Study On Wide Air Gap Dielectric Barrier Discharge Power Supply

In this thesis,DDBD(Double Dielectric Barrier Discharge)with wide air gap is used as a device for treating exhaust gas,because it has the advantages of high efficiency,low energy consumption and no secondary pollution.The main circuit topology of the power supply is full bridge inverter,load loop resonant mode is the use of new transformer secondary series resonant.The main work of this thesis has the following aspects.1,The design of secondary series resonant circuit.Because the load is capacitive state,the device works in the high frequency state,the load of the useful power is very small,so to join the compensation inductance,forming a resonant load circuit.Some of the dielectric barrier discharge devices resonate in a way that selects the primary series resonance,and the benefits are simple and easy to debug.However,the cost of the primary coil is very high,which is a challenge to the safety of the whole circuit,so this thesis selects the new secondary series resonant.2,The design and Calculation of High Frequency Transformer.In addition to the role of step-up transformer,in this thesis also played the role of the front and rear isolation and impedance matching,especially the impedance matching,because the power supply impedance and load impedance does not match,resulting in lower output power efficiency,the transformer plays a matching power source impedance and load impedance function.3,The design of frequency tracking circuit.Due to the load circuit with the change of the working environment,resulting in the load resonant frequency changes,the power supply and load circuit resonant frequency can not be a good match,the output power can not be effectively loaded to the generator,the reactive power is larger,the efficiency is reduced,so it is necessary to add frequency tracking circuit.The principle of frequency tracking is to collect the current zero crossing point of the load,generate the synchronization pulse at the zero crossing,so that the inverter is also operating at zero point,so as to achieve the inverter output voltage and load current phase of the same purpose.4,The design of power regulation circuit.There are many ways to adjust the power circuit,this thesis uses the inverter PWM power adjustment,the advantages of simple operation,strong execution,accurate adjustment,and stable working frequency.The power control part selects the power integrated chip SG3525,through the comparison of the sampled signal and the given signal,the duty cycle of the PWM waveform is controlled,and then the output of the power is adjusted.Finally,the design of a test prototype,the power is 2kW,the load resonant frequency of 40 kHz or so,the design efficiency of more than 85 percent,through a series of experiments and sampling waveform analysis,the machine running in good condition,in line with expectations Claim.