Sudy on he Wide Gap Dielecric Barrier Discharge Device Gaofeng Wang School of Informaion Engineering, Zhengzhou Universiy, Zhengzhou 450001, China 932167312@qq.com Keywords: DBD; Wide air gap; Plasma body; Modeling and simulaion Absrac. A high frequency and high volage power supply for wide air gap dielecric barrier discharge (DBD) is inroduced, and he applicaion of dielecric barrier discharge device in indusrial wase gas reamen is also discussed. The fron sage of he power supply adops he full bridge inverer echnology, he rear sage adops he high frequency ransformer and he load series resonance, and frequency racking echnology, so ha he fron and back frequency maching, o achieve he maximum power oupu. This opic hrough he principle design, modeling and simulaion, physical esing, he final realizaion of power and frequency are coninuously adjusable wide air gap dielecric barrier discharge. Inroducion Wih he developmen of economy, more and more indusrial wase gas produced, hese gases ofen conain sulfides, nirides, and oxic organic compounds [1]. These gases have a grea polluion o he environmen caused by haze, acid rain, greenhouse effec and so on a series of environmenal problems, he greaer harm, cause bronchiis, ashma, emphysema and pulmonary hear disease and oher respiraory diseases [2]. There are many mehods o deal wih he wase gas, such as acivaed carbon adsorpion, caalyic combusion, caalyic oxidaion, acid base neuralizaion, dielecric barrier discharge (DBD). The dielecric barrier discharge (DBD) mehod has he advanages of single paricle producion, relaively low energy consumpion and no polluion once again. The dielecric barrier discharge (DBD) reamen of indusrial wase gas has been widely used in developed counries, especially Germany and he Unied Saes. Bu a presen, here is a big gap beween China and foreign counries in he process of wase gas reamen. Mainly in he single yield low, heavy volume, frequency power supply efficiency problem low in dielecric barrier discharge (DBD) device [3].In dielecric barrier discharge (DBD) device, he power supply is one of he key componens of he dielecric barrier discharge device, inelligen high power high frequency and power of he dielecric barrier discharge (DBD) is he direcion of developmen. Design of Dielecric Barrier Discharge Principle of Dielecric Barrier Discharge. Dielecric barrier discharge (DBD) is a kind of mehod o generae plasma by insering he dielecric ino he discharge space [4]. The discharge space plasma produced by dielecric barrier discharge (DBD) in high pressure and a wide range of frequencies, usually working pressure is 10 ~ 10000Pa. power frequency from 50Hz o 1MHz. elecrode juncions have various forms he full diversiy. A working gas beween he wo elecrode, and one or wo elecrode wih insulaion cover, when applied beween wo elecrodes AC volage is high enough, he gas beween he wo elecrodes can be produced breakdown discharge, which produce dielecric barrier discharge. Dielecric barrier discharge (DBD) equivalen diagram as shown in Fig. 1, he high frequency AC power o he discharge device, which is composed of an insulaing medium discharge device for he upper and lower elecrodes and inermediae. When he volage applied o he discharge device is lower han he discharge volage [5], power supply device for loading equivalen o a capacior. When alernaing curren increases o he minimum discharge over volage discharge device, discharge device o sar work, discharge gap gradually sabilized, he volage across he discharge gap wih he increase of alernaing curren will no change, his device is equivalen o he 2016. The auhors Published by Alanis Press 0757
discharge gap capaciance and dielecric equivalen capaciance in series, wherein he discharge gap capaciance volage is a fixed value. High pressure plae Dielecric medium High-volage alernaing curren Ground Figure 1. Equivalen diagram of DBD device Dielecric barrier discharge (DBD) reamen of wase gas in he process of work, he energy ransfer of he plasma is generally as follows: (1) elecric field + elecron high energy elecron (2) high energy elecron + molecular (or aomic) (excied aom, excied group, free radical) (3) acive group + molecule (aom) produc + hea (4) acive group + acive group produc + hea In he above process, he firs elecronic energy from he elecric field o ransfer energy o he aoms or molecules o obain he exciaion or ionizaion, molecular or aomic energy is excied, while some molecules are ionized, and becoming acive groups[6]; hese acive groups and molecules or aoms collide beween acive group and acive group afer he formaion of sable producs and hea. Design of he Whole Device. A presen, dielecric barrier discharge (DBD) air gap is mainly zero a few millimeers or abou a millimeer, his experimen he discharge gap increased o 5 mm, which need high load volage, increased from several housand vols o ens of housands of vols of high volage power supply. The overall framework is shown in Fig. 2. The inroducion of 220V ciy power, afer he full wave recifier, filer o he full bridge inverer, he oupu of high frequency volage afer he high frequency ransformer o load ino he load side. Elecric Ciy Recifier filer Full bridge inverer load drive conrol module Frequency racking Figure 2. Whole frame of DBD device The Working Principle of he Inverse Power Transfer. The working process of he inverer is shown in Fig. 3. The swich ube is swiched on and off, and he DC volage is chopped ino a 2016. The auhors Published by Alanis Press 0758
recangular wave wih posiive and negaive alernaing curren. In order o preven he opening of he swich ube a he same ime o burn he swich ube [7], you need o se aside he dead ime, he waveform is shown in Fig. 4. The specific process is: Open M2M3, M1M4 close, U=U D ; close M1M4, open M2M3, U=-U D ; When swiching beween M1M4 and M3 M2 a a se frequency, Posiive and negaive alernaing volages are obained on he load, he cycle is 1/f s, This is he working process of he inverer. M 1 M 2 R C L M 4 M 3 Figure 3. Series resonan equivalen diagram M1 M4 M2 M3 U Figure 4. An ideal waveform of he inverer work The conrol chip is SG3525, i is a kind of PWM conrol chip wih excellen performance and complee funcion, I is simple and reliable, and i is very flexible and convenien o use. The oupu driver for he push-pull oupu form, increase he driving capabiliy; conains inernal under volage lockou circui, sof sar conrol circui, PWM lach and he over-curren proecion funcion, frequency adjusable, and can limi he maximum duy raio. The shock frequency of SG3525 is deermined by he exernal resisance capaciance. The saring frequency of SG3525 is f 1, f 1 1 C (0.67R 1.3R ) T T D By adjusing he urn-on ime o adjus he duy cycle o conrol he power oupu of inverer, power adjusmen process is as follows: The sampling volage is delivered o he reverse side of he SG3525 error amplifier and compared wih he reference volage a he same direcion. When he sampling volage is greaer han he reference volage, he duy raio becomes smaller, he oupu power decreases; when he sampling volage is less han he reference volage, he duy raio increases, he oupu power increases. The whole process of work is carried ou so ha he power of auomaic regulaion. Frequency Tracking Technique. Wih he change of he exernal environmen, such as environmenal emperaure, humidiy and exhaus gas reamen concenraion, dielecric barrier discharge (DBD) device characerisics will be changed obviously [8], and he change is nonlinear. 2016. The auhors Published by Alanis Press 0759
This will lead o he power supply canno be good maching of he discharge device, resuling in lower oupu power and he loss is large. The effecive way is o make he swiching frequency of power supply always follow he resonan frequency of he equivalen load. This can conrol he volage and curren load end of he synchronizaion, and also can reduce swiching losses, easy o realize sof swiching of power ube [9], so as o reduce he loss and improve he efficiency of. SG3525 pin 3 has an exernal sync feaure, when he synchronous pulse widh less han 6us and greaer han 0.5us, he frequency of he oscillaion frequency is greaer han he se [10], he chip will follow he exernal synchronizaion pulse oscillaion, and wo frequency afer he oupu pulse. Experimenal Resul Analysis Fig. 5 Schemaic diagram of he experimenal se-up is shown, he harmful gas is colleced in he facory of sulfide niride and oher harmful gases, he harmful gas and air are mixed in he gas mixing vessel and are fully mixed ino he DBD reacor, se up every minue of he gas flow value, and adjus power supply, collecion of samples in he exhaus gas discharged from he back, hrough he analysis of he sample gas, o adjus he power supply, unil he exhaus gas all harmless gas so far. The experimenal daa is shown in Table 1: Table 1 o he gas and load power consumpion Exhaus gas sample sulfide 80% 10% 10% 30% 30% Nirides 10% 80% 10% 30% 30% Organic compound 10% 10% 80% 40% 40% Pass hrough reacor speed 0.2L/M 0.2L/M 0.2L/M 0.2L/M 0.4L/M Power supply 1.82kw 1.67kw 2.15kw 1.98kw 4.24kw sampling harmful gas amosphere Gas mixing conainer DBD reacor Gas discharged afer reamen Power supply Figure 5. Schemaic diagram of experimenal device Through a large number of experimens, collecing waveforms, he waveform of he load side is 2016. The auhors Published by Alanis Press 0760
shown in Fig. 6. Figure 6. Waveform diagram of he load As shown in he figure, he inverer oupu and he load end can be well mached, he oupu volage is basically in accordance wih he recangular wave change, load AC curren can basically be in accordance wih he predeermined sine wave, basically no phase difference. Summary The load will change wih he change of he environmen, he resonance frequency will change, he need o use frequency racking echnology, so ha he frequency of he swich ube is very good maching, racking he resonan frequency of he load. Through a lo of experimens and waveform analysis, differen working condiions, such as he large difference in he gas concenraion, differen maching power and frequency should be se up, oherwise he device will no work or he efficiency will be low. References [1] Jin Youmin, hree. The physical basis of he low emperaure plasma physics [M]. Beijing: Tsinghua Universiy press, 1983.21-30. [2] Wu Jun, Liu Ping. Design of full bridge swiching power supply based on [D] UC3842, Zhengzhou Universiy, 2012, 07:12-16. [3] Zhang Zhansong, Cai Xuansan. Principle and design of swiching power supply (Revised Ediion) [M]. Beijing: Publishing House of elecronics indusry, 2004:288-301. [4] Chu Bin.IR2110 power driver inegraed chip English [A]. Elecronics engineer, 2001,30 (10):38-39. [5] Liu Dianong, Yu Siyuan Liu Jinhua. Frequency racking conrol, processing power and consan ampliude conrol [J]. elecromachining & mould, 2000, (2):68-73. [6] Li Minyuan, Jiang Haipeng, e al. Selecion of opimal dead zone of series resonan inverer [A]. Power elecronics echnology, 20003, 37 (4):23-28. [7] Liu Tao.MOSFET series resonan inverer conrol circui [A]. Science of he sudy, 2001 (26):56-59. [8] Li Chunju, Hou Anonio. High frequency inverer power supply design of [N]. SG3525A and M57959 Engineering Journal of Hunan based on 2008, 18 (4):21-23. [9] Zhang Zhiao, Zhao Yanhui, Dong Kebing, e al. Sudy on he resonance of dielecric barrier discharge sysem [J], high volage echnology, 2004,30 (4): 40-41. [10] Shao Jianshe, Yan Ping. Resonance phenomenon of dielecric barrier discharge power supply resonan inverer [J], high volage elecrical, 2006, 32 (5): 329-330. 2016. The auhors Published by Alanis Press 0761