Design And Implementation Of Soft Switching Buck Inverter

With the gradually serious contradiction between the increasing demands for traditional fossil fuels and the increasing depletion of fossil energy reserves,the world energy consumption system is bound to change,where the proposed slogans of "clean energy","renewable energy" and "efficient energy" indicate the future trend of consumer energy industry.In response to the the trend of "efficient energy" in the power electronics industry and taking the industrial application as the target,this paper designs and establishes a parallel dual-buck soft-switching inverter system.The system focuses on reducing the loss of inverter system and improving the efficiency of inverter conversion,whose main work involves the design of hardware and software as well as the coordination control of different modules in the system.This paper proves a set of feasible overall scheme according to the mentioned indexes,which includes: the parallel dual-buck soft switching inverter cooperates with the softswitching unit to achieve most of the main indexes of hardware and the software monitoring system complements to further improve the inverter system in function and reliability.Firstly,this paper discusses and compares various control schemes of inverters.A parallel dual-buck inverter topology is demonstrated based on the summary of advantages and disadvantages of the mentioned control schemes.The parallel dual-buck inverter topology is designed by adjusting the driving logic and introducing the independent freewheeling diodes on the basis of the full-bridge inverter.Detailed analysis of the operating modes,the double-loop PI control strategy and the corresponding derivation equations are provided in this section.Then,the soft-switching structure is introduced on the basis of dual-buck inverter.The relationship between the duty cycle range of realizing soft switching and the extra voltage and current stress is discussed in detail,while the operating modes of soft switching are introduced.The filter inductor used in the filter unit is designed and fabricated.Besides,modules of the auxiliary power supply circuit,the sampling circuit,the protection circuit,the analog control circuit,the digital control circuit,the display circuit and the monitoring circuit are designed to further consummate the system function.In addition,a set of rigorous control logic,process and timing of the corresponding software are designed according to the practical application conditions,including: the system start-up unit,the sampling unit,the protection unit,the display unit and the remote control unit.The feasibility of the software system is verified by the simulation results,which is running on the PLC hardware and has passed the experimental tests to form a set of perfect local / remote on-line monitoring software system.Finally,a prototype is designed and established.The conversion efficiency reaches up to 97.85% at full load and the prototype has passed the continuous test lasting for 48 hours under high temperature.The validity and feasibility of the system and the design are verified.