A bipolar pulse current type driving circuit and device for a dielectric barrier discharge lamp

Abstract

The present invention discloses a bipolar pulse current type driving circuit and device for a dielectric barrier discharge lamp. The bipolar pulse current type driving circuit disclosed in the present invention comprises a bipolar square wave voltage power supply circuit, a flyback control circuit, at least one flyback synchronous rectification circuit and a dielectric barrier discharge lamp. The circuit topology disclosed in the present invention not only has the advantage of high energy conversion efficiency, but also can realize smooth regulation of the discharge power injected into the dielectric barrier discharge lamp.

Description

Technical Field

[0001] The invention relates to the field of special power supplies for power electronics, and in particular to a bipolar pulse current type driving circuit and equipment for a dielectric barrier discharge lamp. Background Art

[0002] Dielectric Barrier Discharge (DBD), also known as silent discharge, is a type of gas discharge in which insulating materials are inserted into the discharge space. When a sufficiently high excitation voltage is applied between the discharge electrodes, the gas between the electrodes will be broken down and micro-discharge will occur in the micro-discharge channel. This discharge structure enables DBD to produce discharge phenomena within a wide range of excitation voltage frequency and gas pressure. Atmospheric Pressure Dielectric Barrier Discharge (APDBD) is a typical method of generating low-temperature plasma at normal pressure. Since the APDBD device can produce a large number of active particles under conditions close to room temperature and does not require expensive and slow-operating vacuum equipment. Therefore, in recent years, APDBD has developed rapidly in the fields of biomedicine, material surface modification, volatile organic gas (VOCs) treatment and ozone synthesis.

[0003] When the structural parameters of APDBD are determined and the external environment is stable, the type and parameters of the driving circuit become the key factors affecting the performance of APDBD. Currently, the commonly used driving circuits are mainly sinusoidal driving circuits and pulse driving circuits. Numerous experimental results show that APDBD will show better performance under the action of pulse driving circuit than under the action of sinusoidal driving circuit. Although the pulse voltage driving circuit has the advantage of convenient implementation, as a typical capacitive load, if the pulse voltage excitation is directly applied to APDBD, there will be at least two defects: 1) APDBD will have uncontrolled current spikes (the size of the spike is related to the load equivalent current and the applied voltage rise rate), which may cause the protection circuit to operate or even damage the circuit; 2) It is difficult to effectively control the injection current that is closely related to the target product of APDBD (for example, the ozone production in the ozone generator and the luminous flux of the ultraviolet light of the dielectric barrier discharge lamp).

[0004] Therefore, the present invention proposes a bipolar pulse current type driving circuit and device for a dielectric barrier discharge lamp, which not only has high energy conversion efficiency and effectively reduces the voltage value borne by the secondary circuit components of the transformer, but also can effectively and smoothly control the current injected into the dielectric barrier discharge lamp. Summary of the invention

[0005] The purpose of the present invention is to disclose a bipolar pulse current type driving circuit and device for a dielectric barrier discharge lamp based on the above problems. The circuit disclosed by the present invention not only has high energy conversion efficiency and effectively reduces the voltage value of the secondary circuit components of the transformer, but also can effectively and smoothly control the current injected into the dielectric barrier discharge lamp to achieve optimal adjustment of the luminous flux of the ultraviolet light of the dielectric barrier discharge lamp.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A bipolar pulse current type driving circuit for a dielectric barrier discharge lamp is characterized in that the circuit is composed of a bipolar square wave voltage power supply circuit, a flyback control circuit, at least one flyback synchronous rectification circuit and a dielectric barrier discharge lamp.

[0008] Optionally, the bipolar square wave voltage power supply circuit is composed of a DC voltage source DC, a first capacitor C1, a first power switch tube Q1, a second power switch tube Q2, a third power switch tube Q3 and a fourth power switch tube Q4. Among them, the positive electrode of the DC voltage source DC is connected to the positive electrode of the first capacitor C1, the negative electrode of the first capacitor C1 is connected to the negative electrode of the DC voltage source DC, the drain of the first power switch tube Q1 is connected to the positive electrode of the first capacitor C1, the source of the first power switch tube Q1 is connected to the drain of the second power switch tube Q2, the source of the second power switch tube Q2 is connected to the negative electrode of the first capacitor C1, the drain of the third power switch tube Q3 is connected to the drain of the first power switch tube Q1, the source of the third power switch tube Q3 is connected to the drain of the fourth power switch tube Q4, and the source of the fourth power switch tube Q4 is connected to the negative electrode of the first capacitor C1.

[0009] Optionally, the flyback control loop is composed of the primary winding T of the flyback transformer T p , a fifth power switch tube Q5, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. The primary winding T of the flyback transformer T p The same-name terminal is connected to the source of the first power switch tube Q1, and the primary winding T of the flyback transformer T p The non-same-name terminals are connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the first diode D1, the anode of the first diode D1 is connected to the source of the third power switch tube Q3, the cathode of the fourth diode D4 is connected to the anode of the second diode D2, the anode of the fourth diode D4 is connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the source of the third power switch tube Q3, the drain of the fifth power switch tube Q5 is connected to the cathode of the first diode D1, and the source of the fifth power switch tube Q5 is connected to the anode of the third diode D3.

[0010] Optionally, the flyback synchronous rectification circuit is composed of the secondary winding T of the flyback transformer T s1 and T s2 , the sixth power switch tube Q6, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the second capacitor C2, the seventh power switch tube Q7, the ninth diode D9, the tenth diode D10, the eleventh diode D11, the twelfth diode D12 and the third capacitor C3. Among them, the secondary winding T of the flyback transformer T s1 The non-same-name terminal of is connected to the anode of the fifth diode D5, the cathode of the fifth diode D5 is connected to the cathode of the sixth diode D6, the anode of the sixth diode D6 is connected to the cathode of the eighth diode D8, the anode of the eighth diode D8 is connected to the anode of the seventh diode D7, and the cathode of the seventh diode D7 is connected to the secondary winding T of the flyback transformer T. s1 The drain of the sixth power switch tube Q6 is connected to the cathode of the fifth diode D5, the source of the sixth power switch tube Q6 is connected to the anode of the seventh diode D4, the anode of the second capacitor C2 is connected to the anode of the sixth diode D6, the cathode of the second capacitor C2 is connected to the secondary winding T of the flyback transformer T s1 The same-name terminals of the flyback transformer T are connected to the secondary winding T s2 The non-same-name terminal of is connected to the anode of the ninth diode D9, the cathode of the ninth diode D9 is connected to the cathode of the tenth diode D10, the anode of the tenth diode D10 is connected to the cathode of the twelfth diode D12, the anode of the twelfth diode D12 is connected to the anode of the eleventh diode D11, and the cathode of the eleventh diode D11 is connected to the secondary winding T of the flyback transformer T. s2 The drain of the seventh power switch tube Q7 is connected to the cathode of the ninth diode D9, the source of the seventh power switch tube Q7 is connected to the anode of the eleventh diode D11, the anode of the third capacitor C3 is connected to the anode of the tenth diode D10, the cathode of the third capacitor C3 is connected to the secondary winding T of the flyback transformer T s2 terminals of the same name.

[0011] Optionally, the positive electrode of the dielectric barrier discharge lamp is connected to the anode of the second capacitor C2, and the negative electrode of the dielectric barrier discharge lamp is connected to the cathode of the third capacitor C3.

[0012] Optionally, the effective value of the DC voltage source DC can be adjusted according to actual applications, the capacitance value of the first capacitor C1 is large enough, the parameters of the first power switch tube Q1, the second power switch tube Q2, the third power switch tube Q3 and the fourth power switch tube Q4 are consistent, the first power switch tube Q1 and the fourth power switch tube Q4 are controlled by the same drive pulse Pulse1 with a duty cycle of 50%, the second power switch tube Q2 and the third power switch tube Q3 are controlled by the same drive pulse Pulse2 with a duty cycle of 50%, and the drive pulse Pulse1 lags behind or leads the drive pulse Pulse2 by half a cycle.

[0013] Optionally, the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 have consistent parameters, and the fifth power switch tube is controlled by the same drive pulse Pulse3 with a duty cycle lower than 25%, and the frequency value of the drive pulse Pulse3 is twice that of the drive pulse Pulse1 and the drive pulse Pulse2.

[0014] Optionally, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the ninth diode D9, the tenth diode D10, the eleventh diode D11, and the twelfth diode D12 have consistent parameters, the sixth power switch tube Q6 and the seventh power switch tube Q7 have consistent parameters, the second capacitor C2 and the third capacitor C3 have consistent parameters, the sixth power switch tube Q6 and the seventh power switch tube Q7 are controlled by the drive pulse Pulse4, the drive pulse Pulse4 is triggered when the drive pulse Pulse3 is turned off, and is turned off when the current flowing through the sixth power switch tube Q6 and the seventh power switch tube Q7 is zero.

[0015] Optionally, more than one flyback synchronous rectification circuit may be connected in parallel according to the breakdown voltage value of the dielectric barrier discharge lamp to reduce the voltage tolerance value of each component.

[0016] Optionally, a bipolar pulse current type driving device for a dielectric barrier discharge lamp, characterized by comprising a processor and a memory;

[0017] The memory is used to store the program code and transmit the program code to the processor;

[0018] The processor is used to generate pulse signals of the rate switching tubes Q1-Q7 according to the instructions in the program code.

[0019] The advantages of the present invention compared with the prior art are:

[0020] (1) By smoothly controlling the current injected into the dielectric barrier discharge lamp, the problem of uncontrollable current spikes in the dielectric barrier discharge lamp that is inevitable in the existing circuit structure is solved;

[0021] (2) It can not only realize the bidirectional flow of energy, but also realize the efficient transmission of energy;

[0022] (3) The parallel structure of multiple flyback synchronous rectification circuits is utilized to effectively reduce the voltage tolerance of the secondary circuit components of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a circuit structure diagram disclosed in the present invention.

[0024] Figure 2 This is a simplified equivalent electrical model diagram of a dielectric barrier discharge lamp.

[0025] Figure 3 This is the equivalent electrical model diagram of the dielectric barrier discharge lamp when not discharging.

[0026] Figure 4 This is the equivalent electrical model diagram of the dielectric barrier discharge lamp during discharge.

[0027] Figure 5 It is a bipolar square wave power supply voltage waveform diagram, a driving pulse timing diagram of the fifth power switch tube Q5 and the sixth (seventh) power switch tube Q6 (Q7), and a waveform diagram of the current flowing through the dielectric barrier discharge lamp and the voltage applied to the lamp. DETAILED DESCRIPTION

[0028] The specific steps for determining circuit element parameters and circuit control are as follows, where the circuit element numbers refer to Figure 1 and Figure 2 :

[0029] 1. Offline measurement of the dielectric capacitance C of the dielectric barrier discharge lamp when it is not discharged d , air gap equivalent capacitance C g , and the discharge maintenance voltage V of the dielectric barrier discharge lamp th ;

[0030] 2. According to the dielectric capacitance C d , air gap equivalent capacitance C g According to the size of the capacitor, the values ​​of the second capacitor C2 and the third capacitor C3 are determined;

[0031] 3. According to the discharge maintenance voltage V of the dielectric barrier discharge lamp th According to the size of the transformer, determine the number of flyback synchronous rectification circuits on the secondary side and the ratio of the main and secondary coils N;

[0032] 4. Determine the voltage value of the DC voltage source DC according to the turns ratio N of the primary and secondary coils and determine the value of the first capacitor C1 according to the voltage stabilization condition.

[0033] 5. The first power switch tube Q1 and the fourth power switch tube Q4 are controlled by the same drive pulse Pulse1 with a duty cycle of 50%, and the second power switch tube Q2 and the third power switch tube Q3 are controlled by the same drive pulse Pulse2 with a duty cycle of 50%. The drive pulse Pulse1 lags behind or leads the drive pulse Pulse2 by half a cycle.

[0034] 6. The fifth power switch tube is controlled by the same driving pulse Pulse3 with a duty cycle lower than 25%, and the frequency of the driving pulse Pulse3 is twice that of the driving pulse Pulse1 and the driving pulse Pulse2. The sixth power switch tube Q6 and the seventh power switch tube Q7 are controlled by the driving pulse Pulse4, which is triggered when the driving pulse Pulse3 is turned off, and is turned off when the current flowing through the sixth power switch tube Q6 and the seventh power switch tube Q7 is zero.

[0035] According to the above design principles, a set of typical circuit parameters are given below:

[0036] DC voltage: 435V;

[0037] Capacitor C1: 80μF;

[0038] Capacitor C2: 80pF;

[0039] Capacitor C3: 80pF;

[0040] Transformer T: rated frequency 100kHz, primary winding T p Rated voltage 435V, secondary winding T s1 Rated voltage 2610V, secondary winding T s2 Rated voltage 2610V, transformer turns ratio N = T p :T s1 :T s2 =1:6:6;

[0041] Driving pulse Pulse1: frequency 50kHz, duty cycle 50%;

[0042] Driving pulse Pulse2: frequency 50kHz, duty cycle 50%, lagging behind Pulse1 by half a cycle;

[0043] Driving pulse Pulse3: frequency 100kHz, duty cycle 10%;

[0044] Driving pulse Pulse4: frequency 100 kHz, Pulse4 is triggered when Pulse3 is turned off, and is turned off when the current flowing through the sixth power switch tube Q6 and the seventh power switch tube Q7 is zero.

[0045] Under this set of parameters, the circuit operating waveform is as shown in the attached figure. Figure 5 shown.

Claims

1. A bipolar pulse current type driving circuit for a dielectric barrier discharge lamp, characterized in that The circuit is composed of a bipolar square wave voltage power supply circuit, a flyback control circuit, at least one flyback synchronous rectification circuit and a dielectric barrier discharge lamp; The flyback synchronous rectification circuit includes a secondary winding T of a flyback transformer T s1 and T s2 , the sixth power switch tube Q6, the fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the second capacitor C2, the seventh power switch tube Q7, the ninth diode D9, the tenth diode D10, the eleventh diode D11, the twelfth diode D12 and the third capacitor C3; wherein the secondary winding T of the flyback transformer T s1 The non-same-name terminal of is connected to the anode of the fifth diode D5, the cathode of the fifth diode D5 is connected to the cathode of the sixth diode D6, the anode of the sixth diode D6 is connected to the cathode of the eighth diode D8, the anode of the eighth diode D8 is connected to the anode of the seventh diode D7, the cathode of the seventh diode D7 is connected to the secondary winding T of the flyback transformer T s1 The drain of the sixth power switch tube Q6 is connected to the cathode of the fifth diode D5, the source of the sixth power switch tube Q6 is connected to the anode of the seventh diode D4, the anode of the second capacitor C2 is connected to the anode of the sixth diode D6, the cathode of the second capacitor C2 is connected to the secondary winding T of the flyback transformer T s1 The secondary winding T of the flyback transformer T is connected to the same terminal of s2 The non-same-name terminal is connected to the anode of the ninth diode D9, the cathode of the ninth diode D9 is connected to the cathode of the tenth diode D10, the anode of the tenth diode D10 is connected to the cathode of the twelfth diode D12, the anode of the twelfth diode D12 is connected to the anode of the eleventh diode D11, and the cathode of the eleventh diode D11 is connected to the secondary winding T of the flyback transformer T. s2 The drain of the seventh power switch tube Q7 is connected to the cathode of the ninth diode D9, the source of the seventh power switch tube Q7 is connected to the anode of the eleventh diode D11, the anode of the third capacitor C3 is connected to the anode of the tenth diode D10, the cathode of the third capacitor C3 is connected to the secondary winding T of the flyback transformer T s2 terminals of the same name.

2. The bipolar pulse current type driving circuit of the dielectric barrier discharge lamp according to claim 1, characterized in that The bipolar square wave voltage power supply circuit includes a DC voltage source DC, a first capacitor C1, a first power switch tube Q1, a second power switch tube Q2, a third power switch tube Q3 and a fourth power switch tube Q4; wherein, the positive electrode of the DC voltage source DC is connected to the positive electrode of the first capacitor C1, the negative electrode of the first capacitor C1 is connected to the negative electrode of the DC voltage source DC, the drain of the first power switch tube Q1 is connected to the positive electrode of the first capacitor C1, the source of the first power switch tube Q1 is connected to the drain of the second power switch tube Q2, the source of the second power switch tube Q2 is connected to the negative electrode of the first capacitor C1, the drain of the third power switch tube Q3 is connected to the drain of the first power switch tube Q1, the source of the third power switch tube Q3 is connected to the drain of the fourth power switch tube Q4, and the source of the fourth power switch tube Q4 is connected to the negative electrode of the first capacitor C1.

3. The bipolar pulse current type driving circuit of the dielectric barrier discharge lamp according to claim 2, characterized in that The flyback control loop is composed of the primary winding T of the flyback transformer T. p , a fifth power switch tube Q5, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; wherein the primary winding T of the flyback transformer T p The same-name end is connected to the source of the first power switch tube Q1, and the primary winding T of the flyback transformer T p The non-same-name end is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the first diode D1, the anode of the first diode D1 is connected to the source of the third power switch tube Q3, the cathode of the fourth diode D4 is connected to the anode of the second diode D2, the anode of the fourth diode D4 is connected to the anode of the third diode D3, the cathode of the third diode D3 is connected to the source of the third power switch tube Q3, the drain of the fifth power switch tube Q5 is connected to the cathode of the first diode D1, and the source of the fifth power switch tube Q5 is connected to the anode of the third diode D3.

4. The bipolar pulse current type driving circuit of the dielectric barrier discharge lamp according to claim 1, characterized in that The positive electrode of the dielectric barrier discharge lamp is connected to the anode of the second capacitor C2, and the negative electrode of the dielectric barrier discharge lamp is connected to the cathode of the third capacitor C3.

5. The bipolar pulse current driving circuit of the dielectric barrier discharge lamp according to claim 2, characterized in that The parameters of the first power switch tube Q1, the second power switch tube Q2, the third power switch tube Q3 and the fourth power switch tube Q4 are consistent. The first power switch tube Q1 and the fourth power switch tube Q4 are controlled by the same drive pulse Pulse1 with a duty cycle of 50%, and the second power switch tube Q2 and the third power switch tube Q3 are controlled by the same drive pulse Pulse2 with a duty cycle of 50%. The drive pulse Pulse1 lags behind or leads the drive pulse Pulse2 by half a cycle.

6. The bipolar pulse current type driving circuit of the dielectric barrier discharge lamp according to claim 3, characterized in that The parameters of the first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 are consistent, and the fifth power switch tube is controlled by the same driving pulse Pulse3 with a duty cycle lower than 25%, and the frequency value of the driving pulse Pulse3 is twice that of the driving pulse Pulse1 and the driving pulse Pulse2.

7. The bipolar pulse current type driving circuit of the dielectric barrier discharge lamp according to claim 1, characterized in that The fifth diode D5, the sixth diode D6, the seventh diode D7, the eighth diode D8, the ninth diode D9, the tenth diode D10, the eleventh diode D11, and the twelfth diode D12 have consistent parameters, the sixth power switch tube Q6 and the seventh power switch tube Q7 have consistent parameters, the second capacitor C2 and the third capacitor C3 have consistent parameters, the sixth power switch tube Q6 and the seventh power switch tube Q7 are controlled by the drive pulse Pulse4, the drive pulse Pulse4 is triggered when the drive pulse Pulse3 is turned off, and is turned off when the current flowing through the sixth power switch tube Q6 and the seventh power switch tube Q7 is zero.

8. The bipolar pulse current type driving circuit of the dielectric barrier discharge lamp according to claim 1, characterized in that According to the breakdown voltage value of the dielectric barrier discharge lamp, more than one flyback synchronous rectification circuit is connected in parallel to reduce the voltage tolerance value of each component.

9. A bipolar pulse current type driving device for a dielectric barrier discharge lamp, characterized in that: A bipolar pulse current type driving circuit for a dielectric barrier discharge lamp according to any one of claims 1 to 8; including a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to generate the pulse signals of the power switch tubes Q1-Q7 according to the instructions in the program code.

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