformers, and affecting the safe operation of the entire power grid.

[0003] In addition, the existing protection mechanism is not accurate enough in detecting tiny currents, so when the cable in the electrical box discharges tiny currents, the protection mechanism cannot trip immediately. And the long-term existence of local tiny discharges will slowly damage the insulation of the cable, which will eventually lead to insulation breakdown over time.

[0004] In addition, due to its chemical properties, cross-linked polyethylene insulated cables have poor resistance to partial discharge. Long-term partial discharge will accelerate the degradation of its insulation, causing failures and fires. Summary of the invention

[0005] The object of the present invention is to provide a fast-response arc short-circuit mechanical protection device to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a fast-response arc short-circuit mechanical protection device, installed in a ring network box, comprising an arc sensor, a grounding structure and a switch structure for driving the grounding structure to rotate, wherein the arc sensor is arranged on the inner wall of the ring network box, the grounding structure is rotatably arranged in the ring network box, and three grounding contacts are also arranged in the ring network box. The switch structure is communicatively connected with the arc sensor, and the switch structure drives the grounding structure to rotate and connect with the grounding contact.

[0007] Preferably, the grounding structure comprises a main shaft, the main shaft is rotatably mounted on a main shaft bracket, three grounding movable knives are arranged on the main shaft, and the three grounding movable knives can contact the three grounding contacts respectively.

[0008] Preferably, the switch structure includes a permanent magnet mechanism, a trip shaft, a driving bevel gear and a driven main gear, the permanent magnet mechanism drives the trip shaft to rotate, the driving bevel gear is arranged at the top of the trip shaft, the driven bevel gear is arranged on the main shaft, and the driving bevel gear is meshed with the driven bevel gear.

[0009] Preferably, the opening shaft is provided with a transmission arm, and the shaft of the permanent magnet mechanism is connected to the transmission arm.

[0010] Preferably, the permanent magnet mechanism is arranged at the bottom end of the ring network box, and the opening switch shaft passes through the bottom end of the ring network box and extends to the inner cavity of the ring network box.

[0011] Preferably, the grounding contact and the grounding movable knife are both made of T2 copper material.

[0012] Preferably, the main shaft is made of Q235 material.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can initiate tripping within 35MS through the arc sensor in conjunction with the switch structure, and can detect tiny abnormal currents, thereby improving the protection of the electrical system; compared with the traditional technology, the present invention does not require mechanical release, locks, etc., has a simple structure, fewer fault sources, higher reliability, and a long service life, and at the same time controls the opening and closing phases to achieve synchronous control, thereby reducing the impact of overvoltage and surge current on the electrical system, reducing the investment in electrical system protection, and improving the overall life of the electrical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the present invention;

[0015] Figure 2 It is a schematic diagram of the grounding structure of the present invention;

[0016] Figure 3 This is a schematic diagram of the switch structure of the present invention.

[0017] In the figure: 1. Ring network box; 2. Arc sensor; 3. Grounding contact; 4. Main shaft; 5. Main shaft bracket; 6. Grounding moving knife; 7. Permanent magnet mechanism; 8. Opening shaft; 9. Driving bevel gear; 10. Driven bevel gear; 11. Transmission arm. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figures 1 to 3The present invention provides a technical solution: a fast-response arc short-circuit mechanical protection device, which is installed in a ring network box 1, and includes an arc sensor 2, a grounding structure, and a switch structure for driving the grounding structure to rotate. The arc sensor 2 determines whether an arc fault occurs in the electrical system of the ring network box 1 by detecting light radiation of a specific wavelength generated by the arc light. The arc sensor 2 is arranged on the inner wall of the ring network box 1, and the grounding structure is rotatably arranged in the ring network box 1. Three grounding contacts 3 are also arranged in the ring network box 1. The switch structure is communicatively connected to the arc sensor 2, and the switch structure drives the grounding structure to rotate and connect with the grounding contact 3.

[0020] In one embodiment of the present invention, the grounding structure includes a main shaft 4, which is rotatably mounted on a main shaft bracket 5. The main shaft 4 is made of Q235 material. Three grounding movable knives 6 are arranged on the main shaft 4. The rotation of the main shaft 4 drives the grounding movable knives 6 to rotate synchronously. The end of the grounding movable knives 6 contacts the grounding contact 3 after rotating a certain angle, so as to realize three-phase high-voltage grounding. The grounding contact 3 and the grounding movable knives 6 are both made of T2 copper material.

[0021] In one embodiment of the present invention, the switch structure includes a permanent magnet mechanism 7, a trip shaft 8, an active bevel gear 9 and a driven main gear 10. The permanent magnet mechanism 7 drives the trip shaft 8 to rotate. The active bevel gear 9 is arranged at the top of the trip shaft 8, and the driven bevel gear 10 is arranged on the main shaft 4. The active bevel gear 9 is meshed with the driven bevel gear 10. The permanent magnet mechanism 7 is composed of a permanent magnet, a closing coil and an opening coil. The permanent magnet provides a holding force. The closing coil and the opening coil generate a magnetic field when energized, which interacts with the permanent magnet to realize the movement of the moving iron core. The iron core drives the shaft to move. The shaft is used to transmit the movement of the moving iron core. The core of the permanent magnet mechanism is a programmable element FPGA, which realizes multiple functions through pre-set programs, such as constant voltage charging of energy storage capacitors, overcharge cut-off protection, local and remote closing and opening operations, closing and opening remote signal output, and various protection closing and reclosing operations performed in coordination with the automatic integrated protection equipment of the power system.

[0022] In one embodiment of the present invention, the opening shaft 4 is provided with a transmission arm 11 , and the shaft of the permanent magnet mechanism 7 is connected to the transmission arm 11 .

[0023] In one embodiment of the present invention, the permanent magnet mechanism 7 is disposed at the bottom end of the ring network box 1 , and the opening shaft 8 passes through the bottom end of the ring network box 1 and extends to the inner cavity of the ring network box 1 .

[0024] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fast-response arc short-circuit mechanical protection device, installed in a ring network box (1), characterized in that: The invention comprises an arc sensor (2), a grounding structure and a switch structure for driving the grounding structure to rotate, wherein the arc sensor (2) is arranged on the inner wall of a ring network box (1), the grounding structure is rotatably arranged in the ring network box (1), and three grounding contacts (3) are also arranged in the ring network box (1), the switch structure is communicatively connected to the arc sensor (2), and the switch structure drives the grounding structure to rotate and connect with the grounding contacts (3).

2. A fast response arc short circuit mechanical protection device according to claim 1, characterized in that: The grounding structure comprises a main shaft (4), the main shaft (4) is rotatably mounted on a main shaft support (5), and three grounding movable knives (6) are arranged on the main shaft (4). The three grounding movable knives (6) can respectively contact the three grounding contacts (3).

3. A fast response arc short circuit mechanical protection device according to claim 2, characterized in that: The switch structure comprises a permanent magnet mechanism (7), a switch-off shaft (8), a driving bevel gear (9) and a driven main gear (10); the permanent magnet mechanism (7) drives the switch-off shaft (8) to rotate; the driving bevel gear (9) is arranged at the top end of the switch-off shaft (8); the driven bevel gear (10) is arranged on the main shaft (4); and the driving bevel gear (9) meshes with the driven bevel gear (10).

4. A fast response arc short circuit mechanical protection device according to claim 3, characterized in that: The opening shaft (4) is provided with a transmission arm (11), and the shaft of the permanent magnet mechanism (7) is connected to the transmission arm (11).

5. A fast response arc short circuit mechanical protection device according to claim 4, characterized in that: The permanent magnet mechanism (7) is arranged at the bottom end of the ring network box (1), and the opening switch shaft (8) passes through the bottom end of the ring network box (1) and extends to the inner cavity of the ring network box (1).

6. A fast response arc short circuit mechanical protection device according to claim 5, characterized in that: The grounding contact (3) and the grounding movable knife (6) are both made of T2 copper material.

7. A fast response arc short circuit mechanical protection device according to claim 6, characterized in that: The main shaft (4) is made of Q235 material.

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