Method and system for slowing plasma sheath

Abstract

The invention discloses a method and system for slowing down a plasma sheath. The method comprises the steps that firstly, a pressure sensor transmits a pressure signal generated when shock waves pass through to a delay synchronous machine; step 2, the delay synchronous machine takes the received pressure signal as a time reference, and outputs a corresponding pulse signal to a ventilation electromagnetic valve in the gas injection device, so that a gas storage tank in the gas injection device and each reserved small hole of the aircraft model are in a conducting state; and thirdly, the medium in the gas storage tank is sprayed out from the reserved small holes under the action of pressure, and a plasma sheath on the surface of the aircraft is used for slowing down or eliminating the medium. According to the method and the system for slowing down the plasma sheath, tests show that when the pressure intensity of a gas storage tank is 0.5 MPa, the valve opening time of a ventilation electromagnetic valve is directly controlled by a pulse signal to be about 3ms; and after the time delay of the time delay synchronous machine, the control requirement can be met.

Description

Technical Field

[0001] The present invention relates to the field of plasma shock tunnel testing, and more particularly to a method and system for mitigating a plasma sheath. Background Art

[0002] In aerospace, when a spacecraft travels at hypersonic speeds, the surrounding atmospheric density changes dramatically, creating a powerful shock wave at the front, which rapidly heats the surrounding air. This ionizes the surrounding atmosphere and the spacecraft surface, creating a layer of high-temperature plasma known as a plasma sheath. Currently, this plasma sheath is unavoidable; any spacecraft entering any planet's atmosphere will experience a plasma sheath, and the plasma sheath formed by a spacecraft's passage through the atmosphere can also disrupt radio signals.

[0003] To address the issue of radio signal interruption, ground-based plasma shock tunnel experiments attempt to mitigate the plasma sheath by spraying SF6 gas near the plasma sheath. However, in ground-based plasma shock tunnel experiments, methods for mitigating the plasma sheath and precise gas spraying and flow control are crucial. First, due to the high velocity of the shock wave generated in shock tunnel experiments, the time required to control the trigger signal and the opening of the vent solenoid valve is extremely critical, making circuit design and product selection particularly important. Second, plasma shock tunnel experiments are repeated, so the stability of the device is crucial. However, the prior art does not disclose a system specifically designed for mitigating the plasma sheath that can be directly adapted to ground-based plasma shock tunnel experiments, ensuring rapid opening of the vent solenoid valve and completing the gas injection operation while maintaining stability. This is primarily due to the slow response of commercially available solenoid valves. At a pressure differential of 0.5 MPa, the valve opening time of existing solenoid valves is approximately 3 seconds, falling short of the 1-second threshold required for wind tunnel experiments. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] To achieve these objects and other advantages of the present invention, there is provided a method of mitigating a plasma sheath, comprising:

[0006] Step 1: The pressure sensor transmits the pressure signal generated by the shock wave to the time-delay synchronization machine;

[0007] Step 2: The time delay synchronizer uses the received pressure signal as a time reference and outputs a corresponding pulse signal to the ventilation solenoid valve in the gas injection device, so that the gas tank in the injection device and the reserved small holes of the aircraft model are in a conductive state;

[0008] Step three: the medium in the gas tank is ejected from the reserved small holes under the action of pressure, and is slowed down or eliminated by the plasma sheath on the surface of the aircraft.

[0009] Preferably, in step three, the medium is SF6 gas.

[0010] A system for use in a method of mitigating a plasma sheath, comprising:

[0011] A time-delay synchronizer connected to the pressure sensor via optical fiber I;

[0012] A gas injection device connected to the time-delay synchronous machine through optical fiber II;

[0013] The gas injection device includes: a circuit module connected to the time-delay synchronous machine;

[0014] The ventilation solenoid valve module is electrically connected to the circuit module to switch the on / off state between the medium in the gas storage tank and the reserved small hole.

[0015] Preferably, the circuit module includes:

[0016] Thyristor;

[0017] A switch provided between the thyristor and the water solenoid valve module;

[0018] A DC power supply to power the thyristors;

[0019] A resistor arranged in parallel with the ventilation solenoid valve;

[0020] The DC power supply, switch, thyristor and resistor are all integrated on the PVC board;

[0021] The thyristor is connected to the time-delay synchronous machine via an optical fiber to BNC cable, the positive electrode of the DC power supply is connected to the positive electrode of the ventilation solenoid valve, and the negative electrode of the DC power supply is connected to the outer conductor of the BNC cable;

[0022] The anode of the thyristor is connected to the negative electrode of the ventilation electromagnetic valve, the cathode of the thyristor is connected to the negative electrode of the DC power supply, and the gate of the thyristor is connected to the inner core of the BNC line.

[0023] Preferably, the ventilation solenoid valve module includes:

[0024] An air supply pipeline connecting the air storage tank with an external driving air source, and a ball valve provided on the air supply pipeline I;

[0025] An air supply line II is connected between the air storage tank and the reserved small hole, and the ventilation solenoid valve is arranged on the air supply line II;

[0026] Wherein, a needle valve is further provided between the ball valve and the gas storage tank, and a pressure reducing valve is provided between the ball valve and the external driving gas source;

[0027] A pressure gauge is also provided on the connecting branch between the ventilation solenoid valve and the gas storage tank.

[0028] The present invention has at least the following beneficial effects:

[0029] The method of the present invention shortens the valve opening time and can ensure synchronous valve opening when the shock wave reaches the aircraft model. It is suitable for studying plasma shock waves and other related fields. According to tests, when the gas tank pressure is 0.5MPa, the pulse signal directly controls the valve opening time of the ventilation solenoid valve in about 3ms; after the delay of the delay synchronizer, the control requirements can be met.

[0030] The system of the present invention can realize precise control of SF6 gas spraying and flow control in plasma shock tunnel experiments, which is of great significance for studying the mitigation or elimination of plasma sheath.

[0031] The system of the present invention divides the spraying device into two modules: a circuit module and a water solenoid valve module. Through the modular design, the interference of external equipment is reduced and the stability of control is guaranteed.

[0032] Compared with the prior art, the system of the present invention is limited to connecting the time delay synchronizer and the spraying device by using optical fiber, which has the characteristics of fast transmission speed and strong anti-interference ability.

[0033] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the connection between the circuit module of the present invention and the time-delay synchronizer;

[0035] Figure 2 Schematic diagram of the connection of the gas injection device of the present invention;

[0036] Figure 3 This is a system block diagram of the present invention.

[0037] Figure 4 This is a principle block diagram of the time-delay synchronous machine of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0039] A method for slowing down a plasma sheath comprises installing a pressure sensor 12 at the front end of a shock tube. When a shock wave passes through the pressure sensor 12, a pressure signal generated by the pressure sensor 12 is used as a time reference. After passing through a time-delay synchronizer 13, a ventilation solenoid valve 7 is controlled to open and be in a normally open state, so that SF6 gas at a certain pressure reserved in a gas storage tank 5 is injected into an aircraft model 8. A small hole is reserved in the aircraft model 8, and the SF6 gas is ejected from the small hole, thereby slowing down or eliminating the plasma sheath. When a switch is disconnected, the ventilation solenoid valve 7 is closed, and the spraying of SF6 gas is interrupted.

[0040] A system is used in a method for mitigating a plasma sheath, such as Figure 1-Figure 3 As shown, including:

[0041] The delay synchronizer 13 is connected to the pressure sensor 12 via an optical fiber I 17. The delay synchronizer 13 is used to ensure that multiple signals are accurately synchronized in time and to perform adjustable delay processing on the input signal.

[0042] A gas injection device 16 connected to the time delay synchronization machine 13 via an optical fiber II 18;

[0043] The gas injection device 16 primarily comprises a ventilation solenoid valve module 14 and a circuit module 15. The circuit module 15 primarily comprises a DC power supply 11, a thyristor 10, a switch 9, and a high-power resistor 19. The thyristor 10 is designed to quickly conduct when a given pulse signal is applied, thereby controlling the opening of the ventilation solenoid valve 7. In this embodiment, the DC power supply 11 supplies power to the ventilation solenoid valve 7 via the switch 9. Using the signal from the pressure sensor 12 as a time reference, the pulse signal generated by the time-delay synchronizer 13 drives the ventilation solenoid valve 7 to open. Testing has shown that when the pressure in the gas tank 5 is 0.5 MPa, the pulse signal directly controls the opening time of the ventilation solenoid valve 7 within approximately 3 ms. After a delay from the time-delay synchronizer 13, the control requirement is met. This configuration offers the advantage of eliminating the need for manual triggering. Instead, the DC power supply 11 supplies DC power, and the signal generated by the pressure sensor 12 at the front end of the shock tube immediately triggers the ventilation solenoid valve 7.

[0044] Furthermore, in practical applications, Figure 3 As shown, the time delay synchronous machine 13 and the thyristor 10 are connected by optical fiber II 18 to BNC. The advantage of this arrangement is that it prevents electromagnetic interference and ensures transmission speed.

[0045] Furthermore, in practical applications, Figure 2 As shown, the thyristor 10 is a fast thyristor. The advantage of this arrangement is that the thyristor 10 can be turned on quickly, thereby opening the ventilation solenoid valve 7.

[0046] Furthermore, if Figure 1 、 Figure 3 As shown, in actual application, the positive electrode of the DC power supply 11 is connected to the positive electrode of the ventilation solenoid valve 7, the negative electrode of the ventilation solenoid valve 7 is connected to the anode of the thyristor 10, and the cathode of the thyristor 10 is connected to the negative electrode of the DC power supply 11. At the same time, a high-power resistor is connected in parallel at both ends of the ventilation solenoid valve 7; the delay synchronous machine 13 and the thyristor 10 are connected by an optical fiber II 18 to BNC cable, the optical fiber II 18 is connected to the delay synchronous machine 13, the inner core of the BNC cable is connected to the gate of the thyristor 10, and the outer conductor of the BNC cable is connected to the negative electrode of the DC power supply 11.

[0047] Furthermore, in practical applications, Figure 1 As shown, a 30Ω high-power resistor 19 is connected in parallel at both ends of the ventilation solenoid valve 7. The required resistance of the high-power resistor 19 can be determined according to the holding current of the thyristor 10.

[0048] Specifically, by R0 can be obtained, and a threshold is left, taking R 总 Where U represents the DC power supply voltage, and is generally taken as U=24V; I H represents the thyristor holding current, and I H The value can be obtained according to the nameplate; R0 represents the minimum on-state resistance of the thyristor; R 总 Represents the resistance after taking the threshold.

[0049] Use a multimeter to measure the resistance R of the ventilation solenoid valve 7 when it is not conducting. 阀 , use the following parallel formula to get the resistance value R of the parallel resistor:

[0050]

[0051] The calculation shows that the 30Ω high-power resistor connected in parallel at both ends of the ventilation solenoid valve 7 can meet the circuit requirements. The advantage of this setting is that in order to avoid the thyristor 10 from failing to conduct, the overall resistance of the circuit is reduced by connecting a parallel resistor, so that the current flowing through the thyristor 10 is higher than the holding current I H , the thyristor 10 is smoothly turned on to ensure that the ventilation solenoid valve 7 is smoothly opened.

[0052] Furthermore, in practical applications, Figure 1-Figure 2 As shown, the present invention fixes the DC power supply 11, thyristor 10, switch 9, and high-power resistor 19 separately on the PVC board to form a circuit module. The circuits are arranged in an orderly manner, which can avoid current interference between different circuits, effectively isolate the entire circuit from metal objects, play an insulating role, and ensure stable operation of the equipment.

[0053] like Figure 2As shown, the ventilation solenoid valve module 14 generally includes: a ball valve 3, a needle valve 4, an air storage tank 5, a pressure gauge 6 and a ventilation solenoid valve 7, and the gas source 1, the pressure reducing valve 2, the ventilation solenoid valve module 14 and the aircraft model 8 are connected to form an integrated structure through corresponding air pipes, which is convenient for flow control and test operations. In this solution, a gas cylinder is used as the gas source 1 to inject gas into the gas storage tank 5 through the pressure reducing valve 2. During the injection process, the pressure can be adjusted by various valves such as the pressure reducing valve 2, the ball valve 3, and the needle valve 4, and the pressure gauge 6 displays the pressure value in real time. The advantage of this arrangement is that during the injection process, the air pressure can be accurately adjusted through various valves.

[0054] Furthermore, in practical applications, Figure 2 As shown, the ventilation solenoid valve 7 is directly connected to the aircraft model 8, minimizing the distance. Furthermore, the ventilation solenoid valve 7 is a high-speed electromagnetic valve. This configuration minimizes the time it takes for airflow to travel from the outlet of the solenoid valve 7 to the outlet of the aircraft model 8 and allows the valve 7 to open as quickly as possible, thus meeting test requirements. The data from the 20 system tests shown in Table 1 show that when the inflation pressure is approximately 0.5 MPa, the opening delay of the ventilation solenoid valve 7 is approximately 3 ms. Only after the delay by the time-delay synchronizer 13 does the test requirements meet.

[0055] Table 1

[0056] frequency Inflating pressure (MPa) Valve opening delay (ms) 1 0.509 2.93 2 0.506 3.00 3 0.509 3.02 4 0.505 2.92 5 0.509 2.99 6 0.506 2.89 7 0.508 2.88 8 0.505 2.95 9 0.509 3.05 10 0.504 2.90 11 0.507 2.93 12 0.509 2.91 13 0.506 2.99 14 0.508 2.94 15 0.506 3.03 16 0.505 2.91 17 0.505 2.92 18 0.507 2.90 19 0.506 2.99 20 0.508 3.03

[0057] Furthermore, in practical applications, Figure 4 As shown, the delay synchronizer 13 includes a time reference module 20, a delay generation module 21, a synchronization control module 22, a feedback adjustment module 23, and an input / output interface 24. The time reference module provides a high-precision, high-stability time reference, serving as a scale for delay and synchronization and establishing a global time reference. The delay generation module delays the input signal according to a set delay parameter τ, achieving signal time offset. The synchronization control module monitors the phase / timing deviation between the delayed signal and the reference signal and generates adjustment instructions to ensure synchronization of the delayed signal with the reference. The feedback adjustment module periodically sends calibration signals, measures the actual delay, and corrects the parameters, dynamically compensating for errors and ensuring long-term stability. The input / output interface supports a variety of input signal formats, including analog, digital, single-ended, and differential. The output signal's amplitude, edge characteristics, and other characteristics can also be configured to ensure compatibility with the target system.

[0058] Working Principle: The time base module locks onto an external reference source or activates the internal crystal oscillator to generate a stable system clock. The user sets the target delay τ and synchronization mode through the human-machine interface. After passing through the conditioning circuit, the input signal enters the delay generation module. The delayed signal and the reference signal (such as the system master clock) enter the synchronization control module, where the phase detector calculates the phase difference Δθ. If Δθ exceeds the threshold, the feedback module adjusts the parameters of the delay generation module until Δθ is less than the set accuracy. For dynamically changing input signals (such as variable-frequency radar signals), the synchronization control module tracks frequency changes in real time and maintains the delay ratio unchanged through a phase-locked loop. The delayed, synchronized signal is output to the target system through the drive circuit, while also recording the current delay value, synchronization error, and device status. In specific implementation, the time base module locks the external reference source or enables the internal crystal oscillator to generate a stable system clock; the user sets the target delay τ and synchronization mode through the human-machine interface; when the pressure sensor receives the signal, it is amplified and filtered by the conditioning circuit and then transmitted to the delay generation module; the delay generation module delays the input signal according to the set delay parameter τ to obtain the delay signal I; the delayed signal and the reference signal enter the synchronization control module, the phase detector calculates the phase difference Δθ, and the synchronization control module compares the phase Δθ of the delay signal I with the reference signal. If Δθ exceeds the predetermined range, the corresponding adjustment instruction I is generated; feedback regulation The module generates a corresponding delay deviation compensation signal based on the adjustment instruction I, which serves as the secondary input signal of the delay generation module; the delay generation module further delays the secondary input signal based on the delay parameter τ to obtain the delay signal II, and the synchronization control module compares the phase / timing deviation of the delay signal II with the reference signal. If the deviation does not exceed the predetermined range, the delay signal II is used as the driving signal of the driving circuit and several data are output to facilitate the observation and study of the test results. Otherwise, the adjustment instruction II is generated again to perform delay adjustment; and the delayed signal of the delay generation module is directly output to the thyristor through the driving circuit as the trigger signal of the thyristor.

[0059] It should be noted that when the present invention is applied in a wind tunnel test, it is usually combined with other test systems. Therefore, multiple sensors are usually designed at the front end of the shock tube for testing in other links. The present invention uses the first pressure sensor at the front end as the time reference for triggering the thyristor. However, in fact, the time delay synchronizer has two functions: delay and synchronization. The delay function is mainly used to drive the thyristor. The detection data of other links in the wind tunnel test are synchronized. The feedback adjustment module is mainly used to synchronize the time of multiple sensors. The feedback adjustment module mainly includes two parts: frequency domain modeling of the core link of the system and derivation of the closed-loop system transfer function. The derivation of the formulas required for the actual application of these two parts is now described as follows:

[0060] 1. Frequency Domain Modeling of the Core Links of the System

[0061] 1. Phase detector

[0062] The phase detector in the synchronous control module mainly detects the phase difference between the reference signal and the delayed signal, and outputs the error voltage u d (t).

[0063] Input reference signal phase and delayed signal phase. The reference signal phase in time domain is: θ ref (t), the reference signal phase frequency domain is: Θ ref (s); the delayed signal phase time domain is: θ out (t-τ), the delayed signal phase frequency domain is: Θ out (s)e -sτ , where t is the time variable, τ is the delay time, s is the complex frequency variable, e -sτ is the transfer function of the delay link.

[0064] The transfer function is: Θ ref (s)-Θ out (s)e -sτ .

[0065] The ideal phase detector output is proportional to the phase difference, so the phase detector time domain u d (t) is expressed as:

[0066] u d (t) = K p (θ ref (t)-θ out (t-τ))

[0067] Phase detector frequency domain U d (s) is expressed as:

[0068] U d (s) = K p (Θ ref (s)-Θ out (s)e -sτ )

[0069] Among them, K p is the phase-locked gain.

[0070] 2. Loop filter

[0071] There is a loop filter in the feedback regulation module, which mainly filters out the high-frequency noise output by the phase detector. The smooth control voltage (i.e., the voltage frequency domain expression) U LF (s) is:

[0072] U LF (s)=F(s)U d (s)

[0073] Assume a linear time-invariant system with a frequency domain characteristic of F(s). The most commonly used is a first-order RC filter, whose transfer function is:

[0074]

[0075] Wherein, T=RC is the time constant of the filter.

[0076] Then the output voltage frequency domain U LF (s) is expressed as:

[0077]

[0078] 3. Voltage-controlled oscillator

[0079] There is also a voltage-controlled oscillator in the feedback regulation module, whose function is to change the frequency of the output signal with the input voltage, and the phase is the integral of the frequency.

[0080] The instantaneous frequency of the voltage controlled oscillator is ω(t):

[0081] ω(t)=ω0+K v u LF (t)

[0082] Among them, ω0 is the center frequency, K v is the voltage controlled oscillator gain, u LF (t) is the voltage after filtering.

[0083] The phase output time domain of the voltage controlled oscillator θ out (t) is:

[0084]

[0085] Among them, K v is the voltage controlled oscillator gain;

[0086] The phase output frequency domain of the voltage controlled oscillator Θ out (s) is:

[0087]

[0088] Here, we use the small signal approximation to ignore the DC bias ω0 / s 2 ,but

[0089]

[0090] 2. Derivation of Closed-Loop System Transfer Function

[0091] 1. Combine the equations of each link

[0092] From the above we can get:

[0093] Phase detector:

[0094] U d (s) = K p (Θ ref (s)-Θ out (s)e -sτ )

[0095] Loop filter:

[0096] U LF (s)=F(s)U d (s)

[0097] Voltage Controlled Oscillator:

[0098]

[0099] The frequency domain relationship between the phase detector, filter, and voltage-controlled oscillator is combined to obtain:

[0100]

[0101] 2. Arrange the closed-loop transfer function

[0102] will contain Θ out The term (s) is moved to the left:

[0103]

[0104] Extract common factor Θ out (s):

[0105]

[0106] The solution is:

[0107]

[0108] Where H(s) is the closed-loop transfer function;

[0109] If we take a first-order RC filter, we have:

[0110]

[0111] 3. Error transfer function

[0112] Phase error Θ in the frequency domain e (s) is defined as:

[0113] Θ e (s) = Θ ref (s)-Θ out (s)e -sτ

[0114] Substitute Θ out (s)=H(s)Θref (s) shall:

[0115] Θ e (s) = Θ ref (s)-H(s)Θ ref (s)e -sτ =Θ ref (s)(1-H(s)e -sτ )

[0116] Therefore:

[0117]

[0118] If a first-order RC filter is used, the error transfer function H e (s) can be characterized by the following formula:

[0119]

[0120] In this section, the frequency domain U of the phase detector in the synchronous control module is obtained through frequency domain modeling. d (s), the frequency domain U of the loop filter in the feedback regulation module LF (s), the frequency domain Θ of the voltage-controlled oscillator in the feedback regulation module out (s); then by combining and sorting the above three steps, we can get the closed-loop transfer function H(s) and the error transfer function H e (s), completing the synchronous processing and output of multiple sensor signals from the time domain to the frequency domain. In specific implementation, the system clock is used as the reference signal phase. The user sets the target delay τ and synchronization mode through the human-machine interface. Multiple pressure sensors are used as input signals. After amplification and filtering by the conditioning circuit and delay τ by the delay generation module, the delayed signal and the reference signal enter the synchronization control module. The phase detector calculates the phase difference Δθ. After passing through the loop filter and voltage-controlled oscillator, the phase difference is filtered and the output signal phase is synchronized with the reference signal. Finally, each sensor is synchronized through the feedback adjustment module. Compared with the existing technology, the synchronization function of the delay synchronizer in the present invention has more precise synchronization control, ensuring that the synchronization error is controlled within the range of nanoseconds to meet the synchronization accuracy requirements of the experiment.

[0121] The above solution is only an illustration of a preferred embodiment, but is not limited thereto. When implementing the present invention, appropriate replacements and / or modifications can be made according to user needs.

[0122] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A method for mitigating a plasma sheath, characterized in that: include: Step 1: The pressure sensor transmits the pressure signal generated by the shock wave to the time-delay synchronization machine; Step 2: The time delay synchronizer uses the received pressure signal as a time reference and outputs a corresponding pulse signal to the ventilation solenoid valve in the gas injection device, so that the gas tank in the injection device and the reserved small holes of the aircraft model are in a conductive state; Step three: the medium in the gas tank is ejected from the reserved small holes under the action of pressure, and is slowed down or eliminated by the plasma sheath on the surface of the aircraft.

2. The method for moderating a plasma sheath according to claim 1, wherein: In step three, the medium is SF6 gas.

3. A system, applied to the method for mitigating a plasma sheath according to any one of claims 1 to 2, characterized in that: include: A time-delay synchronizer connected to the pressure sensor via optical fiber I; A gas injection device connected to the time-delay synchronous machine through optical fiber II; The gas injection device includes: a circuit module connected to the time-delay synchronous machine; The ventilation solenoid valve module is electrically connected to the circuit module to switch the on / off state between the medium in the gas storage tank and the reserved small hole.

4. The system according to claim 3, wherein: The circuit module includes: Thyristor; A switch provided between the thyristor and the water solenoid valve module; A DC power supply to power the thyristors; A resistor arranged in parallel with the ventilation solenoid valve; The DC power supply, switch, thyristor and resistor are all integrated on the PVC board; The thyristor is connected to the time-delay synchronous machine via an optical fiber to BNC cable, the positive electrode of the DC power supply is connected to the positive electrode of the ventilation solenoid valve, and the negative electrode of the DC power supply is connected to the outer conductor of the BNC cable; The anode of the thyristor is connected to the negative electrode of the ventilation electromagnetic valve, the cathode of the thyristor is connected to the negative electrode of the DC power supply, and the gate of the thyristor is connected to the inner core of the BNC line.

5. The system according to claim 3, wherein: The ventilation solenoid valve module includes: An air supply pipeline connecting the air storage tank with an external driving air source, and a ball valve provided on the air supply pipeline I; An air supply line II is connected between the air storage tank and the reserved small hole, and the ventilation solenoid valve is arranged on the air supply line II; Wherein, a needle valve is further provided between the ball valve and the gas storage tank, and a pressure reducing valve is provided between the ball valve and the external driving gas source; A pressure gauge is also provided on the connecting branch between the ventilation solenoid valve and the gas storage tank.

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