CN101902862A - Harmonic constant current source for atmospheric glow discharge - Google Patents

Abstract

The invention discloses a harmonic constant current source for atmospheric glow discharge. A high-frequency inverter circuit is connected behind a regulator rectifier circuit, a resonance circuit is connected behind the high-frequency inverter circuit, and a discharge gap is connected behind the resonance circuit. The invention can decrease the application cost due to not using vacuum equipment. The capacitors and inductors form the resonance circuit, and discharge converted from glow to arc is restricted by utilizing the constant current characteristic of the circuit, thus glow discharge can be generated between bare metal electrodes without medium block. The invention adopts an even glow discharge mode and has little harm to materials. Compared with a DC glow generating method in a large-resistor ballast mode, the harmonic constant current source for atmospheric glow discharge has higher energy efficiency due to not using energy-consuming elements, such as resistors, and the like.

Description

Harmonic constant current source for atmospheric glow discharge

Technical field

The invention belongs to a kind of resonance constant-current circuit structure, particularly Atomospheric pressure glow discharge resonance constant-current supply device.

Background technology

Fields such as glow discharge plasma is widely used in that surface modification, ozone are synthetic, exhaust-gas treatment and electric light source.The glow discharge that current industrial is used is many to produce under low air pressure condition, needs to use expensive vacuum equipment, and application cost is higher.

Comparatively speaking, Atomospheric pressure glow discharge has characteristics such as discharge is even, power density is moderate, has better industrial application prospect.In the world atmosphere pressure glow discharge has been launched great deal of experimental, the current technology that produces Atomospheric pressure glow discharge mainly contains the direct current glow discharge of DBD (dielectric barrier discharge) and big resistance ballast etc.AC power is used in the DBD discharge, must place dielectric-slab between the sparking electrode, and its discharge mostly is the filament shape, and is bigger to material infringement itself; High-voltage DC power supply is used in the direct current glow discharge of big resistance ballast, needs in the discharge loop to adopt big resistance ballast, is converted into arc discharge to prevent glow discharge, and steady resistance will consume lot of energy in this process, and circuit efficiency is lower.

Summary of the invention

The objective of the invention is to overcome above-mentioned prior art deficiency, a kind of harmonic constant current source for atmospheric glow discharge be provided, be under atmospheric pressure, different electrode form, the glow discharge that produces large volume between pin-pin, pin-plate or the plate-plate electrode etc.

Technical scheme of the present invention is achieved in that

Connect the high-frequency inversion loop behind the voltage regulating rectifier loop, high-frequency inversion connects resonant tank behind the loop, connects discharging gap behind the resonant tank.

The voltage regulating rectifier loop connects the direct voltage that rectifier bridge obtains adjustable amplitude value by AC voltage regulator, after meet electric capacity of voltage regulation C1.

The topological structure in high-frequency inversion loop is full-bridge or semi-bridge inversion loop, the full-bridge inverting loop is formed in parallel after connecting in twos by four full-control type device MOS1, MOS2, MOS3 and MOS4, and half-bridge inversion circuit is formed by the series and parallel of the series connection of two capacitor C b1 and Cb2 and two full-control type device MOS1 and MOS2.

The series connection of inductance L 2 and capacitor C 2 is in parallel with the former limit of pulse transformer in the resonant tank, pulse transformer former limit one end and inductance L 1 series connection, pulse transformer secondary one end and inductance L 3 series connection.The topological structure of resonant tank can change, and concrete parameter needs to obtain by the counting circuit condition of resonance.

Discharging gap separates spacing by two metal electrodes and constitutes, and its structure is pin-pin, pin-plate, plate-plate form.

The present invention can keep stable glow discharge under atmospheric pressure, the discharge diameter can arrive 8mm, and discharge energy is big, and sparking electrode is exposed metal electrode (pin-plate, pin-plate or plate-plate electrode).

The present invention need not use vacuum equipment, can reduce application cost.Utilize electric capacity and inductance to form resonant tank, utilize the constant-current characteristics inhibition discharge of circuit itself to transform to electric arc, can between exposed metal electrode, produce glow discharge, and need not by dielectric impedance by aura; Discharge type is uniform glow discharge, and is little to damage of materials; And the present invention does not use dissipative cells such as resistance, so much higher compared to its energy efficiency of DC glow production method of big resistance ballast mode.

Description of drawings

Fig. 1 is the circuit diagram that is used to introduce resonance constant current loop operation principle.

Fig. 2 is the theory diagram of glow discharge with the harmonic constant current source system.

Fig. 3 is the circuit diagram (inversion circuit be full-bridge circuit) of glow discharge with harmonic constant current source.

Fig. 4 is the circuit diagram (inversion circuit be half-bridge circuit) of glow discharge with harmonic constant current source.

Below in conjunction with accompanying drawing content of the present invention is described in further detail.

Embodiment

Brief introduction of work principle:

As shown in Figure 1, suppose that employed pulse transformer is an ideal transformer, then its former secondary leakage inductance is zero, and magnetizing inductance is infinitely great.Be tied to form upright just like ShiShimonoseki according to circuit theory:

$\left\{\begin{array}{c}{\stackrel{\·}{U}}_1={\stackrel{\·}{I}}_1\mathrm{j\ωL}+\frac{1}{\mathrm{j\ωC}}({\stackrel{\·}{I}}_1-{\stackrel{\·}{I}}_2)\\ \stackrel{\·}{U}2=\frac{1}{\mathrm{j\ωC}}({\stackrel{\·}{I}}_1-{\stackrel{\·}{I}}_2)-\mathrm{j\ωL}{\stackrel{\·}{I}}_2\end{array}\right.$

When circuit satisfies the open circuit condition of resonance

The time, following relational expression is arranged:

$\left\{\begin{array}{c}{\stackrel{\·}{I}}_1=\frac{{-\stackrel{\·}{U}}_2}{\mathrm{j\ωL}}\\ {\stackrel{\·}{I}}_2=\frac{{\stackrel{\·}{U}}_1}{\mathrm{j\ωL}}\end{array}\right.$

According to following formula, when circuit satisfies condition of resonance, as long as power supply angular frequency, resonant capacitance C, resonant inductance L and original edge voltage

Remain unchanged, then output current

Size be not subjected to load effect, promptly output current keeps constant.When circuit connect load, resonance was destroyed, and constant-current characteristics is constant.

As shown in Figure 2, it comprises voltage regulating rectifier loop 101, high-frequency inversion loop 102, resonant tank 103 and 104 4 parts of discharging gap.Voltage regulating rectifier loop 101 is used to produce the stable DC voltage of adjustable amplitude value; High-frequency inversion loop 102 is that frequency is several thousand to the adjustable square-wave voltage of KHz up to a hundred with the direct voltage inversion; Resonant tank 103 can be obtained the sinusoidal voltage of high pressure by square-wave voltage, and has the load current of keeping stable properties; Discharging gap 104 electrode used thereins can be the metal electrodes of various ways such as pin-pin, pin-plate and plate-plate.

Fig. 3 and two kinds of different topology structures that Figure 4 shows that glow discharge usefulness harmonic constant current source circuit diagram, wherein the employed inversion circuit 102 of Fig. 3 is a full-bridge circuit, the employed inversion circuit 102 of Fig. 4 is a half-bridge circuit.Voltage regulating rectifier loop 101 is made up of voltage regulator, rectifier bridge and electric capacity of voltage regulation; Inversion circuit 102 uses full-bridge or semi-bridge inversion loop to produce frequency several thousand to the adjustable high-frequency ac voltage of KHz up to a hundred; Resonant tank 103 is made up of pulse transformer and peripheral resonant circuit, and pulse transformer can improve output voltage amplitude, and peripheral resonant circuit is used for producing resonance with pulse transformer; 104 of discharging gaps are used to produce glow discharge.

Rectifier bridge and electric capacity of voltage regulation need to select according to actual current in the loop and voltage in the voltage regulating rectifier loop 101; The full-bridge of inversion circuit 102 or half-bridge inversion circuit need be selected through-current capability and the suitable full-control type device of voltage endurance capability; Pulse transformer needs to determine layer insulation intensity according to output voltage amplitude in the resonant tank 103, determines the diameter of coiling according to former secondary current size; Discharging gap 104 can use pin-plate, pin-pin or plate-sheetmetal electrode.

The course of work: under lower input voltage, regulate the output voltage frequency of inversion circuit, think that when its output current reaches maximum the loop is in resonance condition; Under resonance condition, the input voltage amplitude that increases power supply is discharged until between electrode, and fit adjustment discharge spacing (the discharge spacing is adjustable at 1mm-20mm) can produce glow discharge.

Claims (5)

1. harmonic constant current source for atmospheric glow discharge is characterized in that, voltage regulating rectifier loop (101) back connects high-frequency inversion loop (102), and high-frequency inversion loop (102) back connects resonant tank (103), and resonant tank (103) back connects discharging gap (104).

2. harmonic constant current source for atmospheric glow discharge according to claim 1 is characterized in that, voltage regulating rectifier loop (101) connect the direct voltage that rectifier bridge obtains adjustable amplitude value by AC voltage regulator, after meet electric capacity of voltage regulation C1.

3. harmonic constant current source for atmospheric glow discharge according to claim 1, it is characterized in that, the topological structure in high-frequency inversion loop (102) is full-bridge or semi-bridge inversion loop, the full-bridge inverting loop is formed in parallel after connecting in twos by four full-control type device MOS1, MOS2, MOS3 and MOS4, and half-bridge inversion circuit is formed by the series and parallel of the series connection of two capacitor C b1 and Cb2 and two full-control type device MOS1 and MOS2.

4. harmonic constant current source for atmospheric glow discharge according to claim 1, it is characterized in that, the series connection of inductance L 2 and capacitor C 2 is in parallel with the former limit of pulse transformer in the resonant tank (103), pulse transformer former limit one end and inductance L 1 series connection, pulse transformer secondary one end and inductance L 3 series connection.

5. harmonic constant current source for atmospheric glow discharge according to claim 1 is characterized in that, discharging gap (104) separates spacing by two metal electrodes and constitutes, and its structure is pin-pin, pin-plate, plate-plate form.

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