Research On DBD Power Supply Design And Load Equivalent Model

Dielectric barrier discharge(DBD),also known as silent discharge,is a nonequilibrium gas discharge that inserts insulating medium into the discharge space.In the application,the high voltage is applied only on the discharge electrode,and the gas between the poles is breakdown through to form the discharge,and the low temperature plasma is produced at the atmospheric pressure.At present,DBD has been applied to excimer lamp and ozone generator,and has good application prospects in environmental engineering,material surface modification and agricultural breeding.In recent years,with the development of power electronics technology,DBD power has been developed from the traditional power frequency boost power supply and the medium low frequency inverter power to a more efficient and higher power high frequency inverter power supply.High frequency inverter power can reduce the volume of the system and increase the energy density.This paper designs the high frequency and high voltage inverter based on the wide air gap load,and study the equivalent model and load characteristic under the wide air gap condition.The main contents of this paper are as follows:1?DBD power supply overall structure design.According to the experimental conditions,the advantages and disadvantages of series resonance and parallel resonance are compared in detail and the series topology is selected.According to the working condition of the load,weakly inductive load or resonance mode is selected.According to power conditioning pattern,pulse width modulation(PWM)is adopted.2?DBD prototype is designed for hardware design and selection of parameters.This paper mainly introduces the parameters selection of the rectifier and filter circuit,the design of the full bridge inverter circuit,the selection of the capacitance,the selection and design of the high frequency transformer,the design of the PWM pulse control circuit,and the frequency tracking circuit in the control part.3?The measurement of the parameters of the load and the establishment of the equivalent model.In this part,the Lissajous graph method is used to obtain theparameters of the discharge load in the steady state,such as the equivalent capacitance and the equivalent resistance.Experiment results show that the discharge load in steady state operation can be equivalent to the equivalent model of capacitor resistance series connection,and the load property is analyzed according to the load model.4?The study of the equivalent model.Starting with the principle of equivalent model,the influence of air gap capacitance resistance on load characteristics is analyzed.Through MATLAB simulation,the influence of air gap resistance on load characteristics is obtained,and a new thought for load characteristic research is proposed.At last,a prototype of DBD power supply with a discharge power of 2k W and a resonant frequency of about 40 k Hz is designed.The load characteristics under different discharge conditions are also studied.