Research Of Dual Buck Inverter With Dual Frequency

With the development of industrial electrification, the inverter, as a core componentin industrial automation and new energy fields such as wind power generation andphotovoltaic power generation, is widely applied. Performance requirement for inverterhas become higher. The topology of modern inverter is mainly the bridge structure, whichhas the merits of simple circuit and mature control method. But the problem ofshort-through between upper and lower bridge reduce the circuit’s reliability. The deadtime added to avoid that brings new problems such as high harmonic content and lowswitching frequency.DC-DC inverter has solved the problems of bridge structure. It keeps the originalconverter’s advantages of high reliability, high frequency of switching, high power densitybut without the problem of straight bridge arm. Dual Buck inverter has been proposedearlier and successfully applied as one kind of DC-DC inverter circuit, which is obtainedby two Buck circuit inputting side series and outputting side parallel. Since there is noneed to add the dead time, the power switch can work at a higher frequency, but in thehard switching conditions, switching losses are still relatively great which reduces theefficiency when power increases. Through research and analysis of the Buck invertercircuit operating principle and dual frequency circuit structure, the Dual Buck inverterwith dual frequency circuit is propose. This circuit retains the characteristics of theoriginal circuit, can also effectively reduce the high frequency switching circuit flowingthrough the tube current to reduce the switching losses and improve the efficiency of theinverter. And small-signal modeling is deduced through the analysis of the circuit workscircuit of high frequency and low frequency circuit decoupling relations. Itimplementation of low frequency unit for high frequency unit of shunt function. Theefficiency of inverter improved.Finally, a prototype is designed in this paper,including the main circuit board andcontrol board. Based on the half-cycle with SPWM control of double Buck inverter anddual-band Buck inverter are studied by simulation and experiment. The experimental results verify the correctness and feasibility of the theoretical analysis strategy.