Studies On Series Resonant Power Supply For Dielectric Barrier Discharge

How to use dielectric barrier discharge (DBD) to come out low-temperature plasma under atmospheric pressure has become hotspot in this research field. Hence, to develop discharge power supply used in DBD is the main question.This paper studies on the capacitive phase-shift PWM control series resonant load full Inverter DBD type power supply. Frequency Tracing Technology is used in DBD load circuit. The experiment results show that the proposed method has the virtues of high power factor and low switch stress. The control system of power supply based on dsPIC30F2020 controller has been designed. The main achievements obtained by this dissertation are:Firstly, by analyzing dielectric barrier discharge series resonant load Inverter and its power regulation method, according to frequency tracing technology of the load current, capacitive phase shifting PWM control full bridge inversion series resonant load circuit is applied to DBD type power supply. The paper mainly analyzes operating process under different operation modes of the inverter. Compared with inductive phase-shift PWM and phase-shift resonant PWM, the capacitive phase-shift PWM has a small frequency fluctuating and fit the inverter that consists of IGBTs. The paper discusses the frequency tracking technology and gives the phase locked loop based on digital electronic circuit.Secondly, the parameter of main circuit is designed in the paper. One kind of digital control system of power supply based on microchip dsPIC30F2020 has been designed, which realize the digitization. According to the frequency tracing technology of the load current, and the generator voltage which is controlled by PID closed-loop, capacitive phase shifting PWM control strategy and the power regulation have been realized.Thirdly, DBD equipment is set up in laboratory. By a series DBD experiment, the influences of the applied voltage, the gas gap distance, and the thickness and dielectric permittivity of the barrier on the discharge characteristics are studied, The results show that the value of power dissipated increases with the increasing of applied voltage and dielectric permittivity of the barrier, and decrease with the increasing of gas gap distance and the thickness of barrier.