Study On The Relationship Between Physical Process And Equivalent Circuit Model Of DBD

Due to its special advantages, atmospheric non-equilibrium plasma has been widely used in the field of environmental protection, synthetize material,PDP,surface treatment and so on.Dielectric barrier discharge(DBD),the most representative way of gerenating atmospheric non-equilibrium plasma,is highly complicated and has a critical size effect that the discharge performance will be weaken when the size of the DBD is increased simply.This bad effect restricts the application of large-scale atmospheric non-equilibrium plasma. So it is very necessary to mak a deep study about the discharge process and mechanism of DBD and get the reason for the size effect.So based on the structre of DBD including two discharge forms:micro-stream discharge and micro-glow discharge,we firstly confirmed the key parameters of DBD device by analyzing its generation mechanism and changed them into equivalent circuit parameters.Then the equivalent circuit of micro-discharge of DBD was built in the MATLAB which was used to simulate the single micro-discharge process interaction between two adjacent micro-discharge channels and the spatial effect when number of the micro-discharge channels increased. Results as bellows:For the single micro-discharge,increase of the total equivalent resistance R of the device and the equivalent capacitance of the unbreakdown part C weakened the performance of the micro-discharge. But increase of the applied voltage,frequency,effective capacitance of dielectric and breakdown capacitance of the gas could improve the performance of DBD.Secondly, DBD had resonance effect because inductance of the applied voltage of DBD and capacitance of DBD constituted a LC oscillation circuit. From the simulation results,it was found that resonance frequency fo decreased with the number of micro-discharge channels of DBD increased.Increasing DBD's size could increase the number of micro-discharge channels,but it also made the equivalent capacitance of DBD increased.Due to this,the resonance frequency decreased and DBD could not get a best performance under the best frequency. So the resonance effect of DBD could weaken the improve effect between frequency and discharge performance. Thirdly,an equivalent circuit to simulate the interaction between two adjacent micro-discharge channels was built.The parameters of the interaction model were changed to simulate the interaction.It was found that the interaction did not change with the change of parameters of the model and the interaction was so small that could be gnored.So in the system of DBD with multi-micro-discharge channels,its equivalent circuit model could be equaled to be parallel of many single micro-discharge channel's equivalent circuit.Generally speaking,study in this paper made us underatand the basic reasons for the size effect of DBD.In order to improve the performance of DBD and reduce the size effect of DBD,we should try to reduce the inductance of DBD's high voltage sources and the equivalent capacitance of DBD.And study in this paper also layed foundation for generating large scale uniform non-equilibrium plasma.