Double-gap rapid high-pressure closing device

Abstract

The utility model provides a double-gap rapid high-voltage closing device. The double-gap rapid high-voltage closing device comprises a pre-breakdown current detection device, an optical fiber, an ignition box, a graphite hemisphere and a voltage-sharing capacitor, every two graphite hemispheres are arranged in a top-to-top manner to form a graphite sphere gap which is used as a discharge electrode, and the graphite hemispheres are provided with arc jet orifices; the pre-breakdown current detection device is arranged in the test loop and is connected with the ignition box through an optical fiber; the voltage-sharing capacitor is connected in parallel with the graphite sphere gap; a capacitor which is fully charged in advance is arranged in the ignition box, the ignition box is connected with the graphite hemispheres through a high-voltage insulated wire, and each graphite hemisphere is connected with an independent ignition box. The high-voltage alternating-current circuit breaker can meet the requirements of the closing test of 550kV and below high-voltage alternating-current circuit breakers, and has the characteristics of high withstand voltage, stability in triggering, wide working voltage range, high through-current capability, firmness and durability.

Description

Technical Field

[0001] This utility model belongs to the field of pulse power technology, and specifically relates to a dual-gap rapid high-voltage shut-off device. Background Technology

[0002] The short-circuit making capability of high-voltage AC circuit breakers is one of the key performance indicators for ensuring the safe operation of power systems. Therefore, the short-circuit making test of circuit breakers has always been a type test item required by IEC and national standards.

[0003] The national standard for high-voltage AC circuit breakers recommends the following closing tests for all AC circuit breakers: (1) a rated (peak) short-circuit closing current test under reduced applied voltage; (2) a closing test under rated applied voltage with maximum pre-arc conditions. Currently, closing tests for AC circuit breakers with voltage levels of 40.5kV and below can be conducted directly in a large-capacity test chamber, while closing tests for high-voltage AC circuit breakers above 72.5kV (2) cannot be conducted directly due to the capacity limitations of the test station and can only be conducted through a synthetic test.

[0004] According to the requirements of the high-voltage closing synthesis test circuit, in order to achieve equivalence with the direct test, the closing device must be able to apply the current source within 300µs after the circuit breaker under test has undergone pre-breakdown. Therefore, the high-voltage fast closing device is the core equipment of the synthesis closing test. It should meet a series of requirements such as high withstand voltage, low operating voltage, short action time, large current carrying capacity, and stable operation after repeated high-current burn-out. Therefore, the research and development of a stable, robust, and durable fast closing device is crucial for the synthesis closing test and is also an important indicator of the testing capabilities of a large-capacity test station. Utility Model Content

[0005] Purpose of the utility model: In order to overcome the above shortcomings, a dual-gap fast high-voltage closing device is proposed, which can meet the closing test requirements of high-voltage AC circuit breakers of 550kV and below. It has the characteristics of high withstand voltage, stable triggering, wide operating voltage range, large current carrying capacity, and robust durability. It can effectively improve the success rate and test efficiency of closing tests in large-capacity test stations. This utility model can also be used as an ignition ball gap switch device in the high-voltage synthetic test voltage source circuit.

[0006] Technical solution: In order to achieve the above objectives, this utility model provides a dual-gap fast high-voltage closing device, including: a pre-breakdown current detection device, an optical fiber, an ignition box, a graphite hemisphere, and a voltage equalization capacitor;

[0007] The graphite hemispheres are arranged in pairs facing each other to form a graphite spherical gap, which serves as a discharge electrode. The graphite hemispheres are provided with an arc injection port.

[0008] The pre-breakdown current detection device is installed in the test circuit and is connected to the ignition box via an optical fiber.

[0009] The equalizing capacitor is connected in parallel with the graphite spherical gap;

[0010] The ignition box is equipped with a pre-charged capacitor, and the ignition box is connected to the graphite hemisphere via a high-voltage insulated wire.

[0011] Each of the graphite hemispheres is connected to an individual ignition box. This increases the ignition energy between the spheres in the closing device, allowing for faster ionization of the air in the graphite gaps.

[0012] Furthermore, it also includes a base, a laminated insulating support, and an insulating support, wherein the insulating support is disposed on the base, the ignition box is disposed at the other end of the insulating support, and the laminated insulating support is disposed on the upper surface of the ignition box.

[0013] Furthermore, the laminate insulation support is provided with guide holes, and the bottom plane of the graphite hemisphere is fixed to a circular aluminum disk of the same diameter through threaded holes. An aluminum rod is threadedly connected to the circular aluminum disk, and the aluminum rod is positioned within the guide holes on the laminate insulation support. The graphite hemisphere, the circular aluminum disk, and the aluminum rod serve as conductors when the closing device is connected to a large current.

[0014] Furthermore, the laminate insulation supports on both sides are equipped with lead screws. These lead screws are rotatably mounted on the laminate insulation supports, and an adjusting plate is threaded onto the lead screw. The adjusting plate is connected to the end of the aluminum rod via bolts, and the lead screw is also equipped with an adjusting handwheel. Rotating the lead screw drives the aluminum rod to move along the guide hole, thereby causing the graphite hemispheres to move and achieving the purpose of adjusting the graphite sphere gap.

[0015] Furthermore, the graphite hemisphere has a hole along its central axis, in which the discharge core of the ignition box is installed, and the installation hole of the discharge core is connected to the arc injection port.

[0016] Furthermore, the insulating support consists of four interconnected 110kV porcelain insulators, and the base is a steel base. The insulating support serves to provide support and insulation to the ground, while the base supports the upper structure and ensures the stability of the entire device.

[0017] Furthermore, the adjustment plate is provided with a terminal block, on which a terminal is provided, and the terminal is connected to a low voltage current source.

[0018] As can be seen from the above technical solution, this utility model has the following beneficial effects:

[0019] 1) This utility model provides a dual-gap fast high-voltage closing device that can meet the closing test requirements of high-voltage AC circuit breakers of 550kV and below. It has the characteristics of high withstand voltage, stable triggering, wide operating voltage range, large current carrying capacity, and robust durability. It can effectively improve the success rate and test efficiency of closing tests in large-capacity test stations. It can also be used as an ignition ball gap switch device in the high-voltage synthetic test voltage source circuit. 2) Each graphite hemisphere is individually connected to an ignition box. The spherical gap arc injection port on the graphite hemisphere increases the ignition energy between the spherical gaps in the closing device, more quickly ionizing the air in the graphite gaps and forming a more stable metal-gas conductive channel. This allows the closing device to close any current source voltage, greatly expanding its operating voltage range. It also enables faster current conduction, improving the success rate of the closing test and effectively preventing the problem of the closing device triggering but not conducting current. Furthermore, increasing the ignition energy between the spherical gaps allows for a larger gap spacing, improving the voltage withstand rating of the closing device. This prevents situations where insufficient ignition energy prevents complete ionization of the channel, leading to excessively long closing current conduction time or no conduction at all. 3) A spherical gap adjustment mechanism is included. Rotating the lead screw adjusts the graphite spherical gap, improving the applicability of the device. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structural principle of this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the graphite hemisphere described in this utility model;

[0022] Figure 3 This is a schematic diagram of the structure of a dual-gap rapid high-pressure closing device according to the present invention;

[0023] Figure 4 This is a schematic diagram showing the connection between the lead screw and the graphite hemisphere described in this utility model.

[0024] In the diagram: 1-Pre-breakdown current detection device, 2-Fiber optic cable, 3-Ignition box, 4-Graphite hemisphere, 5-Equalizing capacitor, 6-Base, 7-Laminated plate insulation support, 8-Insulation support, 9-Aluminum rod, 10-Lead rod, 11-Adjusting plate, 111-Terminal block. Detailed Implementation

[0025] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] like Figure 1-3 As shown: A dual-gap fast high-voltage closing device includes: a pre-breakdown current detection device 1, an optical fiber 2, an ignition box 3, a graphite hemisphere 4, and an equalizing capacitor 5.

[0027] The graphite hemispheres 4 are arranged in pairs facing each other to form a graphite spherical gap, which serves as a discharge electrode. The graphite hemispheres 4 are provided with an arc jet nozzle 41.

[0028] The pre-breakdown current detection device 1 is installed in the test circuit. The pre-breakdown current detection device 1 is connected to the ignition box 3 through the optical fiber 2. After the pre-breakdown current detection device 1 detects the pre-breakdown current of the test sample, it sends a trigger signal to the ignition box 3 through the optical fiber 2.

[0029] The equalizing capacitor 5 is connected in parallel with the graphite sphere gap; the equalizing capacitor 5 can evenly distribute the voltage of the graphite sphere gap, stabilize the voltage fluctuation between the closing devices during the test, prevent the graphite sphere gap from breaking down or the ignition box 3 from malfunctioning, and structurally stabilize the closing device structure to ensure the structural stability of the device when current flows through it.

[0030] The ignition box 3 is equipped with a pre-charged capacitor, and the ignition box 3 is connected to the graphite hemisphere 4 through a high-voltage insulated wire.

[0031] Specifically, each of the graphite hemispheres 4 is connected to an individual ignition box 3, which increases the ignition energy between the graphite spheres in the closing device, ionizes the air in the graphite sphere gaps more quickly, and forms a more stable metal-gas conductive channel. This allows the closing device to close any current source voltage, greatly expanding the operating voltage range of the closing device. At the same time, it can conduct current more quickly, improve the success rate of the closing test, and effectively prevent the problem that the closing device is triggered but the current is not conducted. In addition, increasing the ignition energy between the graphite sphere gaps can appropriately increase the gap spacing, improve the withstand voltage rating of the closing device, and prevent the phenomenon that the ionization channel cannot be fully connected due to insufficient ignition energy after the gap is enlarged, resulting in an excessively long closing current conduction time or no conduction.

[0032] It also includes a base 6, a laminated insulating support 7 and an insulating support 8. The insulating support 8 is located on the base 6, the ignition box 3 is located at the other end of the insulating support 8, and the laminated insulating support 7 is located on the upper surface of the ignition box 3.

[0033] like Figure 4As shown, the laminate insulation support 7 has guide holes. The bottom plane of the graphite hemisphere 4 is fixed to a circular aluminum disk of the same diameter through threaded holes. The circular aluminum disk is threadedly connected to an aluminum rod 9, which is located in the guide holes on the laminate insulation support 7. The laminate insulation supports 7 on both sides are also equipped with lead screws 10, which are rotatably mounted on the laminate insulation support 7. Adjusting plates 11 are threaded onto the lead screws 10, and the adjusting plates 11 are bolted to the ends of the aluminum rods 9. The lead screws 10 also have adjusting handwheels. By adjusting the handwheels and rotating the lead screws 10, the operator can move the aluminum rods 8 along the guide holes, thereby moving the graphite hemispheres 4 to achieve the purpose of adjusting the graphite sphere gap. The two middle graphite hemispheres 4 do not need to be connected to the lead screws 10; the graphite sphere gap can be adjusted using a single lead screw 10.

[0034] Preferably, the graphite hemisphere 4 has a hole along its central axis, in which the discharge core of the ignition box 3 is installed, and the installation hole of the discharge core communicates with the arc jet port 41.

[0035] In a further optimized design, the insulating support 8 consists of four interconnected 110kV porcelain insulators, and the base 6 is a steel base.

[0036] In addition, the adjustment plate 11 is provided with a terminal block 111, and the terminal block 111 is provided with a terminal block, which is connected to a low voltage current source.

[0037] The working principle of the dual-gap rapid high-pressure closing device provided by this utility model is as follows:

[0038] like Figure 1 As shown, after the pre-breakdown current detection device 1 detects the pre-breakdown current i between the ports of the circuit breaker under test in the synthetic closing test circuit, it immediately sends an ignition signal to the four ignition boxes 3 simultaneously through the optical fiber 2. The capacitors in each ignition box 3 are pre-charged. Upon receiving the ignition signal, the ignition box 3 is triggered. Through the high-voltage insulated wire connected to the graphite hemisphere 4, the electrical energy (approximately 200J) stored in the capacitor in the ignition box 3 is injected into the arc nozzle 41 in the graphite gap. Under the action of the large energy of the capacitor short-circuit discharge, a large amount of air around the gap is ionized, and part of the metal of the trigger electrode is vaporized. This high-voltage ionized gas containing metal vapor is sprayed from the arc nozzle to the other pole of the graphite gap until the graphite gap is completely connected by the ionized gas, forming a conductive channel, thereby conducting the short-circuit current of the low-voltage current source and achieving the purpose of closing the short-circuit current.

[0039] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.

Claims

1. A dual-gap rapid high-pressure closing device, characterized in that, include: Pre-breakdown current detection device (1), optical fiber (2), ignition box (3), graphite hemisphere (4), equalizing capacitor (5); The graphite hemispheres (4) are arranged in pairs to form a graphite spherical gap, which serves as a discharge electrode. The graphite hemispheres (4) are provided with an arc jet nozzle (41). The pre-breakdown current detection device (1) is installed in the test circuit and is connected to the ignition box (3) via optical fiber (2). The equalizing capacitor (5) is connected in parallel with the graphite spherical gap; The ignition box (3) is equipped with a pre-charged capacitor, and the ignition box (3) is connected to the graphite hemisphere (4) through a high-voltage insulated wire; Each of the graphite hemispheres (4) is connected to a separate ignition box (3).

2. The dual-gap rapid high-pressure closing device according to claim 1, characterized in that, It also includes a base (6), a laminated insulating support (7) and an insulating support (8), the insulating support (8) being disposed on the base (6), the ignition box (3) being disposed at the other end of the insulating support (8), and the laminated insulating support (7) being disposed on the upper surface of the ignition box (3).

3. The dual-gap rapid high-pressure closing device according to claim 2, characterized in that, The laminate insulation support (7) is provided with a guide hole. The bottom plane of the graphite hemisphere (4) is fixed to a circular aluminum disk with the same diameter through a threaded hole. The circular aluminum disk is connected to an aluminum rod (9) by a thread. The aluminum rod (9) is located in the guide hole on the laminate insulation support (7).

4. The dual-gap rapid high-pressure closing device according to claim 3, characterized in that, The laminate insulation support (7) on both sides is also provided with a lead screw (10), which is rotatably mounted on the laminate insulation support (7). An adjustment plate (11) is threaded onto the lead screw (10), and the adjustment plate (11) is connected to the end of the aluminum rod (9) by bolts. An adjustment handwheel is also provided on the lead screw (10).

5. The dual-gap rapid high-pressure closing device according to claim 1, characterized in that, The graphite hemisphere (4) has a hole along its central axis, in which the discharge core of the ignition box (3) is installed. The installation hole of the discharge core is connected to the arc jet port (41).

6. The dual-gap rapid high-pressure closing device according to claim 2, characterized in that, The insulating support (8) consists of four interconnected 110kV porcelain insulators, and the base (6) is a steel base.

7. The dual-gap rapid high-pressure closing device according to claim 4, characterized in that, The adjustment plate (11) is provided with a terminal block (111), and the terminal block (111) is provided with a terminal block, which is connected to a low voltage current source.

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