Device and continuous triggering method for prolonging electric arc contact maintaining time of quick bypass switch

Abstract

The invention relates to a device for prolonging the arc touch-on holding time of a quick bypass switch, which comprises a high-voltage electrode and a ground electrode which are oppositely arranged, a main gap is arranged between the high-voltage electrode and the ground electrode, and three paths of trigger cavities A, B and C are embedded in the ground electrode; the trigger cavities A, B and C are mutually independent, the trigger cavities A, B and C are respectively and correspondingly connected with the trigger discharge loops A, B and C, and each trigger cavity is triggered by the corresponding trigger discharge loop; the high-voltage electrode is connected with a high voltage and is responsible for providing a working voltage; and the ground electrode is grounded. The invention further discloses a continuous triggering method of the device for prolonging the electric arc contact maintaining time of the quick bypass switch. The device has the advantages of being simple in structure, high in voltage-withstanding parameter, capable of being repeatedly triggered and capable of being reliably touched and conducted under the extremely low working coefficient; the arc contact holding time of the quick bypass switch can be prolonged to an ms level, so that seamless time sequence cooperation between the quick bypass switch and the switching device is realized.

Description

Technical Field

[0001] The invention relates to the technical field of rapid control and protection of distribution networks, and in particular to a device for improving the arc contact maintenance time of a rapid bypass switch and a connection triggering method. Background Art

[0002] The distribution network is a key link between the power system and the user's electrical equipment. With the rapid development of distributed power sources, the increasing scale of electric vehicles, and the continuous expansion of power market construction, the improvement of the power supply guarantee capacity of the distribution network faces great challenges. When the distribution network line is running at high load for a long time or the equipment is planned for maintenance, the load needs to be transferred. At present, the "first on and then off" method is widely used, that is, the bus bypass ring transfer power supply realizes load transfer to meet the power supply reliability requirements of power users. However, at present, there are 35kV transfer power supply with a 30° angle difference in the power system in some areas. When the line maintenance needs to be reversed, it is generally necessary to shut down the power supply and then switch to the backup power supply, which increases the number of power outages for users; when the line fails, personnel are required to perform on-site operations, which increases the power outage time for users, greatly limiting the power supply reliability and the user's power consumption experience.

[0003] The gas gap switch based on the jet plasma trigger type has a simple structure, sub-ms action, and low implementation cost. It has obvious advantages in the fast bypass switch used for bus bypass ring-closing and power transfer, and plays an important role in ensuring the power supply reliability of the distribution network. However, in the actual application of non-stop power supply closing and power transfer, higher working reliability is required for the gas gap switch: first, the gas gap switch needs to maintain the touch-on time for a long time when it is touched, and it is required to be able to reliably maintain the touch-on until the fast mechanical switch is closed (>3ms), but the existing gas gap switch is easy to extinguish the arc, and the touch-on maintenance time is short, only at the level of hundreds of μs, which cannot meet the action requirements of the fast mechanical switch, and there is a timing coordination problem in the process of the two being connected and closed. Therefore, there is an urgent need for a device that can improve the arc touch-on maintenance time of the fast bypass switch and a connection triggering method to solve the above problems. Summary of the invention

[0004] In order to solve the problem that the gas gap is easy to extinguish the arc, the contact maintenance time is short, and the contact cannot be reliably maintained until the fast mechanical switch is closed, the primary purpose of the present invention is to provide a device that can stably and repeatedly trigger at an extremely low working coefficient, has a simple structure, and a contact maintenance time of ms level to improve the arc contact maintenance time of the fast bypass switch.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a device for improving the arc contact maintenance time of a fast bypass switch, comprising a high-voltage electrode and a ground electrode arranged relatively, the high-voltage electrode adopts a T-shaped parallel plate electrode, the ground electrode adopts an I-shaped parallel plate electrode, a main gap is set between the high-voltage electrode and the ground electrode, and three trigger cavities A, B, and C are embedded in the ground electrode; the A-path trigger cavity is formed by tightly pressing the ground electrode, an insulating member, and the A-path trigger electrode, the B-path trigger cavity is formed by tightly pressing the ground electrode, an insulating member, and the B-path trigger electrode, and the C-path trigger cavity is formed by tightly pressing the ground electrode, the insulating member, and the C-path trigger electrode; the A, B, and C-path trigger cavities are independent of each other, the A, B, and C-path trigger cavities are respectively connected to the A, B, and C-path trigger discharge circuits, the circuits of the A, B, and C-path trigger discharge circuits are the same, and each trigger cavity is triggered by the corresponding trigger discharge circuit; the high-voltage electrode is connected to the high voltage and is responsible for providing the working voltage; the ground electrode is grounded.

[0006] The A-way trigger electrode of the A-way trigger cavity is located at the center, and is cylindrical, with an insulating member arranged around its periphery, the outer side of the insulating member is a ground electrode, and a nozzle is arranged upwardly on the A-way trigger electrode, and the nozzle passes through the insulating member and the ground electrode.

[0007] The high-voltage electrode, ground electrode and trigger electrode are all made of brass, and the material of the insulating part is polytetrafluoroethylene; the A-way trigger electrode, the B-way trigger electrode and the C-way trigger electrode are all provided with nozzles upward, and the three nozzles are arranged in a triangle, the diameter of the nozzle is 2 mm, and the height of the nozzle is 5 mm.

[0008] The A-path trigger discharge loop includes an energy storage capacitor C, one end of which is respectively connected to a rectifier silicon stack V and an inductor L, the other end of the inductor L is connected to one end a1 of the primary coil of the pulse transformer T, the other end b1 of the primary coil is connected to the positive electrode of the thyristor SCR, the diode D is anti-parallel connected to the thyristor SCR, the anode of the diode D is connected to the negative electrode of the thyristor SCR and then grounded, and the cathode of the diode D is connected to the positive electrode of the thyristor SCR; one end a2 of the secondary coil of the pulse transformer T is connected to the A-path trigger electrode, the other end b2 of the secondary coil of the pulse transformer T is connected to one end of the protection resistor R1, and the other end of the protection resistor R1 is grounded to the ground electrode; the other end of the rectifier silicon stack V is connected to an external AC high voltage AC POWER through a charging resistor R2, the external AC high voltage AC POWER is used to provide a trigger source, and the rectifier silicon stack V is used to rectify the external AC high voltage AC POWER into direct current to charge the energy storage capacitor C.

[0009] Another object of the present invention is to provide a method for triggering a device for improving the arc contact maintenance time of a fast bypass switch, the method comprising the following steps in sequence:

[0010] (1) applying a DC voltage to a preset value to the high voltage electrode, charging the three energy storage capacitors C to preset values ​​respectively, and setting the time when the three thyristors SCR respond to the trigger signal to preset values ​​respectively;

[0011] (2) First, the A-path trigger cavity is activated, and a high-voltage pulse is applied to the A-path trigger electrode in the A-path trigger cavity to ablate the insulating material of the A-path trigger cavity. Within 100 μs, a high-temperature, high-speed, and high-conductivity plasma jet is formed and ejected from the nozzle just above the A-path trigger cavity, inducing the main gap to be connected;

[0012] (3) When the energy injected into the trigger cavity of path A is insufficient to generate sufficient plasma to maintain the main gap in contact, the trigger cavity of path B is activated, ablating to generate a large amount of plasma, so that the main gap continues to maintain the contact state;

[0013] (4) When the energy injected into the B-path trigger cavity is insufficient to generate sufficient plasma to maintain the main gap on, the C-path trigger cavity is activated, ablating to generate a large amount of plasma, further maintaining the main gap on state, thus achieving the continuous action of the three-path trigger cavity and increasing the main gap on time to the ms level.

[0014] It can be seen from the above technical scheme that the beneficial effects of the present invention are: first, compared with traditional high-voltage and large-capacity power electronic switch equipment and gas switches in the pulse power field, the present invention has the advantages of simple structure, high withstand voltage parameters, repeatable triggering, and reliable contact under extremely low working coefficients; second, in view of the problem that the existing fast bypass switch is easy to extinguish the arc and the contact maintenance time is short, which is only at the level of hundreds of μs and cannot meet the action requirements of the switching device, the present invention can increase the arc contact maintenance time of the fast bypass switch to the ms level, so that the fast bypass switch and the switching device can achieve seamless timing coordination. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the high voltage electrode, the ground electrode and the three-way trigger cavity in the present invention;

[0016] Figure 2 for Figure 1 Cross-sectional view of the middle ground electrode and the three-way trigger cavity along the DD direction;

[0017] Figure 3 It is a circuit connection diagram of the A-path trigger discharge circuit and the A-path trigger cavity in the present invention;

[0018] Figure 4 This is a flow chart of the method for connection triggering in the present invention. DETAILED DESCRIPTION

[0019] like Figure 1 , Figure 2As shown, a device for improving the arc contact maintenance time of a fast bypass switch comprises a high-voltage electrode 1 and a ground electrode 3 arranged relatively, the high-voltage electrode 1 adopts a T-shaped parallel plate electrode, the ground electrode 3 adopts an I-shaped parallel plate electrode, a main gap 2 is set between the high-voltage electrode 1 and the ground electrode 3, and three trigger cavities A, B, and C are embedded in the ground electrode 3; the A-path trigger cavity 5 is formed by tightly pressing the ground electrode 3, the insulating member 9, and the A-path trigger electrode 8, the B-path trigger cavity 7 is formed by tightly pressing the ground electrode 3, the insulating member 9, and the B-path trigger electrode 11, and the C-path trigger cavity 10 is formed by tightly pressing the ground electrode 3, the insulating member 9, and the C-path trigger electrode 6; the A, B, and C three-path trigger cavities are independent of each other, the A, B, and C three-path trigger cavities are respectively connected to the A, B, and C three-path trigger discharge circuits, the A, B, and C three-path trigger discharge circuits have the same circuit, each trigger cavity is independent of each other, and is triggered by the corresponding trigger discharge circuit; the high-voltage electrode 1 is connected to the high voltage and is responsible for providing the working voltage; the ground electrode 3 is grounded.

[0020] like Figure 3 As shown, the A-way trigger electrode 8 of the A-way trigger chamber 5 is located at the center, and the A-way trigger electrode 8 is cylindrical, and an insulating member 9 is arranged around the periphery thereof. The outer side of the insulating member 9 is the ground electrode 3, and the A-way trigger electrode 8 is provided with a nozzle 4 upward, and the nozzle 4 penetrates the insulating member 9 and the ground electrode 3. The high-voltage electrode 1, the ground electrode 3, and the trigger electrode are all made of brass, and the material of the insulating member 9 is polytetrafluoroethylene; the A-way trigger electrode 8, the B-way trigger electrode 11, and the C-way trigger electrode 6 are all provided with nozzles 4 upward, and the three nozzles 4 are arranged in a triangle, and the diameter of the nozzle 4 is 2 mm, and the height of the nozzle 4 is 5 mm.

[0021] like Figure 3As shown, the A-path trigger discharge loop includes an energy storage capacitor C, one end of which is connected to a rectifier silicon stack V and an inductor L respectively, the other end of the inductor L is connected to one end a1 of the primary coil of the pulse transformer T, the other end b1 of the primary coil is connected to the positive electrode of the thyristor SCR, the diode D is anti-parallel connected to the thyristor SCR, the anode of the diode D is connected to the negative electrode of the thyristor SCR and then grounded, and the cathode of the diode D is connected to the positive electrode of the thyristor SCR; one end a2 of the secondary coil of the pulse transformer T is connected to the A-path trigger electrode 8, the other end b2 of the secondary coil of the pulse transformer T is connected to one end of the protection resistor R1, and the other end of the protection resistor R1 is grounded to the ground electrode 3; the other end of the rectifier silicon stack V is connected to an external AC high voltage ACPOWER through a charging resistor R2, the external AC high voltage AC POWER is used to provide a trigger source, and the rectifier silicon stack V is used to rectify the external AC high voltage AC POWER into DC power to charge the energy storage capacitor C. The thyristor SCR is responsible for responding to the trigger signal at the set time and controlling the discharge of the corresponding energy storage capacitor C; the three groups of energy storage capacitors C are charged by the external AC high voltage AC POWER through the rectifier silicon stack V and the charging resistor R2, and are discharged after the thyristor SCR connected thereto is turned on; the three groups of pulse transformers T are responsible for generating high-voltage pulses and applying them to the corresponding trigger electrodes to ablate the insulating parts 9 of the trigger cavity to generate high-temperature, high-speed, and high-conductivity plasma; the inductor L is responsible for extending the discharge time of the energy storage capacitor C, extending the time for the high-voltage pulse to ablate the trigger cavity, and extending the duration of plasma injection.

[0022] The method comprises the following steps in order:

[0023] (1) applying a DC voltage to a preset value to the high voltage electrode 1, charging the three energy storage capacitors C to preset values ​​respectively, and setting the time when the three thyristors SCR respond to the trigger signal to preset values ​​respectively;

[0024] (2) First, the A-path trigger cavity 5 is activated, and a high-voltage pulse is applied to the A-path trigger electrode 8 in the A-path trigger cavity 5, thereby ablating the insulating member 9 material of the A-path trigger cavity 5. Within 100 μs, a high-temperature, high-speed, and high-conductivity plasma jet is formed and ejected from the nozzle 4 directly above the A-path trigger cavity 5, thereby inducing the main gap 2 to be connected;

[0025] (3) When the energy injected into the trigger cavity 5 of the A path is insufficient to generate sufficient plasma to maintain the main gap 2 in contact, the trigger cavity 7 of the B path is activated to generate a large amount of plasma by ablation, so that the main gap 2 continues to maintain the contact state;

[0026] (4) When the energy injected into the B-path trigger chamber 7 is insufficient to generate sufficient plasma to maintain the main gap 2 being on, the C-path trigger chamber 10 is activated, ablating to generate a large amount of plasma, further maintaining the main gap 2 being on, thus achieving the three-path trigger chamber successive action and increasing the main gap 2 on-time to the ms level.

[0027] The following combination Figures 1 to 4 The present invention is further described.

[0028] (1) applying a DC high voltage to a high voltage electrode 1 to a preset value; applying an AC high voltage AC POWER to charge three groups of energy storage capacitors C to preset values ​​through a rectifier silicon stack V and a protective resistor R1; setting the time when the three thyristors SCR respond to the trigger signal: the A thyristor SCR is triggered at the starting time 0, the B thyristor SCR is triggered at the time 1ms, and the C thyristor SCR is triggered at the time 2ms;

[0029] (2) Initially at t = 0 ms, the A-way thyristor SCR first responds to the trigger signal, the A-way energy storage capacitor C discharges, and a high-voltage pulse is applied to the A-way trigger electrode 8 in the A-way trigger cavity 5 through the A-way pulse transformer T, ablating the insulating material 9 of the A-way trigger cavity 5, forming a high-temperature, high-speed, high-conductivity plasma jet within 100 μs, and accumulating in large quantities at the channel nozzle 4 with a surface height of 5 mm and a diameter of 2 mm in the A-way trigger cavity 5, and then ejecting. Finally, at t = 0.13 ms, the plasma jet penetrates the main gap 2, inducing the main gap 2 to break down, forming the A-way main discharge channel from the nozzle 4 of the A-way trigger cavity 5 to the high-voltage electrode 1, and the fast bypass switch is turned on. At this time, the B and C thyristors SCR have not received the trigger signal, so the B and C trigger cavities have not yet acted.

[0030] (3) At t=0.965ms, due to the low residual energy of the A-circuit energy storage capacitor C, the jet plasma generated by the A-circuit trigger cavity 5 in the main gap 2 begins to gradually dissipate, the jet height of the jet plasma decreases, and the A-circuit main discharge channel in the main gap 2 begins to extinguish. The subsequent energy injected into the A-circuit trigger cavity 5 will not be sufficient to generate sufficient plasma to maintain the main gap 2 being connected; at the preset time t=1ms, the B-circuit thyristor SCR responds to the trigger signal, the B-circuit energy storage capacitor C discharges, and a high-voltage pulse is applied to the B-circuit trigger electrode 11 in the B-circuit trigger cavity 7 through the B-circuit pulse transformer T, which also ablates to generate jet plasma, which accumulates in large quantities and is ejected from the nozzle 4 of the B-circuit trigger cavity 7, and penetrates the gap at t=1.08ms, forming a new B-circuit main discharge channel from the nozzle 4 of the B-circuit trigger cavity 7 to the high-voltage electrode 1, so that the main gap 2 continues to maintain the connected state.

[0031] (4) At t=1.97ms, since the energy storage capacitor C of the A-circuit is completely released, the main discharge channel of the A-circuit in the main gap 2 has been completely extinguished, and the residual energy of the energy storage capacitor C of the B-circuit is relatively low, the jet plasma generated by the trigger chamber 7 of the B-circuit begins to gradually dissipate, the jet height of the jet plasma decreases, and the main discharge channel of the B-circuit in the main gap 2 begins to extinguish. Therefore, the subsequent energy injected into the trigger chamber 7 of the B-circuit will not be sufficient to generate sufficient plasma to maintain the main gap 2 being connected; at the preset time t=2ms, the thyristor SCR of the C-circuit responds to the trigger signal, the energy storage capacitor C of the C-circuit is discharged, and a high-voltage pulse is applied to the C-circuit trigger electrode 6 in the C-circuit trigger chamber 10 through the C-circuit pulse transformer T, and a jet plasma is ablated to generate a jet plasma, which is accumulated in large quantities at the nozzle 4 of the C-circuit trigger chamber 10 and then ejected. At t=2.1ms, the gap is penetrated, and a new main discharge channel of the C-circuit is formed between the nozzle 4 of the C-circuit trigger chamber 10 and the high-voltage electrode 1, further maintaining the connected state of the main gap 2, realizing the continuous action of the three-circuit trigger chamber, and significantly prolonging the touch-on time of the main gap 2.

[0032] (5) At t = 3.06 ms, the energy of the three energy storage capacitors C of A, B, and C is completely released, and the jet plasma generated by the three trigger cavities A, B, and C in the main gap 2 is completely dissipated. The touch-through process of the main gap 2 ends, and the touch-through time is maintained for 3 ms.

[0033] In this embodiment, the gas gap switch can trigger a minimum voltage peak of 2kV, a conduction delay of less than 150μs, a touch-on time of more than 3ms, and a trigger life of up to 2000 times.

[0034] In summary, compared with traditional high-voltage and large-capacity power electronic switch equipment and gas switches in the pulse power field, the present invention has the advantages of simple structure, high withstand voltage parameters, repeatable triggering, and reliable contacting at extremely low working coefficients; in view of the problem that the existing fast bypass switch is easy to extinguish the arc, and the contacting maintenance time is short, which is only at the level of hundreds of μs, and cannot meet the operation requirements of the switching device, the present invention can improve the arc contacting maintenance time of the fast bypass switch to the ms level, so that the fast bypass switch and the switching device can achieve seamless timing coordination. Based on the existing gas gap switch, the present invention optimizes the trigger cavity structure. Before the optimization, there is only one trigger cavity. By adding multiple trigger cavities and controlling the corresponding thyristor conduction timing to be triggered continuously, the arc contacting maintenance time of the fast bypass switch can be improved to the ms level, so that the fast bypass switch and the switching device can achieve seamless timing coordination and improve the power supply reliability of the distribution network.

Claims

1. A device for increasing the arc contact maintenance time of a fast bypass switch, characterized in that: It comprises a high-voltage electrode and a ground electrode arranged oppositely, the high-voltage electrode adopts a T-shaped parallel plate electrode, the ground electrode adopts an I-shaped parallel plate electrode, a main gap is arranged between the high-voltage electrode and the ground electrode, and three trigger cavities A, B and C are embedded in the ground electrode; the A trigger cavity is formed by tightly pressing the ground electrode, an insulating member and the A trigger electrode, the B trigger cavity is formed by tightly pressing the ground electrode, an insulating member and the B trigger electrode, and the C trigger cavity is formed by tightly pressing the ground electrode, an insulating member and the C trigger electrode; the A, B and C trigger cavities are independent of each other, the A, B and C trigger cavities are respectively connected to the A, B and C trigger discharge circuits, the circuits of the A, B and C trigger discharge circuits are the same, and each trigger cavity is triggered by the corresponding trigger discharge circuit; the high-voltage electrode is connected to the high voltage and is responsible for providing the working voltage; the ground electrode is grounded.

2. The device for increasing the arc contact maintenance time of a fast bypass switch according to claim 1, characterized in that: The A-way trigger electrode of the A-way trigger cavity is located at the center, and is cylindrical, with an insulating member arranged around its periphery, the outer side of the insulating member is a ground electrode, and a nozzle is arranged upwardly on the A-way trigger electrode, and the nozzle passes through the insulating member and the ground electrode.

3. The device for increasing the arc contact maintenance time of a fast bypass switch according to claim 1, characterized in that: The high-voltage electrode, ground electrode and trigger electrode are all made of brass, and the material of the insulating part is polytetrafluoroethylene; the A-way trigger electrode, the B-way trigger electrode and the C-way trigger electrode are all provided with nozzles upward, and the three nozzles are arranged in a triangle, the diameter of the nozzle is 2 mm, and the height of the nozzle is 5 mm.

4. The device for increasing the arc contact maintenance time of a fast bypass switch according to claim 1, characterized in that: The A-path trigger discharge loop includes an energy storage capacitor C, one end of which is respectively connected to a rectifier silicon stack V and an inductor L, the other end of the inductor L is connected to one end a1 of the primary coil of the pulse transformer T, the other end b1 of the primary coil is connected to the positive electrode of the thyristor SCR, the diode D is anti-parallel connected to the thyristor SCR, the anode of the diode D is connected to the negative electrode of the thyristor SCR and then grounded, and the cathode of the diode D is connected to the positive electrode of the thyristor SCR; one end a2 of the secondary coil of the pulse transformer T is connected to the A-path trigger electrode, the other end b2 of the secondary coil of the pulse transformer T is connected to one end of the protection resistor R1, and the other end of the protection resistor R1 is grounded to the ground electrode; the other end of the rectifier silicon stack V is connected to an external AC high voltage AC POWER through a charging resistor R2, the external AC high voltage AC POWER is used to provide a trigger source, and the rectifier silicon stack V is used to rectify the external AC high voltage AC POWER into direct current to charge the energy storage capacitor C.

5. The method for triggering the device for increasing the arc contact maintenance time of a fast bypass switch according to any one of claims 1 to 4, characterized in that: The method comprises the following steps in order: (1) applying a DC voltage to a preset value to the high voltage electrode, charging the three energy storage capacitors C to preset values ​​respectively, and setting the time when the three thyristors SCR respond to the trigger signal to preset values ​​respectively; (2) First, the A-path trigger cavity is activated, and a high-voltage pulse is applied to the A-path trigger electrode in the A-path trigger cavity to ablate the insulating material of the A-path trigger cavity. Within 100 μs, a high-temperature, high-speed, and high-conductivity plasma jet is formed and ejected from the nozzle just above the A-path trigger cavity, inducing the main gap to be connected; (3) When the energy injected into the trigger cavity of path A is insufficient to generate sufficient plasma to maintain the main gap in contact, the trigger cavity of path B is activated, ablating to generate a large amount of plasma, so that the main gap continues to maintain the contact state; (4) When the energy injected into the B-path trigger cavity is insufficient to generate sufficient plasma to maintain the main gap on, the C-path trigger cavity is activated, ablating to generate a large amount of plasma, further maintaining the main gap on state, thus achieving the continuous action of the three-path trigger cavity and increasing the main gap on time to the ms level.

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