Distributed power supply system of large-scale DBD electrode

Abstract

The invention provides a large-scale DBD electrode distributed power supply system, which is characterized in that a large-scale DBD electrode is divided into a plurality of modules, each large-scale DBD module is independently connected to a power supply module, input ports of the plurality of power supply modules are connected in parallel, and corresponding DC voltage amplitudes are input; the amplitude of the direct-current voltage is in direct proportion to the area of the connected large-scale DBD modules, the corresponding connection method of the output ports and the number of the modules are defined by a user, and the output ends of the large-scale DBD modules are connected in series. In order to solve the problems that a large-scale dielectric barrier discharge (DBD) load is large in discharge area and discharge is uneven due to the fact that a single-port centralized power supply mode is adopted, the invention proposes that based on a plurality of pulse power supply modules, single low-power pulse power supply modules are independently connected to different positions of a large-scale DBD electrode, and full-region uniform discharge of the large-scale DBD load is realized.

Description

Technical Field

[0001] The invention belongs to the field of large-scale DBD and relates to a distributed power supply system for large-scale DBD electrodes. Background Art

[0002] The power setting method for large-scale DBD electrode discharge drive currently adopts a centralized power supply method, that is, the power output interface of the power supply is connected to the fixed and unified power input interface of the large-scale DBD electrode, so as to realize the discharge area to generate the required discharge plasma. However, this centralized power supply method has a serious problem of uneven discharge in the discharge effect of actual application, that is, under the condition of moderate discharge power, only the discharge of the local area can be completed. Only by continuously increasing the output power of the pulse power supply can the discharge of the entire discharge area be achieved. However, the first discharge area enters the over-discharge state, which is very likely to cause local over-discharge, overheating and local breakdown problems. Therefore, in order to solve this problem, the existing technical solution generally adopts water electrodes to achieve the effects of heat dissipation and uniform electric field, which increases the volume, weight and operation reliability of the large-scale DBD whole device.

[0003] After the electrode processing and design of large-scale DBD electrodes are completed, it is difficult to achieve flexible regulation of the discharge plasma in the discharge area. Generally, the discharge power can only be increased indirectly by increasing the output power of the driving power supply, thereby achieving discharge intensity regulation. However, if the average power output of the driving power supply is increased blindly, only a part of the power can effectively improve the discharge process, and most of the energy is consumed in the electrode in the form of loss, which not only aggravates the overheating problem of the DBD electrode, but also causes a large amount of energy waste. At the same time, it is not possible to complete the flexible regulation of the electrode discharge area well, which limits the application field of large-scale DBD electrodes.

[0004] Patent CN106872417A is an experimental device and method for detecting OH concentration using DBD and emission spectrum, but the power output interface of the device is directly connected to the electrode input interface. This centralized power supply drives large-scale DBD electrodes under moderate power conditions, which will cause the electrodes to be unable to discharge locally. At this time, when the power output power is increased to drive the electrode to discharge as a whole, the previously discharged area will heat up severely, resulting in thermal breakdown.

[0005] Patent CN115529708A is a plasma modification device for generating fluorescent color-developing thin films and its control method. After the discharge treatment of the material surface is completed, the film thickness and modification effect can only be determined under ultraviolet light, and the large-scale DBD discharge uniformity cannot be evaluated online.

[0006] Patent CN106553754B is a DBD device used in aircraft. For such a large and difficult to disassemble device, it is impossible to directly perform power supply debugging in the laboratory, and the existing fixed high-voltage capacitors cannot simulate the complex situation when the load is discharged. Summary of the invention

[0007] 1. Technical problems to be solved:

[0008] The large-scale DBD electrode discharge application process encounters the problem of poor discharge uniformity and the limitation of discharge state control means. In order to solve this problem, the existing technical solutions generally use water electrodes to achieve the effect of heat dissipation and uniform electric field, which increases the volume, weight and operation reliability of the large-scale DBD device.

[0009] 2. Technical solution:

[0010] In order to solve the above problems, the present invention provides a distributed power supply system for large-scale DBD electrodes, wherein the large-scale DBD electrodes are divided into multiple modules, each large-scale DBD module is independently connected to a power module, the input ports of multiple power modules are connected in parallel, and corresponding DC voltage amplitudes are input, wherein the magnitude of the DC voltage amplitude is proportional to the area of ​​the connected large-scale DBD modules, the corresponding connection method of the output port and the number of modules are user-defined, and the output ends of multiple large-scale DBD modules are connected in series.

[0011] Furthermore, each large-scale DBD module has the same area.

[0012] Furthermore, the power supply module is an N-channel high-voltage-microsecond pulse power supply module, and the number of the N-channel high-voltage-microsecond pulse power supply modules is the same as the number of large-scale modules.

[0013] Furthermore, the method for generating the pulse voltage in the N-channel high-voltage-microsecond pulse power supply is as follows: the primary side of the high-voltage pulse transformer is equivalent to a large excitation inductor and a discharge output inductor with energy storage capacity, and the power switch tube on the primary side of the transformer controls the charging and discharging. When the input signal PWM wave drives the power tube to turn on, the DC voltage excites the primary energy storage inductor. When the input signal PWM wave drives the power tube to turn off, according to the electromagnetic induction between the transformers, the primary energy is released to the load through the secondary inductor, and according to the Ampere-conservation principle, a pulse voltage is formed for the DBD reactor.

[0014] Furthermore, the signal control terminal of each of the N-channel high-voltage-microsecond pulse power supplies is input through an external PWM.

[0015] Furthermore, the large-scale DBD electrode is divided into four large-scale DBD modules, and excitation is applied to each electrode of each power module. The parasitic inductance generated between the power input terminal and the electrode and between the electrode and the ground terminal due to inconsistent impedance is the same, and the parasitic parameters between modules are consistent.

[0016] The excitation voltage amplitude, current amplitude, discharge resonance frequency, discharge resonance modulus and discharge resonance phase angle of each power module are consistent.

[0017] 3. Beneficial effects:

[0018] The present invention aims at the problem of uneven discharge in a large-scale dielectric barrier discharge (DBD) load with a large discharge area and a single-port centralized power supply method. It proposes a method based on multiple pulse power supply modules to independently connect a single low-power pulse power supply module at different positions of the large-scale DBD electrode, thereby achieving uniform discharge in the entire area of ​​the large-scale DBD load. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the system architecture of the present invention.

[0020] Figure 2 It is a schematic diagram of the equivalent electrical model of distributed power supply.

[0021] Figure 3 It is the distributed current direction of a single module.

[0022] Figure 4 This is a comparison of electrical waveforms at different locations of distributed power supply. Figure 4 (a) is the voltage waveform of each area of ​​distributed power supply; Figure 4 (b) is the voltage fitting waveform of each area of ​​distributed power supply; Figure 4 (c) is the current waveform of each area of ​​distributed power supply; Figure 4 (d) is the current fitting waveform of each area of ​​distributed power supply.

[0023] Figure 5 is a schematic diagram of distributed power supply and light emission, where Figure 5 (a) is a schematic diagram of distributed power supply electrodes; Figure 5 (b) is the distributed power supply luminescence image. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] In the power supply of existing large-scale DBD electrodes, the parasitic parameter resonance characteristics of DBD electrodes with different unit areas are aggravated, making the electrode power supply uneven during DBD discharge, thus leading to the problem of uneven discharge. The present invention provides a distributed power supply system for large-scale DBD electrodes, which is used to solve the problems caused by the existing DBD electrode power supply.

[0026] like Figure 1 and Figure 2 As shown, the large-scale DBD electrode is divided into multiple modules, each large-scale DBD module is independently connected to a power module, the input ports of multiple power modules are connected in parallel, and the corresponding DC voltage amplitude is input. The size of the DC voltage amplitude is proportional to the area of ​​the connected large-scale DBD module, the corresponding connection method of the output port and the number of modules are customized by the user, and the output ends of multiple large-scale DBD modules are connected in series.

[0027] In one embodiment, the area of ​​each large-scale DBD module is the same. The following embodiments are all based on the situation that the area of ​​each large-scale DBD module is the same.

[0028] The entire power module is a parallel input and series output architecture. The main power supply consists of an AC / DC rectifier module with an adjustable output voltage unit, an N-channel high-voltage-microsecond pulse power supply (HV-MPPS) module, and an offline combined connection unit for power output. The large-scale DBD electrode is divided into N modules in an equal-area modular manner and distributedly connected to the output terminals of multiple modules in the system architecture. Figure 1 The input of the medium AC-DC rectifier module is AC power, and the output is adjustable DC voltage U dc , the pulse power level requirements are adjusted according to the actual area of ​​the large-scale DBD electrode.

[0029] The number of N-channel high-voltage-microsecond pulse power supply modules is N (N>1), and the input ports of each module are connected in parallel, inputting the same DC voltage amplitude U dc The corresponding connection method of the output port and the number of modules are determined by the user according to the actual SDBD area. The SDBD is divided into N equal areas, and the N-channel high-voltage-microsecond pulse power supply module is equally connected to each area in the form of IPOP. The N signal control terminals of the N-channel high-voltage-microsecond pulse power supply module are fed in through external PWM, so as to keep the signals of all HV-MPPS modules consistent, so as to achieve consistent power and keep the output energy efficiency of each area consistent.

[0030] In one embodiment, the power supply module is an N-channel high voltage-microsecond pulse power supply (HV-MPPS) module, and the number of the N-channel high voltage-microsecond pulse power supply modules is the same as the number of large-scale modules.

[0031] A pulse power supply is used to drive the large-scale DBD. The pulse power supply has a shorter voltage rise time and a lower repetition frequency. It is mainly used to generate high-energy electrons instead of heating the gas, which increases the discharge rate and the efficiency of generating active particles, while keeping the gas in a lower temperature range, thereby improving the discharge uniformity.

[0032] In one embodiment, the method for generating the pulse voltage in the N-channel high-voltage-microsecond pulse power supply is as follows: Figure 1 As shown, the primary side of the high-voltage pulse transformer T1 can be equivalent to a large excitation inductor L with energy storage capacity. pri1 and the discharge output inductor L sec1 , the power switch tube S on the primary side of the transformer Q1 Control inductance L pri 1 Charging and discharging. When the input signal PWM wave drives the power tube S Q1 DC voltage U during conduction dc is the primary energy storage inductor L pri1 Excitation, when the input signal PWM wave drives the power tube S Q1 When turned off, according to the electromagnetic induction between the transformers, the primary energy passes through the secondary inductor L sec1 Release to load C load On the other hand, according to the Ampere law of conservation of energy, a pulsed high voltage is formed for the DBD reactor.

[0033] Figure 1 In the circuit, the capacitor C in The main function is to provide energy storage source U for the primary side of transformer T dc It can store energy, filter and stabilize voltage. dc The voltage provided remains consistent throughout, providing the necessary stability for subsequent transient power.

[0034] The present invention proposes an equivalent simulated load hardware circuit for a real large-scale DBD, that is, under the condition of determining the physical size and discharge area of ​​the large-scale DBD load, a small surface dielectric barrier discharge (SDBD) electrode sheet is used in combination with a circuit composed of an external inductor element to perform the equivalent. The mechanism is that the discharge area of ​​the small SDBD is equivalent to the actual discharge area of ​​the large-scale DBD, and the parasitic capacitance of the discharge area is equivalent at the same time. The external inductor element is equivalent to the inductance parameter value of the large-scale DBD electrode circuit, and the coupling effect on the pulse power under the action of high dU / dt and dI / dt given by the pulse power is simulated.

[0035] like Figure 2As shown in the figure, it is the equivalent electrical model diagram of SDBD distributed power supply. SDBD is divided into four modules. By applying excitation at each electrode, the characteristics of parallel discharge from the first module to the fourth module under the same excitation characteristics are explored. Since each electrode is excited, there will be parasitic inductance and parasitic resistance between the power input terminal and the electrode and between the electrode and the ground terminal due to inconsistent impedance, such as L1, R1, L 15 , R 15 , there are parasitic parameters between modules, such as R5 and L5, R6 and L6. Since the spacing, material and other processes between modules are the same, the parasitic parameters are also consistent, that is:

[0036] L r =L1=L2=···=L 18 (1)

[0037] C r =C g1 =C g2 =···=C g4 (2)

[0038] R r =R1=R2=···=R 18 (3).

[0039] By analyzing a single module from point to surface to explore its discharge law, Figure 3 This is the distributed current trend diagram of a single-module SDBD. From a single model, the circuit is symmetrical, so it is more convenient to explore the electrical laws of the electrode based on Kirchhoff's law.

[0040] According to the KCL theorem, the current equation at node 1 is:

[0041]

[0042] i pulse1 —Power supply output current of module 1;

[0043] i 1_1 —Branch current of the previous module;

[0044] i 2_1 —Branch current of the subsequent module;

[0045] i b1 —Module 1 breakdown current.

[0046] Finally, the current relationship of each branch out of the single module node 1 is obtained:

[0047] i pulse1 =i b1 (5).

[0048] From equations (4) and (5), we can see that the currents of branches i1 and i2 are 0, and the excitation current of the excitation source is completely applied to the first module, that is, the discharge current of the first module is equal to the current released by the excitation source. Similarly, the relationship between the excitation current and the discharge current from the first module to the fourth module can be inferred:

[0049] i pulse1 =···=i pulse4 =i b1 =···=i b4 (6)

[0050] Since the load parameters of modules 1 to 4 are consistent, the excitation voltage relationship of modules 1 to 4 can be inferred by combining equation (23):

[0051] U pulse1 =···=U pulse4 =U b1 =···=U b4 (7)

[0052] From this, the relationship between the electrical resonant frequency and resonant modulus value of modules 1 to 4 in the circuit can be calculated:

[0053]

[0054] Through equations (6), (7), (8) and (9), we can draw the conclusion that the distributed electrical model is established: the excitation voltage amplitude, current amplitude, discharge resonant frequency, discharge resonant mode value and discharge resonant phase angle of the first module to the fourth module are all consistent.

[0055] use Figure 1 Microsecond pulse power supply multi-module system, current probe (YOKOGAWA 701930), differential probe (SUNRAISE SRS5700), oscilloscope 1 (ZDS3024), oscilloscope 2 (YOKOGAWA DLM3054). Four distributed microsecond pulse modules flow into the four areas of SDBD from nodes A, B, C, and D at the same time. The connection nodes of the four areas use four differential probes and current probes to detect the input pulse voltage and current of the four nodes A, B, C, and D respectively.

[0056] After adding distributed pulse power, the SDBD discharge electrical waveform is as follows: Figure 4 As shown, by fitting the voltage and current waveforms to observe the actual discharge voltage and current distribution in each area, it can be found that

[0057]

[0058] The electrical waveform results are basically consistent with the simulation results. It can be seen that the voltage and current are uniformly distributed in the distributed power supply mode in the large-area DBD discharge. Figure 5 (a) and Figure 5 (b) The luminous image of the distributed power supply can be clearly seen. Therefore, IPOP distributed power supply is a reliable power supply method as a uniform discharge power supply method in large-area DBD discharge, and has practical engineering application value in large-area SDBD uniform discharge applications.

Claims

1. A distributed power supply system for large-scale DBD electrodes, characterized in that: The large-scale DBD electrode is divided into multiple modules, each large-scale DBD module is independently connected to a power module, the input ports of multiple power modules are connected in parallel, and the corresponding DC voltage amplitude is input. The size of the DC voltage amplitude is proportional to the area of ​​the connected large-scale DBD module. The corresponding connection method of the output port and the number of modules are customized by the user, and the output ends of multiple large-scale DBD modules are connected in series.

2. The distributed power supply system for large-scale DBD electrodes according to claim 1, characterized in that: The area of ​​each large-scale DBD module is the same.

3. The distributed power supply system for large-scale DBD electrodes according to claim 1 or 2, characterized in that: The power supply module is an N-channel high-voltage-microsecond pulse power supply module, and the number of the N-channel high-voltage-microsecond pulse power supply modules is the same as the number of large-scale modules.

4. The distributed power supply system for large-scale DBD electrodes according to claim 3, characterized in that: The method for generating the pulse voltage in the N-channel high-voltage-microsecond pulse power supply is as follows: the primary side of the high-voltage pulse transformer is equivalent to a large excitation inductor and a discharge output inductor with energy storage capacity, and the power switch tube on the primary side of the transformer controls the charging and discharging. When the input signal PWM wave drives the power tube to turn on, the DC voltage excites the primary energy storage inductor. When the input signal PWM wave drives the power tube to turn off, according to the electromagnetic induction between the transformers, the primary energy is released to the load through the secondary inductor, and according to the Ampere's law of conservation of power, a pulse voltage is formed for the DBD reactor.

5. The distributed power supply system for large-scale DBD electrodes according to claim 3, characterized in that: The signal control terminal of each of the N-channel high-voltage-microsecond pulse power supplies is input through an external PWM.

6. The distributed power supply system for large-scale DBD electrodes according to claim 3, characterized in that: The large-scale DBD electrode is divided into four large-scale DBD modules, and excitation is applied to each electrode of each power module. The parasitic inductance generated between the power input terminal and the electrode and between the electrode and the ground terminal due to inconsistent impedance is the same, and the parasitic parameters between modules are consistent.

7. The distributed power supply system for large-scale DBD electrodes according to claim 6, characterized in that: The excitation voltage amplitude, current amplitude, discharge resonance frequency, discharge resonance modulus and discharge resonance phase angle of each power module are consistent.

Images