Electric propulsion high-pressure fluid micro-flow control system

Abstract

The invention discloses an electric propulsion high-pressure fluid micro-flow control system and belongs to the technical field of electric propulsion flow control. The problems that an existing pressure reduction system is poor in control precision and low in reliability when working frequently are solved. An outlet of a gas cylinder is connected with a gas inlet of a proportional valve through a gas transmission channel, and a self-locking valve and a pressure adjusting system are sequentially arranged on the gas transmission channel; the proportional valve is connected with three third electromagnetic valves at the same time and is respectively used for controlling the on-off of the anode branch, the cathode branch A and the cathode branch B; the pressure sensor PIII is arranged at an air outlet of the proportional valve and used for collecting the pressure of the air outlet of the proportional valve; the pressure adjusting system collects the pressure of the gas transmission channel and sends the pressure to the controller, and the controller controls the pressure adjusting system, the proportional valve and the three third electromagnetic valves according to the pressure of the gas transmission channel, the pressure of the pressure sensor PIII and the working mode of the system. The method is suitable for electric propulsion system control.

Description

Technical Field

[0001] The invention belongs to the technical field of electric propulsion flow control. Background Art

[0002] In the propulsion system of a spacecraft, the electric propulsion flow control system is used to adjust the high-pressure stored propellant (usually gas, such as xenon or krypton) to a low pressure suitable for the electric propulsion system, and accurately control the flow of the propellant to ensure the accuracy and stability of the spacecraft's attitude control and orbit adjustment. Electric propulsion flow control is a key link in the aerospace propulsion system. Its flow control accuracy and response speed directly affect the performance, life and safety of the thruster. The flow control system is mainly composed of a gas cylinder, a pressure regulation system and a flow regulation module.

[0003] According to the different pressure reducing elements used, the pressure regulating system can be divided into three types: mechanical pressure reducing type using pressure reducing valve, switch control type using series solenoid valve and proportional control type using proportional valve. The mechanical pressure reducing type uses a mechanical pressure reducing valve with negative feedback of outlet pressure as the pressure reducing element. The outlet pressure of the mechanical pressure reducing valve can be set by adjusting the pre-compression of the spring. Its pressure reducing function can be automatically realized without electronic control components, so it has low requirements for the control system. However, the downstream pressure cannot be adjusted during its on-orbit operation and the response is slow, which makes the flow control system poorly adjustable. The switch control type uses a series solenoid valve and a downstream buffer chamber to jointly realize the pressure reducing function. A small amount of gas is released into the downstream buffer chamber through the switch timing control of the series solenoid valve, thereby realizing the pressure reducing and voltage stabilization functions. The switch control type is also called the "Bang-Bang control type". It has good robustness and high reliability, but the pressure control waveform is "sawtooth", and the solenoid valve needs to be opened and closed frequently, the pressure regulation accuracy is low, and the reliability of the solenoid valve is low. The proportional control type uses a proportional valve as a pressure reducing element. By controlling the valve opening of the proportional valve, precise and continuous control of the downstream pressure is achieved. The pressure regulation accuracy is high, but the nonlinear problems of the proportional valve, such as dead zone, creep and heat, bring difficulties to the control.

[0004] The flow regulating module can be divided into two types according to the throttling element: fixed throttling type and variable throttling type. The fixed throttling type uses a throttling device with a fixed throttling area as the throttling element. Under the condition of constant inlet pressure, the flow regulation is achieved by controlling the viscosity of the gas using a thermal control device. The fixed throttling type has high flow control accuracy, but its response is slow and the adjustment range is small. According to different structures, the fixed throttling element can be divided into fixed throttling hole type, capillary type, porous metal sintering type, series tangential hole type, metal etching type and labyrinth type. The variable throttling type uses a proportional valve as the throttling element. Under the condition of constant inlet pressure, the flow regulation is achieved by adjusting the opening of the proportional valve. The variable throttling type has a large flow regulation range and fast response, but it also has the disadvantages of low flow regulation accuracy and poor reliability due to the nonlinear problem of the proportional valve. Summary of the invention

[0005] The present invention aims to solve the problems of poor control accuracy and low reliability of the existing decompression system when the system works frequently, and provides an electric propulsion high-pressure fluid micro-flow control system.

[0006] The electric propulsion high-pressure fluid micro-flow control system of the present invention comprises a self-locking valve, a pressure regulating system, a controller, a flow regulating system and three third solenoid valves;

[0007] The flow regulation system includes a proportional valve, a pressure sensor PIII and three throttling orifice plates;

[0008] The outlet of the gas cylinder is connected to the gas inlet of the proportional valve through a gas transmission channel, and the gas transmission channel is sequentially provided with a self-locking valve and a pressure regulating system;

[0009] The proportional valve is connected to three throttling orifice plates at the same time, and the gas outlets of the three throttling orifice plates are respectively provided with a third solenoid valve, and the three third solenoid valves are respectively used to control the on-off of the anode branch, the cathode branch A and the cathode branch B;

[0010] The pressure sensor PIII is arranged at the air outlet of the proportional valve, and is used to collect the pressure at the air outlet of the proportional valve;

[0011] The pressure regulating system collects the pressure of the gas transmission channel and sends it to the controller. The controller controls the pressure regulating system, the proportional valve and the three third solenoid valves according to the pressure of the gas transmission channel, the pressure of the pressure sensor PIII and the working mode of the system.

[0012] Further, in the present invention, the pressure regulating system includes a first solenoid valve, a small air cavity, a second solenoid valve, a throttle hole, a buffer cavity and a pressure sensor PII;

[0013] The air inlet end of the first solenoid valve is connected to the air outlet port of the self-locking valve; the air outlet of the first solenoid valve is connected to the air inlet of the second solenoid valve through a small air cavity, and the air outlet of the second solenoid valve is connected to the air inlet of the buffer cavity through a throttle hole. A pressure sensor PII is provided in the buffer cavity, and the pressure sensor PII is used to collect the pressure signal in the buffer cavity. The signal output end of the pressure sensor PII is connected to the controller;

[0014] The controller also controls the switching of the second solenoid valve and the first solenoid valve according to the working mode of the system and the pressure collected by the pressure sensor PII;

[0015] The gas output port of the buffer chamber is connected to the gas input port of the proportional valve.

[0016] Furthermore, in the present invention, the working modes include: initialization mode, buffer chamber and pipeline exhaust mode, passage detection process mode, decompression working mode and shutdown mode.

[0017] Furthermore, in the present invention, the flow regulating system further comprises a summary throttling hole, and the summary throttling hole is arranged between the proportional valve and the three throttling orifice plates.

[0018] Furthermore, the present invention also includes a pressure sensor PI, which is arranged at the outlet of the gas cylinder to collect the pressure of the outlet of the gas cylinder and transmit the collected pressure signal to the controller; the controller 5 obtains the amount of gas in the gas cylinder according to the pressure signal collected by the pressure sensor PI.

[0019] Furthermore, the present invention also includes a filling and discharging valve, which is arranged at the mouth of the gas cylinder and is used to connect to the gas filling device to add gas into the gas cylinder.

[0020] In the present invention, the high-pressure gas in the air cavity enters the buffer cavity, and the gas in the buffer cavity is kept in a certain pressure range. Since the volume of the buffer cavity is large, the double solenoid valve does not need to be frequently opened and closed to maintain the gas pressure in the buffer cavity, which effectively reduces the service life requirement of the solenoid valve. Due to the use of the proportional valve, the slowly fluctuating gas in the buffer cavity can obtain a continuous and stable flow output after passing through the proportional valve, which effectively guarantees the control accuracy in the frequent control process, effectively improves the response speed of the frequent control, and effectively improves the reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the system of the present invention;

[0022] Figure 2 It is a stereogram of the system of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0024] Specific implementation method 1: refer to Figure 1 and Figure 2 Specifically describing this embodiment, this embodiment includes a self-locking valve 3, a pressure regulating system 4, a controller 5, a flow regulating system 6 and three third solenoid valves 7;

[0025] The flow regulating system 6 includes a proportional valve 601, a pressure sensor PIII602 and three throttling orifice plates 604;

[0026] The outlet of the gas cylinder is connected to the gas inlet of the proportional valve 601 through a gas transmission channel, and the gas transmission channel is sequentially provided with a self-locking valve 3 and a pressure regulating system 4;

[0027] The proportional valve 601 is connected to three throttling orifice plates 604 at the same time. The gas outlets of the three throttling orifice plates 604 are respectively provided with a third solenoid valve 7. The three third solenoid valves 7 are respectively used to control the on-off of the anode branch, the cathode branch A and the cathode branch B;

[0028] The pressure sensor PIII602 is disposed at the air outlet of the proportional valve 601 and is used to collect the pressure at the air outlet of the proportional valve 601;

[0029] The pressure regulating system 4 collects the pressure of the gas transmission channel and sends it to the controller 5. The controller 5 controls the pressure regulating system 4, the proportional valve 601 and the three third solenoid valves 7 according to the pressure of the gas transmission channel, the pressure of the pressure sensor PIII602 and the working mode of the system.

[0030] Further, in the present invention, the pressure regulating system 4 includes a first solenoid valve 401, a small air cavity 402, a second solenoid valve 403, a throttle hole 404, a buffer cavity 405 and a pressure sensor PII406;

[0031] The air inlet end of the first solenoid valve 401 is connected to the air outlet port of the self-locking valve 3; the air outlet of the first solenoid valve 401 is connected to the air inlet of the second solenoid valve 403 through the small air cavity 402, and the air outlet of the second solenoid valve 403 is connected to the air inlet of the buffer cavity 405 through the throttle hole 404. The buffer cavity 405 is provided with a pressure sensor PII406, and the pressure sensor PII406 is used to collect the pressure signal in the buffer cavity 405. The signal output end of the pressure sensor PII406 is connected to the controller 5;

[0032] The controller 5 also controls the switch of the second solenoid valve 403 and the first solenoid valve 401 according to the working mode of the system and the pressure collected by the pressure sensor PII406;

[0033] The gas output port of the buffer chamber 405 is connected to the gas input port of the proportional valve 601 .

[0034] Furthermore, in the present invention, the working modes include: initialization mode, buffer chamber and pipeline exhaust mode, passage detection process mode, decompression working mode and shutdown mode.

[0035] Furthermore, in the present invention, the decompression working mode:

[0036] Step J1, opening the self-locking valve and a third solenoid valve controlling the cathode branch;

[0037] Step J2, open the third solenoid valve controlling the anode branch, open the first solenoid valve 1S later, close the first solenoid valve and then open the second solenoid valve;

[0038] Step J3, the controller 5 obtains the gas pressure in the buffer chamber according to the pressure signal collected by the pressure sensor PII406, and determines whether the gas pressure in the buffer chamber is greater than the buffer pressure threshold. If so, execute step J4; otherwise, determine whether the opening time of the second solenoid valve is less than or equal to 1s. If so, close the second solenoid valve and delay for 2s to determine whether the pressure signal collected by the pressure sensor PII is greater than or equal to 0.3MPa. If so, execute step J4; otherwise, return to execute step J2;

[0039] Step J4, detecting the pressure of the pressure sensor PIII in real time, and adjusting the opening of the proportional valve in real time according to the pressure of the pressure sensor PIII, so that the pressure of the pressure sensor PIII is close to 0.2Mpa;

[0040] If the pressure of the pressure sensor PIII is less than 0.2 MPa, the opening of the proportional valve is controlled to increase, until the pressure of the pressure sensor PIII is greater than 0.2 MPa, and the opening of the proportional valve is controlled to decrease.

[0041] Furthermore, in the present invention, the buffer chamber and pipeline exhaust mode:

[0042] According to the set exhaust time opening mode, the three third solenoid valves are first opened and kept open until the pressure signal collected by the pressure sensor PIII is less than 0.1MPa. After 1s, the proportional valve is fully opened until the pressure collected by the pressure sensor PII is less than 0.1MPa. After 2s, the first solenoid valve and the second solenoid valve are opened until the pressure signal of the pressure sensor P2 is less than 10Pa. The first solenoid valve, the second solenoid valve and the proportional valve are closed in turn. The closing time interval is 1 second. After the proportional valve is closed for 1s, the three third solenoid valves are closed to complete the exhaust of the buffer chamber and the pipeline.

[0043] Furthermore, in the present invention, the path detection mode process is:

[0044] Step 1: The controller receives a passage detection instruction and controls the self-locking valve to open;

[0045] Step 2: After opening the first solenoid valve for 1 second, close the first solenoid valve; open the second solenoid valve;

[0046] Step 3: Determine whether the pressure signal of the pressure sensor PII is greater than or equal to 0.3MPa or the opening time of the second solenoid valve is less than or equal to 1s. If the pressure condition is met, execute step 4. If the pressure condition is not met, but the time condition is met, close the second solenoid valve, delay for 2s, and again determine whether the pressure signal of the pressure sensor PII is greater than or equal to 0.3MPa. If the pressure condition is still not met, return to execute step 2 until the pressure of the buffer chamber is greater than or equal to 0.3MPa, and execute step 4.

[0047] Step 4, close the second solenoid valve, delay 1s, fully open the proportional valve and three third solenoid valves, delay 600s, detect whether the pressure of the pressure sensor PII is within the range of 0.21Mpa-0.22Mpa, and whether the pressure collected by the pressure sensor PIII is within the range of 0.18-0.19Mpa. If both are satisfied, set the anode normal flag, otherwise, set the anode abnormal flag, and close the third solenoid valve controlling the anode outlet;

[0048] Step 5, open the third solenoid valve controlling the cathode outlet of A, delay 600s, detect whether the pressure of pressure sensor PII is within the range of 0.21Mpa-0.22Mpa, and whether the pressure of pressure sensor PIII is within the range of 0.18Mpa-0.19Mpa. If both meet the required pressure range, set cathode branch A to the normal flag position; if any pressure sensor is not within the corresponding range, set cathode branch A to the abnormal flag position; close the third solenoid valve;

[0049] Step six, open the third solenoid valve that controls the cathode outlet of B, delay for 600s, and detect whether the pressure of pressure sensor PII is within the range of 0.21-0.22Mpa, and whether the pressure of pressure sensor PIII is within the range of 0.18-0.19Mpa. If so, set cathode branch B to the normal flag position; otherwise, set cathode branch B to the abnormal flag position, close the third solenoid valve that controls the cathode outlet of B; close the self-locking valve, and the passage detection is completed.

[0050] Furthermore, in the present invention, the flow regulating system 6 further includes a summary throttling hole 603 , and the summary throttling hole 603 is arranged between the proportional valve 601 and the three throttling orifice plates 604 .

[0051] Furthermore, the present invention also includes a pressure sensor PI1, which is arranged at the outlet of the gas cylinder to collect the pressure of the outlet of the gas cylinder and transmit the collected pressure signal to the controller 5; the controller 5 obtains the amount of gas in the gas cylinder according to the pressure signal collected by the pressure sensor PI1.

[0052] Furthermore, the present invention also includes a filling and discharging valve 2, which is arranged at the mouth of the gas cylinder and is used to connect to a gas filling device to add gas into the gas cylinder.

[0053] The double solenoid valve of the present invention forms a small air cavity + buffer cavity in the middle after the double solenoid valve is connected. The high pressure is reduced, and the double solenoid valve does not need to work frequently. The life requirement is reduced, so the cost is reduced. The existence of the buffer cavity always keeps the pressure within the rated working pressure of the proportional valve. The pressure change before the proportional valve is not obvious, and the air pressure fluctuation is not strong. The life requirement of the proportional valve is reduced. The cost is reduced. Using krypton gas instead of xenon gas reduces the cost a lot. The throttling orifice plate is easy to process, low in price, short in construction period, not easy to be blocked, and does not need to be heated. Specific embodiment:

[0055] The functions of each part of the storage and supply system are as follows:

[0056] Gas cylinder: storage to meet the requirement of 100 hours of on-orbit operation, gas cylinder capacity 1-1.1L. Used to store high-pressure gas. Pressure sensor PI: monitors the pressure in the gas cylinder. Filling and discharging valve: filling and discharging of gas in the gas cylinder. Self-locking valve 1: controls the on-off of the gas circuit.

[0057] First-stage regulation: self-locking valve, first solenoid valve, small air chamber, second solenoid valve, throttle hole, buffer chamber and pressure sensor PII. First-stage regulation realizes closed-loop control mode through the controller. The pressure sensor monitors the pressure in the front buffer chamber in real time. When the pressure is lower than the set value, the controller controls the first solenoid valve at the front end to open. When the pressure reaches the upper limit of the set value, the first solenoid valve is closed.

[0058] Secondary regulation: It consists of a proportional valve and a pressure sensor PIII. Secondary regulation requires high precision and high-speed response. It uses closed-loop control. The pressure sensor PIII monitors the output pressure of the proportional valve in real time. When the pressure is lower than the set value, the proportional valve opening is controlled to increase. When the pressure is higher than the upper limit of the set value, the proportional valve opening is controlled to decrease. Throttle: Stabilizes the flow in the pipeline. Throttle orifice: Controls the flow of gas. The three third solenoid valves are used to control the on and off of the anode and cathode outlets.

[0059] The storage, supply and decompression system provides a stable flow for the Hall thrusters on the satellite to ensure the normal operation of the Hall thrusters. Specific implementation process:

[0060] initialization

[0061] (1) Close the self-locking valve;

[0062] (2) After 2 seconds, close the first solenoid valve;

[0063] (3) Read the pressure of pressure sensor PII and pressure sensor PIII. If the pressure of one of pressure sensor PII and pressure sensor PIII is ≥ 0.12MPa, fully open the proportional valve and three third solenoid valves in sequence to exhaust. When the pressure is less than 0.1MPa, proceed to the next step;

[0064] (4) Close the second solenoid valve;

[0065] (5) After the second solenoid valve is closed for 2 seconds, close the proportional valve.

[0066] (6) After the proportional valve is closed for 2 seconds, the three third solenoid valves are closed.

[0067] Buffer chamber and pipeline exhaust

[0068] After the satellite is counted into orbit, the satellite service system sends an exhaust control signal to the controller 5, and the controller 5 starts timing and starts to perform the exhaust action after 96 hours, or the controller 5 directly performs the exhaust process after receiving the exhaust command from the satellite service control:

[0069] (1) Open the three third solenoid valves in sequence and keep the three third solenoid valves open;

[0070] (2)(2) When the pressure sensor PIII is less than 0.1MPa, the proportional valve remains fully open after 1s;

[0071] (3) When the pressure of the pressure sensor PII is less than 0.1MPa, the first solenoid valve and the second solenoid valve remain fully open after 2 seconds (that is, all valves behind the self-locking valve are in the fully open state);

[0072] (4) When the pressure sensor P2 is less than 10Pa, the first solenoid valve, the second solenoid valve, and the proportional valve are closed in sequence, with a time interval of 1 second. After the proportional valve is closed for 1 second, the three third solenoid valves are closed in sequence, and the exhaust process ends;

[0073] Path detection

[0074] The star service sends the exhaust passage detection command to the controller. The detection process:

[0075] a. Open the self-locking valve.

[0076] b. After opening the first solenoid valve for 1 second, close the first solenoid valve; open the second solenoid valve, and the pressure sensor PII detects the pressure in the buffer chamber and the opening time of the second solenoid valve.

[0077] c. Determine whether the buffer chamber pressure collected by the pressure sensor PII is greater than or equal to 0.3MPa or the opening time of the second solenoid valve is less than or equal to 1s. If the pressure condition is met, execute step d. If the pressure condition is not met, but the time condition is met, close the second solenoid valve, delay for 2s, and again determine whether the pressure signal collected by the pressure sensor PII is greater than or equal to 0.3MPa. If the pressure condition is still not met, execute step b.

[0078] d. Close the second solenoid valve, delay 1s, fully open the proportional valve and three third solenoid valves, and after 600s, check whether the pressure of the pressure sensor PII is 0.21-0.22Mpa, and whether the pressure of the pressure sensor PIII is within the range of 018-0.19Mpa, and set the anode normal flag. If the pressure does not meet the requirements, set the anode abnormal flag and close the third solenoid valve that controls the anode outlet.

[0079] e. Open the third solenoid valve that controls the cathode outlet of A. After 600s, check whether the pressure of pressure sensor PII is within the range of 0.21-0.22Mpa and whether the pressure of pressure sensor PIII is 0.18-0.19Mpa, and set the normal flag of cathode branch A. If the pressure does not meet the requirements, set the abnormal flag of cathode branch A. Close the opened third solenoid valve.

[0080] f. Open the third solenoid valve controlling the cathode outlet of B. After 600s, check whether the pressure of pressure sensor PII is within the range of 0.21-0.22Mpa and whether the pressure of pressure sensor PIII is 0.18-0.19Mpa, and set the cathode branch B normal flag. If the pressure does not meet the requirements, set the cathode branch B abnormal flag. Close the third solenoid valve controlling the cathode outlet of B.

[0081] g. Close the self-locking valve and the passage detection is completed.

[0082] Stress relief work

[0083] a. Open the self-locking valve

[0084] b. After opening the solenoid valve for 1 second, close the first solenoid valve; open the second solenoid valve, and detect the pressure in the buffer chamber and the opening time of the first and second solenoid valves.

[0085] c. Determine whether the buffer chamber pressure collected by the pressure sensor PII is greater than or equal to 0.7MPa or the second solenoid valve opening time is less than or equal to 1s. If the pressure condition is met, execute step c. If the time condition is met, close the second solenoid valve, delay 2s, and determine whether the pressure signal collected by the pressure sensor PII is greater than or equal to 0.3MPa. If so, execute step c. If not, execute step b. When the pressure of the pressure sensor PIII is 0.2Mpa, the controller 5 closed-loop feedback controls the proportional valve opening.

[0086] d. According to the selected working cathode, open the two third solenoid valves controlling one cathode outlet. If the third solenoid valve of one branch cannot be opened, open the third solenoid valve of the other cathode branch instead;

[0087] e. Open the third solenoid valve that controls the anode outlet and the thruster operates normally.

[0088] Shutdown

[0089] (1) After the system issues a shutdown command, the thruster anode is powered off.

[0090] (2) One second after the positive power supply to the anode is cut off, close the self-locking valve.

[0091] (3) After 1 second, close the first solenoid valve and the second solenoid valve.

[0092] (4) After 1 second, close the proportional valve.

[0093] (5) After 1 second, the three third solenoid valves controlling the anode outlet and the two cathode outlets are closed in sequence.

[0094] The present invention adopts a double solenoid valve plus a buffer chamber structure. The existence of the buffer chamber can store more gas that meets the working pressure of the proportional valve, so that the front-end double solenoid valve system can work less times within the time of a working task, avoid frequent work, and reduce the life requirement of the double solenoid valve system.

[0095] Adaptability to complex working conditions: The present invention has strong adaptability and can automatically adjust the decompression parameters according to the dynamic needs of the electric propulsion system, ensure the continuity and stability of the thrust output, and adapt to precise control from low to high pressure ranges.

[0096] High response speed: Compared with the thermal decompression system, the system of the present invention has a faster response time and can respond to the needs of spacecraft attitude adjustment and orbit change in real time, ensuring the flexibility and stability of the system's on-orbit operation. Balance between economy and performance: The present invention adopts a new control architecture that can find the best balance between high-precision decompression and cost-effectiveness.

[0097] High precision and stability: The dual-stage control structure of the present invention combines mechanical and electromagnetic adjustment mechanisms, which can accurately adjust the gas flow and pressure, overcoming the shortcomings of existing systems in decompression accuracy, especially in complex thrust requirements and changes in operating conditions.

[0098] Energy efficiency improvement: This invention optimizes the energy efficiency, avoids the high energy consumption of the thermal decompression system, makes the system more suitable for deep space missions and long-term on-orbit operation, and further improves the economy and sustainability of space missions. The main working fluid of this invention is krypton. The price of krypton is about 1,000 yuan / m 3 Krypton is cheaper than xenon. The existence of the buffer chamber ensures that the gas in the chamber is always below the maximum pressure that the proportional valve can withstand, and the pressure fluctuation is slow and small, reducing the risk of damage to the proportional valve before the end of its service life. The throttling orifice plate has the advantages of easy processing, low price, short construction period, not easy to clog, and no need for heating. Diversion is carried out according to different diameter ratios.

[0099] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. Electric propulsion high-pressure fluid micro-flow control system, characterized in that: It comprises a self-locking valve (3), a pressure regulating system (4), a controller (5), a flow regulating system (6) and three third solenoid valves (7); The flow regulating system (6) comprises a proportional valve (601), a pressure sensor PIII (602) and three throttling orifice plates (604); The outlet of the gas cylinder is connected to the gas inlet of the proportional valve (601) through a gas transmission channel, and the gas transmission channel is sequentially provided with a self-locking valve (3) and a pressure regulating system (4); The proportional valve (601) is simultaneously connected to three throttling orifice plates (604), and each of the gas outlets of the three throttling orifice plates (604) is provided with a third solenoid valve (7), and the three third solenoid valves (7) are used to control the on / off of the anode branch, the cathode branch A, and the cathode branch B, respectively; The pressure sensor PIII (602) is arranged at the air outlet of the proportional valve (601) and is used to collect the pressure at the air outlet of the proportional valve (601); The pressure regulating system (4) collects the pressure of the gas transmission channel and sends it to the controller (5). The controller (5) controls the pressure regulating system (4), the proportional valve (601) and the three third solenoid valves (7) according to the pressure of the gas transmission channel, the pressure of the pressure sensor PIII (602) and the working mode of the system.

2. The electric propulsion high-pressure fluid micro-flow control system according to claim 1 is characterized in that: The pressure regulating system (4) comprises a first solenoid valve (401), a small air cavity (402), a second solenoid valve (403), a throttle hole (404), a buffer cavity (405) and a pressure sensor PII (406); The air inlet end of the first solenoid valve (401) is connected to the air outlet port of the self-locking valve (3); the air outlet of the first solenoid valve (401) is connected to the air inlet of the second solenoid valve (403) through a small air cavity (402); the air outlet of the second solenoid valve (403) is connected to the air inlet of a buffer cavity (405) through a throttle hole (404); a pressure sensor PII (406) is provided in the buffer cavity (405); the pressure sensor PII (406) is used to collect a pressure signal in the buffer cavity (405); and a signal output end of the pressure sensor PII (406) is connected to a controller (5); The controller (5) also controls the switching of the second solenoid valve (403) and the first solenoid valve (401) according to the working mode of the system and the pressure collected by the pressure sensor PII (406); The gas output port of the buffer chamber (405) is connected to the gas input port of the proportional valve (601).

3. The electric propulsion high-pressure fluid micro-flow control system according to claim 2 is characterized in that: The working modes include: initialization mode, buffer chamber and pipeline exhaust mode, passage detection process mode, decompression working mode and shutdown mode.

4. The electric propulsion high-pressure fluid micro-flow control system according to claim 1 is characterized in that: The flow regulating system (6) further comprises a summary throttling hole (603), wherein the summary throttling hole (603) is arranged between the proportional valve (601) and the three throttling orifice plates (604).

5. The electric propulsion high-pressure fluid micro-flow control system according to claim 1 is characterized in that: The invention also comprises a pressure sensor PI (1), which is arranged at the outlet of the gas cylinder and is used to collect the pressure at the outlet of the gas cylinder and transmit the collected pressure signal to the controller (5); the controller (5) obtains the amount of gas in the gas cylinder according to the pressure signal collected by the pressure sensor PI (1).

6. The electric propulsion high-pressure fluid micro-flow control system according to claim 1 is characterized in that: It also comprises a filling and discharging valve (2), which is arranged at the mouth of the gas cylinder and is used to connect to a gas filling device to add gas into the gas cylinder.

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