Dynamic variable topology resonance compensation circuit and control method for Marx generator

Abstract

This invention discloses a dynamic variable topology resonant compensation circuit and control method for Marx generators, belonging to the field of power electronics technology. (Including V) comp The multi-stage Marx circuit and dynamic variable topology resonant compensation circuit connected at the point of connection infer the magnitude of the top drop of the output pulse by collecting the voltage before and after the discharge of a certain stage capacitor in the Marx circuit. Then, the number of resonant compensation units participating in the discharge compensation is controlled in a closed loop, thereby enabling dynamic compensation of the output top drop of the Marx generator over a wide load range, improving the waveform quality of the output pulse voltage of the Marx generator, and achieving a precise and flat pulse voltage.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, and more specifically, relates to a dynamic variable topology resonance compensation circuit and control method for Marx generators. Background Technology

[0002] Many industrial applications currently have high requirements for the flatness of pulse voltage. However, since Marx generators essentially achieve high output voltage through the series discharge of capacitors, there will inevitably be a voltage drop at the top of the output pulse. The size of the voltage drop varies depending on the load size; the heavier the load and the longer the discharge time, the greater the voltage drop.

[0003] Currently available methods include Figure 1 As shown, the entire circuit mainly consists of two parts: a resonant compensation unit and a standard Marx unit. Both parts can be modularized and stacked in multiple stages. Each Marx unit is a positive polarity Marx topology, consisting of a discharge tube S. ai Charging tube S bi Diode D i and capacitor C i It consists of, and each stage of the resonant compensation unit is composed of a resonant tube S. resi Discharge tube S aresi Charging tube S bresi Diode D resi Capacitor C resi and inductor L resi The system is composed of components, and the capacitance in each stage of the resonant compensation unit is equal, i.e., C. res1 =C res2 =···=C resn At the same time, the inductance values ​​are equal, i.e., L res1 =L res2 =···=L resn Among them, discharge tube S ai S aresi and charging tube S bi S bresi It does not include an anti-parallel diode to prevent the resonant inductor L from operating in resonant mode. resi Through S aresi or S bresi The reverse freewheeling current in the body diode affects the normal single-resonance process of the resonant compensation unit. The switching transistor S at the input terminal of the circuit... dc Controls the charging of the entire circuit.

[0004] Under normal circumstances, the output pulse width is relatively small, the capacitor discharge time in the Marx circuit is relatively short, and the output voltage drops in a near-linear manner. The working principle of the harmonic compensation unit is to use the near-linear part of the resonant voltage waveform to compensate for the voltage drop, so that the discharge pulse starts at zero resonant voltage, and the required resonant voltage is added to the discharge pulse, thereby compensating for the voltage drop that occurs in the discharge pulse.

[0005] Figure 2 This refers to the drive signal and waveform of the circuit. The entire circuit has three main operating modes in each discharge cycle: charging mode, resonant mode, and discharging mode. First, in charging mode, the charging transistor S in the Marx circuit... bi The charging tube S in the resonant compensation unit bresi and the switching transistor S dc When the circuit is turned on, the DC source supplies power to capacitor C. resi C i During charging, all other switching transistors are in the off state. Secondly, in resonant mode, all capacitors are charged to V. in Then, the charging tube is turned off, while the discharging tube remains off, and the resonant tube S is turned on. resi , so that capacitor C resi With inductor L resi A resonant circuit is formed, and each resonant unit simultaneously begins its own single-resonance process. Finally, in discharge mode, when resonance begins t... d After a certain time, that is, the resonant capacitor voltage V Cresi When the waveform just crosses the coordinate axis and becomes a positive voltage, the discharge tube S in the Marx circuit... ai The discharge tube S in the resonance compensation unit aresi Turning on the capacitor C of the resonant compensation unit will turn on the capacitor C. resi With the capacitor C of the Marx circuit i By connecting them in series to discharge the load, compensation for the discharge waveform is achieved. The resonance process continues during discharge, so the near-linearly increasing voltage of the resonant capacitors can be applied to the discharge pulse to compensate for the output waveform.

[0006] In existing technologies, the resonant compensation unit shares a DC input power supply with the Marx circuit, and the capacitor in the resonant compensation unit must participate in the charging and discharging of each cycle. Therefore, the compensated voltage value of the resonant compensation unit cannot be adjusted after the design is completed. This results in the entire circuit maintaining a flat pulse top voltage only at one load point. As the load increases, the pulse top drop increases; as the load decreases, the pulse top voltage rises. Existing circuits cannot control the number of resonant compensation units participating in discharge compensation in a closed loop according to the load size, thus failing to achieve accurate and flat pulse voltages over a wide load range. Furthermore, each resonant compensation unit in existing technologies has the same resonant parameters and the same compensated voltage. Achieving a large compensation voltage range requires stacking many stages, resulting in high cost and large size. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a dynamic variable topology resonant compensation circuit and control method for Marx generators. This invention addresses the problems of traditional resonant compensation circuits, such as low top-drop compensation accuracy for Marx generators, inability to control the number of resonant compensation units involved in top-drop compensation, large size, and inability to perform closed-loop adjustment of the compensation voltage. The invention achieves accurate and flat pulse voltage over a wide load range.

[0008] To achieve the above objectives, the present invention provides a dynamic variable topology resonance compensation circuit for Marx generators, including V comp The multi-stage Marx circuit and dynamic variable topology resonant compensation circuit are connected at the point, wherein the dynamic variable topology resonant compensation circuit is composed of a DC source V in2 Separate power supply, the DC source V in2 DC source V of multi-stage Marx circuit in1 Common ground; the dynamic variable topology resonant compensation circuit includes multiple superimposed resonant compensation units, and the resonant frequency ω of each resonant compensation unit. resi Different, set to ω resn ≈2ω res(n-1) ≈4ω res(n-2) ≈···≈2 n-1 ω res1 , where n is the number of resonant compensation units, 1≤i≤n, and the combination of resonant compensation units participating in discharge compensation is determined according to the load size, used to compensate for the voltage drop at the top of the output pulse of the Marx generator.

[0009] Furthermore, the dynamic variable topology resonant compensation circuit includes a switching transistor S. dc2 Resistance R dc2 And a multi-stage superimposed resonant compensation unit, DC source V in2 With the switching transistor S dc2 Connected, series resistor R dc2Multiple resonant compensation units are cascaded to form a circuit. Each resonant compensation unit includes a resonant transistor S. resi Discharge tube S aresi Charging tube S bresi , capacitor branch transistor S cresi Diode D resi D aresi Capacitor C resi and inductor L resi capacitor branch transistor S cresi With capacitor C resi Series connection, resonant tube S resi With inductor L resi Series connection, diode D aresi With discharge tube S aresi The three series branches are connected in parallel at their upper ends and then connected to diode D. resi With the negative terminal connected, capacitor C resi and inductor L resi The lower end of the branch is connected in parallel and passes through the charging tube S. bresi With discharge tube S aresi The branch roads are connected.

[0010] Furthermore, each stage of the Marx circuit includes a switching transistor S. dc1 Resistance R dc1 Load R L And multiple cascaded Marx units, DC source V in1 With the switching transistor S dc1 Connected, series resistor R dc1 Multiple Marx units are then cascaded together, and then connected to the load R. L The circuit is formed by connecting them in series. Each Marx circuit stage includes a discharge tube S. ai Charging tube S bi Diode D i D bi and capacitor C i Capacitor C i The upper end is connected to the discharge tube S ai After the collectors are connected in parallel with diode D i With the negative terminal connected, capacitor C i The lower end is connected to the discharge tube S ai Emitter through S bi and diode D bi Connected.

[0011] This invention also provides a control method for the above-mentioned dynamic variable topology resonant compensation circuit for a Marx generator, which collects the energy storage capacitor C of a certain stage in a multi-stage Marx circuit. i The voltage difference before and after discharge is used to calculate the output drop ΔV. o According to ΔV oThe magnitude of the voltage determines the combination of resonant compensation units in the next pulse cycle, changing the total compensation voltage of the dynamic variable topology resonant compensation circuit in the next pulse cycle, thereby achieving real-time adjustment of the compensation voltage according to the load size. The dynamic variable topology resonant compensation circuit is used to compensate for the voltage drop at the top of the Marx generator's output pulse, and through a closed-loop control method, the number of resonant compensation units participating in discharge compensation can be controlled according to the load size, enabling relatively accurate and flat pulse voltages over a wide load range.

[0012] Furthermore, a binary method is used to set the compensation voltage of each stage of the resonant compensation unit, and each stage of the resonant compensation unit is individually controlled to participate in each cycle of charging and discharging. The circuit's operating mode is more flexible, thus allowing adjustment of the overall voltage value compensated by the dynamically variable topology resonant compensation circuit.

[0013] Furthermore, by changing the capacitance C resi and inductor L resi The size of the value determines the resonant frequency of each resonant compensation unit, which is set to ω. resn ≈2ω res(n-1) ≈4ω res(n-2) ≈···≈2 n-1 ω res1 , where n is the number of resonant compensation units, such that the compensation voltage of each resonant compensation unit increases proportionally.

[0014] The present invention also provides a control system for a dynamic variable topology resonance compensation circuit for a Marx generator, comprising: a computer-readable storage medium and a processor;

[0015] The computer-readable storage medium is used to store executable instructions;

[0016] The processor is used to read executable instructions stored in the computer-readable storage medium and execute the control method described above.

[0017] Compared with the prior art, the above technical solutions conceived in this invention can achieve the following results.

[0018] Beneficial effects:

[0019] 1. The dynamic variable topology resonant compensation circuit proposed in this invention uses an independent power supply, and each resonant compensation unit can be individually controlled to participate in each cycle of charging and discharging, making the entire circuit more flexible. When the load is heavy, multiple resonant compensation units can be controlled to work and participate in the output drop compensation in each cycle; when the load becomes light, several resonant compensation units can be turned off to reduce the drop compensation voltage during the discharge process.

[0020] 2. This invention infers the magnitude of the top drop of the output pulse by collecting the voltage before and after the discharge of a capacitor in a Marx circuit. Then, it controls the number of resonant compensation units participating in the discharge compensation in a closed loop, thereby enabling dynamic compensation of the output top drop of the Marx generator over a wide load range, improving the waveform quality of the output pulse voltage of the Marx generator, and achieving a precise and flat pulse voltage.

[0021] 3. In this invention, each resonant compensation unit has a different resonant frequency. By using the bisection method to set the compensation voltage of each resonant compensation unit, a large compensation voltage adjustment range can be achieved with a small number of resonant compensation units, thereby reducing cost and volume. Attached Figure Description

[0022] Figure 1 It is a traditional Marx generator and its resonant compensation circuit;

[0023] Figure 2 These are the drive signals and circuit waveforms of a traditional Marx generator and its resonant compensation circuit;

[0024] Figure 3 This invention relates to the Marx circuit and the dynamic variable topology resonant compensation circuit.

[0025] Figure 4 This is an embodiment of the Marx circuit and the dynamic variable topology resonant compensation circuit of the present invention;

[0026] Figure 5 This refers to the driving signal and circuit waveform of the circuit under full load in one embodiment of the present invention;

[0027] Figure 6 This is the charging operation mode of the circuit under full load in one embodiment of the present invention;

[0028] Figure 7 This is the resonant operating mode of the circuit under full load in one embodiment of the present invention;

[0029] Figure 8 This is the discharge operation mode of the circuit under full load in one embodiment of the present invention;

[0030] Figure 9 This is a logic block diagram of closed-loop control of the circuit in one embodiment of the present invention;

[0031] Figure 10 This is an embodiment of the present invention showing the allocation of resonant compensation unit combinations for different top voltage drop magnitudes;

[0032] Figure 11 This is the driving signal and circuit waveform when the resonant compensation unit is combined as (1,0,1) in one embodiment of the present invention;

[0033] Figure 12 This is the resonant operating mode of the resonant compensation circuit when the resonant compensation unit combination is (1,0,1) in one embodiment of the present invention.

[0034] Figure 13 This is the discharge working mode of the resonant compensation circuit when the resonant compensation unit combination is (1,0,1) in one embodiment of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The circuit of the present invention is as follows Figure 3 As shown, it mainly consists of two parts: a multi-stage Marx circuit and a multi-stage dynamic variable topology resonant compensation circuit. The two circuits are located at V... comp They are connected together. Each stage of the Marx circuit consists of a discharge tube S. ai Charging tube S bi Diode D i D bi and capacitor C i Composition, in which diode D bi Its function is to prevent the circuit from overloading R when operating in resonant mode. L Discharge, switching transistor S drop The resonant compensation circuit is composed of multiple stacked resonant compensation units and uses an independent DC source V. in2 Separate power supply, DC source V in2 With Marx's DC source V in1 Common ground. Each stage of the resonant compensation unit consists of a resonant tube S. resi Discharge tube S aresi Charging tube S bresi , capacitor branch transistor S cresi Diode D resi D aresi Capacitor C resi and inductor L resi Composition. The resonant frequency ω of each stage of the resonant compensation unit. resi Different, set to ω resn ≈2ω res(n-1) ≈4ω res(n-2) ≈···≈2 n-1 ω res1 ,in (The resonant frequency of the i-th resonant compensation unit). Both circuits have a switching transistor S connected in series at their input terminals. dci and resistance R dci Switch S dci Controls the charging of the entire circuit, R dci Its function is to reduce the instantaneous current during capacitor charging.

[0037] An embodiment of the present invention is as follows: Figure 4 As shown, the Marx circuit has a total of 6 stacked levels, the resonant compensation unit has a total of 3 stacked levels, and 4ω res1 =2ω res2 =ω res3 The drive signals and circuit waveforms under full load conditions in the embodiment are as follows: Figure 5 As shown, the circuit can be mainly divided into three operating modes: charging mode, resonant mode, and discharging mode.

[0038] Charging working mode such as Figure 6 As shown, the charging tube S in the Marx circuit bi , resonant control transistor S drop and switching transistor S dc1 On, DC source V in1 Give capacitor C i Charging; charging tube S in the resonant compensation unit bresi , capacitor branch transistor S cresi and switching transistor S dc2 On, DC source V in2 Give capacitor C resi During charging, all other switching transistors are in the off state.

[0039] Resonant operating mode such as Figure 7 As shown, all the capacitors in the Marx circuit are charged to V. in1 Furthermore, all the capacitors in the resonant compensation circuit are charged to V. in2 Afterwards, all the switching transistors used in the Marx circuit are turned off, and the resonant compensation circuit turns off the charging transistor S. bresi and switching transistor S dc2 The resonant transistors S are turned on sequentially according to the resonant unit sequence. res1 , resonant tube S res2 , resonant tube S res3 , so that capacitor C resi With inductor L resi A resonant circuit is formed, and each resonant unit begins its own single-resonance process sequentially. The turn-on time of each resonant tube must be calculated based on the resonant period to ensure that the capacitor voltages of these three resonant compensation units simultaneously cross the zero-crossing point and become positive voltages at the moment of discharge.

[0040] Discharge operating modes such as Figure 8As shown, when the capacitor voltages of the three resonant compensation units simultaneously cross the zero-crossing point and become positive voltages, the discharge tube S in the Marx circuit... ai The discharge tube S in the resonance compensation unit aresi Turning on the capacitor C of the resonant compensation unit will turn on the capacitor C. resi With the capacitor C of the Marx circuit i By connecting them in series to discharge to the load, compensation of the discharge waveform is achieved. The resonance process continues during the discharge, so the near-linearly increasing resonant capacitor voltages of the three different units can be applied to the discharge pulse to compensate the output waveform.

[0041] The circuit closed-loop control logic block diagram of this embodiment is as follows: Figure 9 As shown, the voltage difference of capacitor C1 before and after discharge is first collected, and then multiplied by 6 (Marx circuit stage number) to calculate the output drop ΔV. o Next, based on the magnitude of the output drop, the combination of resonant compensation units in the next pulse cycle is determined, and the total compensation voltage of the resonant compensation circuit in the next pulse cycle is changed. This allows for real-time adjustment of the compensation voltage according to the load size, enabling the circuit to achieve accurate and flat pulse voltages over a wide load range. The combination of resonant compensation units (a1, a2, a3) represents the operating state of each resonant compensation unit. When a... i When a = 1, it indicates that the i-th resonant compensation unit participates in the top-down compensation of the next discharge cycle; when a i When ΔV = 0, it indicates that the i-th resonant compensation unit does not participate in the top-drop compensation of the next discharge cycle. Assuming that the compensation voltage of resonant compensation unit 1 at the end of discharge is 10V, and since the slope of the resonant voltage near the zero-crossing point is approximately linear, based on the relationship between the resonant frequencies of each unit, the compensation voltage of resonant compensation unit 2 at the end of discharge is 20V, and the compensation voltage of resonant compensation unit 3 at the end of discharge is 40V. Therefore, the Marx circuit outputs a top-drop ΔV. o The resonant compensation unit combination and allocation in the range of 0V to 70V is as follows: Figure 10 As shown, in this embodiment, only three resonant compensation units need to be superimposed to achieve a compensation voltage range of 0V to 70V with a compensation accuracy of 10V.

[0042] In this embodiment, the driving signal and circuit waveform when the resonant compensation unit is combined as (1,0,1) are as follows: Figure 11 As shown. The difference between the circuit's operating principle and that under full load is that the resonant compensation unit 2 does not participate in the resonance and discharge processes. When the resonant compensation unit combination is (1,0,1), the resonant operating mode and discharge operating mode of the resonant compensation circuit are as follows: Figure 12 , Figure 13 As shown.

[0043] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dynamic variable topology resonance compensation circuit for a Marx generator, characterized in that, Included in V comp The multi-stage Marx circuit and dynamic variable topology resonant compensation circuit are connected at the junction. Each stage of the Marx circuit includes a switching transistor S. dc1 Resistance R dc1 Load R L And multiple cascaded Marx units, DC source V in1 With the switching transistor S dc1 Connected, series resistor R dc1 Multiple Marx units are then cascaded together, and then connected to the load R. L The circuit is formed by connecting them in series. Each stage of the Marx circuit includes a discharge tube S. ai Charging tube S bi Diode D i D bi and capacitor C i Capacitor C i The upper end is connected to the discharge tube S ai After the collectors are connected in parallel with diode D i With the negative terminal connected, capacitor C i The lower end is connected to the discharge tube S ai Emitter through S bi and diode D bi The circuit is connected in series; the compensation output terminal of the dynamic variable topology resonant compensation circuit is connected to the lower end of capacitor C1 of the first-stage Marx unit in the multi-stage Marx circuit, forming a compensation node V. comp The dynamic variable topology resonant compensation circuit consists of a DC source V in2 The DC source V is powered separately. in2 DC source V of multi-stage Marx circuit in1 Common ground; the dynamic variable topology resonant compensation circuit includes multiple superimposed resonant compensation units, and the resonant frequency ω of each resonant compensation unit. resi Different, set to ω resn ≈2ω res(n-1) ≈4ω res(n-2) ≈···≈2 n-1 ω res1 , where n is the number of resonant compensation units, 1≤i≤n, and the combination of resonant compensation units participating in discharge compensation is determined according to the load size, used to compensate for the voltage drop at the top of the output pulse of the Marx generator.

2. The dynamic variable topology resonant compensation circuit according to claim 1, characterized in that, The dynamic variable topology resonant compensation circuit includes the switching transistor S. dc2 Resistance R dc2 And a multi-stage superimposed resonant compensation unit, DC source V in2 With the switching transistor S dc2 Connected, series resistor R dc2 Multiple resonant compensation units are cascaded to form a circuit. Each resonant compensation unit includes a resonant transistor S. resi Discharge tube S aresi Charging tube S bresi , capacitor branch transistor S cresi Diode D resi D aresi Capacitor C resi and inductor L resi capacitor branch transistor S cresi With capacitor C resi Series connection, resonant tube S resi With inductor L resi Series connection, diode D aresi With discharge tube S aresi The three series branches are connected in parallel at their upper ends and then connected to diode D. resi With the negative terminal connected, capacitor C resi and inductor L resi The lower end of the branch is connected in parallel and passes through the charging tube S. bresi With discharge tube S aresi The branch roads are connected.

3. A control method for a dynamic variable topology resonance compensation circuit for a Marx generator as described in claim 1 or 2, characterized in that, Collect the energy storage capacitor C of a certain stage in a multi-stage Marx circuit. i The voltage difference before and after discharge is used to calculate the output drop ΔV. o According to ΔV o The magnitude of the voltage determines the combination of resonant compensation units in the next pulse cycle, and changes the total compensation voltage of the dynamic variable topology resonant compensation circuit in the next pulse cycle, thereby realizing real-time adjustment of the compensation voltage according to the load size.

4. The control method according to claim 3, characterized in that, The compensation voltage of each resonant compensation unit is set using a binary method, and each resonant compensation unit is individually controlled to participate in each cycle of charging and discharging.

5. The control method according to claim 3, characterized in that, By changing the capacitance C resi and inductor L resi The size of the value determines the resonant frequency of each stage of the resonant compensation unit, which is set to ω. resn ≈2ω res(n-1) ≈4ω res(n-2) ≈···≈2 n-1 ω res1 , where n is the number of resonant compensation units, such that the compensation voltage of each resonant compensation unit increases proportionally.

6. A control system for a dynamic variable topology resonance compensation circuit for a Marx generator, characterized in that, include: Computer-readable storage media and processors; The computer-readable storage medium is used to store executable instructions; The processor is configured to read executable instructions stored in the computer-readable storage medium and execute the control method according to any one of claims 3 to 5.

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