Low voltage long gap discharge device and method

Abstract

The application provides a low-voltage long-distance discharge device, which comprises first to fifth semiconductor long strips (101-1-101-5), first to sixth metal electrodes (104-1-104-6), first to fifth capacitors (102-1-102-5) for triggering discharge, first to fifth diodes (103-1-103-5) for inhibiting energy release and a discharge tube (105) as a discharge voltage controller. The application also provides a low-voltage long-distance discharge method. The application has the unique advantages of large discharge distance (the discharge distance is more than 10 cm) and small required voltage (not more than 5 kV); the initial fire core size can be increased by several times, the fire core propagation speed in the ignition process can be accelerated, and the ignition reliability of a combustion chamber under extreme conditions can be improved.

Description

Technical Field

[0001] This invention relates to plasma technology, specifically to a low-voltage, long-spacing discharge device and method based on the principle of sequential energy loading and breakdown, utilizing the flashover characteristics of semiconductor surfaces. Background Technology

[0002] Aerospace plasma technology is a cutting-edge technology that rapidly releases electrical energy through plasma discharge, converting it into mechanical and thermal energy to achieve functions such as flow control and ignition / combustion enhancement. Arc plasma discharge devices are a common type of aerospace plasma excitation system. They create a discharge plasma channel by breaking down air under high voltage, transforming the air from an insulator into a conductor. The power system rapidly releases energy through this plasma channel, generating thermal, chemical, and dynamic effects to control airflow and improve the ignition capability of the ignition system.

[0003] Whether for flow control or ignition and combustion, generating a large-area discharge region is a crucial way to improve the performance of the excitation system. However, since plasma discharge is achieved by breaking down air with high voltage, the discharge gap is always affected by the power supply output voltage. According to Paschen's Law, under standard atmospheric conditions, a 1mm air gap requires approximately 3kV to ensure reliable discharge. While increasing the voltage can increase the discharge gap to some extent, the discharge gap in existing plasma excitation systems is typically on the order of millimeters due to limitations in material insulation strength, making it difficult to increase it to the centimeter level.

[0004] In summary, the current field of aerospace plasma flow control and ignition combustion has a prominent problem of small discharge area, which seriously affects the flow control area and initial fire core size, making it difficult to meet actual needs. Summary of the Invention

[0005] To address the prominent problem of small discharge area in existing plasma flow control and ignition combustion technologies, this invention proposes a low-voltage, long-spacing discharge device. This device includes first to fifth semiconductor strips (101-1 to 101-5), first to sixth metal electrodes (104-1 to 104-6), first to fifth capacitors (102-1 to 102-5) for triggering discharge, first to fifth diodes (103-1 to 103-5) for suppressing energy release, and a discharge tube 105 serving as a discharge voltage controller.

[0006] The first to fifth semiconductor strips (101-1 to 101-5) are arranged sequentially along the length direction, and are connected in series with the second to fifth metal electrodes (104-2 to 104-5) to form a whole;

[0007] The high-voltage stages of the first to fifth capacitors (102-1 to 102-5) are connected to the high-voltage stage input to the discharge device, and the low-voltage stages are respectively connected to the second to sixth metal electrodes (104-2 to 104-6) connected to the end of the semiconductor strip; the low-voltage stages of the first to fifth capacitors (102-1 to 102-5) are also respectively connected to the positive terminals of the first to fifth diodes (103-1 to 103-5);

[0008] The negative terminals of the first to fifth diodes (103-1 to 103-5) are all connected to the ground terminal of the device;

[0009] The front end of the first semiconductor strip 101-1 is connected to the first metal electrode 104-1. The first metal electrode 104-1 is connected to one end of the discharge tube 105, and the other end of the discharge tube 105 is connected to the high voltage input of the discharge device.

[0010] In one embodiment of the present invention, the first to fifth semiconductor strips (101-1 to 101-5) are not less than 20 mm in length, 1 to 3 mm in width, and 1 to 3 mm in thickness.

[0011] In another embodiment of the present invention, the first to sixth metal electrodes (104-1 to 104-6) have the same thickness and width as the first to fifth semiconductor strips (101-1 to 101-5), and a length of 2 to 4 mm.

[0012] In another embodiment of the present invention, the withstand voltage of the first to fifth capacitors (102-1 to 102-5) is greater than the maximum value of the input voltage of the entire discharge device.

[0013] In another embodiment of the present invention, the withstand voltage of the first to fifth diodes (103-1 to 103-5) is greater than the maximum value of the input voltage of the entire discharge device.

[0014] In another embodiment of the invention, the trigger voltage of the discharge tube 105 is sufficient to ensure that the capacitor stores enough energy, while not exceeding the input voltage of the entire discharge device.

[0015] In one specific embodiment of the present invention, the semiconductor strip (101-1 to 101-5) has a size of 20×1×2mm; the metal electrode (104-1 to 104-6) is 2mm long and made of copper; the first to fifth capacitors (102-1 to 102-5) have a withstand voltage of 4kV and a capacitance of 0.47μF; the first to fifth diodes (103-1 to 103-5) have a withstand voltage of 5kV and a permissible current of 2A; the discharge tube 105 is an R-12 discharge tube with a trigger voltage of 2.5±0.1kV.

[0016] A low-voltage long-pitch discharge method is also provided, which is based on the low-voltage long-pitch discharge device described above. The entire discharge device operates as follows: When a high voltage is input externally, before the trigger voltage of the discharge tube 105 is reached, the input high voltage charges each capacitor (102-1 to 102-5) through the first to fifth diodes (103-1 to 103-5); as the capacitor voltage increases, the voltage across the discharge tube 105 reaches the breakdown voltage and conducts; when the discharge tube 105 breaks down and conducts, the discharge tube 105 becomes a conductor, and the energy stored in the capacitors (102-1 to 102-5) is loaded onto the first to fifth semiconductor strips (101-1 to 101-5); since the energy density loaded per unit length of the first semiconductor strip 101-1 is the largest, it reaches the breakdown condition first and forms a surface flash. The first metal electrode 104-1 and the second metal electrode 104-2 are connected to form a plasma discharge channel. When the first semiconductor strip 101-1 flashes over and forms a discharge channel, the first metal electrode 104-1 and the second metal electrode 104-2 are essentially short-circuited due to the high conductivity of plasma. At this time, the energy density loaded on the subsequent semiconductor strip will increase. All the energy stored in the second capacitor 102-2 is loaded onto the second semiconductor strip 101-2, causing the second semiconductor strip 101-2 to also quickly undergo surface flashover and form a discharge channel. Similarly, each subsequent semiconductor strip will reach the breakdown condition in turn to generate surface flashover discharge and form a plasma discharge channel. Finally, a plasma discharge channel with a large discharge gap is formed between the first metal electrode 104-1 and the sixth metal electrode 104-6.

[0017] This invention utilizes the flashover characteristics of semiconductor surfaces to achieve single-stage long-pitch discharge, increasing the discharge spacing from millimeters to centimeters. Through a uniquely designed discharge drive circuit, the energy required for semiconductor breakdown is sequentially transferred, achieving sequential breakdown and enabling synchronous discharge of multiple semiconductor discharge units. This allows the discharge spacing to be increased from centimeters to over 10 centimeters, representing a significant leap forward in discharge spacing. Furthermore, the maximum breakdown voltage required for discharge does not exceed 5kV, which is generally sufficient for high-voltage conductors.

[0018] Compared to existing discharge devices and methods, the low-voltage, long-spacing discharge device and method proposed in this invention have unique advantages such as a large discharge spacing (exceeding 10 cm) and a low required voltage (not exceeding 5 kV). Based on this discharge device and method, it can support the design of a high-efficiency aerospace plasma flow control excitation system, meet the requirements of large-area flow control, support the design of aerospace plasma ignition and combustion booster exciters, increase the size of the existing initial fire core several times, accelerate the fire core propagation speed during the ignition process, and improve the ignition reliability of combustion chambers under extreme conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the low-voltage long-gap discharge device and its main circuit connections according to the present invention. Detailed Implementation

[0020] See Figure 1 The low-voltage long-pitch discharge device of the present invention mainly consists of first to fifth semiconductor strips (101-1 to 101-5), first to sixth metal electrodes (104-1 to 104-6), first to fifth capacitors (102-1 to 102-5) for triggering discharge, first to fifth diodes (103-1 to 103-5) for suppressing energy release, and discharge tube 105 as a discharge voltage controller.

[0021] The first to fifth semiconductor strips (101-1 to 101-5) are made of silicon carbide semiconductors, with a length of not less than 20 mm, a width of 1 to 3 mm, and a thickness of 1 to 3 mm. These strips are arranged sequentially along their length and connected in series with the second to fifth metal electrodes (104-2 to 104-5). The first to sixth metal electrodes (104-1 to 104-6) have the same thickness and width as the first to fifth semiconductor strips (101-1 to 101-5), and a length of 2 to 4 mm. They can be made of stainless steel, copper, tungsten, or other metal materials. The first to fifth capacitors (102-1 to 102-5) provide energy to trigger flashover discharge on the semiconductor surface. The high-voltage stage of the first to fifth capacitors (102-1 to 102-5) is connected to the high-voltage stage input to the discharge device, and the low-voltage stages are connected to the second to sixth metal electrodes (104-2 to 104-6) at the ends of the semiconductor strips. Simultaneously, the low-voltage terminals of the first to fifth capacitors (102-1 to 102-5) are also connected to the positive terminals of the first to fifth diodes (103-1 to 103-5), respectively. For example, the low-voltage terminal of the second capacitor 102-2 is connected to the third metal electrode 104-3 at the end of the second semiconductor strip 101-2, and also to the positive terminal of the second diode 103-2. The withstand voltage of the first to fifth capacitors (102-1 to 102-5) must be greater than the maximum value of the input voltage of the entire discharge device, typically not less than 3kV, and the capacitance value must be not less than 0.4μF. The negative terminals of the first to fifth diodes (103-1 to 103-5) are all connected to the ground terminal of the device. The withstand voltage of the first to fifth diodes (103-1 to 103-5) must be greater than the maximum value of the input voltage of the entire discharge device, typically not less than 3kV, and the allowable current is not less than 1A. The front end of the first semiconductor strip 101-1 is connected to the first metal electrode 104-1, and the first metal electrode 104-1 is connected to one end of the discharge tube 105. The other end of the discharge tube 105 is connected to the high-voltage stage input to the discharge device. The trigger voltage of the discharge tube 105 should be sufficient to ensure that the capacitor stores enough energy, and should not exceed the input voltage of the entire discharge device, typically ranging from 2 to 4 kV.

[0022] With this design, the entire discharge device operates as follows: When a high voltage is input externally, before the trigger voltage of the discharge tube 105 is reached, the input high voltage charges each capacitor (102-1 to 102-5) through the first to fifth diodes (103-1 to 103-5). As the capacitor voltage increases, the voltage across the discharge tube 105 reaches its designed breakdown voltage and turns on. When the discharge tube 105 breaks down and turns on, it becomes a conductor, and the energy stored in the capacitors (102-1 to 102-5) is loaded onto the first to fifth semiconductor strips (101-1 to 101-5). Since the energy density loaded per unit length of the first semiconductor strip 101-1 is the highest, it will reach the breakdown condition first and form a surface flashover, thus forming a plasma discharge channel between the first metal electrode 104-1 and the second metal electrode 104-2. When the first semiconductor strip 101-1 flashes over and forms a discharge channel, due to the high conductivity of plasma, the first metal electrode 104-1 and the second metal electrode 104-2 are essentially short-circuited, increasing the energy density loaded onto subsequent semiconductor strips. All the energy stored in the second capacitor 102-2 is transferred to the second semiconductor strip 101-2, causing it to quickly also flash over and form a discharge channel. This process continues, with each subsequent semiconductor strip reaching the breakdown condition and generating surface flashover discharge to form a plasma discharge channel. Ultimately, a plasma discharge channel with a discharge gap exceeding 10 cm is formed between the first metal electrode 104-1 and the sixth metal electrode 104-6. Specific Implementation

[0024] See Figure 1The low-voltage, long-pitch discharge device of the present invention mainly consists of first to fifth semiconductor strips (101-1 to 101-5), first to sixth metal electrodes (104-1 to 104-6), first to fifth capacitors (102-1 to 102-5) for triggering discharge, first to fifth diodes (103-1 to 103-5) for suppressing energy release, and a discharge tube 105 serving as a discharge voltage controller. The semiconductor strips (101-1 to 101-5) are made of silicon carbide semiconductors and have dimensions of 20×1×2mm. The first to fifth semiconductor strips are arranged sequentially and connected in series with each other by second to fifth metal electrodes (104-2 to 104-5). The metal electrodes (104-1 to 104-6) have the same thickness and width as the semiconductor strips, a length of 2mm, and are made of copper. The high-voltage stages of the first to fifth capacitors (102-1 to 102-5) are connected to the high-voltage input of the discharge device, and their low-voltage stages are connected to the second to sixth metal electrodes (104-2 to 104-6), respectively. Simultaneously, the low-voltage stages of the first to fifth capacitors (102-1 to 102-5) are also connected to the positive terminals of the first to fifth diodes (103-1 to 103-5), respectively. For example, the low-voltage stage of the second capacitor 102-2 is connected to the third metal electrode 104-3 at the end of the second semiconductor strip 101-2, and also to the positive terminal of the second diode 103-2. The first to fifth capacitors (102-1 to 102-5) have a withstand voltage of 4kV and a capacitance of 0.47μF. The negative terminals of the first to fifth diodes (103-1 to 103-5) are all connected to the device's ground terminal, and when combined, they have a withstand voltage of 5kV and a permissible current of 2A. The front end of the first semiconductor strip 101-1 is connected to the first metal electrode 104-1, and the first metal electrode 104-1 is connected to one end of the discharge tube 105. The other end of the discharge tube 105 is connected to the high voltage input of the discharge device. The discharge tube 105 is an R-12 discharge tube with a trigger voltage of 2.5±0.1kV.

Claims

1. A low-voltage, long-gap discharge device, characterized in that, Its discharge spacing exceeds 10 cm, and the discharge voltage does not exceed 5 kV. The device includes first to fifth semiconductor strips (101-1 to 101-5), first to sixth metal electrodes (104-1 to 104-6), first to fifth capacitors (102-1 to 102-5) to trigger discharge, first to fifth diodes (103-1 to 103-5) to suppress energy release, and a discharge tube (105) as a discharge voltage controller. in The first to fifth semiconductor strips (101-1 to 101-5) are arranged sequentially along the length direction and connected in series with the second to fifth metal electrodes (104-2 to 104-5) to form a whole. The rear end of the fifth semiconductor strip (101-5) is connected to the sixth metal electrode (104-6). The high-voltage stages of the first to fifth capacitors (102-1 to 102-5) are connected to the high-voltage stage input to the discharge device, and the low-voltage stages are connected to the second to sixth metal electrodes (104-2 to 104-6), respectively; the low-voltage stages of the first to fifth capacitors (102-1 to 102-5) are also connected to the positive terminals of the first to fifth diodes (103-1 to 103-5), respectively. The negative terminals of the first to fifth diodes (103-1 to 103-5) are all connected to the ground terminal of the device; The front end of the first semiconductor strip (101-1) is connected to the first metal electrode (104-1), the first metal electrode (104-1) is connected to one end of the discharge tube (105), and the other end of the discharge tube (105) is connected to the high voltage input of the discharge device. The length of the first to fifth semiconductor strips (101-1 to 101-5) shall not be less than 20 mm.

2. The low-voltage long-gap discharge device as described in claim 1, characterized in that, The first to fifth semiconductor strips (101-1 to 101-5) are 1 to 3 mm wide and 1 to 3 mm thick.

3. The low-voltage long-gap discharge device as described in claim 1, characterized in that, The first to sixth metal electrodes (104-1 to 104-6) have the same thickness and width as the first to fifth semiconductor strips (101-1 to 101-5), and a length of 2 to 4 mm.

4. The low-voltage long-gap discharge device as described in claim 1, characterized in that, The withstand voltage of the first to fifth capacitors (102-1 to 102-5) is greater than the maximum value of the input voltage of the entire discharge device.

5. The low-voltage long-gap discharge device as described in claim 1, characterized in that, The withstand voltage of the first to fifth diodes (103-1 to 103-5) is greater than the maximum value of the input voltage of the entire discharge device.

6. The low-voltage long-gap discharge device as described in claim 1, characterized in that, The trigger voltage of the discharge tube (105) is not higher than the input voltage of the entire discharge device.

7. The low-voltage long-gap discharge device as described in claim 1, characterized in that, The semiconductor strip (101-1 to 101-5) measures 20×1×2mm; the metal electrode (104-1 to 104-6) is 2mm long and made of copper; the first to fifth capacitors (102-1 to 102-5) have a withstand voltage of 4kV and a capacitance of 0.47μF; the first to fifth diodes (103-1 to 103-5) have a withstand voltage of 5kV and a permissible current of 2A; the discharge tube (105) is an R-12 discharge tube with a trigger voltage of 2.5±0.1kV.

8. A low-voltage long-gap discharge method, comprising using the low-voltage long-gap discharge device as described in any one of claims 1 to 7, characterized in that, The entire discharge device will operate as follows: When a high voltage is input externally, before the trigger voltage of the discharge tube (105) is reached, the input high voltage charges each capacitor (102-1 to 102-5) through the first to fifth diodes (103-1 to 103-5); as the capacitor voltage increases, the voltage across the discharge tube (105) reaches the breakdown voltage and conducts; when the discharge tube (105) breaks down and conducts, the discharge tube (105) becomes a conductor, and at this time the energy stored in the capacitors (102-1 to 102-5) is loaded onto the first to fifth semiconductor strips (101-1 to 101-5); due to the first semiconductor strip (101-1) per unit length The highest energy density is applied first, reaching the breakdown condition and forming a surface flashover, thus creating a plasma discharge channel between the first metal electrode (104-1) and the second metal electrode (104-2). After the first semiconductor strip (101-1) forms a discharge channel through surface flashover, due to the high conductivity of plasma, the first metal electrode (104-1) and the second metal electrode (104-2) are essentially short-circuited, increasing the energy density applied to the subsequent semiconductor strip. All the energy stored in the second capacitor (102-2) is transferred to the second semiconductor strip (101-2), causing the second semiconductor strip (101-2) to also undergo surface flashover and form a discharge channel. In sequence, each semiconductor strip will eventually reach the breakdown condition, generating surface flashover discharge to form a plasma discharge channel; finally, a plasma discharge channel is formed between the first metal electrode (104-1) and the sixth metal electrode (104-6).

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