Time sequence synchronous trigger control method and system of LTD module multi-path pulse switch

Abstract

The invention relates to the technical field of pulse power, in particular to a time sequence synchronous trigger control method for a multi-path pulse switch of an LTD module, which comprises the following steps: S01, measuring the inherent delay time of each discharge branch in the LTD module from trigger signal input to gas switch conduction; and S02, inputting the measured inherent delay time value of each branch into a pulse time sequence controller as a compensation parameter, and setting the delay time of each output channel of the pulse time sequence controller. Through system calibration and programmable delay compensation of the pulse time sequence controller, in combination with high-precision time sequence control of the FPGA, the multi-way switch conduction time deviation can be controlled at the nanosecond level, the energy synthesis efficiency is greatly improved, inductance isolation transmission is achieved through magnetic ring coupling, traditional resistance isolation is replaced, pulse leading edge distortion is avoided, and the energy synthesis efficiency is improved. And meanwhile, high-voltage isolation safety is guaranteed, and trigger signal transmission quality is stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pulse power technology, in particular to a timing synchronization trigger control method and system for a multi-channel pulse switch of an LTD module. BACKGROUND

[0002] As one of the core devices of pulse power technology, the linear transformer driver (LTD) plays a key role in major scientific and technological fields such as inertial confinement fusion experiments, high-power microwave generation, and nuclear radiation simulation. The core function of the LTD module is to concentrate the dispersed energy output as a high-power pulse through the synchronous operation of multiple parallel discharge branches. The timing synchronization trigger precision of the multi-channel pulse switch directly determines the energy synthesis efficiency and output pulse quality of the module. In the prior art, there are many bottlenecks in the trigger of the LTD module multi-channel switch: first, due to differences in physical layout and component parameter dispersion, there are inherent conduction delay differences between each discharge branch, which leads to non-strict synchronous conduction of the switch and reduces the energy synthesis efficiency; second, the transmission of the trigger pulse is usually done in a resistive isolation manner, which easily causes distortion of the pulse front, further deteriorating the synchronization precision; third, the voltage distribution of each gap is uneven due to the poor voltage equalization effect of the suspended intermediate electrode inside the gas switch, leading to unstable switch conduction delay; fourth, the life of the traditional pulse capacitor is usually less than one million times, which cannot meet the long-term operation requirements of the high-repetition-rate LTD module. Therefore, we propose a timing synchronization trigger control method and system for a multi-channel pulse switch of an LTD module. SUMMARY

[0003] The present application provides a timing synchronization trigger control method and system for a multi-channel pulse switch of an LTD module, which has the advantages of high synchronization precision, good reliability, and long life, and solves the problem of multiple bottlenecks in the trigger of the LTD module multi-channel switch.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a timing synchronization trigger control method for a multi-channel pulse switch of an LTD module, comprising the following steps: S01, measuring the inherent delay time of each discharge branch in the LTD module from the input of the trigger signal to the conduction of the gas switch; S02, inputting the measured inherent delay time value of each branch into the pulse timing controller as a compensation parameter, and setting the delay time of each output channel; S03, the pulse timing controller receives an external synchronization signal, generates N-channel trigger logic signals after time compensation according to the set delay time of each channel, and drives the corresponding gas switch to realize synchronous conduction after amplification and isolation transmission of the N-channel signals.

[0005] Preferably, the isolation transmission in step S03 is inductive isolation transmission, specifically: the amplified high-voltage trigger pulse is input to the primary coil of the magnetic loop coupler, coupled to the secondary coil through electromagnetic induction, and then injected into the trigger electrode of the gas switch.

[0006] Preferably, the gas switch is a multi-gap gas switch, which connects each suspended intermediate electrode through a parallel voltage-equalizing resistor chain for voltage-equalizing optimization of the switch gap.

[0007] Preferably, the main electrode of the multi-gap gas switch is a ring-shaped knife-edge electrode.

[0008] Preferably, the discharge branch contains a high-energy pulse capacitor with a repetition frequency discharge life of not less than one million times.

[0009] A timing synchronization trigger control system of an LTD module multi-channel pulse switch, comprising: a pulse timing controller for receiving a synchronization signal and generating N-channel trigger logic signals with independent programmable delays; N-channel pulse amplifiers for amplifying the N-channel trigger logic signals into high-voltage trigger pulses; a magnetic loop coupling unit containing N magnetic loop couplers for isolating and coupling the N high-voltage trigger pulses to the trigger electrodes of N gas switches, respectively; a multi-switch LTD module containing N parallel discharge branches, each branch containing at least one gas switch and one pulse capacitor.

[0010] Preferably, the gas switch is a multi-gap gas switch, which includes: a ring-shaped knife-edge main electrode; a plurality of suspended intermediate electrodes; a parallel voltage-equalizing resistor chain connected between the main electrode and the intermediate electrodes and between each intermediate electrode.

[0011] Preferably, the pulse timing controller takes FPGA as the core, and the programmable delay has a precision better than 1 nanosecond.

[0012] Preferably, the pulse capacitor is a high-energy capacitor with a repetition frequency discharge life of not less than one million times.

[0013] Preferably, the system further includes a sealed cavity, and all electrodes and insulators of the multi-switch LTD module are fixed in the sealed cavity through a central pull rod pre-tightening structure.

[0014] Compared with the prior art, the beneficial effects of the present application are as follows: 1. This invention, through system calibration and programmable delay compensation of the pulse timing controller, combined with the high-precision timing control of the FPGA, can control the conduction time deviation of multiple switches to the nanosecond level, thereby significantly improving energy synthesis efficiency. 2. This invention uses magnetic ring coupling to achieve inductive isolation transmission, replacing traditional resistor isolation, avoiding pulse leading-edge distortion, while ensuring high-voltage isolation safety and stable trigger signal transmission quality. 3. This invention uses a ring-shaped blade-shaped main electrode of a multi-gap gas switch to optimize the electric field distribution, and a parallel voltage equalization resistor chain to achieve gap voltage equalization. Combined with a sealed package with a pre-tightened central tie rod, it reduces the probability of self-breakdown and parameter drift, resulting in high reliability of the switch operation. 4. The present invention uses a high-energy pulse capacitor with a repetition rate discharge life of not less than one million times, which meets the long-term high repetition rate operation requirements of LTD module and extends the equipment maintenance cycle. Attached Figure Description

[0015] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system diagram of the present invention; Figure 3 This is a schematic diagram of the multi-gap gas switch structure of the present invention; Figure 4 This is a schematic diagram of the magnetic ring coupler structure of the present invention; Figure 5 This is a schematic diagram illustrating the working principle of the magnetic ring coupler of the present invention; Figure 6 This is a schematic diagram illustrating the calibration principle of the system of the present invention; Figure 7 This is a comparison chart of the timing compensation effects of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-7 As shown, the present invention provides a technical solution: a timing synchronization triggering control method for a multi-channel pulse switch of an LTD module, the method comprising the following steps: S01. Using high-precision delay measurement equipment such as high-speed photoelectric probes, perform delay measurement on each discharge branch in the LTD module—the entire process from trigger signal input to complete gas switch conduction, and record the inherent delay deviation value of each branch relative to the preset reference branch (e.g., , … This step provides basic data for subsequent accurate compensation, ensuring that the compensation is targeted. S02. Input the inherent delay deviation values ​​of each branch measured in S01 into the pulse timing controller. The controller configures a programmable delay unit for each output channel, setting the delay value to the negative of the corresponding deviation value (e.g., ...). , … Through reverse compensation, the inherent delay difference of the branch is offset, laying the parameter basis for synchronous triggering; after receiving the external synchronization signal, S03 and the pulse timing controller generate N time-compensated low-voltage trigger logic signals according to the delay parameters of each channel set by S02; these N signals are respectively sent to N pulse amplifiers, and after power amplification and pulse shaping, they are converted into high-voltage trigger pulses (usually tens of kilovolts); then, inductive isolation transmission is achieved through a magnetic ring coupler - the high-voltage trigger pulse is input to the primary coil of the magnetic ring, coupled to the secondary coil through electromagnetic induction, and then injected into the trigger pole of the corresponding gas switch, finally driving all gas switches to conduct synchronously within the nanosecond time window.

[0018] Among them, the gas switch has a multi-gap structure, and each suspended intermediate electrode is connected by a parallel voltage equalizing resistor chain to ensure uniform voltage in each gap; its main electrode is a ring-shaped blade to optimize the electric field distribution; the high-energy pulse capacitor in the discharge branch has a repetition rate discharge life of no less than one million times, which is suitable for high repetition rate conditions.

[0019] A timing synchronization triggering control system for an LTD module multi-pulse switch This system, used to implement the above method, includes a pulse timing controller, an N-channel pulse amplifier, a magnetic ring coupling unit, and a multi-switch LTD module. Pulse timing controller: With FPGA as the core controller, the input end receives external synchronization signals and the output end can generate N independent programmable delay trigger logic signals. The programmable delay accuracy is better than 1 nanosecond. By preset delay parameters, it can accurately compensate for the inherent delay difference of each branch and is the "control center" of timing synchronization. N-channel pulse amplifier: Each channel receives one trigger logic signal, amplifies the low-pressure signal into a high-pressure pulse that meets the triggering requirements of the gas switch (amplitude adapted to the switch triggering threshold), and provides sufficient power for triggering; Magnetic ring coupling unit: contains N magnetic ring couplers, each corresponding to one pulse amplifier and one gas switch. The magnetic ring adopts a high bandwidth and low loss magnetic core, which can realize high voltage isolation between the trigger circuit and the main circuit of the switch, and can transmit nanosecond-level trigger pulses with low distortion, ensuring pulse fidelity. Multi-switch LTD module: Contains N parallel discharge branches, each branch containing one gas switch and one pulse capacitor. The gas switch has a multi-gap structure, including a ring-shaped knife-edge main electrode, multiple floating intermediate electrodes, and a parallel voltage-equalizing resistor chain (connecting the main electrode and the intermediate electrodes, and each intermediate electrode); the pulse capacitor is a high-energy-density capacitor with a repetition rate discharge life of not less than one million times. In addition, the system also includes a sealed cavity, in which all electrodes and insulators of the multi-switch LTD module are fixed to the cavity by a central tie rod pre-tightening structure. The tie rod is made of high-strength material and is fixed by pre-tightening with nuts to ensure structural rigidity and sealing, and to avoid parameter drift caused by loose parts.

[0020] In this embodiment, the LTD module contains 4 parallel discharge branches (N=4), and the parameters of each component in the system are as follows: Pulse timing controller: adopts Xilinx Kintex-7 series FPGA, with a delay adjustment accuracy of 0.5 nanoseconds, supports 0-2000 nanosecond delay settings, and receives external 10MHz synchronization signals via Ethernet. N-channel pulse amplifier: 4 independent channels, input logic signal amplitude 5-15V, output high voltage pulse amplitude 40kV, pulse leading edge ≤8 nanoseconds, suitable for switch triggering requirements. Magnetic ring coupling unit: The magnetic ring adopts a Mn-Zn ferrite core, with 12 turns in the primary coil and 6 turns in the secondary coil. The transmission bandwidth is 100kHz-1GHz, and the insertion loss is ≤1dB, ensuring low-distortion pulse transmission. Multi-switch LTD module: Each branch gas switch has a six-gap structure. The main electrode is made of tungsten copper alloy ring blade (blade angle 30°). Four floating intermediate electrodes are connected by a voltage equalization resistor chain composed of 100MΩ high-precision resistors. The pulse capacitor uses composite dielectric material. After electrode structure optimization, the repetition frequency discharge life reaches 5 million times. All electrodes and alumina insulators are pre-tightened and fixed in the aluminum alloy sealed cavity by stainless steel central tie rod. The tie rod pre-tightening force is 50kN, and the cavity is filled with 0.5MPa SF6 gas.

[0021] The process of implementing timing synchronization triggering using the above system is as follows: System calibration: Using a high-speed photoelectric probe with a response time of 0.2 nanoseconds, the conduction delay time of the four branches was measured to obtain the deviation value relative to the reference branch. =7.2ns =5.8ns =9.1ns =6.5ns.

[0022] Parameter settings: Input the deviation value into the pulse timing controller and set the delay values ​​for the 4 channels to -7.2ns, -5.8ns, -9.1ns, and -6.5ns. Synchronous Trigger: After an external synchronization signal is input, the controller generates four compensated logic signals, which are amplified into 40kV high-voltage pulses and injected into the switch trigger poles through a magnetic ring coupler. Tests show that the conduction time deviation of the four switches is ≤3ns, the leading edge of the module output pulse is ≤20ns, and it runs continuously for 1000 hours at a 10kHz repetition rate without any abnormalities.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A timing synchronization triggering control method for a multi-channel pulse switch in an LTD module, characterized in that, Includes the following steps: S01. Measure the inherent delay time from the trigger signal input to the gas switch being turned on for each discharge branch in the LTD module; S02. The measured inherent delay time values ​​of each branch are input as compensation parameters into the pulse timing controller to set the delay time of each output channel. S03. The pulse timing controller receives an external synchronization signal and generates N time-compensated trigger logic signals according to the set delay time of each channel. After amplification and isolation transmission, the N signals drive the corresponding gas switches to achieve synchronous conduction.

2. The timing synchronization triggering control method for a multi-channel pulse switch of an LTD module according to claim 1, characterized in that: The isolation transmission mentioned in step S03 is inductive isolation transmission, specifically: the amplified high-voltage trigger pulse is input to the primary coil of the magnetic ring coupler, coupled to the secondary coil through electromagnetic induction, and then injected into the trigger electrode of the gas switch.

3. The timing synchronization triggering control method for a multi-channel pulse switch in an LTD module according to claim 1, characterized in that: The gas switch is a multi-gap gas switch, which connects each suspended intermediate electrode by setting a parallel voltage-equalizing resistor chain for voltage equalization optimization of the switch gap.

4. The timing synchronization triggering control method for a multi-channel pulse switch in an LTD module according to claim 3, characterized in that: The main electrode of the multi-gap gas switch is a ring-shaped knife-edge electrode.

5. The timing synchronization triggering control method for a multi-channel pulse switch in an LTD module according to claim 1, characterized in that: The discharge branch includes a high-energy-density pulse capacitor with a repetition rate discharge life of not less than one million times.

6. A timing synchronization triggering control system for an LTD module multi-channel pulse switch used to implement the method of any one of claims 1-5, characterized in that, include: A pulse timing controller is used to receive a synchronization signal and generate N trigger logic signals with independent programmable delays; An N-channel pulse amplifier is used to amplify the N-channel trigger logic signals into high-voltage trigger pulses; The magnetic ring coupling unit includes N magnetic ring couplers, which are used to isolate and couple the N high-voltage trigger pulses to the trigger poles of N gas switches respectively; The multi-switch LTD module contains N parallel discharge branches, each branch containing at least one gas switch and one pulse capacitor.

7. The timing synchronization triggering control system for a multi-channel pulse switch of an LTD module according to claim 6, characterized in that: The gas switch is a multi-gap gas switch, which includes: Ring-shaped blade-shaped main electrode; Multiple suspended intermediate electrodes; A parallel voltage equalizing resistor chain is connected between the main electrode and the intermediate electrode, as well as between each intermediate electrode.

8. The timing synchronization triggering control system for a multi-channel pulse switch of an LTD module according to claim 6, characterized in that: The pulse timing controller is based on an FPGA, and the programmable delay has an accuracy better than 1 nanosecond.

9. A timing synchronization triggering control system for an LTD module multi-channel pulse switch according to claim 6, characterized in that: The pulse capacitor is a high-energy-density capacitor with a repetition rate discharge life of not less than one million cycles.

10. A timing synchronization triggering control system for an LTD module multi-channel pulse switch according to claim 6, characterized in that: The system also includes a sealed cavity, in which all electrodes and insulators of the multi-switch LTD module are fixed to the sealed cavity by a central tie rod pre-tightening structure.

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