High-peak power pulse modulator

Abstract

When microwave peak power output by a high-power microwave source reaches several megawatts or even tens of megawatts, a pulse modulator of the high-power microwave source requires to output high-voltage modulation pulses of hundreds of kilovolts and hundreds of amperes, and meanwhile, the pulse is required to be small in front and back edges, high in efficiency, small in size and light in weight. In order to overcome the defects that an existing high-power pulse modulator is large in size and heavy in weight, the invention provides a high-peak-power pulse modulator which is constructed on the basis of a modularized large-current modulation switch assembly and a multi-primary-winding high-transformation-ratio pulse transformer and is low in loop inductance and small in pulse front and back edges. The requirements of tens of MW microsecond high-power microwave sources on power, pulse width, front and back edges, reliability and platform adaptability of the pulse modulator are met.

Description

Technical Field

[0001] The invention belongs to the field of microwave technology, and in particular relates to a high peak power pulse modulator. Background Art

[0002] In the field of high-power microwaves, pulse power technology is the foundation of high-power microwave research, and high-power pulse modulators are an important part of pulse power technology. With the development of pulse power and radar, the requirements for peak power are getting higher and higher, and the requirements for reducing the size, weight, and cost of pulse modulators are also getting higher and higher, laying the foundation for the miniaturization, lightweight, and modularization of high-power microwave sources, thereby realizing the array expansion of high-power microwave sources. When the peak power of high-power microwave sources outputs microwaves of several megawatts or even tens of megawatts, their pulse modulators are required to output high-voltage modulated pulses of hundreds of kilovolts and hundreds of amperes, and at the same time, they are required to have small leading and trailing edges, high efficiency, small size, and light weight. Summary of the invention

[0003] In order to solve the shortcomings of existing high-power pulse modulators such as large size and heavy weight, the present invention proposes a high-peak power pulse modulator with low loop inductance and small pulse leading and trailing edges, which is constructed based on a modular large-current modulation switch component and a multi-primary winding high-ratio pulse transformer. It meets the requirements of tens of MW and several microseconds high-power microwave sources for pulse modulators in terms of power, pulse width, leading and trailing edges, reliability, and platform adaptability. The high-peak power pulse modulator of the present invention has the characteristics of modularization, combination, low cost, small size, light weight, and strong platform adaptability. It can solve the problems of large size and heavy weight of high-power microwave sources, realize the miniaturization, light weight, and modularization of high-power microwave sources, and lay the foundation for the array expansion of high-power microwave sources.

[0004] The present invention mainly includes a multi-primary winding high-ratio pulse transformer T1, a blocking inductor L1, N low-inductance high-current cables, N high-current modulation switch components, etc. Figure 1 The output + of the large current modulation switch component is connected to the + of the A end of the low inductance large current cable, the output - of the large current modulation switch component is connected to the - of the A end of the low inductance large current cable, the + of the B end of the low inductance large current cable is connected to the primary winding + of the multi-primary winding high transformation ratio pulse transformer T1, and the - of the B end of the low inductance large current cable is connected to the primary winding - of the multi-primary winding high transformation ratio pulse transformer T1, that is, N large current modulation switch components are respectively connected to the primary winding of the multi-primary winding high transformation ratio pulse transformer T1 through N low inductance large current cables; the 2 end of the blocking inductor is connected to the demagnetization winding + of the multi-primary winding high transformation ratio pulse transformer T1.

[0005] The multi-primary winding high transformation ratio pulse transformer T1 mainly includes 2 magnetic cores, 4 primary windings, 2 secondary windings, 1 demagnetization winding, etc. Its main function is to boost the modulation pulse of about 1kV generated by the large current modulation switch component to the required high voltage modulation pulse of hundreds of kV. Figure 2 and Figure 3 , the four primary windings are installed on the two vertical arms of the magnetic cores, the two secondary windings respectively bypass the two primary windings on the same side of the vertical arm of the magnetic core, and are installed on the outside of the two primary windings of the vertical arm, and the demagnetization winding is installed on the horizontal arm of the magnetic core close to the low-voltage output end of the secondary winding. Since each of the primary windings bypasses only one magnetic core, and the secondary winding bypasses two magnetic cores, when the ratio of the number of turns of the primary winding to the number of turns of the secondary winding is n, the secondary winding output can obtain a voltage that is 2n times the input voltage of the primary winding. In order to effectively control the leakage inductance of the multi-primary winding high-transformation ratio pulse transformer to ensure the leading and trailing edges of the output waveform of the modulator of the present invention, the following measures are taken: ① The number of turns of the four primary windings is designed to be 1 turn, and a 0.5 mm thick copper plate is wound on the two vertical arms of the magnetic core, and a certain insulating material is added between the copper plate and the magnetic core to ensure insulation; ② The secondary winding adopts a conical structure, the high-voltage output end of the secondary winding is far away from the primary winding, and the low-voltage output end of the secondary winding is close to the primary winding. When ensuring that the insulation requirements between the primary winding and the secondary winding are met, the gap between them is the smallest; ③ The two secondary windings respectively bypass the two primary windings on the vertical arms on the same side of the magnetic core, and the two secondary windings are connected in parallel.

[0006] The main function of the choking inductor L1 is to block the influence of the several thousand volts of induced voltage on the demagnetization winding of the multi-primary winding high-transformation ratio pulse transformer T1 on the demagnetization power supply during the modulation pulse. The demagnetization power supply is connected in series with the choking inductor L1 to apply a reverse bias current of tens of amperes to the demagnetization winding of T1 to avoid bias saturation of the multi-primary winding high-transformation ratio pulse transformer.

[0007] The low-inductance high-current cable includes an electrical connector and a coaxial low-inductance high-current cable. Its main function is to achieve the connection between the N high-current modulation switch components and the primary winding of the multi-primary winding high-ratio pulse transformer T1. The transmission cable of the low-inductance high-current cable adopts a coaxial low-inductance high-current cable to minimize the parasitic inductance of the connection and minimize the influence of the connection cable on the modulator output waveform.

[0008] The large current modulation switch assembly includes a modulation switch V1, a storage capacitor C1, a current limiting resistor R1, an absorption capacitor Ca1, an absorption resistor Ra1, an absorption diode Va1, a freewheeling diode Vb1, and a driving circuit A1. Figure 4, the internal connection relationship of the large current modulation switch component is as follows:

[0009] ① The input + of the large current modulation switch component is the 1 end of the current limiting resistor R1, and the input - of the large current modulation switch component is the E end of the modulation switch V1; the C end of the modulation switch V1, the 2 ends of the current limiting resistor R1, and the 1 end of the energy storage capacitor C1 are connected; the output + of the large current modulation switch component is the 2 ends of the energy storage capacitor, and the input - of the large current modulation switch component is the E end of the modulation switch V1.

[0010] ② The absorption capacitor Ca1, the absorption resistor Ra1, and the absorption diode Va1 form an RCD absorption circuit connected in parallel between the C terminal and the E terminal of the modulation switch V1. The anode of the absorption diode Va1, the 1 terminal of the absorption capacitor Ca1, and the C terminal of the modulation switch V1 are connected, the cathode of the absorption diode Va1, the 2 terminals of the absorption capacitor Ca1, and the 1 terminal of the absorption resistor Ra1 are connected, and the 2 terminals of the absorption resistor Ra1 and the E terminal of the modulation switch V1 are connected.

[0011] ③ The anode of the freewheeling diode Vb1 is connected to the 2 end of the energy storage capacitor C1, and the cathode of the freewheeling diode Vb1 is connected to the E end of the modulation switch V1.

[0012] ④The G terminal of the driving circuit A1 is connected to the G terminal of the modulation switch V1, the E terminal of the driving circuit A1 is connected to the E terminal of the modulation switch V1, the trigger input + of the large current modulation switch component is the trigger + terminal of the driving circuit A1, and the trigger input - of the large current modulation switch component is the trigger - terminal of the driving circuit A1.

[0013] The main function of the modulation switch V1 is to turn on and off the modulation switch V1 according to the driving signal generated by the driving circuit A1. When the modulation switch V1 is turned on, the energy on the energy storage capacitor C1 is transmitted to the output end of the large current modulation switch component through the modulation switch V1, and a voltage is generated between the output end + and the output - of the large current modulation switch component. When the modulation switch V1 is turned off, there is no voltage between the output end + and the output - of the large current modulation switch component, so that the modulation switch V1 is turned on and off by control, and a modulation pulse is generated at the output end of the large current modulation switch component. In order to reduce the volume, weight and cost, based on the current development status of semiconductor switch devices, the design capacity of the large current modulation switch component is 1000V / 1000A. The modulation switch V1 uses the IGBT module with large usage and low price in the market, Infineon's FZ600R17KE3, and many domestic companies such as Yangzhou Guoyang Electronics Co., Ltd. have replaced it with domestic products, such as WGL600A170F45P.

[0014] The main function of the energy storage capacitor C1 is to store charge energy and maintain the voltage drop across the energy storage capacitor C1 during the modulation pulse to meet the modulation pulse waveform requirements. The capacitor is generally a low-inductance non-polarized capacitor.

[0015] The main function of the current limiting resistor R1 is to limit the current of the input DC power supply of the input + and input - of the large current modulation switch component during the conduction period of the modulation switch V1, so as to avoid damage to the DC power supply due to excessive current of the DC power supply.

[0016] The absorption capacitor Ca1, the absorption resistor Ra1, and the absorption diode Va1 form an RCD absorption circuit, which is used to absorb the voltage spike between the C terminal and the E terminal of the modulation switch V1 when it is turned off, so as to prevent the voltage spike from exceeding the rated voltage of the modulation switch V1 and causing voltage breakdown and damage to the modulation switch V1.

[0017] The main function of the freewheeling diode Vb1 is to freewheel the current of the primary winding of the multi-primary winding high-transformation ratio pulse transformer T1 and the low-inductance high-current cable during the trailing edge of the modulation pulse of the high-current modulation switch component, and simulate the voltage generated by the parasitic inductance of the primary winding of the multi-primary winding high-transformation ratio pulse transformer T1 and the low-inductance high-current cable during the current reduction process, so that the voltage spike between the C terminal and the E terminal of the modulation switch V1 increases when the modulation switch V1 is turned off, and then a voltage spike occurs that exceeds the rated working voltage of the modulation switch V1, causing voltage breakdown and causing damage to the modulation switch V1.

[0018] The driving circuit A1 mainly consists of a driving transformer Tc1, a driving resistor Rc1, two voltage regulator diodes Vc1 / Vc2, and a resistor Rc2. Its main function is to generate a driving signal of the modulation switch V1 and send it to the G and E terminals of the modulation switch V1 according to the trigger signal sent from the trigger + terminal and the trigger - terminal of the driving circuit A1. Figure 5 , the internal connection relationship of the driving circuit A1 is as follows: the trigger + terminal of the driving circuit A1 is the input + terminal of the driving transformer Tc1, and the trigger - terminal of the driving circuit A1 is the input - terminal of the driving transformer Tc1; the output + terminal of the driving transformer Tc1 is connected to the 1 terminal of the driving resistor Rc1; the 2 terminals of the driving resistor Rc1, the anode of the voltage-stabilizing diode Vc1, and the 1 terminal of the resistor Rc2 are connected; the output - terminal of the driving transformer, the anode of the voltage-stabilizing diode Vc2, and the 2 terminals of the resistor Rc2 are connected; the cathode of the voltage-stabilizing diode Vc1 and the cathode of the voltage-stabilizing diode Vc2 are connected; the output G terminal of the driving circuit A1 is the 2 terminals of the driving resistor Rc1, and the output E terminal of the driving circuit A1 is the output - terminal of the driving transformer Tc1. In order to ensure the synchronization of the N large current modulation switch components, the driving circuit A1 adopts a driving transformer isolation drive, and the N large current modulation switch components are triggered simultaneously by a trigger signal; in order to ensure that the large current modulation switch components are effectively and quickly turned off, the driving waveform of the modulation switch V1 is a negative voltage turn-off, and the negative voltage is maintained for 3-5μs. The schematic waveform of the output G terminal of the driving circuit A1 relative to the output E terminal is as follows: Figure 6 , the driving voltage is about +20V, so that the conduction voltage drop of the modulation switch V1 is small during the conduction process.

[0019] The beneficial effects of the present invention are

[0020] A high peak power pulse modulator that can be modularized, combined, low-cost, small, lightweight, and highly adaptable to platforms can be realized, meeting the requirements of miniaturization, lightweight, modularization, and arrayable expansion of high-power microwave sources. While realizing the miniaturization and lightweight of the modulator, the modularization and combination of the modulator are also realized, and the power level of the modulator can be determined according to the number of module units, with the flexibility of design adjustment; at the same time, the high peak power pulse modulator of the present invention does not have high requirements on the withstand voltage and power of components, has low cost, is easy to realize, and can be adapted to a variety of occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The schematic diagram of the circuit of the present invention is shown in FIG.

[0022] Figure 2 This is the schematic diagram of a multi-primary winding high-ratio pulse transformer.

[0023] Figure 3 Schematic diagram of a multi-primary winding high-ratio pulse transformer.

[0024] Figure 4 This is the circuit schematic diagram of the high current modulation switch component.

[0025] Figure 5 Schematic diagram of the driving circuit A1.

[0026] Figure 6 Schematic diagram of output driving waveform of driving circuit A1.

[0027] Figure 7 Schematic diagram of the output voltage waveform of the pulse modulator. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Combination Figure 1-5 The present invention mainly includes a multi-primary winding high-ratio pulse transformer T1, a choke inductor L1, N low-inductance high-current cables, N high-current modulation switch components, etc. The output + end of the high-current modulation switch component is connected to the + end of the low-inductance high-current cable A end, the output - end of the high-current modulation switch component is connected to the - end of the low-inductance high-current cable A end, the + end of the low-inductance high-current cable B end is connected to the primary winding + end of the multi-primary winding high-ratio pulse transformer, and the - end of the low-inductance high-current cable B end is connected to the primary winding - end of the multi-primary winding high-ratio pulse transformer, that is, the N high-current modulation switch components are respectively connected to the primary winding of the multi-primary winding high-ratio pulse transformer T1 through the N low-inductance high-current cables; the two ends of the choke inductor L1 are connected to the demagnetization winding + end of the multi-primary winding high-ratio pulse transformer T1.

[0030] The large current modulation switch components respectively pass about 1000V DC at their input ends through the current limiting resistor R1 in the large current modulation switch components to store the charge energy in the energy storage capacitor C1. The driving circuit A1 in the large current modulation switch components controls the modulation switch V1 to turn on / off according to its trigger input signal, and generates a modulation pulse of about 1000V at the output end of the large current modulation switch components.

[0031] The modulated pulses of about 1000V generated by the N large current modulation switch components are respectively transmitted to the primary winding of the multi-primary winding high-ratio pulse transformer T1 through the corresponding low-inductance large current cables. The modulated pulses of about 1000V generated by the large current modulation switch components are boosted by the multi-primary winding high-ratio pulse transformer T1 with a primary-to-secondary turns ratio of n, and the modulated pulses are boosted to a high-voltage modulated pulse of 2nkV. At the same time, the demagnetization power supply applies a reverse bias current of more than ten amperes to the demagnetization winding of the multi-primary winding high-ratio pulse transformer T1 through the series-connected choke inductor L1 to prevent the multi-primary winding high-ratio pulse transformer T1 from being biased and saturated.

[0032] The high current modulation switch assembly of the present invention is a low-cost modular design. When combined with the multi-primary winding high-ratio pulse transformer, the modulator power level can be determined according to the number of module units, with the flexibility of design adjustment, and modularization and combination can be achieved. At the same time, the high voltage of the high peak power pulse modulator of the present invention is only limited to the secondary of the pulse transformer, and the withstand voltage and power requirements of the components are not high. It is low in cost, easy to implement, and can be adapted to a variety of occasions.

[0033] The high peak power pulse rate modulator of the present invention provides the required 140kV / 230A high voltage modulation pulse for a certain high peak power klystron as an example for detailed description. The voltage of the high voltage modulation pulse output by the high peak power pulse modulator of the present invention is 140kV, and the high current modulation switch assembly of the present invention can generate a modulation pulse of about 1000V / 1000A, and thus the primary-to-secondary turns ratio n of the multi-primary winding high transformation ratio pulse transformer T1 can be determined to be 70, and thus the primary current of the multi-primary winding high transformation ratio pulse transformer T1 can be determined to be 2n times the secondary current, i.e. 32.2kA, and thus the number N of the high current modulation switch assemblies required for the high peak power pulse modulator of the present invention can be determined to be 32.

[0034] like Figure 6 and 7 As shown, the high peak power pulse modulator of the present invention has been applied in a miniaturized high power microwave source. The modulator outputs a pulse voltage of -140 kV, an output pulse current of 230 A, a pulse leading edge of ≤230 ns, and a pulse trailing edge of ≤630 ns.

[0035] The present invention is not limited to the above specific implementations, and the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made to the above implementations based on the technical essence of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high peak power pulse modulator, characterized in that: It comprises a multi-primary winding high transformation ratio pulse transformer T1, a choke inductor L1, N low inductance high current cables, and N high current modulation switch components; the output + end of the high current modulation switch component is connected to the + end of the low inductance high current cable A end, the output - end of the high current modulation switch component is connected to the - end of the low inductance high current cable A end, the + end of the low inductance high current cable B end is connected to the primary winding + end of the multi-primary winding high transformation ratio pulse transformer T1, the - end of the low inductance high current cable B end is connected to the primary winding - end of the multi-primary winding high transformation ratio pulse transformer T1, and the N high current modulation switch components are respectively connected to the primary winding of the multi-primary winding high transformation ratio pulse transformer T1 through the N low inductance high current cables; the two ends of the choke inductor L1 are connected to the demagnetization winding + end of the multi-primary winding high transformation ratio pulse transformer T1.

2. A high peak power pulse modulator according to claim 1, characterized in that: The multi-primary winding high-transformation ratio pulse transformer T1 includes 2 magnetic cores, 4 primary windings, 2 secondary windings, and 1 demagnetization winding; the 4 primary windings are installed in pairs on the 2 vertical arms of the magnetic cores, and the 2 secondary windings respectively bypass the secondary windings of the vertical arms on the same side of their respective magnetic cores and are installed on the outside of the 2 primary windings, and the demagnetization winding is installed on the lateral arm of the magnetic core close to the low-voltage output end of the secondary winding; since each of the primary windings only bypasses 1 magnetic core, and the secondary winding bypasses 2 magnetic cores, when the ratio of the number of turns of the primary winding to the number of turns of the secondary winding is n, the secondary winding output can obtain a voltage that is 2n times the input voltage of the primary winding.

3. A high peak power pulse modulator according to claim 2, characterized in that: In order to effectively control the leakage inductance of the multi-primary winding high-transformation ratio pulse transformer, the following measures are taken: ① The number of turns of the four primary windings is designed to be 1 turn, and a 0.5 mm thick copper plate is wound on the two vertical arms of the magnetic core, and insulating material is added between the copper plate and the magnetic core; ② The secondary winding adopts a conical structure, the high-voltage output end of the secondary winding is far away from the primary winding, and the low-voltage output end of the secondary winding is close to the primary winding. When ensuring that the insulation requirements between the primary winding and the secondary winding are met, the gap between them is the smallest; ③ The two secondary windings are connected in parallel by bypassing the primary windings of the vertical arms on the same side of the magnetic core respectively.

4. A high peak power pulse modulator according to claim 2 or 3, characterized in that: During the modulation pulse, the choking inductor L1 blocks the influence of the several thousand volts induced voltage on the demagnetization winding of the multi-primary winding high transformation ratio pulse transformer T1 on the demagnetization power supply. The demagnetization power supply is connected in series with the choking inductor L1 to apply a reverse bias current to the demagnetization winding of the multi-primary winding high transformation ratio pulse transformer T1, thereby avoiding bias saturation of the multi-primary winding high transformation ratio pulse transformer.

5. A high peak power pulse modulator according to claim 2 or 3, characterized in that: The low-inductance high-current cable includes an electrical connector and a coaxial low-inductance high-current cable; the N high-current modulation switch components are connected to the primary winding of the multi-primary winding high-ratio pulse transformer T1 through the electrical connector and the coaxial low-inductance high-current cable, so that the connection parasitic inductance is reduced.

6. A high peak power pulse modulator according to claim 1, characterized in that: The large current modulation switch component includes a modulation switch V1, an energy storage capacitor C1, a current limiting resistor R1, an absorption capacitor Ca1, an absorption resistor Ra1, an absorption diode Va1, a freewheeling diode Vb1, and a drive circuit A1; The input + end of the large current modulation switch component is the 1 end of the current limiting resistor R1, the input - end of the large current modulation switch component is the E end of the modulation switch V1, the C end of the modulation switch V1, the 2 ends of the current limiting resistor R1, and the 1 end of the energy storage capacitor C1 are connected; the output + end of the large current modulation switch component is the 2 ends of the energy storage capacitor C1, and the input - end of the large current modulation switch component is the E end of the modulation switch V1; The absorption capacitor Ca1, the absorption resistor Ra1, and the absorption diode Va1 form an RCD absorption circuit, which is connected in parallel between the C terminal and the E terminal of the modulation switch V1; the anode of the absorption diode Va1, the 1 terminal of the absorption capacitor Ca1, and the C terminal of the modulation switch V1 are connected, the cathode of the absorption diode Va1, the 2 terminals of the absorption capacitor Ca1 and the 1 terminal of the absorption resistor Ra1 are connected, and the 2 terminals of the absorption resistor Ra1 are connected to the E terminal of the modulation switch V1; The anode of the freewheeling diode Vb1 is connected to the 2 end of the energy storage capacitor C1, and the cathode of the freewheeling diode Vb1 is connected to the E end of the modulation switch V1; The G end of the driving circuit A1 is connected to the G end of the modulation switch V1, the E end of the driving circuit A1 is connected to the E end of the modulation switch V1, the trigger input + end of the large current modulation switch component is the trigger + end of the driving circuit A1, and the trigger input - end of the large current modulation switch component is the trigger - end of the driving circuit A1.

7. A high peak power pulse modulator according to claim 6, characterized in that: The driving circuit A1 includes a driving transformer Tc1, a driving resistor Rc1, two voltage stabilizing diodes Vc1 and Vc2, and a resistor Rc2; The trigger + terminal of the driving circuit A1 is the input + terminal of the driving transformer Tc1, and the trigger - terminal of the driving circuit A1 is the input - terminal of the driving transformer Tc1; The output + terminal of the driving transformer Tc1 is connected to the 1 terminal of the driving resistor Rc1; The two ends of the driving resistor Rc1, the anode of the voltage zener diode Vc1, and one end of the resistor Rc2 are connected; the output end of the driving transformer, the anode of the voltage zener diode Vc2, and the two ends of the resistor Rc2 are connected; the cathode of the voltage zener diode Vc1 and the cathode of the voltage zener diode Vc2 are connected; The output G terminal of the pole driving circuit A1 is the 2 terminal of the driving resistor Rc1, and the output E terminal of the driving circuit A1 is the output - terminal of the driving transformer Tc1.

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