Dual-source coupled self-stabilized arc plasma ignition and combustion assisting device and method

Abstract

The application relates to an innovative proposal that high-voltage pulse ignition and high-power sustain functions are coupled by division of labor, initial breakdown and dynamic ignition of a discharge gap are completed through a high-voltage pulse ignition branch, high-current and high-power sustain energy after breakdown is provided through a ZVS high-frequency resonance main power branch, and bidirectional isolation and collaborative output between two types of different electric energy waveforms are realized through a passive frequency division isolation structure.

Description

Technical Field

[0001] This invention belongs to the field of plasma ignition devices and power electronics technology, and relates to a dual-source coupled self-stabilized arc plasma ignition and combustion aid device and method. Background Technology

[0002] Plasma ignition and combustion-supporting technology can generate high-energy electrons, active particles, and localized high-temperature regions in the working fluid through the discharge process, thereby promoting rapid fuel ignition and stable combustion. It has significant application value in scramjet engines, high-speed combustion chambers, high-speed jet combustion devices, and other highly dynamic combustion systems. In these application scenarios, the working fluid typically exhibits characteristics such as high flow velocity, high turbulence intensity, short residence time, and significant fluctuations in pressure and composition. Traditional spark ignition or low-power discharge methods are prone to problems such as difficulty in flame nucleus formation, dispersion of the discharge channel, and limited flame stability range. Therefore, plasma ignition and combustion-supporting power sources with higher energy density and stronger disturbance resistance are required.

[0003] However, plasma arcs in high-speed airflow and strong turbulence environments are not stable linear loads, but rather nonlinear loads with significant dynamic impedance characteristics. Before arc breakdown, the discharge gap is in a high-impedance or near-open-circuit state, requiring a high instantaneous voltage to break down the gas medium and establish an initial plasma channel. After breakdown, the discharge gap is ionized and conducts, and the load impedance drops rapidly. At this point, maintaining arc stability mainly depends on sufficient arc-continuing current and continuous power. Especially under high-speed working fluid scouring, the arc channel is also affected by stretching, deflection, cooling, and arc root jump, leading to continuous fluctuations in arc voltage, arc current, and load impedance. The arc is prone to entering a critical extinction or instantaneous arc-breaking state.

[0004] Existing high-voltage ignition power supplies can typically provide high open-circuit voltages or pulse voltages, suitable for initial breakdown of gas gaps. However, their continuous output current and power are limited, making it difficult to maintain a stable and continuous high-power plasma arc under high-speed airflow or high-turbulence conditions. Conversely, welding machine power supplies and high-power inverter power supplies, while possessing strong current output capabilities and able to provide arc-renewing energy after the arc has been established, often suffer from insufficient output voltage or instantaneous breakdown capability. In scenarios with large discharge gaps, high-speed flowing working fluids, or reignition after arc interruption, they often struggle to reliably initiate and re-ignite the arc.

[0005] To balance high-voltage arc ignition and high-power arc sustaining, existing technologies combine high-voltage pulse ignition power supplies with main power arc sustaining power supplies. However, the output waveforms, voltage levels, frequency components, and output impedances of these two types of power supplies differ significantly. Without effective coupling and isolation structures, the high-voltage pulse can easily flow back into the main power circuit, impacting the inverter, transformer, and resonant devices. The main power arc sustaining voltage may also couple backward to the pulse ignition module, causing it to mis-trigger, fail, or be damaged. Furthermore, some dual-source solutions still employ single-ignition logic, shutting down the pulse ignition unit after arc ignition. This lacks the ability to quickly re-ignite when high-speed airflow disturbances weaken or extinguish the arc, making it difficult to adapt to continuously changing combustion flow fields.

[0006] Therefore, for applications such as scramjet engines and high-speed gas flow ignition and combustion, existing plasma power supply devices still struggle to simultaneously meet the requirements of high-voltage reliable arc ignition, high-current high-power arc continuation, dual-source power supply with anti-backflow isolation, and supplementary ignition and arc stabilization under dynamic disturbances. There is an urgent need for a plasma ignition power supply device that can adapt to the dynamic impedance changes of the plasma arc and achieve reliable arc ignition, continuous arc continuation, and adaptive arc stabilization under conditions of high-speed gas flow, strong turbulence, and multi-working-medium disturbances. Summary of the Invention

[0007] Technical problems to be solved To avoid the shortcomings of existing technologies, and addressing the difficulties in initiating plasma arcs, unstable arc continuation, and rapid reignition after arc breakage under high-speed airflow and strong turbulence conditions, as well as the problems of mutual backflow and waveform crosstalk that easily occur when the high-voltage ignition power supply and the high-power arc continuation power supply are simply coupled, this invention proposes a dual-source coupled self-stabilizing arc plasma ignition and combustion aid device and method.

[0008] Technical solution A dual-source coupled self-stabilized arc plasma ignition and combustion aid device, characterized in that it includes an EMI filter module 2, an AC / DC converter, a ZVS inverter LC oscillation resonant unit 5, a bidirectional transient suppression element 6, a high-frequency step-up transformer 7, a grounded Y-type safety capacitor 8, a secondary-side dual-sided high-frequency choke coil group 9, an adjustable air sphere gap 10, a pulse igniter 11, and a plasma generation chamber 13; the primary windings of the EMI filter module 2, AC / DC converter, ZVS inverter LC oscillation resonant unit 5, bidirectional transient suppression element 6, and high-frequency step-up transformer 7 are connected in parallel to the AC input terminal; the secondary windings of the high-frequency step-up transformer 7 output two... The high-voltage transformer 7 is connected in series with the plasma generating cavity 13 via two secondary double-sided high-frequency choke coil groups 9. A Y-safety capacitor 8 is connected in parallel between the secondary winding of the high-frequency step-up transformer 7 and the secondary double-sided high-frequency choke coil group 9. The secondary double-sided high-frequency choke coil group 9 and the plasma generating cavity 13 are connected to the pulse igniter 11 via a parallel adjustable air gap 10. The pulse igniter 11 is connected to the isolation pulse power supply terminal 12 and outputs an ignition isolation pulse. The two high-voltage output leads of the high-voltage pulse igniter are connected to the end of the main power line behind the high-frequency choke coil after passing through the adjustable air gap 10. Finally, the leads are connected to the discharge gap position inside the plasma generating cavity 13.

[0009] The peak voltage of the high-voltage pulse igniter is set between 10kV and 1000kV, and the pulse repetition arc ignition frequency is continuously adjustable, with an adjustment range of 1Hz to 5kHz.

[0010] The adjustable air gap 10 includes an embedded electrode 19, a tapping support structure 21, an exhaust port 22, a hemispherical discharge structure 23, a gap discharge cavity 24, and a housing 25. The gap discharge cavity 24 is connected to the housing 25 at both ends. The discharge hemisphere of the hemispherical discharge structure 23 is located inside the gap discharge cavity 24, and the other end connected to the discharge hemisphere is located inside the housing 25 and connected to the embedded electrode 19 via a wire. The two hemispherical discharge structures 23 inside the gap discharge cavity 24 are arranged opposite each other, with a gap L between the arc apexes of the two opposite hemispheres. The gap discharge cavity 24 has multiple exhaust ports 22. The hemispherical discharge structure 23 located inside the fixed housing 25 is fixed to the housing 25 by the tapping support structure 21.

[0011] The gap L between the relative hemispherical apexes is 5mm to 10mm.

[0012] There are four exhaust ports 22.

[0013] The discharge hemisphere 23 is made of arc-resistant ablation-resistant metal material, including stainless steel, tungsten copper alloy, copper alloy or nickel-based alloy.

[0014] The tapping support structure 21 is made of ceramic or PEEK insulating material.

[0015] The capacitance of the Y-type safety capacitor is preferably 10pF to 1000pF.

[0016] The resonant inductance of the ZVS inverter LC oscillation resonant unit 5 is 7μH to 15.3μH, and the resonant capacitor is 3.96μF. Based on the component parameters, a standard ZVS soft-switching inverter topology is formed. After being powered on and oscillating, it converts constant DC power into high-frequency sinusoidal alternating power with a stable frequency in the range of 20kHz to 30kHz.

[0017] An ignition method using the aforementioned dual-source coupled self-stabilized arc plasma ignition and combustion aid device, characterized in that: 1. Working condition matching voltage regulation: By switching the winding turns section corresponding to the center tap of the secondary side of the high-frequency step-up transformer through the output voltage regulation switch, the arc-continuation output voltage of the transformer secondary side can be adjusted to be selected in the range of 1kV to 5kV to match the steady-state arc-continuation power requirements corresponding to the current working fluid and airflow pressure. 2. Pulse parameter tuning: Based on the discharge gap size of the plasma generating chamber and the airflow conditions of 0.45MPa~0.55MPa, adjust the output pulse peak voltage of the pulse igniter so that the pulse peak voltage is simultaneously higher than the adjustable air sphere gap breakdown threshold and the plasma generating chamber discharge gap breakdown threshold, so that the pulse can break down the two gaps in sequence. 3. Staged pulse output control: Initial arc initiation stage: The control pulse igniter continuously outputs a continuous high-voltage pulse to break down the adjustable air sphere gap and the internal air gap of the plasma generation chamber, establishing an initial plasma discharge channel; Steady-state arc sustaining stage: After the electric arc is established, the pulse igniter is switched to intermittent pulse output mode, and the ZVS inverter unit continuously outputs high-frequency sinusoidal power to maintain the arc self-sustaining. Dynamic ignition stage: Real-time acquisition of arc voltage and arc current signals. When the arc impedance increases and is close to extinction, the ignition pulse is triggered to re-break down the gap and rebuild the discharge channel. 4. Passive frequency division isolation and coordinated operation: The main power arc-continuing power is delivered to the discharge cavity through the high-frequency choke coil with low resistance, and the pulse spike is blocked by the high resistance of the choke coil; during the arc-continuing stage, the regulating air ball gap is automatically cut off due to the voltage drop at both ends, blocking the high voltage backflow of the main power to the pulse branch, and realizing bidirectional isolation between the two waveforms.

[0018] Beneficial effects This invention proposes a dual-source coupled self-stabilized arc plasma ignition and combustion aid device and method, which creatively proposes to separate and couple the high-voltage pulse arc ignition function and the high-power arc continuation function. The initial breakdown and dynamic ignition of the discharge gap are completed through the high-voltage pulse ignition branch, and the high current and high-power arc continuation energy after breakdown is provided through the ZVS high-frequency resonant main power branch. The bidirectional isolation and coordinated output between the two different electrical energy waveforms are realized through a passive frequency division isolation structure.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) Improve the arc ignition and arc sustaining capabilities under high-speed airflow conditions. This invention adopts a dual-source structure combining a high-voltage pulse igniter and a ZVS high-frequency resonant main power branch. The high-voltage pulse igniter completes the initial breakdown and supplementary ignition, while the ZVS high-frequency resonant main power branch provides continuous arc sustaining energy after the arc is established. This balances reliable high-voltage arc ignition and high-current, high-power arc sustaining, improving the problems of difficulty in stabilizing the arc with a single high-voltage, low-current power supply and difficulty in reliably initiating the arc with a single high-power power supply.

[0020] (2) Reduce backflow and device impact during dual-source coupling. This invention sets up high-frequency choke coil groups on both sides of the output lines of the secondary side of the high-frequency step-up transformer, and couples the high-voltage pulse igniter to the plasma generator through an adjustable air gap, forming a passive frequency division isolation structure between the high-voltage pulse ignition branch and the main power arc-continuing branch. This structure reduces the risk of high-voltage pulse backflow to the ZVS high-frequency resonant inverter unit and the high-frequency step-up transformer, while also reducing the possibility of the main power arc-continuing voltage being reverse-coupled to the high-voltage pulse igniter, thus improving the electrical reliability of the device.

[0021] (3) Improve the adaptability of arc stabilization under complex flow fields and multiple working fluids. This invention enables the device to re-establish the discharge channel when there is high-speed airflow disturbance, arc decay or instantaneous arc interruption by using the graded breakdown coordination between the adjustable air ball gap and the discharge gap of the plasma generator, as well as the intermittent supplementary ignition working mode of the high-voltage pulse igniter; at the same time, combined with the multi-tap adjustment of the high-frequency step-up transformer, the common-mode discharge of high-voltage output and the grounding shielding structure, the device's adaptability and operational stability under different airflow velocities, working pressures, discharge gaps and working fluid types are improved. Attached Figure Description

[0022] Figure 1 A dual-source coupled self-stabilized arc plasma ignition and combustion aid device 1-220V AC input; 2-EMI filter module; 3-Fuse element; 4-High-power AC / DC power supply; 5-ZVS inverter LC resonant unit; 6-Bidirectional transient suppression element; 7-High-frequency step-up transformer; 8-Grounding Y-safety capacitor; 9-Secondary side dual-sided high-frequency choke coil group; 10-Adjustable air gap; 11-Pulse igniter; 12-Isolation pulse power supply terminal; 13-Plasma generation chamber; 14-High-speed airflow duct; 15-Transformer secondary side center tap; 16-Output voltage adjustment switch; 17-Pulse igniter switch.

[0023] Figure 2 Adjustable air gap structure diagram 18-High voltage conductor; 19-Embedded electrode; 20-Conductor; 21-Tapping support structure; 22-Exhaust hole; 23-Hemispherical discharge structure; 24-Gap discharge cavity; 25-Shell; Figure 3 : Transformer primary current, voltage, power-time diagram of dual-source coupled self-stabilized arc plasma ignition and combustion aid device. Detailed Implementation

[0024] The present invention will now be further described in conjunction with the embodiments and accompanying drawings: A dual-source coupled self-stabilized arc plasma ignition and combustion aid device includes a main power arc-continuing branch, a pulsed arc-initiating branch, a passive frequency-division isolation network, and a plasma generator. The main power arc-continuing branch provides continuous arc-continuing energy after the plasma channel is established. The pulsed arc-initiating branch provides high-voltage pulsed arc-initiating energy during initial arc initiation and critical arc-breaking states. The passive frequency-division isolation network is located between the main power arc-continuing branch and the pulsed arc-initiating branch to achieve frequency-division coupling and bidirectional isolation between the two power supplies. The plasma generator is used to form a plasma arc in a high-speed flowing working fluid.

[0025] The main power arc-continuing branch includes a ZVS high-frequency resonant inverter unit and a high-frequency step-up transformer. The input terminal of the ZVS high-frequency resonant inverter unit is connected to a low-voltage, high-current DC power supply, and the output terminal is connected to the primary winding of the high-frequency step-up transformer, used to convert low-voltage DC power into high-frequency alternating power. The ZVS high-frequency resonant inverter unit includes a resonant inductor, a resonant capacitor, and a switching transistor assembly, and its operating frequency is preferably 10kHz to 50kHz. The primary side of the ZVS high-frequency resonant inverter unit or the high-frequency step-up transformer is also provided with at least one of the following: transient suppression element, RC absorption circuit, RCD absorption circuit, or varistor protection element, used to suppress switching spikes and overvoltage impacts generated by high-voltage pulse coupling.

[0026] The high-frequency step-up transformer includes a primary winding, a secondary winding, and a high-voltage insulation structure. The primary winding is connected to a ZVS high-frequency resonant inverter unit, and the secondary winding adopts a double-ended high-voltage output structure, with a first high-voltage output terminal and a second high-voltage output terminal respectively led out from both ends of the secondary winding. The secondary output voltage of the high-frequency step-up transformer is lower than the pulse peak voltage of the high-voltage pulse igniter, preferably 1kV to 5kV, and more preferably 3kV, for maintaining arc combustion after the plasma channel is established. The high-frequency step-up transformer can adopt a multi-tap structure, with multiple taps set on the primary winding and / or the secondary winding, so that the secondary arc-continuing output voltage can be switched under different operating conditions.

[0027] The pulse arc ignition branch includes an independently configured high-voltage pulse igniter. The high-voltage pulse igniter is independently isolated and its power supply terminal is electrically isolated from the main power arc continuation branch power supply terminal. The output terminal of the high-voltage pulse igniter is connected to the input terminal of the plasma generator via an adjustable air gap. The high-voltage pulse igniter is not directly connected in parallel with the secondary output terminal of the high-frequency step-up transformer. The pulse peak voltage of the high-voltage pulse igniter can be selected from 10kV to 1000kV, with 800kV preferred to ensure arc ignition effect under high-speed airflow. The pulse arc ignition frequency is adjustable, preferably from 1Hz to 5kHz. The pulse output modes include continuous pulse output during the initial arc ignition stage, intermittent pulse output after arc ignition, and supplementary ignition pulse output triggered by arc voltage, arc current, or ignition control signals. The output pulse peak voltage of the high-voltage pulse igniter is higher than the breakdown threshold of the adjustable air gap and the breakdown threshold of the plasma generator discharge gap.

[0028] The passive frequency division isolation network includes a secondary-side dual-sided high-frequency choke coil assembly and an adjustable air gap. The dual-sided high-frequency choke coil assemblies are connected in series at the first and second high-voltage output terminals of the secondary side of the high-frequency step-up transformer, respectively, and are located between the high-frequency step-up transformer and the plasma generator. Each side of the high-frequency choke coil assembly consists of one or more high-voltage resistant inductors connected in series or parallel. Its windings use high-voltage resistant insulated wire, insulated frame, segmented winding structure, or potting structure, with a rated withstand voltage higher than the maximum pulse voltage of the high-voltage pulse igniter. The high-frequency choke coil assembly can also use a magnetic ring with good high-frequency filtering performance. The high-frequency choke coil assembly allows the main power arc-continuing energy to pass through within the operating frequency range of the ZVS high-frequency resonant inverter unit, and exhibits high impedance isolation characteristics in the steep edge frequency band of the high-voltage pulse output pulse, thereby reducing the risk of high-voltage pulses flowing back to the ZVS high-frequency resonant inverter unit through the secondary winding, distributed capacitance, or return path.

[0029] The adjustable air gap includes a first discharge hemisphere and a second discharge hemisphere arranged opposite each other. The first discharge hemisphere is connected to the output line of the high-voltage pulse igniter, and the second discharge hemisphere is connected to the input line of the plasma generator. The first and second discharge hemispheres are made of stainless steel, tungsten-copper alloy, copper alloy, nickel-based alloy, or other arc-erosion-resistant metal materials, and are mounted on PEEK, ceramic, PTFE, or other high-voltage resistant insulating supports. The distance between the first and second discharge hemispheres is adjustable, preferably 5mm to 10mm. The breakdown threshold of the adjustable air gap is set to be higher than the normal operating voltage or steady-state arc voltage of the main power arc-continuing branch, and lower than the pulse peak voltage of the high-voltage pulse igniter, so that it remains cut off in the main power arc-continuing state and momentarily breaks down and conducts during pulse arc ignition or supplementary ignition.

[0030] The plasma generator includes a discharge electrode, a discharge chamber, and a high-speed airflow channel. The discharge electrode is disposed within the discharge chamber, and the high-speed airflow channel is used to deliver air, water vapor, argon, or other ionizable working fluid into the discharge chamber. The discharge gap of the plasma generator and the adjustable air sphere gap form a graded breakdown fit. The discharge gap, electrode structure, nozzle structure, and airflow channel dimensions of the plasma generator are matched with the breakdown threshold of the adjustable air sphere gap, so that a discharge channel can be established within the plasma generator after the high-voltage pulse is conducted through the adjustable air sphere gap. The discharge electrode can be made of tungsten, tungsten-copper alloy, stainless steel, copper alloy, or ablation-resistant conductive material. The discharge chamber or nozzle can be equipped with a heat-resistant insulating bushing, an ablation-resistant nozzle, or a replaceable electrode structure.

[0031] Furthermore, the secondary output line or high-voltage output reference node of the high-frequency step-up transformer is connected to the grounded metal casing via a Y-type safety capacitor or a high-voltage common-mode discharge capacitor. The Y-type safety capacitor or high-voltage common-mode discharge capacitor has a withstand voltage higher than the main power arc-continuing branch output voltage and the high-voltage pulse coupling voltage, and its capacitance is preferably 10pF to 1000pF. The grounded metal casing is used for protective grounding and electromagnetic shielding and is not used as a working return path for the high-voltage pulse ignition current or plasma arc-continuing current. A PEEK, ceramic, PTFE, or other high-voltage insulating panel is installed between the grounded metal casing and the high-voltage output terminals to improve the creepage distance and electrical safety in the high-voltage output area.

[0032] In practice: The 220V AC power is connected to the entire equipment from terminal 1. The AC power is first sent into the EMI filter module 2. The module can filter out high-frequency noise interference and line conducted interference introduced by the power grid, and optimize the power input quality. After filtering, the AC power passes through the fuse element 3 and is connected to the high-power AC / DC power supply 4. The high-power DC power supply completes the rectification and conversion of AC power to DC power, and outputs stable DC bus power, thereby providing a stable and reliable rated operating power supply for the downstream ZVS inverter resonant unit 5.

[0033] Furthermore, the fuse element 3 connected in series in the power supply line has short circuit and overload protection functions. When a short circuit fault occurs in the whole circuit or the downstream load is abnormally overloaded, the fuse element can quickly melt and cut off the front-end power supply circuit, forming effective overload protection for downstream precision power devices such as ZVS inverter and step-up transformer from the input end, and avoiding instantaneous overcurrent burnout of the devices.

[0034] The stable DC power output from the high-power DC power supply is entirely fed into the ZVS inverter LC resonant unit 5. This unit is the core inverter module of the main power of the device, which integrates a resonant inductor, a resonant capacitor, and a full-bridge switching transistor assembly. The resonant inductor has a value of 7μH to 15.3μH, and the resonant capacitor has a value of 3.96μF. Based on the component parameters, a standard ZVS soft-switching inverter topology is formed. After power-on and oscillation, the constant DC power is converted into high-frequency sinusoidal alternating power with a stable frequency in the range of 20kHz to 30kHz, providing an alternating power supply that meets the frequency requirements for the subsequent boost stage.

[0035] Furthermore, the bidirectional transient suppression element 6 is installed in parallel across the primary winding of the high-frequency step-up transformer 7. The element can absorb the instantaneous spike overvoltage generated when the ZVS power transistor is switched on and off in real time, effectively suppressing the noise interference caused by the circuit switching oscillation, preventing the instantaneous high voltage from breaking down the power switching device inside the ZVS, and ensuring that the ZVS resonant circuit can maintain a stable soft-switching oscillation state for a long time.

[0036] The high-frequency sinusoidal electrical energy generated by the ZVS inverter resonant unit is entirely fed into the primary winding of the high-frequency step-up transformer 7. This transformer employs a fully sealed potting structure, housing the primary winding, secondary winding, and a multi-layer composite high-voltage insulation structure. The insulation level meets the requirements for high-voltage operation. The secondary winding adopts a symmetrical double-ended high-voltage output structure, with the first and second high-voltage output terminals respectively led out from both ends.

[0037] Furthermore, the secondary winding of the transformer is equipped with a secondary center tap 15, which, together with the matching output voltage regulating switch 16, forms a multi-level voltage regulation structure. The center tap divides the secondary winding into multiple turns segments. The output voltage regulating switch can be connected to different winding segments according to actual operating conditions, thereby changing the actual output turns ratio of the transformer and flexibly switching the secondary output voltage level. Operators can manually switch the output voltage regulating switch 16 to match the corresponding arc-sustaining voltage according to different combustion conditions, working fluid type, discharge gap size, and cavity working pressure. In this embodiment, the transformer's normal arc-sustaining output voltage is controlled within the range of 1kV to 5kV, preferably with rated output voltages of 1kV and 3kV, specifically matching the working requirements of the arc self-sustaining stage under argon and air flow conditions. This ensures sufficient arc-sustaining current and output power without increasing the insulation pressure of components due to excessive voltage. Relying on the high-frequency electromagnetic coupling, the voltage is boosted in the secondary winding of the transformer to generate high-frequency high-voltage sinusoidal power with a higher amplitude. Two independent high-voltage output cables are led out from the secondary side of the high-frequency step-up transformer. Each high-voltage cable is connected in series with a grounding Y safety capacitor 8 and a high-frequency choke coil group 9 near the transformer output end. An adjustable air gap 10 is connected between the main power line and the pulse output branch on the back side of the high-frequency choke coil group. The grounding Y capacitor, the double-sided choke coil group and the adjustable air gap together form a complete passive frequency division isolation network.

[0038] Furthermore, the grounding Y-type safety capacitor 8 is mainly used to filter out high-frequency common-mode interference generated by the secondary circuit of the transformer. Its withstand voltage level is higher than the output voltage of the main power arc-continuing branch and the high-voltage pulse coupling voltage, suppressing electromagnetic noise radiated outward during the operation of the whole machine and improving the electromagnetic compatibility performance of the device. The high-frequency choke coil group 9 connected in series in the line has differentiated impedance characteristics. It presents a low impedance state to the low-frequency sinusoidal arc-continuing power output by ZVS, ensuring that the main power power is transmitted to the plasma generation cavity without loss. However, it presents a high impedance characteristic to the nanosecond-level steep-edge high-voltage pulse output by the pulse igniter. Relying on the impedance barrier, it physically blocks the pulse peak from flowing back into the high-frequency step-up transformer and the front-end ZVS main circuit, achieving the first layer of isolation protection from the main power side.

[0039] The pulse igniter 11 constitutes an independent high-voltage pulse arc ignition branch, powered separately by an independently configured isolated pulse power supply terminal 12. This power supply circuit is completely electrically isolated from the low-voltage DC power supply terminal of the main power arc continuation branch, completely eliminating crosstalk between the two power supplies. The high-voltage pulse igniter adopts a modular integrated design and is not directly connected in parallel with the secondary output terminal of the high-frequency step-up transformer. Electrical coupling is achieved only through an adjustable air gap, further improving the isolation effect. In this embodiment, the pulse peak voltage of the high-voltage pulse igniter is set in the range of 10kV to 1000kV. Considering the actual working conditions of high-speed gas flow ignition and combustion, an 800kV pulse voltage is preferred, which can easily break down large-size discharge gaps and high-speed flowing gas media. The pulse repetition arc ignition frequency is continuously adjustable, with an adjustment range of 1Hz to 5kHz, which can be flexibly set according to changes in the flow field. The pulse output modes are divided into three categories: continuous pulse output during the initial arc ignition stage, intermittent pulse output after the arc is established, and supplementary ignition pulse output triggered by arc voltage, arc current detection signals, or external ignition control signals. This multi-mode output design comprehensively adapts to the arc ignition and stabilization requirements under different operating conditions. The peak voltage of the high-voltage pulse igniter's output pulse is higher than both the breakdown threshold of the adjustable air sphere gap and the breakdown threshold of the plasma generator's discharge gap, ensuring that the pulse signal can sequentially break down the two gaps and successfully establish a plasma discharge channel. The high-voltage output lead of the high-voltage pulse igniter passes through the adjustable air sphere gap 10 and is connected to the end of the main power line behind the high-frequency choke coil, ultimately connecting to the discharge gap inside the plasma generation chamber 13.

[0040] Furthermore, the adjustable air gap 10 is the core component for achieving bidirectional isolation and graded breakdown. The pulse igniter 11 constitutes an independent high-voltage pulse arc ignition branch, powered separately by an independently set isolation pulse power supply terminal 12. This power supply circuit is completely electrically isolated from the low-voltage DC power supply terminal of the main power arc continuation branch, completely eliminating crosstalk between the two power supplies. The high-voltage pulse igniter adopts a modular integrated design and is not directly connected in parallel with the secondary output terminal of the high-frequency step-up transformer. Electrical coupling is achieved only through the adjustable air gap, further improving the isolation effect. In this embodiment, the pulse peak voltage of the high-voltage pulse igniter is set in the range of 10kV to 1000kV. Considering the actual working conditions of high-speed airflow ignition and combustion, an 800kV pulse voltage is preferred, which can easily break down large-size discharge gaps and high-speed flowing gas media. The pulse repetition arc ignition frequency is continuously adjustable, with an adjustment range of 1Hz to 5kHz, which can be flexibly set according to changes in the flow field. The pulse output modes are divided into three categories: continuous pulse output during the initial arc ignition stage, intermittent pulse output after the arc is established, and supplementary ignition pulse output triggered by arc voltage, arc current detection signals, or external ignition control signals. This multi-mode output design comprehensively adapts to the arc ignition and stabilization requirements under different operating conditions. The peak voltage of the high-voltage pulse igniter's output pulse is higher than both the breakdown threshold of the adjustable air sphere gap and the breakdown threshold of the plasma generator's discharge gap, ensuring that the pulse signal can sequentially break down the two gaps and successfully establish a plasma discharge channel. The two high-voltage output leads of the high-voltage pulse igniter pass through the adjustable air sphere gap 10 and are connected to the end of the main power line behind the high-frequency choke coil. Finally, the leads are connected to the discharge gap inside the plasma generation chamber 13.

[0041] Furthermore, the adjustable air gap 10 is the core component for achieving bidirectional isolation and graded breakdown. Its upper and lower discharge hemispheres 23 are made of tungsten-copper alloy or other ablation-resistant metals and are mounted on a ceramic or PEEK insulating tapped support structure 21. The distance between the two hemispheres can be finely adjusted within the range of 5mm to 10mm. Four exhaust holes are opened around the discharge gap. One end is connected to the embedded electrode 19 and the high-voltage wire via a wire 20, and the other end is connected to the pulse igniter circuit. In terms of structural and voltage matching design, this device adopts a graded breakdown approach, setting the breakdown voltage of the adjustable air gap to be higher than the steady-state arc voltage of the main power while being lower than the peak voltage of the pulse igniter. The discharge electrodes inside the plasma generating chamber 13 are made of erosion-resistant tungsten-based alloy. The chamber is connected to a high-pressure, high-speed airflow duct 14. The breakdown voltage of the discharge gap inside the chamber is further lower than the breakdown voltage of the adjustable air sphere gap. This matching method ensures that: when the main power arc-continuing voltage is applied to the entire circuit, only the gap inside the plasma generating chamber is broken down to maintain arc self-sustaining, and the adjustable air sphere gap remains closed, preventing the main power high voltage from flowing back to the pulse branch; only when the high-voltage pulse is applied can the adjustable air sphere gap and the chamber discharge gap be broken down sequentially to complete the arc ignition action, ensuring that the air sphere gap remains non-conductive during the main power arc continuation.

[0042] Furthermore, after the equipment is powered on, the AC / DC unit initially supplies power to the main power ZVS circuit. Due to the inability to break down the high-pressure working gas in the air duct 14, it remains in a standby resonant state. When the ignition switch 17 is activated, the isolated power supply circuit supplies power to the pulse igniter. The pulse igniter outputs continuous high-voltage pulses. The pulse energy successively breaks down the adjustable air sphere gap and the discharge gap inside the plasma generating chamber, breaking down the high-pressure working gas flowing in the air duct 14 and quickly establishing an initial plasma arc. After the arc is formed, the discharge gap is ionized and conducts, and the overall circuit voltage drops rapidly. The adjustable air sphere gap returns to the cutoff state because the voltage at both ends is lower than the breakdown threshold. At this time, the two power supplies are electrically isolated, reliably preventing the reverse backflow of the resonant high voltage on the ZVS side into the pulse igniter 11. The frequency division and bidirectional electrical isolation of the two power supply waveforms with different characteristics are achieved by relying on passive devices.

[0043] Furthermore, relying on its inherent constant current limiting characteristics, the ZVS resonant circuit can adaptively adjust its output conditions in accordance with the real-time changes in the nonlinear load of the arc, continuously outputting high-power sinusoidal electrical energy to maintain stable arc combustion. Throughout the entire cycle of continuous arc sustaining of the entire device, the pulse igniter always maintains an intermittent cyclic output mode. Once changes in operating conditions such as high-speed airflow disturbances or switching of working fluid components occur, and the load impedance inside the cavity abnormally increases and the arc is on the verge of extinction, the pulse igniter outputs a high-voltage pulse again to break down the ball gap and discharge gap, quickly completing the re-ignition action. Through the working mode of multiple cyclic arc ignition and arc sustaining, the device completely avoids the problems of arc interruption and arc extinction under the harsh operating conditions of 0.45MPa~0.55MPa high pressure, high flow rate, and multiple working fluids.

[0044] This embodiment relies on a pure hardware passive frequency division isolation architecture and a graded breakdown design to achieve stable arc ignition and arc continuation without relying on ultra-high transformer step-up, effectively solving the problems of current attenuation and power reduction caused by traditional high-ratio step-up structures. Combined with supporting designs such as multi-tap voltage regulation of the transformer, multi-stage overvoltage protection, high-voltage insulation shielding, and ablation-resistant electrodes, the whole machine has a compact structure, strong anti-interference ability, and simple operation and maintenance. It can operate stably for a long time in high-dynamic combustion systems such as scramjet engines and high-speed combustion chambers, with a wide range of engineering applications and outstanding practical value.

Claims

1. A dual-source coupled self-stabilized arc plasma ignition and combustion aid device, characterized in that... The system includes an EMI filter module (2), an AC / DC converter (3), a ZVS inverter LC resonant unit (5), a bidirectional transient suppression element (6), a high-frequency step-up transformer (7), a grounded Y-type safety capacitor (8), a secondary-side dual-sided high-frequency choke coil group (9), an adjustable air gap (10), a pulse igniter (11), and a plasma generation chamber (13). The primary windings of the EMI filter module (2), AC / DC converter (3), ZVS inverter LC resonant unit (5), bidirectional transient suppression element (6), and high-frequency step-up transformer (7) are connected in parallel to the AC input terminal. The output terminals of the secondary windings of the high-frequency step-up transformer (7) are connected to two secondary windings respectively. The double-sided high-frequency choke coil group (9) is connected in series with the plasma generating cavity (13); the secondary winding of the high-frequency step-up transformer (7) is connected in parallel with the secondary double-sided high-frequency choke coil group (9) and the Y-safety capacitor (8) is connected to ground; the secondary double-sided high-frequency choke coil group (9) and the plasma generating cavity (13) are connected to the pulse igniter (11) through the adjustable air ball gap (10) in parallel; the pulse igniter (11) is connected to the isolation pulse power supply terminal (12) and outputs the ignition isolation pulse; the two high-voltage output leads of the high-voltage pulse igniter are connected to the end of the main power line behind the high-frequency choke coil after passing through the adjustable air ball gap (10), and finally the leads are connected to the discharge gap position inside the plasma generating cavity (13).

2. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 1, characterized in that: The peak voltage of the high-voltage pulse igniter is set between 10kV and 1000kV, and the pulse repetition arc ignition frequency is continuously adjustable, with an adjustment range of 1Hz to 5kHz.

3. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 1, characterized in that: The adjustable air gap (10) includes an embedded electrode (19), a tapping support structure (21), an exhaust port (22), a hemispherical discharge structure (23), a gap discharge cavity (24), and a housing (25). The gap discharge cavity (24) is connected to the housing (25) at both ends. The discharge hemisphere of the hemispherical discharge structure (23) is located in the gap discharge cavity (24), and the other end connected to the discharge hemisphere is located in the housing (25) and connected to the embedded electrode (19) by a wire. The two hemispherical discharge structures (23) in the gap discharge cavity (24) are arranged opposite to each other, and a gap L is provided between the arc apex of the two opposite hemispheres. The gap discharge cavity (24) is provided with multiple exhaust ports (22). The hemispherical discharge structure (23) located in the fixed housing (25) is fixed to the housing (25) by the tapping support structure (21).

4. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 5, characterized in that: The gap L between the relative hemispherical apexes is 5mm to 10mm.

5. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 5, characterized in that: There are four exhaust ports (22).

6. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 5, characterized in that: The discharge hemisphere (23) is made of arc-resistant ablation-resistant metal materials, including stainless steel, tungsten copper alloy, copper alloy or nickel-based alloy.

7. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 5, characterized in that: The tapping support structure (21) is made of ceramic or PEEK insulating material.

8. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 1, characterized in that: The capacitance of the Y-type safety capacitor is preferably 10pF to 1000pF.

9. The dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to claim 1, characterized in that: The resonant inductance of the ZVS inverter LC oscillation resonant unit (5) is 7μH to 15.3μH, and the resonant capacitor is 3.96μF. Based on the component parameters, a standard ZVS soft-switching inverter topology is formed. After being powered on and oscillating, it converts constant DC power into high-frequency sinusoidal alternating power with a stable frequency in the range of 20kHz to 30kHz.

10. An ignition method using the dual-source coupled self-stabilized arc plasma ignition and combustion aid device according to any one of claims 1 to 9, characterized in that: 1) Working condition matching voltage regulation: By switching the winding turns section corresponding to the center tap of the secondary side of the high-frequency step-up transformer through the output voltage regulation switch, the arc-continuation output voltage of the transformer secondary side can be adjusted to be selected in the range of 1kV to 5kV to match the steady-state arc-continuation power requirements corresponding to the current working fluid and airflow pressure. 2) Pulse parameter tuning: Based on the discharge gap size of the plasma generating chamber and the airflow conditions of 0.45MPa~0.55MPa, adjust the output pulse peak voltage of the pulse igniter so that the pulse peak voltage is simultaneously higher than the adjustable air sphere gap breakdown threshold and the plasma generating chamber discharge gap breakdown threshold, so that the pulse can break down the two gaps in sequence. 3) Staged pulse output control: Initial arc initiation stage: The control pulse igniter continuously outputs a continuous high-voltage pulse to break down the adjustable air sphere gap and the internal air gap of the plasma generation chamber, establishing an initial plasma discharge channel; Steady-state arc sustaining stage: After the electric arc is established, the pulse igniter is switched to intermittent pulse output mode, and the ZVS inverter unit continuously outputs high-frequency sinusoidal power to maintain the arc self-sustaining. Dynamic ignition stage: Real-time acquisition of arc voltage and arc current signals. When the arc impedance increases and is close to extinction, the ignition pulse is triggered to re-break down the gap and rebuild the discharge channel. 4) Passive frequency division isolation and coordinated operation: The main power arc-continuing power is delivered to the discharge cavity through the high-frequency choke coil with low resistance, and the pulse spike is blocked by the high resistance of the choke coil; during the arc-continuing stage, the air gap is automatically cut off due to the voltage drop at both ends, blocking the high voltage backflow of the main power to the pulse branch, and realizing bidirectional isolation between the two waveforms.

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