Experimental device and method for studying influence of pre-ionization parameters on discharge characteristics of switch gap

Abstract

The application relates to a device and a method for studying the influence of switch parameters on switch discharge characteristics, in particular to a device and a method for studying the influence of pre-ionization parameters on switch gap discharge characteristics, and solves the technical problem that the prior art cannot obtain the influence of a single pre-ionization parameter on switch gap discharge characteristics. The device for studying the influence of pre-ionization parameters on switch gap discharge characteristics comprises a first charging capacitor, a second charging capacitor, a load resistor, a double-path output square wave source, a pre-ionization resistor and an experimental switch; the device can respectively study the discharge characteristics of a trigger gap and an overvoltage gap. The method can separately study the influence of each pre-ionization parameter, namely a pre-ionization injection time, a pre-ionization current amplitude and a pre-ionization current duration, on the discharge characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to a device and method for studying the influence of switch parameters on switch discharge characteristics, in particular to a device and method for studying the influence of pre-ionization parameters on switch gap discharge characteristics. BACKGROUND

[0002] Pulse power technology is an important means to obtain strong radiation and extreme high energy density physical conditions in the laboratory, and has important applications in strong radiation environment simulation, high energy density physics, Z-pinch inertial confinement fusion and other frontier scientific and technological researches. Large-scale pulse power devices usually contain hundreds to tens of thousands of triggered high-power gas switches, and require the gas switches to have the characteristics of low jitter, low trigger threshold, low inductance, low self-discharge probability and long service life. The ultraviolet pre-ionization switch is a switch that increases an ultraviolet pre-ionization structure in the switch and uses the ultraviolet light generated by the discharge as an auxiliary ionization source. The ultraviolet pre-ionization switch has the advantages of low jitter and low trigger threshold, and also has the characteristics of low inductance and long service life due to its easy formation of multi-channel discharge, which can effectively reduce electrode ablation and insulation pollution. In view of the advantages of the ultraviolet pre-ionization switch, it has good application prospect and potential in the field of pulse power technology.

[0003] Although the ultraviolet pre-ionization switch has unique advantages, the research on this switch in the prior art is not sufficient, mainly reflected in the following points: 1. The research on the ultraviolet pre-ionization switch mostly stays in the research on the influence of switch macroscopic parameters on its discharge characteristics, such as the influence of work coefficient, trigger voltage, pre-ionization gap distance and switch structure on switch discharge characteristics. The research on the influence of each pre-ionization parameter (important parameters include: pre-ionization injection time, pre-ionization current amplitude and pre-ionization current duration) on switch discharge characteristics is still less and not systematic; 2. For the research on the influence of each pre-ionization parameter on switch discharge characteristics, it is difficult to control a single variable, that is, there is a lack of research on the influence of a single pre-ionization parameter on switch discharge characteristics; 3. The existing research is all for the whole switch, and lacks separate research on different types of switch gaps (which can be divided into trigger gap and overvoltage gap). The limitations of the above research restrict the expansion of the advantages of the ultraviolet pre-ionization switch and its practical application. SUMMARY

[0004] The purpose of the present application is to solve the technical problem that the prior art cannot obtain the influence of a single pre-ionization parameter on the discharge characteristics of each gap of the switch, and to provide an experimental device and method for studying the influence of pre-ionization parameters on switch gap discharge characteristics.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The utility model relates to an experimental device for the influence of preionization parameters on the discharge characteristics of a switch gap, and has the special features that it comprises a first charging capacitor, a second charging capacitor, a load resistor, a double-channel output square wave source, a preionization resistor and an experimental switch.

[0007] The experimental switch comprises an insulating shell, a positive electrode coaxially arranged on the upper end of the insulating shell and a negative electrode coaxially arranged on the lower end of the insulating shell, a middle electrode, a first preionization electrode and a second preionization electrode, four through holes arranged on the side wall of the insulating shell, namely a third through hole, a fourth through hole and a first through hole and a second through hole arranged opposite to each other, the middle electrode coaxially arranged in the insulating shell, two electrode through holes arranged opposite to each other on the side wall of the middle electrode corresponding to the first through hole and the second through hole, one end of the first preionization electrode and one end of the second preionization electrode passing through the first through hole and the second through hole of the insulating shell respectively, the other end of the first preionization electrode and the other end of the second preionization electrode coaxially arranged in the middle electrode, a preionization gap formed between the other end of the first preionization electrode and the other end of the second preionization electrode, a trigger gap formed between the positive electrode and the middle electrode, and an overvoltage gap formed between the negative electrode and the middle electrode, the middle axis of the first preionization electrode and the second preionization electrode being perpendicular to the middle axis of the positive electrode and the negative electrode.

[0008] The positive electrode, the first charging capacitor, the load resistor, the second charging capacitor and the negative electrode are connected in sequence to form a discharge circuit, and the connection end of the load resistor and the second charging capacitor is grounded; the connection end of the first charging capacitor and the positive electrode is used for connecting with a positive direct current charging power supply; the connection end of the second charging capacitor and the negative electrode is used for connecting with a negative direct current charging power supply.

[0009] The double-channel output square wave source is used for outputting a negative square wave pulse, one output end of the double-channel output square wave source passes through the third through hole and is connected with the middle electrode, and the other output end is connected with one end of the first preionization electrode; one end of the second preionization electrode is grounded through the preionization resistor; the fourth through hole is used for connecting with an external air pipe and inflating the insulating shell.

[0010] Further, the insulating shell is in a cylindrical structure, and two electrode covers are arranged on the upper end and the lower end of the insulating shell respectively; the positive electrode is arranged on the electrode cover on the upper end of the insulating shell; and the negative electrode is arranged on the electrode cover on the lower end of the insulating shell.

[0011] The four through holes are arranged on the side wall of the insulating shell in the circumferential direction, and the axis angle of adjacent through holes is 90°.

[0012] A first circular ring is arranged on the inner wall of the insulating shell, and a first gap is formed between the upper surface of the first circular ring and the positions corresponding to the four through holes; the first gap corresponding to the first through hole and the second through hole is used for positioning the first preionization electrode and the second preionization electrode.

[0013] The middle electrode is connected to the first ring.

[0014] Furthermore, the first pre-ionization electrode includes a first cylinder and a second cylinder coaxially connected to one end of the first cylinder;

[0015] The other end of the first cylinder is tapered;

[0016] The second cylinder is connected to the other output terminal of the dual-output square wave source;

[0017] The second pre-ionization electrode has the same structure as the first pre-ionization electrode;

[0018] A preionization gap is formed between the other end of the first cylinder of the first preionization electrode and the other end of the first cylinder of the second preionization electrode; and the second cylinder of the second preionization electrode is grounded via a preionization resistor.

[0019] Furthermore, it also includes a first pre-ionization sleeve coaxially sleeved on the first pre-ionization electrode and a second pre-ionization sleeve coaxially sleeved on the second pre-ionization electrode;

[0020] The first pre-ionization sleeve includes a first cylinder and a second cylinder coaxially connected to one end of the first cylinder; the inner diameter of the first cylinder matches the outer diameter of the first cylinder; the inner diameter of the second cylinder matches the outer diameter of the second cylinder, and the second cylinder is disposed in the first gap between the first through hole and the first ring;

[0021] The second pre-ionization sleeve has the same structure as the first pre-ionization sleeve, and the second cylinder of the second pre-ionization sleeve is arranged in the first gap between the second through hole and the first ring.

[0022] Furthermore, the positive electrode includes a third cylinder, a second ring coaxially connected to the lower end of the third cylinder, and a trigger gap is formed between the second ring and the intermediate electrode;

[0023] The negative electrode has the same structure as the positive electrode, and an overvoltage gap is formed between the second ring of the negative electrode and the middle electrode;

[0024] The first charging capacitor is connected to the third cylinder of the positive electrode; the second charging capacitor is connected to the third cylinder of the negative electrode.

[0025] Furthermore, the intermediate electrode includes a third cylinder and a third ring coaxially sleeved on the outside of the third cylinder;

[0026] Two electrode through holes are oppositely arranged on the side wall of the third cylinder and perpendicular to the axis of the third cylinder, and are respectively a fifth through hole and a sixth through hole;

[0027] The third ring is connected to the first ring, and is provided with a second notch adapted to the outer diameter of the first cylinder; the positions of the second notch correspond to the fifth through hole and the sixth through hole respectively;

[0028] The inner diameters of the fifth through hole and the sixth through hole are respectively adapted to the outer diameter of the first cylinder;

[0029] The other end of the first cylinder of the first pre-ionization electrode extending into the third cylinder and the other end of the first cylinder of the second pre-ionization electrode extending into the third cylinder form a pre-ionization gap in the third cylinder; a trigger gap is formed between the second circular ring of the positive electrode and the upper end of the third cylinder, and an overvoltage gap is formed between the second circular ring of the negative electrode and the lower end of the third cylinder;

[0030] One output end of the dual-output square wave source is connected to the third ring.

[0031] Furthermore, a sealing ring is provided between the upper end of the insulating shell and the electrode cover, and between the lower end of the insulating shell and the electrode cover.

[0032] A sealing ring is provided between the second cylinder and the second barrel of the first pre-ionization electrode and between the second cylinder and the second barrel of the second pre-ionization electrode;

[0033] The first charging capacitor and the second charging capacitor are both plastic case capacitors;

[0034] The load resistor is a liquid resistor;

[0035] The pre-ionization resistor is a solid resistor;

[0036] The insulating shell is made of transparent insulating material;

[0037] The first pre-ionization sleeve and the second pre-ionization sleeve are both made of PEEK or polyethylene.

[0038] Furthermore, the device further comprises a first charging resistor and a second charging resistor;

[0039] One end of the first charging resistor is connected to the connection end of the first charging capacitor and the positive electrode, and the other end of the first charging resistor is connected to a positive polarity DC charging power supply;

[0040] One end of the second charging resistor is connected to the connection end of the second charging capacitor and the negative electrode, and the other end of the second charging resistor is connected to the negative polarity DC charging power supply;

[0041] The first charging resistor and the second charging resistor are both ceramic resistors.

[0042] Furthermore, the method further includes at least three cameras arranged outside the experimental switch, for taking pictures of the discharge channels of the experimental switch to obtain the number of discharge channels in the trigger gap and the overvoltage gap.

[0043] At the same time, the present invention also provides a method for the influence of pre-ionization parameters on the discharge characteristics of the switch gap. Based on the above experimental device for the influence of pre-ionization parameters on the discharge characteristics of the switch gap, the present invention is special in that: by adjusting the pre-ionization parameters, the discharge characteristics of the trigger gap and the overvoltage gap of the experimental switch, as well as the number and position of the discharge channels, are tested, thereby obtaining the influence of the pre-ionization parameters on the discharge characteristics of the switch gap;

[0044] Adjusting the preionization parameters includes adjusting the preionization injection time, adjusting the preionization current amplitude, and adjusting the preionization current duration;

[0045] The specific adjustment of pre-ionization injection time is:

[0046] Adjust the time difference between the delay of the first output square wave pulse and the delay time difference of the second output square wave pulse of the dual-output square wave source, and change the time difference between the first output square wave pulse being applied to the middle electrode and the second output square wave pulse being applied to the first pre-ionization electrode;

[0047] The specific adjustment of the pre-ionization current amplitude is:

[0048] Adjust the amplitude of the second output square wave pulse of the dual-output square wave source, or by adjusting the resistance of the pre-ionization resistor;

[0049] Adjust the preionization current duration specifically as follows:

[0050] Adjust the pulse width of the second output square wave pulse of the dual output square wave source.

[0051] Beneficial effects of the present invention:

[0052] 1. The present invention provides an experimental device for studying the influence of pre-ionization parameters on the discharge characteristics of a switch gap. A first pre-ionization electrode and a second pre-ionization electrode are used to form a pre-ionization gap in an intermediate electrode. The positive electrode and the intermediate electrode form a trigger gap, and the negative electrode and the intermediate electrode form an overvoltage gap. The discharge characteristics of the trigger gap and the overvoltage gap can be studied respectively by measuring the voltage waveform on the intermediate electrode and the current waveform flowing in the load resistor.

[0053] 2. The present invention provides an experimental device for studying the influence of pre-ionization parameters on the discharge characteristics of a switch gap. The device uses at least three cameras to take pictures of the experimental switch from multiple angles, and can obtain the number of discharge channels in the trigger gap and the overvoltage gap, as well as the position coordinates of each discharge channel.

[0054] 3. The method of the present invention for studying the influence of preionization parameters on the discharge characteristics of the switch gap can independently study the influence of each preionization parameter, namely, the preionization injection time, the preionization current amplitude, and the preionization current duration on the discharge characteristics.

[0055] 4、The method of the present application can also be used to study the influence of the above-mentioned parameters on the discharge characteristics (including the average delay time and its jitter) of the trigger gap and the overvoltage gap and on the number and location of the discharge channels by changing the electrode structure, electrode material, gas type, working coefficient, working voltage, etc. of the experimental switch. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 Structure diagram of the experimental device for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application;

[0057] Figure 2 Structure diagram of the experimental switch in the experimental device for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application (cut along the middle line of the second notch);

[0058] Figure 3 Structure diagram of the first pre-ionization electrode in the experimental device for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application;

[0059] Figure 4 Structure diagram of the first pre-ionization sleeve in the experimental device for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application;

[0060] Figure 5 Structure diagram of the positive electrode in the experimental device and method for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application;

[0061] Figure 6 Structure diagram of the intermediate electrode in the experimental device for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application;

[0062] Figure 7 Structure diagram of the insulating shell in the experimental device for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap according to the present application.

[0063] Explanation of reference numerals: 1-positive polarity DC charging power supply, 2-negative polarity DC charging power supply, 31-first charging resistor, 32-second charging resistor, 41-first charging capacitor, 42-second charging capacitor, 5-load resistor, 6-dual output square wave source, 7-pre-ionization resistor, 8-experimental switch, 81-positive electrode, 811-third cylinder, 812-second ring, 82-negative electrode, 83-electrode cover, 84-middle electrode, 841-third cylinder, 8 42-third ring, 843-fifth through hole, 844-sixth through hole, 85-insulating shell, 851-first through hole, 852-second through hole, 853-third through hole, 854-fourth through hole, 855-first ring, 86-first pre-ionization electrode, 861-first cylinder, 862-second cylinder, 87-second pre-ionization electrode, 88-first pre-ionization sleeve, 881-first cylinder, 882-second cylinder, 89-second pre-ionization sleeve. DETAILED DESCRIPTION

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0065] like Figure 1 As shown, an experimental device for the influence of pre-ionization parameters on the discharge characteristics of the switch gap includes a first charging resistor 31, a second charging resistor 32, a first charging capacitor 41, a second charging capacitor 42, a load resistor 5, a dual-output square wave source 6, a pre-ionization resistor 7 and an experimental switch 8.

[0066] like Figure 2 As shown, the experimental switch 8 includes a positive electrode 81, a negative electrode 82, an insulating shell 85, an intermediate electrode 84, a first pre-ionization electrode 86, and a second pre-ionization electrode 87; the experimental switch 8 has a height of 104 mm and a diameter of 120 mm. The insulating shell 85 is a cylindrical structure with an inner diameter, an outer diameter, and a height of 80 mm, 100 mm, and 76 mm, respectively. Figure 7As shown, the sidewall of the insulating shell 85 is provided with four M10 threaded through holes, i.e. a third through hole 853, a fourth through hole 854, and oppositely arranged first and second through holes 851 and 852, which are arranged at an interval of 90 degrees in the circumferential direction. The first through hole 851 is used for mounting the first pre-ionization electrode 86, the second through hole 852 is used for mounting the second pre-ionization electrode 87, the third through hole 853 is used for introducing one output end of the double-output square wave source 6 into the intermediate electrode 84, and the fourth through hole 854 is used for connecting with an external air pipe and inflating the insulating shell 85. The inner wall of the insulating shell 85 is provided with a first annular ring 855, which forms a first gap with the four through holes, and is used for positioning the first and second pre-ionization electrodes 86 and 87. The inner diameter and outer diameter of the first annular ring 855 are 60 mm and 80 mm, respectively, and the distance between the upper end surface of the first annular ring 855 and the upper end surface of the insulating shell 85 is 41 mm. The first annular ring 855 is provided with four M4 threaded holes in the circumferential direction, which are used for mounting the intermediate electrode 84. The material of the insulating shell 85 is transparent organic glass.

[0067] The upper end and lower end of the insulating shell 85 are respectively provided with two electrode covers 83 matched therewith, and the upper end of the insulating shell 85 and the electrode cover 83, and the lower end of the insulating shell 85 and the electrode cover 83 are respectively provided with sealing rings. The outer edges of the upper end and lower end of the insulating shell 85 are provided with M100 threads, and the inner edges of the two electrode covers 83 are provided with M100 threads, so that the two electrode covers 83 are respectively threadedly connected with the insulating shell 85. The electrode cover 83 is a circular cover with a height of 27.50 mm and a diameter of 120 mm. The electrode cover 83 is provided with a circular through hole with a diameter of 30 mm in the middle, and the positive electrode 81 is coaxially arranged in the circular through hole of the electrode cover 83 at the upper end of the insulating shell 85. The negative electrode 82 is coaxially arranged in the circular through hole of the electrode cover 83 at the lower end of the insulating shell 85. The material of the electrode cover 85 is PEEK.

[0068] As shown in FIG. 6, the positive electrode 81 is provided with a plurality of M3 threaded holes in the circumferential direction, which are used for mounting the positive electrode 81 on the insulating shell 85. The negative electrode 82 is provided with a plurality of M3 threaded holes in the circumferential direction, which are used for mounting the negative electrode 82 on the insulating shell 85. Figure 3As shown in the figure, the first pre-ionization electrode 86 comprises a first cylinder 861 and a second cylinder 862 coaxially connected at one end of the first cylinder 861; the other end of the first cylinder 861 is tapered with a taper angle of 88 degrees; the second pre-ionization electrode 87 has the same structure as the first pre-ionization electrode 86; the other end of the second cylinder of the second pre-ionization electrode 87 is grounded through a pre-ionization resistor 7. Sealing rings are respectively arranged between the second cylinder 862 of the first pre-ionization electrode 86 and the second cylinder 882, and between the second cylinder of the second pre-ionization electrode 87 and the second cylinder. The diameter of the first cylinder 861 is 2 mm and the length is 42.5 mm; the diameter of the second cylinder 862 is 6 mm and the length is 15 mm; the other end of the second cylinder 862 of the first pre-ionization electrode 86 is provided with a circular hole with a diameter of 3 mm and a depth of 9 mm for connecting with the other output end of the double-output square wave source 6. The materials of the first pre-ionization electrode 86 and the second pre-ionization electrode 87 are tungsten-copper alloy, which is resistant to ablation.

[0069] The central axis of the first pre-ionization electrode 86 and the second pre-ionization electrode 87 is perpendicular to the central axis of the positive electrode 81 and the negative electrode 82; a first pre-ionization sleeve 88 is arranged between the first pre-ionization electrode 86 and the insulating shell 85, and a second pre-ionization sleeve 89 is arranged between the second pre-ionization electrode 87 and the insulating shell 85; the first pre-ionization sleeve 88 is sleeved on the first pre-ionization electrode 86, and the second pre-ionization sleeve 89 is sleeved on the second pre-ionization electrode 87.

[0070] As shown in the figure, Figure 4 The first pre-ionization sleeve 88 comprises a first cylinder 881 and a second cylinder 882 coaxially connected at one end of the first cylinder 881; the outer diameter of the first cylinder 881 matches the inner diameter of the second cylinder 882, and the inner diameter of the first cylinder 881 matches the outer diameter of the first cylinder 861; the inner diameter of the second cylinder 882 matches the outer diameter of the second cylinder 862, and the second cylinder 882 is arranged in the first gap between the first through hole 851 and the first annular ring 855; the second pre-ionization sleeve 89 has the same structure as the first pre-ionization sleeve 88, and the materials of the first pre-ionization sleeve 88 and the second pre-ionization sleeve 89 are polyethylene; the second cylinder of the second pre-ionization sleeve 89 is arranged in the first gap between the second through hole 852 and the first annular ring 855. The outer diameter of the first cylinder 881 is 6 mm, the inner diameter is 2 mm, and the length is 36.5 mm; the outer diameter of the second cylinder 882 is 10 mm, the inner diameter is 6 mm, and the length is 13.5 mm; the outer surface of the second cylinder 882 is provided with threads. The materials of the first pre-ionization sleeve 88 and the second pre-ionization sleeve 89 are PEEK, and in other embodiments, the first pre-ionization sleeve 88 and the second pre-ionization sleeve 89 can also be made of polyethylene.

[0071] As shown in the figure, Figure 5As shown, the positive electrode 81 comprises a third cylinder 811 and a second ring 812 coaxially connected to the lower end of the third cylinder 811; the negative electrode 82 has the same structure as the positive electrode 81; the first charging capacitor 41 is connected to the upper end of the third cylinder 811 of the positive electrode 81; and the second charging capacitor 42 is connected to the upper end of the third cylinder of the negative electrode 82. The diameter and height of the third cylinder 811 are 30 mm and 14 mm respectively, and an M5 threaded hole is arranged at the upper end of the third cylinder 811 for connecting the first charging capacitor 41; the inner diameter, outer diameter and height of the second ring 812 are 20 mm, 50 mm and 20 mm respectively, and the bottom of the second ring 812 is rounded with a radius of 5 mm.

[0072] As shown in the figure, Figure 6 As shown, the intermediate electrode 84 comprises a third cylinder 841 and a third ring 842 coaxially sleeved outside the third cylinder 841; the third cylinder 841 is provided with a fifth through hole 843 perpendicular to its axis and a sixth through hole 844 coaxially communicating with the fifth through hole 843; the third ring 842 is provided with a second notch matching the outer diameter of the first cylinder 881, and the width of the second notch is 6 mm; the positions of the second notch correspond to the fifth through hole 843 and the sixth through hole 844 respectively; the third ring 842 is provided with four circular through holes with a diameter of 5 mm in the circumferential direction for fixing the third ring 842 of the intermediate electrode 84 to the first ring 855 of the insulating shell 85 through four M4 screws; the inner diameters of the fifth through hole 843 and the sixth through hole 844 match the outer diameter of the first cylinder 881 respectively. The diameters of the fifth through hole 843 and the sixth through hole 844 are both 6 mm; the diameter and thickness of the third ring 842 are 80 mm and 4 mm respectively; the inner diameter and outer diameter of the third cylinder 841 are 20 mm and 50 mm respectively, and the inner and outer edges of the ring are rounded with a radius of 5 mm.

[0073] The positive electrode 81, the first charging capacitor 41, the load resistor 5, the second charging capacitor 42 and the negative electrode 82 are connected in sequence to form a discharge circuit, and the connection end of the load resistor 5 and the second charging capacitor 42 is grounded; one end of the first charging resistor 31 is connected to the connection end of the first charging capacitor 41 and the positive electrode 81, and the other end of the first charging resistor 31 is used for connecting the positive polarity direct current charging power supply 1; one end of the second charging resistor 32 is connected to the connection end of the second charging capacitor 42 and the negative electrode 82, and the other end of the second charging resistor 32 is used for connecting the negative polarity direct current charging power supply 2. The dual-channel output square wave source 6 is used for outputting negative polarity square wave pulses, one output end of which is connected to the third ring 842 through the third through hole 853, and the other output end is connected to the other end of the second cylinder 862; the other end of the second pre-ionization electrode 87 is grounded through the pre-ionization resistor 7; the fourth through hole 854 is used for connecting an external air pipe and inflating the insulating shell 85.

[0074] The other end of the first cylinder 861 extending into the third cylinder 841 and the other end of the first cylinder of the second pre-ionization electrode 87 extending into the third cylinder 841 form a 2mm pre-ionization gap in the third cylinder 841; the second ring 812 of the positive electrode 81 and the upper end of the third cylinder 841 form a 7mm trigger gap, and the second ring of the negative electrode 82 and the lower end of the third cylinder 841 form a 7mm overvoltage gap.

[0075] Preferably, three cameras are arranged outside the experimental switch 8 to take pictures of the discharge channels of the experimental switch 8 from three angles of 0 degrees, 120 degrees and 240 degrees, so as to artificially judge and obtain the number of discharge channels in the trigger gap and the overvoltage gap. On this basis, by measuring the relative geometric positions of each camera and the experimental switch 8, combining the discharge images taken by each angle camera, and using an image inversion algorithm, the position coordinates of each discharge channel in the trigger gap and the overvoltage gap can be obtained respectively.

[0076] In the embodiment, the positive polarity direct current charging power supply 1 is a positive polarity direct current charging power supply with adjustable output voltage, and the output voltage is 0-+100kV; the negative polarity direct current charging power supply 2 is a negative polarity direct current charging power supply with adjustable output voltage, and the output voltage is 0--100kV. The first charging resistor 31 and the second charging resistor 32 are both ceramic resistors, and the resistance values of the first charging resistor 31 and the second charging resistor 32 are both 2M; the first charging capacitor 41 and the second charging capacitor 42 are both double-ended plastic shell capacitors, and the capacitance values of the first charging capacitor 41 and the second charging capacitor 42 are both 40nF; the load resistor 5 is a high-power liquid resistor with a resistance value of 3Ω; the double-channel output square wave source 6 can output two channels of negative polarity square wave pulses with adjustable amplitude of 0-100kV, adjustable pulse width of 0-100ns and adjustable delay of 0-100ns. The pre-ionization resistor 7 is a high-power solid resistor with adjustable resistance value of 0-10kΩ.

[0077] The working principle of the above embodiment is specifically as follows:

[0078] The positive polarity direct current charging power supply 1 and the negative polarity direct current charging power supply 2 charge the positive electrode 81 and the negative electrode 82 of the experimental switch 8 through the first charging resistor 31 and the second charging resistor 32 respectively. When the square wave pulse generated by the first output end of the double-channel output square wave source 6 is applied to the middle electrode 84 and the square wave pulse generated by the second output end is applied to the first pre-ionization electrode 86, the pre-ionization gap of the experimental switch 8 breaks down first and generates a pre-ionization effect, and then the trigger gap and the overvoltage gap of the experimental switch 8 break down in turn. The device can separately study the influence of each pre-ionization parameter (i.e. pre-ionization injection time, pre-ionization current amplitude and pre-ionization current duration) on the discharge characteristics (including average delay time and its jitter) of the trigger gap and the overvoltage gap of the gas switch and on the number and position of discharge channels.

[0079] The method can adjust the pre-ionization injection time, the pre-ionization current amplitude and the pre-ionization current duration by adjusting the parameters of the device, so as to study the influence of the parameters on the discharge characteristics of the switch trigger gap and the overvoltage gap.

[0080] The pre-ionization injection time is adjusted specifically as follows:

[0081] The delay time difference of the first output end and the second output end of the double-output square wave source 6 is adjusted, so that the time difference between the first output square wave pulse applied to the middle electrode 84 and the second output square wave pulse applied to the first pre-ionization electrode 86 is changed. In the embodiment, the double-output square wave source 6 can output square wave pulses with a delay of 0-100 ns, so the pre-ionization injection time of the trigger gap within 0-100 ns can be adjusted.

[0082] The pre-ionization current amplitude is adjusted specifically as follows:

[0083] The amplitude of the second output square wave pulse of the double-output square wave source 6 is adjusted; in other embodiments, the resistance value of the pre-ionization resistor 7 can also be adjusted; when the resistance value of the pre-ionization resistor 7 is 10Ω and the amplitude of the second output square wave pulse of the double-output square wave source 6 ranges from 0 to 10kV, the pre-ionization current amplitude can be adjusted from 0 to 1000 amperes.

[0084] The pre-ionization current duration is adjusted specifically as follows:

[0085] The pulse width of the second output square wave pulse of the double-output square wave source 6 is adjusted, so that the pre-ionization current duration in the pre-ionization gap is adjusted. In the embodiment, the double-output square wave source 6 can output square wave pulses with a pulse width of 0-100 ns, so the pre-ionization current duration within 0-100 ns can be adjusted.

[0086] The method can also measure the voltage waveform on the middle electrode 84 and the current waveform flowing through the load resistor 5 to study the discharge characteristics (including the average delay time and the jitter) of the trigger gap and the overvoltage gap, specifically as follows:

[0087] The starting time and the first peak time of the voltage waveform on the middle electrode 84 are measured, and the difference between the two is taken as the trigger gap delay time. The average value of at least 30 discharge delay times is taken as the trigger gap average delay time, and the standard deviation of at least 30 discharge delay times is taken as the trigger gap jitter.

[0088] The first peak time of the voltage waveform on the intermediate electrode 84 and the start time of the current waveform in the load resistor 5 are measured, and the difference between the two is taken as the overvoltage gap delay time. The average of at least 30 discharge delay times is taken as the average overvoltage gap delay time, and the standard deviation of at least 30 discharge delay times is taken as the overvoltage gap jitter.

[0089] In addition, the method for studying the influence of the pre-ionization parameters on the discharge characteristics of the switch gap can be used to study the influence of the pre-ionization injection time, the pre-ionization current amplitude, the pre-ionization current duration, the switch electrode structure, the electrode material, the gas type, the working coefficient, and the working voltage on the discharge characteristics (including the average delay time and the jitter) of the switch trigger gap and the overvoltage gap, and on the number and position of the discharge channels.

[0090] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any change or replacement within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An experimental device for studying the influence of preionization parameters on the discharge characteristics of a switch gap, characterized by: It includes a first charging capacitor (41), a second charging capacitor (42), a load resistor (5), a dual-output square wave source (6), a pre-ionization resistor (7), and an experimental switch (8); The experimental switch (8) comprises an insulating shell (85), a positive electrode (81) coaxially arranged at the upper end of the insulating shell (85), a negative electrode (82) coaxially arranged at the lower end of the insulating shell (85), an intermediate electrode (84), a first pre-ionization electrode (86), and a second pre-ionization electrode (87); four through holes are arranged on the side wall of the insulating shell (85), namely a third through hole (853), a fourth through hole (854), and a first through hole (851) and a second through hole (852) arranged oppositely; the intermediate electrode (84) is coaxially arranged in the insulating shell (85), and two electrode through holes corresponding to the first through hole (851) and the second through hole (852) are arranged oppositely on the side wall of the intermediate electrode (84); the first through hole (853) and the second through hole (854) are arranged oppositely. One end of a pre-ionization electrode (86) and one end of a second pre-ionization electrode (87) pass through a first through hole (851) and a second through hole (852) on an insulating shell (85), respectively, and the other ends pass through two electrode through holes of an intermediate electrode (84) and are coaxially arranged in the intermediate electrode (84). A pre-ionization gap is formed between the other end of the first pre-ionization electrode (86) and the other end of the second pre-ionization electrode (87), a trigger gap is formed between the positive electrode (81) and the intermediate electrode (84), and an overvoltage gap is formed between the negative electrode (82) and the intermediate electrode (84); and the central axis of the first pre-ionization electrode (86) and the second pre-ionization electrode (87) is perpendicular to the central axis of the positive electrode (81) and the negative electrode (82). The positive electrode (81), the first charging capacitor (41), the load resistor (5), the second charging capacitor (42), and the negative electrode (82) are sequentially connected to form a discharge circuit, and the connection end between the load resistor (5) and the second charging capacitor (42) is grounded; the connection end between the first charging capacitor (41) and the positive electrode (81) is used to connect to a positive polarity DC charging power supply (1); and the connection end between the second charging capacitor (42) and the negative electrode (82) is used to connect to a negative polarity DC charging power supply (2); The dual-output square wave source (6) is used to output negative polarity square wave pulses, one output end of which passes through the third through hole (853) and is connected to the middle electrode (84), and the other output end is connected to one end of the first pre-ionization electrode (86); one end of the second pre-ionization electrode (87) is grounded through the pre-ionization resistor (7); and the fourth through hole (854) is used to connect to an external air pipe and inflate the insulating shell (85).

2. The experimental device for measuring the influence of preionization parameters on switch gap discharge characteristics according to claim 1, characterized in that: The insulating shell (85) is a cylindrical structure, and two electrode covers (83) are respectively provided at the upper and lower ends thereof; the positive electrode (81) is provided on the electrode cover (83) at the upper end of the insulating shell (85); the negative electrode (82) is provided on the electrode cover (83) at the lower end of the insulating shell (85); The four through holes are arranged on the side wall of the insulating shell (85) along the circumferential direction, and the axis angle between adjacent through holes is 90°; A first circular ring (855) is provided on the inner wall of the insulating shell (85); a first notch is formed on the upper surface of the first circular ring (855) corresponding to the positions of the four through holes; the first notches corresponding to the first through hole (851) and the second through hole (852) are used to position the first pre-ionization electrode (86) and the second pre-ionization electrode (87); and the intermediate electrode (84) is connected to the first circular ring (855).

3. The experimental device for the influence of preionization parameters on switch gap discharge characteristics according to claim 2, characterized in that: The first pre-ionization electrode (86) comprises a first cylinder (861) and a second cylinder (862) coaxially connected to one end of the first cylinder (861); The other end of the first cylinder (861) is tapered; The second cylinder (862) is connected to the other output end of the dual-output square wave source (6); The second pre-ionization electrode (87) has the same structure as the first pre-ionization electrode (86); A pre-ionization gap is formed between the other end of the first cylinder (861) of the first pre-ionization electrode (86) and the other end of the first cylinder of the second pre-ionization electrode (87); The second cylinder of the second pre-ionization electrode (87) is grounded via the pre-ionization resistor (7).

4. The experimental device for measuring the influence of preionization parameters on switch gap discharge characteristics according to claim 3, characterized in that: It also includes a first pre-ionization sleeve (88) coaxially sleeved on the first pre-ionization electrode (86) and a second pre-ionization sleeve (89) coaxially sleeved on the second pre-ionization electrode (87); The first pre-ionization sleeve (88) comprises a first cylinder (881) and a second cylinder (882) coaxially connected to one end of the first cylinder (881); the inner diameter of the first cylinder (881) matches the outer diameter of the first cylindrical body (861); the inner diameter of the second cylinder (882) matches the outer diameter of the second cylindrical body (862), and the second cylinder (882) is arranged in a first gap between the first through hole (851) and the first ring (855); The second pre-ionization sleeve (89) has the same structure as the first pre-ionization sleeve (88), and the second cylinder of the second pre-ionization sleeve (89) is arranged in the first gap between the second through hole (852) and the first ring (855).

5. The experimental device for the influence of preionization parameters on switch gap discharge characteristics according to claim 4, characterized in that: The positive electrode (81) includes a third cylinder (811), a second ring (812) coaxially connected to the lower end of the third cylinder (811), and a trigger gap is formed between the second ring (812) and the middle electrode (84); The negative electrode (82) has the same structure as the positive electrode (81), and an overvoltage gap is formed between the second ring of the negative electrode (82) and the middle electrode (84); The first charging capacitor (41) is connected to the third cylinder (811) of the positive electrode (81); and the second charging capacitor (42) is connected to the third cylinder of the negative electrode (82).

6. The experimental device for measuring the effect of preionization parameters on switch gap discharge characteristics according to claim 5, characterized in that: The intermediate electrode (84) includes a third cylinder (841) and a third ring (842) coaxially sleeved outside the third cylinder (841); Two electrode through holes are arranged oppositely on the side wall of the third cylinder (841) and are perpendicular to the axis of the third cylinder (841), and are respectively a fifth through hole (843) and a sixth through hole (844); The third circular ring (842) is connected to the first circular ring (855), and a second notch is provided on the third circular ring (842) that matches the outer diameter of the first cylinder (881); the positions of the second notch correspond to the fifth through hole (843) and the sixth through hole (844) respectively; The inner diameters of the fifth through hole (843) and the sixth through hole (844) are respectively adapted to the outer diameter of the first cylinder (881); The other end of the first cylinder (861) of the first pre-ionization electrode (86) extending into the third cylinder (841) and the other end of the first cylinder of the second pre-ionization electrode (87) extending into the third cylinder (841) form a pre-ionization gap in the third cylinder (841); a trigger gap is formed between the second ring (812) of the positive electrode (81) and the upper end of the third cylinder (841); and an overvoltage gap is formed between the second ring (812) of the negative electrode (82) and the lower end of the third cylinder (841); One output end of the dual-output square wave source (6) is connected to the third circular ring (842).

7. The experimental device for measuring the influence of preionization parameters on switch gap discharge characteristics according to claim 6, characterized in that: A sealing ring is provided between the upper end of the insulating shell (85) and the electrode cover (83), and between the lower end of the insulating shell (85) and the electrode cover (83). A sealing ring is provided between the second cylinder (862) and the second cylinder (882) of the first pre-ionization electrode (86), and between the second cylinder and the second cylinder of the second pre-ionization electrode (87); The first charging capacitor (41) and the second charging capacitor (42) are both plastic-shell capacitors; The load resistor (5) is a liquid resistor; The pre-ionization resistor (7) is a solid resistor; The insulating shell (85) is made of a transparent insulating material; The first pre-ionization sleeve (88) and the second pre-ionization sleeve (89) are both made of PEEK or polyethylene.

8. The experimental device for the influence of preionization parameters on switch gap discharge characteristics according to any one of claims 1 to 7, characterized in that: It also includes a first charging resistor (31) and a second charging resistor (32); One end of the first charging resistor (31) is connected to the connection end of the first charging capacitor (41) and the positive electrode (81), and the other end of the first charging resistor (31) is connected to the positive polarity DC charging power supply (1); One end of the second charging resistor (32) is connected to the connection end of the second charging capacitor (42) and the negative electrode (82), and the other end of the second charging resistor (32) is connected to a negative polarity DC charging power supply (2); The first charging resistor (31) and the second charging resistor (32) are both ceramic resistors.

9. The experimental device for measuring the influence of preionization parameters on switch gap discharge characteristics according to claim 8, characterized in that: It also includes at least three cameras arranged outside the experimental switch (8) for taking pictures of the discharge channels of the experimental switch (8) to obtain the number of discharge channels in the trigger gap and the overvoltage gap.

10. An experimental method for the influence of preionization parameters on the discharge characteristics of a switch gap, based on the experimental device for the influence of preionization parameters on the discharge characteristics of a switch gap as claimed in any one of claims 1 to 8, characterized in that: By adjusting the pre-ionization parameters, the discharge characteristics of the trigger gap and the overvoltage gap of the experimental switch (8) as well as the number and position of the discharge channels are tested, thereby obtaining the influence of the pre-ionization parameters on the discharge characteristics of the switch gap; The adjusting of the preionization parameters includes adjusting the preionization injection time, adjusting the preionization current amplitude, and adjusting the preionization current duration; The adjustment of the pre-ionization injection time is specifically as follows: Adjusting the time difference between the delay of the first output square wave pulse and the delay of the second output square wave pulse of the dual output square wave source (6), and changing the time difference between the first output square wave pulse being applied to the middle electrode (84) and the second output square wave pulse being applied to the first pre-ionization electrode (86); The adjustment of the pre-ionization current amplitude is specifically as follows: Adjusting the amplitude of the second square wave pulse output of the dual-output square wave source (6), or by adjusting the resistance of the pre-ionization resistor (7); The specific method for adjusting the pre-ionization current duration is as follows: The pulse width of the second output square wave pulse of the dual-output square wave source (6) is adjusted.

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