Device and method for improving through-flow arc control of high-voltage large-capacity gas gap switch

Abstract

The invention relates to a device for improving the through-flow arc control of a high-voltage large-capacity gas gap switch, and the device comprises a test cavity which is used for providing a controllable gas insulation environment and serves as a carrier of a high-voltage large-current discharge test; the trigger discharge loop is used for generating a high-voltage pulse to drive the trigger cavity to generate plasma jet and induce the main gap to be broken down and conducted at a preset moment; and the large current generation loop is used for storing energy and generating a high-energy fault current simulating an actual working condition after the main gap is conducted. A main gap can form a stable and controllable initial discharge channel under high-voltage and large-gap conditions, active constraint is carried out on an arc movement track in a high-energy fault current flowing stage, and long-term residence of an arc root in a local area of an electrode is avoided, so that the ablation degree of the electrode is remarkably reduced, the through-flow life is prolonged, and meanwhile, the service life of the electrode is prolonged. A transverse magnetic field generated by the spiral groove structure enables an electric arc to rotate along the surface of the electrode, the stability of an arc column is effectively improved, and the reliability under the condition of large current flow is improved.

Description

Technical Field

[0001] This invention relates to the field of surplus power management technology in flexible DC transmission systems, and in particular to a device and method for improving current flow control and arc control in high-voltage, high-capacity gas gap switches. Background Technology

[0002] In flexible DC transmission systems, surplus power management relies on fast bypass switches to enable rapid switching on and off of energy-consuming devices. These switches must meet stringent requirements, including an action time of <1ms, a rated voltage of 100kV, a short-time current of tens ofkA, and a long operating life. Traditional power electronic switches are complex in structure, expensive, and limited by voltage and current change rates. In contrast, gas gap switches are the preferred solution due to their simple structure, sub-millisecond action response, and low cost.

[0003] However, high-voltage, high-capacity gas gap switches, as critical equipment, bear the heavy responsibility of carrying tens of kA of fault current within milliseconds, but they face severe challenges in practical applications. Traditional gas gap switches mostly employ simple flat plate electrode structures. Under the influence of high-energy fault currents, the arc plasma is susceptible to drift, contraction, or diffusion due to electromagnetic forces and thermal convection, leading to unstable displacement at the arc root and causing localized overheating and ablation of the electrodes. While existing technologies attempt to constrain the arc by optimizing electrode materials or introducing magnetic blowout devices, these methods are often complex, costly, and prone to insulation recovery delays under high voltage gradients. Furthermore, the lifespan of the switches significantly decreases under repeated operations, failing to meet the comprehensive requirements of modern power grids for equipment reliability, economy, and long lifespan.

[0004] Therefore, there is an urgent need for a fast bypass switch current control arc control device that is suitable for high-voltage and high-capacity scenarios, has strong arc restraint capability and long current carrying life, to solve the problem of arc control in high-energy fault current handling. Summary of the Invention

[0005] To address the problem of high current-carrying energy and prominent current-carrying failure issues in gas gap switches used in power grids, which significantly increase safety risks, the primary objective of this invention is to provide a device for improving arc control in high-voltage, high-capacity gas gap switches by effectively improving arc column stability, enhancing reliability under high current-carrying conditions, thereby significantly reducing electrode erosion and extending current-carrying life.

[0006] To achieve the above objectives, the present invention employs the following technical solution: a device for improving the current control and arc regulation of a high-pressure, high-capacity gas gap switch, comprising:

[0007] The test chamber contains a high-voltage electrode and a ground electrode, with a main gap between them. The ground electrode contains a trigger chamber. The test chamber is used to provide a controllable gas insulation environment and serves as a carrier for high-voltage and high-current discharge tests.

[0008] The trigger discharge circuit is used to generate a high-voltage pulse to drive the trigger cavity to generate a plasma jet, which induces the main gap to break down and conduct at a predetermined time.

[0009] A high-current generation circuit is used to store energy and generate a high-energy fault current that simulates actual working conditions after the main gap is turned on.

[0010] The high current generating circuit is connected to the high voltage lead of the test chamber, and the trigger discharge circuit is connected to the trigger electrode of the test chamber.

[0011] The high-voltage electrode is located above the ground electrode. The high-voltage electrode consists of a first conductive rod and a first spiral groove electrode plate. The first conductive rod is integrally formed with the first spiral groove electrode plate, which has an upward-facing spiral groove on its surface. The depth of the spiral groove is the same as the thickness of the electrode plate. The ground electrode consists of a second spiral groove electrode plate, a second conductive rod, and a base plate, all integrally formed. The second conductive rod is downward-facing from the second spiral groove electrode plate, and the base plate is downward-facing from the second conductive rod. The second spiral groove electrode plate has a spiral groove on its surface. The second spiral groove has a depth consistent with the thickness of the second spiral groove electrode plate; a nozzle is opened at the center of the second spiral groove electrode plate; the first conductive rod, the first spiral groove electrode plate, the second spiral groove electrode plate, the second conductive rod, and the base plate are arranged from top to bottom and located on the same central axis; the ground electrode is embedded with an independent trigger cavity, which is a coaxial laminated structure, formed by tightly pressing the trigger electrode and the insulating component, with the trigger electrode located at the center of the insulating component, the insulating component located at the center of the ground electrode, and the cavity above the trigger electrode and the nozzle connected.

[0012] The high-voltage electrode is connected to the high-voltage lead, and the ground electrode is placed on an insulating base; one end of the high-voltage lead is connected to a DC high voltage to provide the working voltage, and the other end of the high-voltage lead is connected to a high-current generating circuit to simulate a high-energy fault current; the ground electrode is grounded.

[0013] The trigger discharge circuit includes an energy storage capacitor C. One end of the energy storage capacitor C is connected to one end a1 of the primary winding of the pulse transformer T, and the other end of the energy storage capacitor C is grounded to the ground electrode. The other end b1 of the primary winding of the pulse transformer T is connected to the positive terminal of the thyristor SCR. Diode D3 is connected in parallel with the thyristor SCR. The cathode of diode D3 is connected to the positive terminal of the thyristor SCR, and the anode of diode D3 is connected to the negative terminal of the thyristor SCR and then grounded to the ground electrode. One end a2 of the secondary winding of the pulse transformer T is connected to the trigger electrode, and the other end b2 of the secondary winding of the pulse transformer T is connected to one end of the protection resistor R3. The other end of the protection resistor R3 is grounded to the ground electrode.

[0014] The high-current generating circuit includes a high-voltage DC power supply DC. The positive terminal of the high-voltage DC power supply DC is connected to one end of the charging resistor R1, and the negative terminal of the high-voltage DC power supply DC is grounded. The other end of the charging resistor R1 is connected to one end of the charging switch K1, and the other end of the charging switch K1 is connected to the energy storage capacitor bank CA. The energy storage capacitor bank CA and the discharge resistor R2 are connected in parallel and share a common ground. The parallel end is connected to one end of the inductor L. The time control switch K2 is connected in parallel to the inductor L. The other end of the inductor L is connected to one end of the closing control switch K3, and the other end of the closing control switch K3 is connected to the high-voltage lead.

[0015] The trigger electrode is cylindrical and made of brass; the nozzle has a diameter of 3mm and a height of 8mm; the insulating component is made of polytetrafluoroethylene modified material.

[0016] Both the high-voltage electrode and the ground electrode are made of CuW80 alloy; the first and second spiral grooves are both arranged axially, with a width of 1mm, a diameter of 110mm, and a thickness of 8mm; the first and second conductive rods are both cylindrical structures, with a diameter of 40mm and a height of 35mm; the distance between the high-voltage electrode and the ground electrode is 20mm.

[0017] Another object of the present invention is to provide a method for handling high-energy fault current in a device for improving the current control and arc control of a high-pressure, high-capacity gas gap switch, the method comprising the following sequential steps:

[0018] (1) Apply a DC voltage to the high voltage electrode to a preset value, and at the same time charge the energy storage capacitor C of the trigger discharge circuit to a preset value, and set the time when the thyristor SCR responds to the trigger signal;

[0019] (2) When the charging switch K1 is closed, the high voltage DC power supply DC charges the energy storage capacitor bank CA through the charging resistor R1. After reaching the preset value, the charging switch K1 is disconnected.

[0020] (3) When the closing control switch K3 is closed, the energy storage capacitor bank CA and the inductor L form an oscillating circuit, generating a high-energy fault current. The current passes through the high-voltage electrode and the main gap to form a circuit.

[0021] (4) The trigger cavity is activated, and a high voltage pulse is applied to the trigger electrode to ablate the insulating material of the trigger cavity, forming a high temperature, high speed and high conductivity plasma jet, which is ejected from the nozzle and induces the main gap to open.

[0022] (5) When the high-energy fault current passes through the main gap, under the action of the transverse magnetic field generated by the first spiral groove and the second spiral groove, the main gap arc rotates at high speed along the surface of the first spiral groove electrode plate and the second spiral groove electrode plate. The main gap arc column is constrained within the first spiral groove electrode plate and the second spiral groove electrode plate to avoid concentrated ablation of the electrode local when the current flows through.

[0023] (6) After the current carrying time reaches the preset value, the time control switch K2 is closed, and the current in the main gap is transferred to the parallel circuit of inductor L and time control switch K2, so that the arc in the main gap is extinguished and the insulation recovery begins;

[0024] (7) After the energy is discharged, disconnect the charging switch K1, the time control switch K2 and the closing control switch K3, and the device returns to the standby state.

[0025] In step (4), the plasma jet is formed within 100 μs, and the main gap contact delay is within 200 μs; in step (5), the arc rotation speed is greater than or equal to 100 m / s, and the current flow time is maintained at 30 ms; in step (6), the insulation recovery time after arc extinction is completed within 100 ms; the preset values ​​include a high voltage electrode voltage of 5 kV, a charging voltage of energy storage capacitor C of 1.8 kV, and a charging voltage of energy storage capacitor bank CA of 10 kV.

[0026] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: First, by introducing a trigger cavity and a spiral groove to coordinate arc control in the gas gap switch, the present invention enables the main gap to form a stable and controllable initial discharge channel under high pressure and large gap conditions, and actively constrains the arc trajectory during the high-energy fault current flow stage, avoiding the arc root from remaining in the local area of ​​the electrode for a long time, thereby significantly reducing the degree of electrode ablation and extending the current-carrying life. At the same time, the transverse magnetic field generated by the spiral groove structure causes the arc to rotate along the electrode surface, effectively improving the stability of the arc column and increasing the reliability under high current conditions; Second, through the trigger cavity design, the main gap is connected... The duration is improved to the millisecond level, meeting the timing requirements of fast mechanical switches and solving the problem of easy arc extinction under low voltage and low current. Third, by reasonably configuring the trigger cavity structure and the gas medium in the main gap, the arc can be quickly extinguished and insulation can be accelerated after the current is passed, meeting the application requirements of fast bypass, fault isolation and energy discharge in high voltage and large capacity systems. Fourth, the device has a simple structure and controllable cost, achieving a cost reduction of 80% to 90% compared with power electronic switches, and has a fast action response speed, which can meet the rapid energy discharge requirements of surplus power management in flexible DC transmission systems, and is also suitable for rapid fault isolation and load transfer scenarios in traditional power systems. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the high-voltage electrode, ground electrode, and trigger cavity in this invention;

[0028] Figure 2 for Figure 1 Sectional view along axis AA;

[0029] Figure 3 This is a schematic diagram of the circuit connection between the high current generating circuit, the trigger discharge circuit, and the test chamber in this invention;

[0030] Figure 4 This is a timing diagram of the main switching actions of the circuit circuits of the high current generation circuit, the trigger discharge circuit, and the test chamber in this invention. Detailed Implementation

[0031] like Figure 1 , Figure 2 , Figure 3 As shown, a device for improving the current control and arc control of a high-pressure, high-capacity gas gap switch includes:

[0032] The test chamber 12 is a sealed shell with a built-in high-voltage electrode and a ground electrode. A main gap 4 is set between the two. The ground electrode has a built-in trigger chamber. The test chamber 12 is used to provide a controllable gas insulation environment and serves as a carrier for high-voltage and high-current discharge tests.

[0033] Trigger discharge circuit 16 is used to generate a high voltage pulse to drive the trigger cavity to generate a plasma jet, inducing the main gap 4 to break down and conduct at a predetermined time.

[0034] The high current generating circuit 15 is used to store energy and generate a high-energy fault current simulating actual working conditions after the main gap 4 is turned on.

[0035] The high current generating circuit 15 is connected to the high voltage lead 13 of the test chamber 12, and the trigger discharge circuit 16 is connected to the trigger electrode 11 of the test chamber 12.

[0036] like Figure 1 , Figure 2 , Figure 3As shown, the high-voltage electrode is located above the ground electrode. The high-voltage electrode consists of a first conductive rod 1 and a first spiral groove plate 2. The first spiral groove plate 2 has the first conductive rod 1 mounted upwards and is integrally formed with the first conductive rod 1. A first spiral groove 3 is formed on the surface of the first spiral groove plate 2, and the depth of the first spiral groove 3 is the same as the thickness of the surface of the first spiral groove plate 2. The ground electrode consists of a second spiral groove plate 5, a second conductive rod 7, and a base plate 8, all integrally formed. The second spiral groove plate 5 has the second conductive rod 7 mounted downwards, and the second conductive rod 7 is mounted downwards on the base plate 8. A second spiral groove 3 is formed on the surface of the second spiral groove plate 5. The spiral groove 6 has a depth consistent with the thickness of the second spiral groove electrode plate 5; a nozzle 9 is opened at the center of the second spiral groove electrode plate 5; the first conductive rod 1, the first spiral groove electrode plate 2, the second spiral groove electrode plate 5, the second conductive rod 7, and the base plate 8 are arranged from top to bottom and located on the same central axis; the ground electrode is embedded with an independent trigger cavity, which is a coaxial laminated structure, formed by tightly pressing the trigger electrode 11 and the insulating component 10. The trigger electrode 11 is located at the center of the insulating component 10, and the insulating component 10 is located at the center of the ground electrode. The cavity above the trigger electrode 11 is connected to the nozzle 9.

[0037] The high-voltage electrode is connected to the high-voltage lead 13, and the ground electrode is placed on the insulating base 14; one end of the high-voltage lead 13 is connected to the DC high voltage to provide the working voltage, and the other end of the high-voltage lead 13 is connected to the high current generating circuit 15 to simulate high-energy fault current; the ground electrode is grounded.

[0038] like Figure 3 As shown, the trigger discharge circuit 16 includes an energy storage capacitor C. One end of the energy storage capacitor C is connected to one end a1 of the primary coil of the pulse transformer T, and the other end of the energy storage capacitor C is grounded with the ground electrode. The other end b1 of the primary coil of the pulse transformer T is connected to the positive terminal of the thyristor SCR. Diode D3 is connected in parallel with the thyristor SCR. The cathode of diode D3 is connected to the positive terminal of the thyristor SCR, and the anode of diode D3 is connected to the negative terminal of the thyristor SCR and then grounded. One end a2 of the secondary coil of the pulse transformer T is connected to the trigger electrode 11, and the other end b2 of the secondary coil of the pulse transformer T is connected to one end of the protection resistor R3. The other end of the protection resistor R3 is grounded with the ground electrode.

[0039] like Figure 3As shown, the high current generating circuit 15 includes a high-voltage DC power supply DC. The positive terminal of the high-voltage DC power supply DC is connected to one end of the charging resistor R1, and the negative terminal of the high-voltage DC power supply DC is grounded. The other end of the charging resistor R1 is connected to one end of the charging switch K1, and the other end of the charging switch K1 is connected to the energy storage capacitor group CA. The energy storage capacitor group CA and the discharge resistor R2 are connected in parallel and grounded together. The parallel end is connected to one end of the inductor L. The time control switch K2 is connected in parallel to the inductor L. The other end of the inductor L is connected to one end of the closing control switch K3, and the other end of the closing control switch K3 is connected to the high-voltage lead 13.

[0040] The trigger electrode 11 is cylindrical and made of brass; the nozzle 9 has a diameter of 3 mm and a height of 8 mm; the insulating component 10 is made of polytetrafluoroethylene modified material.

[0041] Both the high-voltage electrode and the ground electrode are made of CuW80 alloy; the first spiral groove 3 and the second spiral groove 6 are both arranged axially, and the width of the first spiral groove 3 and the second spiral groove 6 is 1mm; the diameter of the first spiral groove electrode plate 2 is 110mm and the thickness is 8mm; the first conductive rod 1 and the second conductive rod 7 are both cylindrical structures, and the diameter of the first conductive rod 1 and the second conductive rod 7 is 40mm and the height is 35mm; the distance between the high-voltage electrode and the ground electrode is 20mm.

[0042] This method includes the following steps in sequence:

[0043] (1) Apply a DC voltage to the high voltage electrode to a preset value, and at the same time charge the energy storage capacitor C of the trigger discharge circuit 16 to a preset value, and set the time when the thyristor SCR responds to the trigger signal;

[0044] (2) When the charging switch K1 is closed, the high voltage DC power supply DC charges the energy storage capacitor bank CA through the charging resistor R1. After reaching the preset value, the charging switch K1 is disconnected.

[0045] (3) When the closing control switch K3 is closed, the energy storage capacitor bank CA and the inductor L form an oscillating circuit, generating a high-energy fault current. The current passes through the high-voltage electrode and the main gap 4 to form a circuit.

[0046] (4) The trigger cavity is activated, and a high voltage pulse is applied to the trigger electrode 11 to ablate the insulating material 10 of the trigger cavity, forming a high temperature, high speed and high conductivity plasma jet, which is ejected from the nozzle 9 and induces the main gap 4 to be connected.

[0047] (5) When the high-energy fault current passes through the main gap 4, under the action of the transverse magnetic field generated by the first spiral groove 3 and the second spiral groove 6, the arc of the main gap 4 rotates at high speed along the surface of the first spiral groove plate 2 and the second spiral groove plate 5. The arc column of the main gap 4 is constrained within the first spiral groove plate 2 and the second spiral groove plate 5 to avoid concentrated ablation of the electrode when the current flows through.

[0048] (6) After the current carrying time reaches the preset value, the time control switch K2 is closed, and the current in the main gap 4 is transferred to the parallel circuit of inductor L and time control switch K2, so that the arc of the main gap 4 is extinguished and the insulation recovery begins;

[0049] (7) After the energy is discharged, disconnect the charging switch K1, the time control switch K2 and the closing control switch K3, and the device returns to the standby state.

[0050] In step (4), the plasma jet is formed within 100 μs, and the contact delay of the main gap 4 is within 200 μs; in step (5), the arc rotation speed is greater than or equal to 100 m / s, and the current flow time is maintained at 30 ms; in step (6), the insulation recovery time after arc extinction is completed within 100 ms; the preset values ​​include a high voltage electrode voltage of 5 kV, a charging voltage of energy storage capacitor C of 1.8 kV, and a charging voltage of energy storage capacitor bank CA of 10 kV.

[0051] Example 1

[0052] In practice:

[0053] (1) Apply DC high voltage to the high voltage electrode to the preset value; set the timing of the thyristor SCR response trigger signal: the thyristor SCR is triggered at the initial 0 time;

[0054] (2) Close the charging switch K1. The high voltage DC power supply DC charges the energy storage capacitor bank CA through the charging resistor R1. The charging voltage is monitored in real time by the voltage monitoring device. When the voltage reaches the preset value of 10kV, the charging switch K1 is disconnected.

[0055] (3) When the closing control switch K3 is closed, the energy storage capacitor bank CA and the inductor L form an oscillating circuit to generate a simulated high-energy fault current. The peak current can reach more than 30kA. The current passes through the high-voltage electrode and the main gap 4 to form a circuit.

[0056] (4) At the initial t=0 ms, the SCR first responds to the trigger signal, the energy storage capacitor C discharges, and the high voltage pulse is applied to the trigger electrode 11 in the trigger cavity through the pulse transformer T, which ablates the insulating material 10 of the trigger cavity. Within 100 μs, a high temperature, high speed and high conductivity plasma jet is formed. After accumulating in a large amount at the nozzle 9 of the channel with a height of 15 mm and a diameter of 3 mm in the trigger cavity, it is ejected. Finally, at t=0.1 ms, the plasma jet penetrates the main gap 4, induces the main gap 4 to break down, and forms the main discharge channel from the nozzle 9 of the trigger cavity to the high voltage electrode, and the switch is turned on.

[0057] (5) When the high-energy fault current passes through the main gap 4, under the action of the transverse magnetic field generated by the first spiral groove 3 and the second spiral groove 6, the arc of the main gap 4 rotates at high speed along the surface of the first spiral groove plate 2 and the second spiral groove plate 5, with a rotation speed ≥100 m / s. The arc column of the main gap 4 is constrained within the first spiral groove plate 2 and the second spiral groove plate 5 to avoid concentrated ablation of the electrode during current flow. During the current flow process, the arc of the main gap 4 remains stable, the temperature distribution on the surface of the spiral groove plate is uniform, and the current flow time can be sustained for 30 ms.

[0058] (6) After the current carrying time reaches the preset value of 30 ms, the time control switch K2 is closed, and the current in the main gap 4 is transferred to the parallel circuit of inductor L and time control switch K2. The current in the main gap 4 gradually decreases, the arc in the main gap 4 cools down and extinguishes quickly, and the insulation performance begins to recover after 100 ms.

[0059] (7) After the energy is discharged, disconnect the charging switch K1, the time control switch K2 and the closing control switch K3, and the device returns to the standby state to prepare for the next operation.

[0060] like Figure 4 As shown, the purple line represents the state of the time-controlled switch K2. Initially, it is in the open state, at which point K2 is disconnected. At the end of the current flow, K2 switches to the closed state, performing current transfer and guiding the current in the main gap 4 to the parallel circuit of "L+K2" to assist in the extinction of the gap arc.

[0061] The yellow line represents the state of the closing control switch K3. Before the main gap 4 is turned on, K3 first switches from open to closed, forming a circuit between the energy storage capacitor bank CA and the inductor L, preparing for the generation of fault current. After the energy is discharged, K3 returns to the open state.

[0062] The blue line represents the state of main gap 4. Initially, it is in the insulation stage, and main gap 4 remains insulated with no current flowing through it. At 0ms, the trigger chamber is activated, and main gap 4 breaks down and becomes conductive. Subsequently, main gap 4 enters the conductive state and is accompanied by arcing. Finally, the current flow ends, and as K2 closes to complete the current transfer, the gap extinguishes the arc, returns to the insulation state, and insulation restoration is performed.

[0063] In summary, this invention, by introducing a trigger cavity and spiral groove in the gas gap switch to coordinate arc control, enables the main gap 4 to form a stable and controllable initial discharge channel under high pressure and large gap conditions. Furthermore, it actively constrains the arc trajectory during the high-energy fault current flow stage, preventing the arc root from lingering in localized areas of the electrode, thereby significantly reducing electrode erosion and extending current-carrying life. Simultaneously, the transverse magnetic field generated by the spiral groove structure causes the arc to rotate along the electrode surface, effectively improving arc column stability and reliability under high current conditions. Through the trigger cavity design, the contact maintenance time of the main gap 4 is increased to milliseconds. The device operates at the second level, meeting the timing requirements for coordination with fast mechanical switches and solving the problem of easy arc extinguishing under low voltage and low current. Through reasonable configuration of the trigger cavity structure and the gas medium in the main gap 4, it can achieve rapid arc extinguishing and accelerate insulation recovery after the current flows out, meeting the application requirements of fast bypass, fault isolation and energy discharge in high-voltage and high-capacity systems. The device has a simple structure and controllable cost, achieving a cost reduction of 80% to 90% compared with power electronic switches, and has a fast action response speed. It can meet the rapid energy discharge requirements for surplus power management in flexible DC transmission systems, and is also suitable for rapid fault isolation and load transfer scenarios in traditional power systems.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A device for improving the current flow control and arc control of a high-pressure, high-capacity gas gap switch, characterized in that: include: The test chamber contains a high-voltage electrode and a ground electrode, with a main gap between them. The ground electrode contains a trigger chamber. The test chamber is used to provide a controllable gas insulation environment and serves as a carrier for high-voltage and high-current discharge tests. The trigger discharge circuit is used to generate a high-voltage pulse to drive the trigger cavity to generate a plasma jet, which induces the main gap to break down and conduct at a predetermined time. A high-current generation circuit is used to store energy and generate a high-energy fault current that simulates actual working conditions after the main gap is turned on. The high current generating circuit is connected to the high voltage lead of the test chamber, and the trigger discharge circuit is connected to the trigger electrode of the test chamber.

2. The device for improving the flow control and arc control of a high-pressure, high-capacity gas gap switch according to claim 1, characterized in that: The high-voltage electrode is located above the ground electrode. The high-voltage electrode consists of a first conductive rod and a first spiral groove electrode plate. The first conductive rod is integrally formed with the first spiral groove electrode plate. A first spiral groove is formed on the surface of the first spiral groove electrode plate, and the depth of the first spiral groove is the same as the thickness of the first spiral groove electrode plate. The ground electrode consists of a second spiral groove electrode plate, a second conductive rod, and a base plate, which are integrally formed. The second conductive rod is integrally formed with the second spiral groove electrode plate. The second conductive rod is integrally formed with the second conductive rod. The base plate is integrally formed with the second spiral groove electrode plate. A second spiral groove is formed on the surface of the second spiral groove electrode plate, and the depth of the second spiral groove is the same as the thickness of the second spiral groove electrode plate. A nozzle is opened at the center of the second spiral groove electrode plate; the first conductive rod, the first spiral groove electrode plate, the second spiral groove electrode plate, the second conductive rod, and the base plate are arranged from top to bottom and located on the same central axis; the ground electrode is embedded with an independent trigger cavity, which is a coaxial laminated structure, formed by tightly pressing the trigger electrode and the insulating component. The trigger electrode is located at the center of the insulating component, the insulating component is located at the center of the ground electrode, and the cavity above the trigger electrode is connected to the nozzle.

3. The device for improving the flow control and arc control of a high-pressure, high-capacity gas gap switch according to claim 1, characterized in that: The high-voltage electrode is connected to the high-voltage lead, and the ground electrode is placed on an insulating base; one end of the high-voltage lead is connected to a DC high voltage to provide the working voltage, and the other end of the high-voltage lead is connected to a high-current generating circuit to simulate a high-energy fault current; the ground electrode is grounded.

4. The device for improving the current flow control and arc control of a high-pressure, high-capacity gas gap switch according to claim 1, characterized in that: The trigger discharge circuit includes an energy storage capacitor C. One end of the energy storage capacitor C is connected to one end a1 of the primary winding of the pulse transformer T, and the other end of the energy storage capacitor C is grounded to the ground electrode. The other end b1 of the primary winding of the pulse transformer T is connected to the positive terminal of the thyristor SCR. Diode D3 is connected in parallel with the thyristor SCR. The cathode of diode D3 is connected to the positive terminal of the thyristor SCR, and the anode of diode D3 is connected to the negative terminal of the thyristor SCR and then grounded to the ground electrode. One end a2 of the secondary winding of the pulse transformer T is connected to the trigger electrode, and the other end b2 of the secondary winding of the pulse transformer T is connected to one end of the protection resistor R3. The other end of the protection resistor R3 is grounded to the ground electrode.

5. The device for improving the current flow control and arc control of a high-pressure, high-capacity gas gap switch according to claim 1, characterized in that: The high-current generating circuit includes a high-voltage DC power supply DC. The positive terminal of the high-voltage DC power supply DC is connected to one end of the charging resistor R1, and the negative terminal of the high-voltage DC power supply DC is grounded. The other end of the charging resistor R1 is connected to one end of the charging switch K1, and the other end of the charging switch K1 is connected to the energy storage capacitor bank CA. The energy storage capacitor bank CA and the discharge resistor R2 are connected in parallel and share a common ground. The parallel end is connected to one end of the inductor L. The time control switch K2 is connected in parallel to the inductor L. The other end of the inductor L is connected to one end of the closing control switch K3, and the other end of the closing control switch K3 is connected to the high-voltage lead.

6. The device for improving the flow control and arc control of a high-pressure, high-capacity gas gap switch according to claim 2, characterized in that: The trigger electrode is cylindrical and made of brass; the nozzle has a diameter of 3mm and a height of 8mm; the insulating component is made of polytetrafluoroethylene modified material.

7. The device for improving the current flow control and arc control of a high-pressure, high-capacity gas gap switch according to claim 2, characterized in that: Both the high-voltage electrode and the ground electrode are made of CuW80 alloy; the first and second spiral grooves are both arranged axially, with a width of 1mm, a diameter of 110mm, and a thickness of 8mm; the first and second conductive rods are both cylindrical structures, with a diameter of 40mm and a height of 35mm; the distance between the high-voltage electrode and the ground electrode is 20mm.

8. The high-energy fault current handling method of the device for improving the current control and arc control of a high-pressure, high-capacity gas gap switch according to any one of claims 1 to 7, characterized in that: The method includes the following steps in sequence: (1) Apply a DC voltage to the high voltage electrode to a preset value, and at the same time charge the energy storage capacitor C of the trigger discharge circuit to a preset value, and set the time when the thyristor SCR responds to the trigger signal; (2) When the charging switch K1 is closed, the high voltage DC power supply DC charges the energy storage capacitor bank CA through the charging resistor R1. After reaching the preset value, the charging switch K1 is disconnected. (3) When the closing control switch K3 is closed, the energy storage capacitor bank CA and the inductor L form an oscillating circuit, generating a high-energy fault current. The current passes through the high-voltage electrode and the main gap to form a circuit. (4) The trigger cavity is activated, and a high voltage pulse is applied to the trigger electrode to ablate the insulating material of the trigger cavity, forming a high temperature, high speed and high conductivity plasma jet, which is ejected from the nozzle and induces the main gap to open. (5) When the high-energy fault current passes through the main gap, under the action of the transverse magnetic field generated by the first spiral groove and the second spiral groove, the main gap arc rotates at high speed along the surface of the first spiral groove electrode plate and the second spiral groove electrode plate. The main gap arc column is constrained within the first spiral groove electrode plate and the second spiral groove electrode plate to avoid concentrated ablation of the electrode local when the current flows through. (6) After the current carrying time reaches the preset value, the time control switch K2 is closed, and the current in the main gap is transferred to the parallel circuit of inductor L and time control switch K2, so that the arc in the main gap is extinguished and the insulation recovery begins; (7) After the energy is discharged, disconnect the charging switch K1, the time control switch K2 and the closing control switch K3, and the device returns to the standby state.

9. The high-energy fault current handling method according to claim 8, characterized in that: In step (4), the plasma jet is formed within 100 μs, and the main gap contact delay is within 200 μs; in step (5), the arc rotation speed is greater than or equal to 100 m / s, and the current flow time is maintained at 30 ms; in step (6), the insulation recovery time after arc extinction is completed within 100 ms; the preset values ​​include a high voltage electrode voltage of 5 kV, a charging voltage of energy storage capacitor C of 1.8 kV, and a charging voltage of energy storage capacitor bank CA of 10 kV.

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