Energy feedback type bipolar pulse drive circuit suitable for excimer lamp

Abstract

The utility model discloses an energy feedback type bipolar pulse drive circuit suitable for an excimer lamp. Comprising a direct-current power supply, a first resonant inductor (L1), a second resonant inductor (L2), a first diode (D1), a second diode (D2), a third diode (D3), a fourth diode (D4), a fifth diode (D5), a sixth diode (D6), a seventh diode (D7), an eighth diode (D8), a first resonant capacitor (C1), a second resonant capacitor (C2), a first power switch tube (Q1), a second power switch tube (Q2) and a boosting transformer with a center tap. The drive circuit disclosed by the utility model not only can generate high-frequency bipolar pulse excitation waveforms on the excimer lamp, but also is suitable for various loads in different forms, such as an ozone generator and the like.

Description

Technical Field

[0001] The utility model relates to the field of power supply for power electronics, in particular to a power supply suitable for a dielectric barrier discharge excimer lamp. Background Art

[0002] Both theoretical analysis and experimental results show that the shape and frequency of the excitation voltage applied to the excimer lamp have an important influence on the discharge efficiency of the excimer lamp. Further experimental results show that a bipolar excitation waveform with a suitable rise rate and fall rate, the necessary excitation voltage idle time, and the suppression of multiple oscillations of the excitation voltage waveform can greatly reduce the intensity of the glow discharge, produce a more uniform discharge, and reduce the operating temperature of the excimer lamp. In order to achieve this goal, researchers have proposed various pulse power supplies with different structures. Although power supplies based on multi-level circuits, Marx circuits, and magnetic compression circuits can generate unipolar or bipolar quasi-square wave excitation pulses on excimer lamps, these power supplies that can generate quasi-square wave excitation pulses are not practical, and have defects such as a large number of components, low operating frequency, and low power supply efficiency. Therefore, in practical applications, bipolar pulse excitation is often generated on excimer lamps based on the resonance principle. However, although the existing power supply based on the resonance principle has solved the high-frequency operation and pulsed excitation waveform of the excimer lamp to a good extent, it is still unable to adjust the rise and fall rates of the bipolar excitation voltage waveform, the idle time of the excitation voltage, suppress multiple oscillations of the excitation voltage waveform, and realize energy feedback on the excimer lamp according to the characteristics of the excimer lamp.

[0003] Therefore, how to provide a bipolar pulse driving circuit for an excimer lamp that solves the above technical problems is a problem that those skilled in the art need to solve at present. Summary of the invention

[0004] The present application provides an energy feedback bipolar pulse drive circuit suitable for excimer lamps. The drive circuit has the advantages of simple circuit structure and easy switch control, and can also adjust circuit parameters according to the specific conditions of the excimer lamp to ensure that the excimer lamp works in the optimal state.

[0005] The purpose of the utility model is achieved through the following technical solutions:

[0006] An energy feedback bipolar pulse drive circuit suitable for an excimer lamp, characterized in that it comprises: a direct current power supply, a first resonant inductor (L1), a second resonant inductor (L2), a first diode (D1), a second diode (D2), a third diode (D3), a fourth diode (D4), a fifth diode (D5), a sixth diode (D6), a seventh diode (D7), an eighth diode (D8), a first resonant capacitor (C1), a second resonant capacitor (C2), a first power switch tube (Q1), a second power switch tube (Q2) and a step-up transformer with a center tap;

[0007] The anode of the DC power supply is respectively connected to the first end of the first resonant inductor (L1), the first end of the second resonant inductor (L2), the cathode of the fifth diode (D5) and the cathode of the sixth diode (D6);

[0008] The second end of the first resonant inductor (L1) is connected to the anode of the first diode (D1);

[0009] The cathode of the first diode (D1) is connected to the anode of the second diode (D2) and the first end of the first resonant capacitor (C1) respectively;

[0010] The cathode of the second diode (D2) is connected to the first end of the first power switch tube (Q1);

[0011] The second end of the first resonant capacitor (C1) is connected to the anode of the third diode (D3) and the first end of the first primary winding of the transformer;

[0012] The cathode of the DC power supply is respectively connected to the second end of the first power switch tube (Q1), the second end of the second power switch tube (Q2), the second end of the first primary winding of the transformer, and the first end of the second primary winding of the transformer;

[0013] The second end of the second resonant inductor (L2) is connected to the anode of the fourth diode (D4);

[0014] The cathode of the fourth diode (D4) is respectively connected to the anode of the seventh diode (D7) and the first end of the second resonant capacitor (C2);

[0015] The cathode of the seventh diode (D7) is connected to the first end of the second power switch tube (Q2);

[0016] The second end of the second resonant capacitor (C2) is respectively connected to the anode of the eighth diode (D8) and the second end of the second primary winding of the transformer;

[0017] The first end and the second end of the secondary winding of the transformer are respectively connected to the two ends of the excimer lamp.

[0018] Preferably, the capacitance value of the first resonant capacitor (C1) is equal to the capacitance value of the second resonant capacitor (C2).

[0019] Preferably, the inductance value of the first resonant inductor (L1) is equal to the inductance value of the second resonant inductor (L2).

[0020] Preferably, the operating frequency and duty cycle of the first power switch tube (Q1) and the second power switch tube (Q2) are equal, and the duty cycle is not higher than 0.1.

[0021] Preferably, the operating phases of the first power switch tube (Q1) and the second power switch tube (Q2) differ by 180 degrees.

[0022] Preferably, the first diode (D1), the second diode (D2), the third diode (D3), the fourth diode (D4), the fifth diode (D5), and the sixth diode (D6) are all fast recovery diodes.

[0023] Preferably, the first power switch tube (Q1) and the second power switch tube (Q2) are both NMOS, wherein the first ends of the first power switch tube (Q1) and the second power switch tube (Q2) are both drains of the NMOS; and the second ends of the first power switch tube (Q1) and the second power switch tube (Q2) are both sources of the NMOS.

[0024] Preferably, the first power switch tube (Q1) and the second power switch tube (Q2) can be changed to adjust the output frequency of the power supply.

[0025] Preferably, the secondary side of the transformer can be connected to loads of various types, such as an ozone generator.

[0026] The advantages of the utility model compared with the prior art are:

[0027] (1) A bipolar pulse excitation waveform can be generated on an excimer lamp;

[0028] (2) The driving circuit can make the excimer lamp discharge linearly four times in one cycle, which can give full play to the performance of the excimer lamp load.

[0029] (3) The rise rate of the excitation waveform can be changed by changing the value of the resonant capacitor

[0030] (4) The excitation voltage applied to the excimer lamp will not oscillate multiple times.

[0031] (5) Ability to feed back energy from the excimer to the DC power supply BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 This is a structural diagram of the drive circuit of the utility model.

[0034] Among them, the power supply provided in this figure is a DC power supply, Q1 is the first power switching device, Q2 is the second power switching device, D1 is the first diode, D2 is the second diode, D3 is the third diode, D4 ​​is the fourth diode, D5 is the fifth diode, D6 is the sixth diode, C1 is the first resonant capacitor, C2 is the second resonant capacitor, T is a high-frequency transformer with an intermediate tap, L1 is the first resonant inductor, and L2 is the second resonant inductor.

[0035] Figure 2 This is the voltage waveform on the gas discharge lamp in steady state.

[0036] Figure 3 This is the waveform diagram of the current flowing through the gas discharge lamp in steady state.

[0037] Figure 4 It is a schematic diagram of the working state 1 of the driving circuit in the positive half cycle.

[0038] Figure 5 Schematic diagram of working state 2 of the driving circuit in the positive half cycle.

[0039] Figure 6 Schematic diagram of working state 3 of the driving circuit in the positive half cycle. DETAILED DESCRIPTION

[0040] The present application provides an energy feedback bipolar pulse drive circuit suitable for an excimer lamp, which is used to generate a pulse excitation voltage on the excimer lamp and to simplify the structure of an existing pulse excitation drive circuit.

[0041] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0042] The specific steps of circuit implementation are:

[0043] Step 1: Using the equivalent circuit of the excimer lamp, offline measure the air gap equivalent capacitance Cd, the dielectric barrier layer equivalent capacitance Cg and the discharge maintenance voltage Vth of the excimer lamp;

[0044] Step 2: Determine the operating frequency ω of the driving circuit according to the requirements of the excimer lamp, determine the resonant angular frequency ω of the load circuit according to the resonant circuit where the secondary winding of the transformer is located, determine the inductance of the secondary winding of the transformer, the primary and secondary coil turns Np1 / Np2 / Na1 of the transformer, and the voltage value of the DC voltage source;

[0045] Step 3: According to the rated power provided by the driving circuit, the voltage value flowing through the energy storage inductors L1 and L2 is calculated, and the values ​​of the inductors L1 and L2 are determined accordingly;

[0046] Step 4: Determine the primary-secondary turns ratio of the high-frequency transformer according to the discharge voltage of the excimer lamp and the current value of the energy storage inductor;

[0047] Step 5: Set the working timing of the two power switch tubes to form a driving signal.

[0048] According to the above design steps, a set of typical parameters of the drive circuit are given below:

[0049] DC voltage source Vdc: 300V

[0050] Inductor L1, inductor L2: 4mH;

[0051] Capacitor C1, capacitor C2: 0.47nF;

[0052] Transformer T: rated frequency 100kHz, primary-secondary turns ratio 1:1:11.5; magnetizing inductance 300uH; leakage reactance converted to the secondary side of the transformer 1.5uH.

[0053] The operating frequency of the first power switch tube (Q1) and the second power switch tube (Q2) is 100kHz; the duty cycle of the first power switch tube (Q1) and the second power switch tube (Q2) is 10%;

[0054] Work status analysis

[0055] Specifically, the energy feedback bipolar pulse drive circuit suitable for excimer lamps provided by the utility model has three working modes in the positive half cycle. The working state of the energy feedback bipolar pulse drive circuit suitable for excimer lamps provided by the utility model is introduced as follows:

[0056] Working status 1:

[0057] Attached Figure 4 The figure is a schematic diagram of working state 1. In working state 1, diode D1 is turned on, diodes D2, D4, D5, D6, power switches Q1 and Q2 are turned off. A loop consisting of E→L1→D1→C1→N1 is formed on the primary side of the transformer.

[0058] The main functions of this circuit are as follows:

[0059] The DC power supply E and the resonant inductor L1 charge the resonant capacitor C1. The voltage of the capacitor C1 continues to rise, and the charging current flows through the coil N1. The voltage of the DBD load changes.

[0060] Second loop: A smaller current flows through coil N1. At this time, the current flowing through the DBD load is close to zero and the voltage of the DBD load changes slowly.

[0061] Working status 2:

[0062] Attached Figure 5 The figure is a schematic diagram of working state 2. In working state 2, diodes D1, D2, and power switch tube Q1 are turned on, and diodes D4, D5 and D6, and power switch tube Q2 are turned off. Two loops are formed on the primary side of the transformer: the first loop is composed of E→L1→D1→D2→Q1; the second loop is composed of C1→D2→Q1→N1.

[0063] The main functions of each circuit are as follows:

[0064] First circuit: DC power supply E charges the resonant inductor L1, and the inductor current rises;

[0065] The second circuit: forms a resonant circuit of C1→N1→DBD load. Since the value of C1, the transformer leakage reactance and the DBD complex equivalent capacitance are all small, this will form a large pulse current in the secondary winding N1 of the transformer, which will form a pulse voltage with a high rise rate on the DBD load.

[0066] Working status 3:

[0067] Attached Figure 6 FIG. 3 is a schematic diagram of working state 3. In working state 3, only diode D5 is turned on. A loop consisting of N1→D5→E is formed on the primary side of the transformer.

[0068] The main function of this circuit is to feed back the energy stored in the load on the excimer lamp to the DC power supply E.

[0069] As a preferred embodiment, the capacitance value of the first resonant capacitor (C1) is equal to the capacitance value of the second resonant capacitor (C2); the inductance value of the first resonant inductor (L1) is equal to the inductance value of the second resonant inductor (L2); the resistance value of the first absorption resistor is equal to the resistance value of the second absorption resistor; the operating frequency and duty cycle of the first power switch tube (Q1) and the second power switch tube (Q2) are equal, and the duty cycle is not higher than 0.1; the first diode (D1), the second diode (D2), the third diode (D3), the fourth diode (D4), the fifth diode (D5), and the sixth diode (D6) are all fast recovery diodes; the first power switch tube (Q1) and the second power switch tube (Q2) are both NMOS, wherein. The first ends of the first power switch tube (Q1) and the second power switch tube (Q2) are both drains of NMOS; the second ends of the first power switch tube (Q1) and the second power switch tube (Q2) are both sources of NMOS; the operating frequencies of the first power switch tube (Q1) and the second power switch tube (Q2) can be changed to adjust the output frequency of the power supply.

[0070] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. An energy feedback bipolar pulse drive circuit suitable for excimer lamps, characterized in that: include: A direct current power supply, a first resonant inductor (L1), a second resonant inductor (L2), a first diode (D1), a second diode (D2), a third diode (D3), a fourth diode (D4), a fifth diode (D5), a sixth diode (D6), a seventh diode (D7), an eighth diode (D8), a first resonant capacitor (C1), a second resonant capacitor (C2), a first power switch tube (Q1), a second power switch tube (Q2) and a step-up transformer with a center tap; The anode of the DC power supply is respectively connected to the first end of the first resonant inductor (L1), the first end of the second resonant inductor (L2), the cathode of the fifth diode (D5) and the cathode of the sixth diode (D6); The second end of the first resonant inductor (L1) is connected to the anode of the first diode (D1); The cathode of the first diode (D1) is connected to the anode of the second diode (D2) and the first end of the first resonant capacitor (C1) respectively; The cathode of the second diode (D2) is connected to the first end of the first power switch tube (Q1); The second end of the first resonant capacitor (C1) is connected to the anode of the third diode (D3) and the first end of the first primary winding of the transformer; The cathode of the DC power supply is respectively connected to the second end of the first power switch tube (Q1), the second end of the second power switch tube (Q2), the second end of the first primary winding of the transformer, and the first end of the second primary winding of the transformer; The second end of the second resonant inductor (L2) is connected to the anode of the fourth diode (D4); The cathode of the fourth diode (D4) is respectively connected to the anode of the seventh diode (D7) and the first end of the second resonant capacitor (C2); The cathode of the seventh diode (D7) is connected to the first end of the second power switch tube (Q2); The second end of the second resonant capacitor (C2) is respectively connected to the anode of the eighth diode (D8) and the second end of the second primary winding of the transformer; The first end and the second end of the secondary winding of the transformer are respectively connected to the two ends of the excimer lamp.

2. The energy feedback bipolar pulse drive circuit suitable for excimer lamp according to claim 1, characterized in that: The capacitance value of the first resonant capacitor (C1) is equal to the capacitance value of the second resonant capacitor (C2).

3. The energy feedback bipolar pulse drive circuit suitable for excimer lamp according to claim 1, characterized in that: The inductance value of the first resonant inductor (L1) is equal to the inductance value of the second resonant inductor (L2).

4. An energy feedback bipolar pulse drive circuit suitable for an excimer lamp according to any one of claims 1 to 3, characterized in that: The first diode (D1), the second diode (D2), the third diode (D3), the fourth diode (D4), the fifth diode (D5), and the sixth diode (D6) are all fast recovery diodes.

5. An energy feedback bipolar pulse drive circuit suitable for an excimer lamp according to any one of claims 1 to 3, characterized in that: The first power switch tube (Q1) and the second power switch tube (Q2) are both NMOS, wherein the first ends of the first power switch tube and the second power switch tube (Q2) are both drains of the NMOS; and the second ends of the first power switch tube (Q1) and the second power switch tube (Q2) are both sources of the NMOS.

6. An energy feedback bipolar pulse drive circuit suitable for an excimer lamp according to any one of claims 1 to 3, characterized in that: The secondary side of the transformer is connected to various loads.

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