High-voltage ultra-short pulse power supply based on solid-state switch and transmission line

Abstract

The invention relates to the technical field of pulse power supplies, in particular to a high-voltage ultra-short pulse power supply based on a solid-state switch and a transmission line, which realizes nanosecond pulse rising edge output, high repetition frequency output and adjustable pulse parameter output by integrating the solid-state switch (such as an IGBT (Insulated Gate Bipolar Transistor) and an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor)) and a transmission line structure (such as a coaxial cable and a microstrip line). The power supply solves the problems of large arc loss and short service life of a traditional mechanical switch, optimizes the energy transmission efficiency through impedance matching of a transmission line, and is suitable for material science experiments, environmental tests, industrial processing and other scenes requiring high-precision pulse energy. The technical effects comprise that the pulse width is less than or equal to 10ns, the repetition frequency is greater than or equal to 1kHz, the adjustable range of the voltage amplitude is 1kV-100kV, and the device has the advantages of no arc, long service life, low electromagnetic interference and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pulse power supply, in particular to a high-voltage extremely short pulse power supply based on solid-state switch and transmission line. BACKGROUND

[0002] High-voltage pulse power supply has wide application in material modification, plasma generation, electromagnetic compatibility test and other fields. Traditional pulse power supply relies on mechanical switch (such as spark gap, rotating switch), which has the following problems:

[0003] Arc loss: mechanical switch produces arc when cutting off current, resulting in energy loss and equipment aging;

[0004] Lifetime limitation: mechanical parts wear out, resulting in short switch life (usually ≤100,000 times);

[0005] Slow response speed: mechanical switch response time ≥ microsecond level, difficult to meet nanosecond pulse demand;

[0006] Parameter adjustment difficulty: pulse width, amplitude and other parameters adjustment depends on hardware replacement, poor flexibility.

[0007] In recent years, solid-state switch technology (such as IGBT, SiC MOSFET) gradually replaces mechanical switch due to its non-contact, fast response (nanosecond level) and long life (≥100 million times). At the same time, transmission line structure can optimize pulse energy transmission and reduce reflection loss through impedance matching. However, the existing technology still has the following problems in the collaborative design of solid-state switch and transmission line:

[0008] Solid-state switch drive circuit is complex, resulting in large system volume;

[0009] Transmission line parameters and pulse source impedance are not matched, causing energy reflection;

[0010] Pulse parameter adjustment depends on external control, poor real-time performance.

[0011] The present application proposes a high-voltage extremely short pulse power supply based on solid-state switch and transmission line, which solves the above problems through integrated design. SUMMARY

[0012] The present application aims to provide a high-voltage extremely short pulse power supply based on solid-state switch and transmission line to solve the problems raised in the background art.

[0013] To achieve the above purpose, the present application provides the following technical solution: a high-voltage extremely short pulse power supply based on solid-state switch and transmission line, including a power supply body, characterized in that: the power supply body inside includes the following modules: high-voltage charging module, solid-state switch module, transmission line module, pulse forming module, control and feedback module;

[0014] The high-voltage charging module: uses a high-frequency switching power supply to step up the mains to the target voltage (1kV-100kV), and stores energy through a capacitor array;

[0015] The solid-state switch module: selects silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) as the main switch, with a conduction resistance ≤10mΩ and a switching speed ≤50ns, and cooperates with the driving circuit to realize nanosecond-level timing control;

[0016] The transmission line module: uses a coaxial cable as the pulse transmission path, with a characteristic impedance of 50Ω, matched with the load impedance to reduce energy reflection;

[0017] The pulse forming module: forms a high-voltage pulse with a pulse width ≤10ns through the short-circuit or open-circuit structure at the end of the transmission line, combined with the timing control of the solid-state switch;

[0018] The control and feedback module: based on field programmable gate array (FPGA), monitors pulse parameters (amplitude, width, frequency) in real time, and dynamically adjusts the driving signal of the solid-state switch through closed-loop control.

[0019] Preferably, the driving circuit of the solid-state switch module adopts a double-pulse control strategy

[0020] Pre-charge pulse: before the main switch is turned on, a narrow pulse (width ≤10ns) is applied to the gate capacitance of the SiC MOSFET for pre-charge, reducing the conduction loss;

[0021] Main switch pulse: immediately after the pre-charge pulse, the main driving pulse is applied to control the switch conduction, realizing nanosecond-level current rising edge;

[0022] Dynamic timing adjustment: FPGA dynamically adjusts the time interval (Δt ≤5ns) between the pre-charge pulse and the main switch pulse according to the real-time data of the feedback module, to compensate for the effects of temperature drift and device aging on switch performance.

[0023] Preferably, the control and feedback module includes the following functional units

[0024] Parameter monitoring unit: measures pulse current through a Rogowski coil, and measures pulse voltage through a high-voltage voltage divider, with a sampling frequency ≥100MHz;

[0025] Closed-loop control algorithm: adopts proportional-integral-derivative (PID) control, dynamically adjusts the output voltage of the high-voltage charging module and the driving timing of the solid-state switch according to the deviation between the monitoring data and the set value;

[0026] Fault protection mechanism: When overcurrent (≥1.2 times rated current) or overvoltage (≥1.1 times rated voltage) is monitored, the FPGA turns off the solid-state switch within 100 ns and releases the remaining energy through the transmission line energy absorption circuit.

[0027] Preferably, the integrated design of the power supply body includes the following structure

[0028] Sealed module: The high-voltage charging module, solid-state switch module, and transmission line module are packaged in a metal shell with a protection level ≥ IP65, suitable for humid or dusty environments;

[0029] Heat dissipation structure: Liquid cooling channels are provided at the connection between the SiC MOSFET and the transmission line, and the temperature rise is controlled to ≤ 40℃ by circulating cooling liquid (such as deionized water);

[0030] Electromagnetic shielding: The inner layer of the shell is lined with conductive rubber, and the outer layer is made of galvanized steel plate, with a shielding effectiveness ≥ 40 dB (frequency range 10 kHz-1 GHz).

[0031] Preferably, the transmission line module supports multiple frequency band operation modes:

[0032] Frequency band switching: By embedding an adjustable inductor in the coaxial cable, the pulse frequency can be switched within the range of 1 kHz-1 MHz;

[0033] Impedance adaptation: When the frequency band is switched, the FPGA automatically adjusts the position of the short-circuit point at the end of the transmission line to maintain the matching of the characteristic impedance and the load impedance;

[0034] Harmonic suppression: In high-frequency mode (≥100 kHz), the transmission line structure suppresses 3rd and higher harmonics, with total harmonic distortion (THD) ≤ 3%.

[0035] Preferably, the power supply body supports multiple pulse sequence output modes:

[0036] Pulse sequence programming: Users can set pulse sequence parameters (such as single pulse, double pulse, periodic pulse train) through the host computer software, and the FPGA converts the parameters into driving signals;

[0037] Pulse interval control: In periodic pulse train mode, the pulse interval time can be adjusted within the range of 1 μs-1 s, suitable for material fatigue testing or plasma sustained excitation scenarios;

[0038] Energy balance management: In multiple pulse output, the control and feedback module dynamically allocates the energy storage of the capacitor array to ensure the stability of the amplitude and width of each pulse.

[0039] Compared with the prior art, the beneficial effects of the present application are:

[0040] 1. The solid-state switch is cooperatively designed with the transmission line: the traditional design only takes the solid-state switch as an independent element, and the application optimizes the working condition of the switch through the impedance matching of the transmission line, reduces the conduction loss (30% lower than the traditional design).

[0041] 2. The solid-state switch is turned off in advance before the current zero-crossing point to avoid arc generation, and the energy absorption circuit of the transmission line is combined to realize lossless interruption. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The system block diagram of the high-voltage extremely short pulse power supply based on the solid-state switch and the transmission line is provided. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0044] Please refer to Figure 1 The application provides a technical solution: a high-voltage extremely short pulse power supply based on a solid-state switch and a transmission line, comprising a power supply body, characterized in that: the power supply body comprises the following modules inside: a high-voltage charging module, a solid-state switch module, a transmission line module, a pulse forming module, a control and feedback module.

[0045] The high-voltage charging module: a high-frequency switching power supply is used to step up the mains to the target voltage (1kV-100kV), and the energy is stored through a capacitor array.

[0046] The solid-state switch module: silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) is selected as the main switch, the on-resistance thereof is ≤10mΩ, and the switching speed thereof is ≤50ns, which realizes nanosecond-level timing control in cooperation with the driving circuit.

[0047] The transmission line module: a coaxial cable is used as the pulse transmission path, the characteristic impedance thereof is 50Ω, and the load impedance is matched to reduce energy reflection.

[0048] The pulse forming module: through the short-circuit or open-circuit structure at the end of the transmission line, in combination with the timing control of the solid-state switch, a high-voltage pulse with a pulse width ≤10ns is formed.

[0049] The control and feedback module: based on a field programmable gate array (FPGA), the pulse parameters (amplitude, width, frequency) are monitored in real time, and the driving signal of the solid-state switch is dynamically adjusted through closed-loop control.

[0050] The drive circuit of the solid-state switch module adopts a double-pulse control strategy

[0051] Pre-charge pulse: Before the main switch is turned on, a narrow pulse (width ≤ 10 ns) is applied to pre-charge the gate capacitance of the SiC MOSFET, reducing the conduction loss;

[0052] Main switch pulse: Immediately after the pre-charge pulse, the main drive pulse is applied to control the switch conduction, achieving a nanosecond-level current rising edge;

[0053] Dynamic timing adjustment: The FPGA dynamically adjusts the time interval (Δt ≤ 5 ns) between the pre-charge pulse and the main switch pulse according to real-time data from the feedback module, to compensate for the effects of temperature drift and device aging on switch performance.

[0054] The control and feedback module includes the following functional units

[0055] Parameter monitoring unit: Measure pulse current with a Rogowski coil, measure pulse voltage with a high-voltage divider, sampling frequency ≥ 100 MHz;

[0056] Closed-loop control algorithm: Use proportional-integral-derivative (PID) control to dynamically adjust the output voltage of the high-voltage charging module and the drive timing of the solid-state switch according to the deviation between the monitoring data and the set value;

[0057] Fault protection mechanism: When overcurrent (≥ 1.2 times rated current) or overvoltage (≥ 1.1 times rated voltage) is detected, the FPGA turns off the solid-state switch within 100 ns and releases the remaining energy through a transmission line energy absorption circuit.

[0058] The integrated design of the power supply body includes the following structure

[0059] Sealing module: The high-voltage charging module, solid-state switch module, and transmission line module are packaged in a metal shell, with a protection level ≥ IP65, suitable for humid or dusty environments;

[0060] Heat dissipation structure: Liquid cooling channels are set at the connection between the SiC MOSFET and the transmission line, and the temperature rise is controlled to ≤ 40℃ through circulating cooling liquid (such as deionized water);

[0061] Electromagnetic shielding: The inner layer of the shell is lined with conductive rubber, and the outer layer is made of galvanized steel plate, with a shielding effectiveness ≥ 40 dB (frequency range 10 kHz-1 GHz).

[0062] The transmission line module supports multiple frequency band operation modes:

[0063] Frequency band switching: By embedding an adjustable inductor in the coaxial cable, the pulse frequency can be switched within the range of 1 kHz-1 MHz;

[0064] Impedance adaptation: when frequency band switching, FPGA automatically adjusts the position of the short-circuit point at the end of the transmission line, maintaining the matching of the characteristic impedance and the load impedance;

[0065] Harmonic suppression: in high frequency mode (≥100kHz), the transmission line structure suppresses 3rd and higher harmonics, with total harmonic distortion (THD) ≤3%.

[0066] The power supply body supports multiple pulse sequence output modes:

[0067] Pulse sequence programming: users can set pulse sequence parameters (such as single pulse, double pulse, periodic pulse train) through the host computer software, and FPGA converts the parameters into driving signals;

[0068] Pulse interval control: in periodic pulse train mode, the pulse interval time can be adjusted in the range of 1μs-1s, suitable for material fatigue testing or plasma sustained excitation scenarios;

[0069] Energy balance management: in multiple pulse output, the control and feedback module dynamically allocates the energy storage of the capacitor array to ensure the stability of the amplitude and width of each pulse.

[0070] The following invention details the technical implementation path of the high-voltage extremely short pulse power supply based on solid-state switch and transmission line through three dimensions of hardware design, control strategy, and experimental verification, ensuring the feasibility and technical effects of the invention content: hardware design and integration

[0071] (1) High-voltage charging module

[0072] Adopting high-frequency switch power supply architecture, input mains (220V / 50Hz) is converted into DC through a rectifier bridge, and then high-frequency AC (frequency 20kHz-50kHz) is generated through a full-bridge inverter circuit, and then boosted to the target voltage (1kV-100kV) through a high-frequency transformer. The boosted voltage is stored by a capacitor array (withstanding voltage ≥120% of the rated voltage), and the capacitance value is calculated according to the pulse energy demand:

[0073] Where E is the single pulse energy (J), C is the capacitance value (F), and V is the charging voltage (V). For example, to generate a 10kV, 10ns pulse (energy 10J), the capacitance value needs to be ≥20μF.

[0074] (2) Solid-state switch module

[0075] SiC MOSFET (model C2M0080120D) is selected as the main switch, with the following key parameters: on-resistance R DS(on) ≤8mΩ, switching speed ≤30ns, withstand voltage 1200V. The driving circuit adopts a double-pulse control strategy:

[0076] Pre-charge pulse: a narrow pulse with 5 ns width and 10 V amplitude charges the gate capacitance, reducing the on-state loss;

[0077] Main switch pulse: a pulse with 100 ns width and 15 V amplitude controls the switch to turn on, realizing the nanosecond-level current rising edge (di / dt≥10 A / ns).

[0078] (3) Transmission line module

[0079] Coaxial cable (model RG402) is used as the pulse transmission path, with a characteristic impedance of 50 Ω, and the length is calculated according to the pulse width requirement:

[0080] where L is the length of the transmission line (m), c is the speed of light (3×10 8 m / s), τ is the pulse width (s), and ∈r is the relative dielectric constant of the medium (the ∈r of RG402 is approximately 2.2). For example, when generating a 10 ns pulse, the length of the transmission line needs to be ≤1.5 m. An adjustable short circuit structure is provided at the end of the transmission line, which can change the position of the short circuit point by screw rotation, adjusting the pulse width range of 1 ns-10 ns.

[0081] (4) Control and feedback module

[0082] Real-time monitoring and closed-loop control are realized based on FPGA (model Xilinx Kintex-7):

[0083] Parameter monitoring: Rogowski coil (sensitivity 1 mV / A) measures the pulse current, high-voltage divider (division ratio 1000:1) measures the pulse voltage, sampling frequency 200 MHz;

[0084] Closed-loop control algorithm: PID control is used to dynamically adjust the output voltage of the high-voltage charging module and the driving timing of the solid-state switch according to the deviation between the monitoring data and the set value;

[0085] Fault protection: when overcurrent (≥1.2 times the rated current) or overvoltage (≥1.1 times the rated voltage) is monitored, the FPGA turns off the solid-state switch within 50 ns, and the remaining energy is released through the transmission line energy absorption circuit (resistor array + IGBT switch).

[0086] 2. Control strategy implementation

[0087] (1) Double-pulse driving timing optimization

[0088] The effect of the time interval (Δt) between the pre-charge pulse and the main switch pulse on the switch performance is calibrated through experiments. For example, the conduction loss of SiC MOSFET decreases by 40% at Δt = 5 ns compared to Δt = 0 ns, and the current rise time stabilizes at ≤8 ns. The FPGA dynamically adjusts Δt based on the data feedback from the temperature sensor (NTC thermistor) to compensate for temperature drift (a 10°C temperature rise causes the on-resistance to increase by 5%).

[0089] (2) Multi-pulse sequence output control

[0090] The user sets the pulse sequence parameters (such as a double-pulse interval of 10 μs and a periodic pulse train frequency of 1 kHz) through the host computer software (LabVIEW platform). The FPGA converts the parameters into driving signals and distributes the energy storage of the capacitor array through an energy equalization management algorithm. For example, when continuously outputting 10 pulses, the capacitor voltage fluctuation is ≤5%, ensuring the stability of the amplitude of each pulse.

[0091] (3) Multi-band operation mode switching

[0092] By embedding an adjustable inductor (inductance range 10 nH-1 μH) in the coaxial cable, the pulse frequency can be switched within the range of 1 kHz-1 MHz. The FPGA automatically adjusts the position of the short-circuit point at the end of the transmission line based on the frequency setting value to maintain the matching of the characteristic impedance and the load impedance. For example, in the 1 MHz mode, the transmission line length is shortened to 0.3 m, and the total harmonic distortion (THD) is controlled at ≤3% through a harmonic suppression algorithm (based on fast Fourier transform, FFT).

[0093] 3. Experimental verification and results

[0094] (1) Pulse width adjustment experiment

[0095] Adjust the position of the short-circuit point at the end of the transmission line and measure the output pulse width. The results are shown in the table below, and the pulse width and the position of the short-circuit point show a linear relationship (R 2 ≥0.99), verifying the effectiveness of the adjustable short-circuit structure.

[0096] Short point position (mm) Pulse width (ns) 0 (end short) 1.2 50 3.8 100 6.5 150 9.1

[0097] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.

[0098] While the embodiments of the application have been shown and described herein, it will be understood by those skilled in the art that many changes, modifications, substitutions and alterations to these embodiments can be made without departing from the principles and spirits of the application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-voltage ultra-short pulse power supply based on solid-state switches and transmission lines, comprising a power supply body, characterized in that: The power supply unit includes the following modules: a high-voltage charging module, a solid-state switch module, a transmission line module, a pulse forming module, and a control and feedback module. The high-voltage charging module uses a high-frequency switching power supply to boost the mains voltage to the target voltage (1kV-100kV) and stores energy through a capacitor array. The solid-state switch module uses silicon carbide (SiC) metal oxide semiconductor field-effect transistors (MOSFETs) as the main switch, with an on-resistance of ≤10mΩ and a switching speed of ≤50ns, which, together with the drive circuit, achieves nanosecond-level timing control. The transmission line module uses a coaxial cable as the pulse transmission path, with a characteristic impedance of 50Ω, which is matched with the load impedance to reduce energy reflection. The pulse forming module: through a short-circuit or open-circuit structure at the end of the transmission line, combined with the timing control of a solid-state switch, it forms a high-voltage pulse with a pulse width ≤10ns; The control and feedback module monitors pulse parameters (amplitude, width, and frequency) in real time based on a field-programmable gate array (FPGA) and dynamically adjusts the drive signal of the solid-state switch through closed-loop control.

2. The high-voltage ultra-short pulse power supply based on solid-state switches and transmission lines according to claim 1, characterized in that: The driving circuit of the solid-state switch module adopts a dual-pulse control strategy. Pre-charge pulse: Before the main switch is turned on, a narrow pulse (width ≤ 10ns) is applied to pre-charge the gate capacitance of the SiC MOSFET to reduce conduction losses; Main switching pulse: Immediately following the pre-charge pulse, the main drive pulse is applied to control the switch to turn on, achieving a nanosecond-level current rise edge; Dynamic timing adjustment: The FPGA dynamically adjusts the time interval (Δt≤5ns) between the precharge pulse and the main switch pulse based on real-time data from the feedback module to compensate for the impact of temperature drift and device aging on switching performance.

3. The high-voltage ultra-short pulse power supply based on solid-state switches and transmission lines according to claim 1, characterized in that: The control and feedback module includes the following functional units. Parameter monitoring unit: measures pulse current through Rogowski coil and pulse voltage through high voltage divider, with a sampling frequency ≥100MHz; Closed-loop control algorithm: Proportional-integral-derivative (PID) control is adopted, which dynamically adjusts the output voltage of the high-voltage charging module and the drive timing of the solid-state switch according to the deviation between the monitored data and the set value. Fault protection mechanism: When overcurrent (≥1.2 times rated current) or overvoltage (≥1.1 times rated voltage) is detected, the FPGA will turn off the solid-state switch within 100ns and release the remaining energy through the transmission line energy absorption circuit.

4. The high-voltage ultra-short pulse power supply based on solid-state switches and transmission lines according to claim 1, characterized in that: The integrated design of the power supply body includes the following structure. Sealed module: The high-voltage charging module, solid-state switch module, and transmission line module are encapsulated in a metal shell with a protection level of ≥IP65, suitable for humid or dusty environments; Heat dissipation structure: A liquid cooling channel is set at the connection between the SiC MOSFET and the transmission line, and the temperature rise is controlled to ≤40℃ by circulating coolant (such as deionized water); Electromagnetic shielding: The inner layer of the outer shell is lined with conductive rubber, and the outer layer is made of galvanized steel plate, with a shielding effectiveness of ≥40dB (frequency range 10kHz-1GHz).

5. A high-voltage ultra-short pulse power supply based on solid-state switches and transmission lines according to claim 1, characterized in that: The transmission line module supports multi-band operating modes: Frequency band switching: By embedding an adjustable inductor in the coaxial cable, the pulse frequency can be switched within the range of 1kHz-1MHz; Impedance Adaptive: When switching frequency bands, the FPGA automatically adjusts the position of the short-circuit point at the end of the transmission line to maintain the matching of characteristic impedance and load impedance; Harmonic suppression: In high-frequency mode (≥100kHz), the transmission line structure suppresses the third and higher harmonics, and the total harmonic distortion (THD) is ≤3%.

6. A high-voltage ultra-short pulse power supply based on solid-state switches and transmission lines according to claim 1, characterized in that: The power supply unit supports multi-pulse sequence output mode: Pulse sequence programming: Users can set pulse sequence parameters (single pulse, double pulse, periodic pulse train) through host computer software, and the FPGA converts the parameters into drive signals; Pulse interval control: In periodic pulse train mode, the pulse interval time is adjustable from 1μs to 1s, which is suitable for material fatigue testing or continuous plasma excitation scenarios. Energy balance management: During multi-pulse output, the control and feedback module dynamically allocates the energy stored in the capacitor array to ensure the stability of the amplitude and width of each pulse.

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