Repetition frequency nanosecond pulse square wave current source with adjustable rising front edge

Abstract

The utility model discloses a rising leading edge adjustable repetition frequency nanosecond pulse square wave current source, which comprises a high-voltage direct current power supply part, a transmission cable and a pulse square wave current generation part, the high-voltage direct current power supply part comprises a high-voltage direct current generation device HVDC and a charging resistor R0, the grounding end of the high-voltage direct current generation device HVDC is grounded, and the charging resistor R0 is connected with the high-voltage direct current generation device HVDC. The high-voltage end of the HVDC generator is connected in series with a charging resistor R0 and then is connected with one end of a core wire of the transmission cable, and one end of a shielding layer of the transmission cable is grounded; one end of the pulse square wave current generating part is connected with the other end of the core wire of the transmission cable, the other end of the pulse square wave current generating part is connected with the other end of the shielding layer of the transmission cable, the pulse square wave current generating part comprises a matching resistor Z and a gas switch, and the gas pressure of filling gas of the gas switch is adjustable. The pulse square wave generator has the advantages that the front edge of the pulse square wave is adjustable, the frequency of the pulse square wave is adjustable, and repeated-frequency operation can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of pulse power and pulse signal generation, in particular to a repetition-frequency nanosecond pulse square wave current source with adjustable rising front edge. Background Art

[0002] Pulse power supply is widely used and plays a very important role in the current scientific research field, especially in the technical fields of pulse power technology, electromagnetic technology and automatic control. With the rapid development of power electronics technology and the widespread application of plasma technology in life, pulse power supply has been widely used in environmental protection, plasma physics, controlled nuclear fusion, biomedicine, food sterilization and advanced weapons manufacturing due to its advantages of small size, light weight and high efficiency.

[0003] Pulse power supplies with adjustable rising front edges are one of the important development directions for industrial and scientific research applications. Adjusting the rising front edge of a pulse power supply can meet more usage scenarios, especially in the field of repetition-frequency nanosecond pulse square wave current sources. As industrial production technology becomes more and more perfect, pulse source technology has also gained a wider range of applications. The performance parameters of pulse sources required in various fields are becoming more and more stringent. Therefore, the adjustability of the rising front edge of a repetition-frequency pulse current source is becoming more and more important. In addition, the pulse square wave frequency of a repetition-frequency pulse square wave current source should also be adjustable to suit different work and scientific research purposes. Therefore, it is urgent to propose a new type of pulse square wave current source that makes the rising front edge adjustable and the frequency of the repetition-frequency pulse square wave generated adjustable while ensuring that the performance of the repetition-frequency pulse square wave is not disturbed. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies of the above prior art and provide a repetition rate nanosecond pulse square wave current source with adjustable rising front edge. The repetition rate nanosecond pulse square wave current source has the advantage of adjustable pulse square wave front edge.

[0005] The purpose of the utility model is achieved through the following technical solutions: a nanosecond pulse square wave current source with adjustable rising front, comprising: a high-voltage DC power supply part, a transmission cable and a pulse square wave current generating part, wherein the high-voltage DC power supply part comprises a high-voltage DC generating device HVDC and a charging resistor R 0 The grounding terminal of the high voltage direct current generating device HVDC is grounded, and the high voltage terminal of the high voltage direct current generating device HVDC is connected in series with a charging resistor R 0Then it is connected to one end of the core wire of the transmission cable, and one end of the shielding layer of the transmission cable is grounded; one end of the pulse square wave current generating part is connected to the other end of the core wire of the transmission cable, and the other end of the pulse square wave current generating part is connected to the other end of the shielding layer of the transmission cable, the pulse square wave current generating part includes a matching resistor Z and a gas switch, and the gas pressure of the filling gas of the gas switch is adjustable.

[0006] Preferably, the charging resistor R 0 The resistance value is adjustable.

[0007] Preferably, the charging resistor R 0 The resistance value is greater than 1MΩ.

[0008] Preferably, the gas pressure of the filling gas of the gas switch is greater than or equal to 1 standard atmospheric pressure.

[0009] Preferably, the wave impedance of the transmission cable is 50Ω.

[0010] Preferably, the resistance value of the matching resistor Z is equal to the wave impedance of the transmission cable.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] The utility model provides a repetitive frequency nanosecond pulse square wave current source with adjustable rising front edge. A high voltage direct current generator is used as a power source to charge a transmission cable. The transmission cable is used to store energy and generate pulses. The pulse square wave current generating part converts the pulses generated by the transmission cable into pulse square wave current. A gas switch with adjustable air pressure is used to control the air pressure of the gas switch, thereby controlling the breakdown voltage of the gas switch, thereby realizing the adjustable rising front edge function of the repetitive frequency pulse square wave. A charging resistor with adjustable resistance value is used to control the charging time of the transmission cable by adjusting the resistance value of the charging resistor, thereby realizing the frequency adjustable function of the repetitive frequency pulse square wave. The utility model has a simple structure, and has the advantages of adjustable pulse square wave front edge, adjustable pulse square wave frequency, and repetitive operation. It has important application significance in the field of repetitive frequency nanosecond pulse square wave current source. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model is a schematic diagram of a nanosecond pulse square wave current source with adjustable rising front edge and repetition rate.

[0014] Figure 2 It is a pulse square wave generated by the repetition-rate nanosecond pulse square wave current source of the utility model under normal pressure.

[0015] Figure 3 It is a pulse square wave generated by the repetition-rate nanosecond pulse square wave current source of the utility model under 0.3Mpa. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0017] like Figures 1 to 3 As shown, a repetition rate nanosecond pulse square wave current source with adjustable rising front edge comprises: a high voltage DC power supply part, a transmission cable and a pulse square wave current generating part, wherein the high voltage DC power supply part comprises a high voltage DC generating device HVDC and a charging resistor R 0 The grounding terminal of the high voltage direct current generating device HVDC is grounded, and the high voltage terminal of the high voltage direct current generating device HVDC is connected in series with a charging resistor R 0 After that, it is connected to one end of the core wire of the transmission cable, and one end of the shielding layer of the transmission cable is grounded; one end of the pulse square wave current generating part is connected to the other end of the core wire of the transmission cable, and the other end of the pulse square wave current generating part is connected to the other end of the shielding layer of the transmission cable, and the pulse square wave current generating part includes a matching resistor Z and a gas switch, and the gas pressure of the filling gas of the gas switch is adjustable. The gas pressure of the filling gas of the gas switch is greater than or equal to 1 standard atmospheric pressure.

[0018] Specifically, Figure 1 The schematic diagram of a nanosecond pulse square wave current source with adjustable rising edge is shown in the utility model. The high voltage direct current generating device HVDC is used to output a direct current voltage through a charging resistor R 0 The transmission cable is charged until the gas switch is broken down, generating a pulse square wave current. 0 It is used to limit the current of the circuit, and the transmission cable is used to store energy and generate pulses. A gas switch with adjustable air pressure is used to adjust the air pressure at the gas switch, thereby adjusting the breakdown voltage at the gas switch, and realizing the adjustable rising front edge of the repetitive pulse square wave. Since the breakdown of the gas switch requires a certain amount of time, the breakdown time can be up to nanoseconds. For gas switches with the same gap distance, the higher the air pressure, the higher the voltage required for the gas switch to break down, the faster the gas switch conduction process, that is, the shorter the time required for the gas switch to break down, and the shorter the rising front edge of the repetitive pulse square wave current.

[0019] In this embodiment, the high voltage DC power supply voltage is set to 20 kV, the charging resistor is 50 MΩ, the wave impedance of the transmission cable is 50 Ω, the length of the transmission cable is 10 m, the matching resistor is 50 Ω, and the gap of the gas switch is 1 mm. The gas pressure of the gas switch is pressurized to different values.

[0020] like Figure 2As shown, the gas pressure of the gas switch is pressurized to 1 standard atmospheric pressure. Under this normal pressure, a pulse square wave is generated using the above parameters, and the pulse square wave is measured using a Rogowski coil. The leading edge of the pulse square wave under normal pressure is 20ns; Figure 3 As shown, the gas switch is pressurized to 0.3MPa, and the other parameters remain unchanged. Two different Rogowski coils are used to measure the pulse square wave. It can be seen that the leading edge of the pulse square wave is reduced to 5ns when the pressure is increased to 0.3MPa.

[0021] The utility model has a simple structure, effectively realizes the function of adjustable pulse square wave front edge, and has important practical application significance in the field of repetition rate nanosecond level pulse square wave current source.

[0022] The charging resistor R 0 The resistance value of the charging resistor R 0 The resistance value is greater than 1MΩ.

[0023] Specifically, in this embodiment, the charging time of the transmission cable is controlled by adjusting the resistance value of the charging resistor, thereby controlling the voltage rise time at the gas switch, thereby adjusting the frequency of the repetitive pulse square wave current. The larger the resistance value, the longer the charging time of the transmission cable, the longer the time for the voltage of the transmission cable to reach the breakdown voltage of the gas switch, and the lower the frequency of the repetitive pulse square wave current.

[0024] When the high voltage direct current generator HVDC charges the transmission cable through the charging resistor, the charging power supply voltage is assumed to be U 0 , then the relationship between the voltage U of the transmission cable and the charging time t when charging the transmission cable is: Where C is the capacitance per unit length of the transmission cable.

[0025] According to the above formula, the product of the charging time t, the resistance value of the charging resistor and the capacitance per unit length of the transmission cable is R 0 C, usually 3 to 5 times R 0 C.

[0026] When the voltage of the transmission cable reaches the breakdown voltage of the gas switch, the gas switch is broken down, and the transmission cable discharges through the matching resistor to generate a pulse square wave current. The width of the pulse square wave current is related to the length of the transmission cable. In this embodiment, for the transmission cable with polyethylene medium, it is considered that the width of the pulse square wave current is related to the length of the transmission cable is 10ns / m. When the voltage of the transmission cable is released through the matching resistor, the voltage drop of the transmission cable is 0, and the gas switch recovers the insulation state. Then the transmission cable continues to be charged by the high-voltage direct current generator HVDC. When the voltage of the transmission cable reaches the breakdown voltage of the gas switch again, the gas switch is broken down, and a pulse square wave current is generated again. The cycle is repeated in sequence to generate a pulse square wave current with a repetition frequency. It can be seen that the repetition frequency is directly related to the charging time of the cable. The larger the resistance value of the charging resistor, the longer the charging time of the transmission cable, the longer the time for the voltage of the transmission cable to reach the breakdown voltage of the gas switch, and the lower the frequency of the repetition frequency pulse square wave current.

[0027] In this embodiment, the high-voltage DC power supply voltage is set to 20kV, the wave impedance of the transmission cable is 50Ω, the length of the transmission cable is 10m, the matching resistance is 50Ω, the gap of the gas switch is 1mm, the gas pressure of the gas switch is 0.3MPa, the charging resistance is adjusted to 10MΩ, 50MΩ and 200MΩ respectively, and the frequencies of the obtained pulse square wave current are 30Hz, 6Hz and 1.5Hz respectively. It can be seen that the use of a charging resistor with adjustable resistance also enables the utility model to have the advantage of repetitive frequency operation.

[0028] The wave impedance of the transmission cable is 50Ω. The resistance value of the matching resistor Z is equal to the wave impedance of the transmission cable. Specifically, for a cable with a wave impedance of 50Ω, its capacitance per unit length C is approximately 100pF / m.

[0029] The above-mentioned specific implementation modes are preferred embodiments of the present invention and cannot be used to limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. A nanosecond pulse square wave current source with adjustable rising front, characterized in that: include: A high-voltage direct current power supply part, a transmission cable and a pulse square wave current generating part, wherein the high-voltage direct current power supply part comprises a high-voltage direct current generating device HVDC and a charging resistor R0, the grounding end of the high-voltage direct current generating device HVDC is grounded, the high-voltage end of the high-voltage direct current generating device HVDC is connected in series with the charging resistor R0 and then connected to one end of the core wire of the transmission cable, and one end of the shielding layer of the transmission cable is grounded; one end of the pulse square wave current generating part is connected to the other end of the core wire of the transmission cable, and the other end of the pulse square wave current generating part is connected to the other end of the shielding layer of the transmission cable, and the pulse square wave current generating part comprises a matching resistor Z and a gas switch, and the gas pressure of the filling gas of the gas switch is adjustable.

2. The nanosecond pulse square wave current source with adjustable rising front edge according to claim 1, characterized in that: The resistance value of the charging resistor R0 is adjustable.

3. The nanosecond pulse square wave current source with adjustable rising front edge according to claim 2, characterized in that: The resistance value of the charging resistor R0 is greater than 1 MΩ.

4. The nanosecond pulse square wave current source with adjustable rising front edge according to claim 1, characterized in that: The gas pressure of the filling gas of the gas switch is greater than or equal to 1 standard atmospheric pressure.

5. The nanosecond pulse square wave current source with adjustable rising front edge according to claim 1, characterized in that: The wave impedance of the transmission cable is 50Ω.

6. The nanosecond pulse square wave current source with adjustable rising front edge according to claim 5, characterized in that: The resistance value of the matching resistor Z is equal to the wave impedance of the transmission cable.

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