Research On DC Voltage Boost Converter Based On Resonant Switched Capacitor

In recent years,with the rapid development of power electronics technology,miniaturization,high frequency and high efficiency of converters have become the basic requirements of the design of switching power supply.Switched capacitor converters have been widely used in small and medium power applications because of its small size and high energy density.However,in the process of realizing high frequency,the switches work under hard switching conditions.High switching loss and serious electromagnetic interference(EMI)will be caused if increasing the switching frequency directly.It will also reduce the efficiency in DC converter and limiting the increasing of switching frequency.Switching loss and EMI have been effectively reduced after the emergence and application of soft-switching technology.Among the soft switching technologies of DC switching power supply,resonant converters have been widely researched and used in high frequency switched capacitor DC converter due to its natural soft switching characteristics and low EMI.This thesis takes a systematic study of switched capacitor converter firstly.A smaller resonant inductor is added to solve the problems that input current is pulsating and the switches operate at hard switching conditions.Then several typical resonant switched capacitor converters are introduced.A novel resonant switched capacitor DC voltage boost converter has been proposed to solve the problems of high voltage stress of components and difficulties in realization of soft switching and design of resonant inductors.In this thesis,the novel topology can realize zero voltage switching of switches without adding any components.The efficiency of the converter is further improved.At the same time,the design of inductors is simplified.The voltage stress of component is reduced.The range of output voltage gain is effectively broadened in the converter.The losing regulation of output voltage caused by discontinuous inductors current and the instability of system when the current of inductor switching from discontinuous to continuous are avoid,because the current of inductors is continuous.In this thesis,the principles of the novel topology are introduced in detail.The voltage stress,output voltage gain,output characteristics and loss of each element are analyzed.The design of parameters is given according to the theoretical analysis.Finally,a simulation model of 140W is built using Saber simulation of 2012.The effectiveness of the novel converter is verified according to its simulation results.