A nanosecond pulse high-voltage source based on a differential circuit and a method for generating the same

Abstract

The present invention discloses a nanosecond pulse high-voltage source based on a differential circuit and a method for generating the same. By regulating the on-off control of the integrated high-speed switch module to control the charging and discharging of the energy storage capacitor, a high-voltage pulse electric field with adjustable pulse width is obtained. In order to adapt to the huge differences in the electrical characteristics of biological loads, the biological load port is divided into a high-resistance load port and a low-resistance load port, and corresponds to high-resistance and low-resistance load modes respectively. The low-resistance load mode can simultaneously apply a pulse electric field sequence with different parameters to two different biological loads; the high-resistance load mode can greatly improve the waveform quality of the pulse and the adjustable pulse width range. At the same time, in order to reduce the development cost and improve the system efficiency, the present invention adopts a centralized energy storage capacitor architecture rather than the distributed capacitor architecture of the traditional Marx circuit. In summary, the present invention achieves higher biological load adaptability, better waveform quality, a larger adjustable pulse width range and controllable development costs through innovations in circuit architecture.

Description

Technical Field

[0001] The present invention relates to the technical fields of bioelectronics and nanosecond pulse high-voltage sources, and in particular to a high-voltage pulse electric field circuit with adjustable pulse width and adaptability to a wide range of loads based on an architecture and a high-speed high-voltage switch. Background Art

[0002] High-voltage pulsed electric field technology is widely used in various fields, including but not limited to environmental governance, electric vehicles, high-speed railways, nuclear energy control, biomedicine, etc. The equipment of the present invention is mainly designed to meet the special needs of basic research on the regulation of cell effects by high-voltage pulsed electric fields in the biomedical field. The effect of high-voltage pulsed electric fields on cells varies with the changes in pulse parameters and is used to regulate different cell effects; different pulse parameters can induce reversible electroporation effects and irreversible electroporation effects on cell membranes. The reversible electroporation effect is more of a combination of biochemical means. After the cell membrane is reversibly perforated by electric pulses, the perforations can promote the entry of large molecules such as anti-cancer drugs into the cell; the irreversible perforation effect is that the electric pulse acts on the cell membrane to produce irreparable perforations, thereby inducing tumor cell necrosis. This technology is called "nano-knife technology." When a pulsed electric field with a pulse width of microseconds to milliseconds and a peak electric field strength of 100V / m to 1kV / cm acts on the cell membrane, reversible electroporation can be induced; when the pulse width is in the nanosecond to microsecond level and the peak electric field strength is above 1kV / cm, the cell membrane begins to produce irreversible electroporation.

[0003] Currently, most mainstream technologies for generating high-voltage pulses use Marx circuits or are based on Marx circuit concepts. Existing technologies suffer from the following issues: Traditional Marx circuits suffer from non-adjustable pulse widths and large size. New Marx circuits offer advantages such as adjustable pulse width, high frequency, and compact size, but suffer from low voltage and current levels. Furthermore, both traditional and new Marx circuits suffer from the problem of decreasing voltage conversion efficiency with higher Marx levels. This is due to the increased complexity of the circuit and the resulting increase in parasitic parameters. Furthermore, the excessive number of capacitors contributes to significant parasitic parameters. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention uses a single centralized capacitor charging and discharging architecture and switch modularization to achieve the purpose of reducing circuit parasitic parameters, improving voltage conversion efficiency, and adapting different loads according to different output ports. The following technical solutions are adopted:

[0005] A nanosecond pulse high-voltage source based on a differential circuit includes an integrated high-voltage direct current module, an integrated high-speed switch module, an energy storage capacitor module, a digital control module, and a biological load port. The high-speed switch module includes a first and a second group of high-speed switch devices. The energy storage capacitor module includes a first and a second energy storage capacitor module. The load port includes a high-resistance load port and a first and a second low-resistance load port, which can adapt to different biological loads, such as biological cells, muscle tissue, etc. The high-voltage direct current module is respectively connected to one end of the first energy storage capacitor module, the second energy storage capacitor module, the first group of high-speed switch devices, and the second group of high-speed device modules. The first group of high-speed The other end of the switching device is respectively connected to one end of the high-resistance load port and one end of the first low-resistance load port. The other end of the second group of high-speed switching devices is respectively connected to the other end of the high-resistance load port and one end of the second low-resistance load port. The other end of the first low-resistance load port is connected to the other end of the first energy storage capacitor module, and the other end of the second low-resistance load port is connected to the other end of the second energy storage capacitor module. The first and second low-resistance load ports are respectively connected in parallel with a first bypass resistor and a second bypass resistor. The digital control module is respectively connected to the first and second groups of high-speed switching devices and is used to adjust the control signal of the high-speed switching module. The load port is used to generate pulses. The integrated high-speed switching module has high voltage and current levels, and the voltage and current levels increase with the increase in the number of integrated switching devices. By controlling the integrated high-speed switching modules, the DC voltage is modulated into a pulse voltage.

[0006] Furthermore, the first and second groups of high-speed switching devices are X×X electronic switch arrays.

[0007] Furthermore, the high-voltage direct current module is integrated, and the X×X electronic switch array is integrated through the copper-clad ceramic substrate, thereby reducing the parasitic parameters of the electronic switch.

[0008] Furthermore, the electronic switch includes SiC MOSFET, GaN HEMT, and IGBT.

[0009] Furthermore, a protection resistor is connected in series between the integrated high-voltage direct current module and the integrated high-speed switch module.

[0010] Furthermore, the load port is a biological load port, and pulse electric field sequences with different parameters are applied to different biological loads through the output of the load port.

[0011] Furthermore, the voltage level of the integrated high-speed switch module depends on the number of switch devices connected in series, and the current level depends on the number of switch devices connected in parallel. The voltage and current levels are within 3kV~5kV and 100A~150A.

[0012] Furthermore, the energy storage capacitor module is designed based on a centralized capacitor charging and discharging architecture. Compared with the traditional Marx circuit's dispersed energy storage capacitors, this architecture has the advantage that under the same capacitance value, the number of energy storage modules and integrated switch modules required for the nanosecond pulse high-voltage source is greatly reduced. The centralized capacitor architecture only requires two energy storage capacitor modules, which reduces the number of energy storage capacitors used and reduces the cost, thereby greatly reducing the circuit parasitic parameters of the nanosecond pulse high-voltage source based on a single centralized energy storage capacitor charging and discharging architecture.

[0013] A method for generating a nanosecond pulse high voltage source based on a differential circuit comprises the following steps:

[0014] S11, the integrated high-voltage DC module discharges the first and second energy storage capacitor modules through the first bypass resistor and the second bypass resistor respectively;

[0015] S12, the first group of high-speed switching devices is turned on first, and the first energy storage capacitor module starts to discharge;

[0016] S13, the second group of high-speed switching devices is turned on with a delay, and the second energy storage capacitor module starts to discharge;

[0017] S14, obtaining a pulse voltage outputted by the high-resistance load port to its load according to the difference between the two discharge voltages.

[0018] A method for generating a nanosecond pulse high voltage source based on a differential circuit comprises the following steps:

[0019] S21, the high-resistance load interface is not acting on the high-resistance load biological tissue, so it is in the disconnected state;

[0020] S22, when the first and second high-speed switching devices are disconnected, the first and second energy storage capacitor modules are charged to the voltage input by the integrated high-voltage DC module;

[0021] S23, when the first and second high-speed switching devices are closed, the first and second energy storage capacitor modules respectively apply pulsed electric field sequences with the same or different parameters to two different or the same biological loads simultaneously through the first and second low-load ports.

[0022] The advantages and beneficial effects of the present invention are:

[0023] The integrated high-speed switch module used in the present invention has high voltage and current levels, and the voltage and current levels increase with the increase in the number of integrated switch devices. By controlling the integrated high-speed switch module, the DC voltage is modulated into a pulse voltage; the load port can adapt to different biological loads; the parasitic parameters of the electronic switch are reduced; the energy storage capacitor is reduced, the cost is lower, and the parasitic parameters brought by the energy storage capacitor module are less affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a circuit topology diagram of the present invention.

[0025] Figure 2 This is a topological diagram of the integrated high-speed switch module in the present invention.

[0026] Figure 3 This is a topological diagram of the circuit discharge loop in the high-resistance load mode of the present invention.

[0027] Figure 4 This is a topological diagram of the circuit discharge loop in the low-resistance load mode of the present invention.

[0028] Figure 5 This is a control timing diagram in the present invention.

[0029] Figure 6 This is a simulation waveform diagram of the output under high-resistance load mode in the present invention.

[0030] Figure 7 This is a simulation waveform diagram of the outputs of two different output ports under the low-resistance load mode of the present invention. DETAILED DESCRIPTION

[0031] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0032] In the present invention, a nanosecond pulse high-voltage source based on a differential circuit is provided. The present invention obtains a high-voltage pulse electric field with adjustable pulse width by adjusting the control signal of the integrated high-speed switch module. The period and duty cycle of the integrated high-speed switch module signal are controlled, and the parameters thereof are different according to different working modes. In the low-resistance load working mode, the period and duty cycle parameters of the two control signals output by the digital control module can be different, but in the high-resistance load working mode, the period of the two control signals output by the digital control module is the same, but the duty cycle is different. The present invention solves the problems of low voltage conversion efficiency and high circuit parasitic parameters of the traditional Marx circuit by using a differential circuit method, thereby reducing costs and improving voltage conversion efficiency.

[0033] like Figure 1 As shown, the present invention provides a nanosecond pulse high voltage source based on a differential circuit, comprising a high voltage direct current power supply HVDC (1), a protective resistor R P (2), integrated high-speed switch modules S1 (5) and S2 (7), energy storage capacitor modules C1 (9) and C2 (14), bypass resistor R L1 (10) and R L2 (13).

[0034] like Figure 2As shown, a 5X5 array of electronic switch SiC MOSFET (15) (this is only used as an example, not limited to SiCMOSFET, and can also be based on electronic switches such as GaN HEMT, IGBT, and the matrix is not limited to 5X5), an electronic switch SiC MOSFET (15) integrated module, a 5X5 electronic switch SiC MOSFET (15) array is integrated into a module through a copper-clad ceramic substrate process technology, and its advantage is that the parasitic parameters of the electronic switch SiC MOSFET (15) module are reduced.

[0035] The working principle of the circuit of the present invention is mainly to utilize the charging and delayed discharge process of the energy storage capacitor module. The following is the working mode of the nanosecond pulse high voltage source and high resistance load: Figure 3 As shown, the high voltage DC power supply HVDC (16) is connected to the R L1 (24), R L2 (25) Charge the energy storage capacitors C1 (23) and C2 (26). Theoretically, the voltage of the energy storage capacitors is equal to the high-voltage DC charging voltage. Their relationship is as follows:

[0036] (1)

[0037] In order to ensure that the potential generated by the circuit is the same, the design of both sides of the circuit needs to be consistent. Figure 1 , the voltage formula for large load output is:

[0038] (2)

[0039] When only one-sided circuit is working, the equivalent load formula is as follows:

[0040] or (3)

[0041] When the unilateral circuit works, the output formula is:

[0042] or (4)

[0043] From the formula, we can see that when SMA3 high resistance load R L3 (6) Much larger than R L2 (13) When R L2 The partial pressure of (13) can be ignored. Similarly, when R L3 (6) Much larger than R L1 (10) When R L1 The partial pressure of (10) can be neglected.

[0044] In order to ensure that the output voltages of the left and right circuits are equal, it is necessary to The selection of R is mainly affected by the maximum current level I of the integrated high-speed switch module. D Impact, R and I D The relationship is as follows:

[0045] (5)

[0046] For large loads R L3 The selection of (6) depends on the required voltage conversion efficiency. Assuming that the voltage conversion efficiency is to be above 80%, the following relationship needs to be satisfied:

[0047] (6)

[0048] You can get R L3 (6)>4R, so once R is determined, R can be determined based on the conversion efficiency. L3 (6) Scope.

[0049] like Figure 5 As shown, the integrated high-speed switch module S1 (5) is turned on first, and the energy storage capacitor C1 (9) begins to discharge, and the discharge voltage is V1 (4). The integrated high-speed switch module S2 (7) switches on with a delay of The time is turned on, and the energy storage capacitor C2 (14) begins to discharge, and the discharge voltage is V2 (8). According to the output voltage formula (2), the high resistance load can be obtained Output pulse voltage waveform Output pulse.

[0050] like Figure 4 As shown, since the high-resistance load interface does not act on the high-resistance load biological tissue, it is in a disconnected state. At this time, the integrated high-speed switch modules S1 (30) and S2 (31) are disconnected, and the energy storage capacitors C1 (33) and C2 (38) are charged to the voltage input by the high-voltage DC module HVDC (27). When the integrated high-speed switch modules S1 (30) and S2 (31) are closed, the energy storage capacitors C1 (33) and C2 (38) apply pulse electric field sequences with different parameters to different biological loads through the low-load output port.

[0051] To further explain the details, a specific example is given below. Protecting the resistor in high resistance load mode , energy storage capacitor , high resistance load output port bypass resistor , high resistance load output port simulates the resistance of biological tissue , high voltage DC source When the energy storage capacitor is fully charged, the integrated high-speed switch module First connected, the switch closing time is , energy storage capacitor Start discharging, delay Finally, integrated high-speed switch module Start connecting, The switch closing time is At this time, the energy storage capacitor Also starts to discharge, the discharge circuit of the circuit is as follows Figure 3 As shown, under large load The pulse at the beginning of the falling edge until The pressure difference is zero, so it can be used under large load A pulse width of , with an amplitude close to pulse.

[0052] Protective resistor in low resistance load mode , energy storage capacitor , low resistance load output port bypass resistor , the resistance of the low resistance load output port simulating biological tissue is , high voltage DC source When the energy storage capacitor is fully charged, the integrated high-speed switch module Integrated high-speed switch module Start to connect, integrated high-speed switch module The switch closing time is , integrated high-speed switch module The switch closing time is At this time, the energy storage capacitor and Start discharging, the discharge circuit of the circuit is as follows Figure 4 As shown, pulses with a pulse width of 40 ns and an amplitude of nearly 1000 V and a pulse width of 60 ns and an amplitude of nearly 1000 V are obtained at the low-resistance load output ports SMA1 (35) and SMA2 (36), respectively.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nanosecond pulse high voltage source based on a differential circuit, comprising an integrated high voltage DC module, an integrated high speed switch module, an energy storage capacitor module, a digital control module and a load port, characterized in that The high-speed switch module includes first and second groups of high-speed switch devices, the energy storage capacitor module includes first and second energy storage capacitor modules, and the load port includes a high-resistance load port and first and second low-resistance load ports. The high-voltage DC module is respectively connected to one end of the first energy storage capacitor module, the second energy storage capacitor module, the first group of high-speed switch devices, and the second group of high-speed device modules. The other end of the first group of high-speed switch devices is respectively connected to one end of the high-resistance load port and one end of the first low-resistance load port. The other end of the second group of high-speed switch devices is respectively connected to the other end of the high-resistance load port and one end of the second low-resistance load port. The other end of the first low-resistance load port is connected to the other end of the first energy storage capacitor module, and the other end of the second low-resistance load port is connected to the other end of the second energy storage capacitor module. The first and second low-resistance load ports are respectively connected in parallel with a first bypass resistor and a second bypass resistor. The digital control module is respectively connected to the first and second groups of high-speed switch devices and is used to adjust the control signal of the high-speed switch module. The load ports are used to generate pulses. The first and second groups of high-speed switch devices are X×X electronic switch arrays.

2. The nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that The integrated high-voltage direct current module integrates an X×X electronic switch array through a copper-clad ceramic substrate.

3. The nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that The electronic switches include SiC MOSFET, GaN HEMT, and IGBT.

4. The nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that A protection resistor is connected in series between the integrated high-voltage direct current module and the integrated high-speed switch module.

5. The nanosecond pulse high voltage source based on differential circuit according to claim 1, characterized in that The load port is a biological load port, and pulse electric field sequences with different parameters are applied to different biological loads through the output of the load port.

6. The nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that The voltage level of the integrated high-speed switch module depends on the number of switch devices connected in series, and the current level depends on the number of switch devices connected in parallel. The voltage and current levels are within 3kV~5kV and 100A~150A.

7. The nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that The energy storage capacitor module is designed based on a centralized capacitor charging and discharging architecture.

8. A method for generating a nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that The steps include: S11, the integrated high-voltage DC module discharges the first and second energy storage capacitor modules through the first bypass resistor and the second bypass resistor respectively; S12, the first group of high-speed switching devices is turned on first, and the first energy storage capacitor module starts to discharge; S13, the second group of high-speed switching devices is turned on with a delay, and the second energy storage capacitor module starts to discharge; S14, obtaining a pulse outputted by the high-resistance load port to its load according to the difference between the two discharge voltages.

9. A method for generating a nanosecond pulse high voltage source based on a differential circuit according to claim 1, characterized in that The steps include: S21, high resistance load interface disconnected; S22, when the first and second high-speed switching devices are disconnected, the first and second energy storage capacitor modules are charged to the voltage input by the integrated high-voltage DC module; S23, when the first and second high-speed switching devices are closed, the first and second energy storage capacitor modules respectively apply the same or different pulses to two different or same loads simultaneously through the first and second low-load ports.

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