Research And Realization Of The Optimization Design Of Soft Switching Parameters In The Inverter Power Supply

The development of modern power electronics technology tends to be miniaturized and high-frequency,and miniaturization requires higher and higher switching frequency,however,the increase of switching frequency will bring on and off loss.The application of soft switch in inverter power supply reduces on and off loss by using resonance conversion technology,making it possible to miniaturize and lighten inverter power supply.In this thesis,the influence of soft switching parameters in high frequency inverter power supply is deeply studied.In this thesis,the common inverter circuit in high frequency state is briefly described,and the development,current situation and principle of soft switching technology in inverter power supply and power electronic converter are described.The circuit principle topology and circuit working state of soft switch realized by full-bridge phase shift control are analyzed,and the phase shift control signal and the working state of soft switch realized in the circuit are simulated and analyzed under the working environment of Pspice circuit simulation software.On the part of soft switch parameters optimization design,firstly,the influence of resonance parameters is discussed and analyzed under the working environment of Pspice circuit simulation software,and the zero voltage conduction of leading bridge arm and zero current shutdown of lagging bridge arm as well as the commutation process and working waveform of transformer are described in detail.The influence of soft switch resonance parameters on the circuit soft switching process is discussed,and the simulation analysis of transformer excitation inductance on the conduction and disconnection process of the switch tube is carried out,and the influence of soft switch parameters on the circuit soft switching process is obtained by the resonance inductance and resonance capacitance.A certain resonance inductance is helpful to the realization of soft switching in the circuit,and the excitation inductance can reduce the current spike when it is turned on.In the aspect of hardware system design and implementation,the main power devices of inverter circuit are selected and calculated,appropriate devices are selected and circuit parameters are calculated.The digital signal processor TMS320F28335 generates the phase shift control signal to turn on and off the switching tube in the inverter circuit.The circuit is provided with a driving circuit,an over current protection circuit and an auxiliary power circuit.Finally,the inverter power supply after the hardware system is built is analyzed and verified,and the driving control signal experiment and soft switching circuit experiment in the circuit are carried out.At the same time,the voltage and current changes at both ends of the switch tube in soft switch and hard switch state are compared and analyzed.The results show that zero voltage conduction and zero current turn-off of the switch tube are realized in high frequency operation state,and the turn-on and turn-off loss of the switch tube is reduced.