Research On High Gain DC/DC Converter With One-cycle Control Method

Economic development and improvement of living standards have significantly increased the consumption for energy,and fossil energy is facing the danger of depletion.At the same time,concern on environmental pollution has improved.Novel energy power generation technologies,such as solar photovoltaic power generation,have attracted tremendous attentions.The output voltages of these new energy power generations haves the disadvantage of low voltage,which makes them difficult to connect to the AC grid and applications in the DC grid.High-gain DC/DC converters have become one of the hot research topics in power electronics technology.With coupled inductor,high gain DC/DC converter is established and one cycle control technology is adopted.Main works of the thesis are listed as follows:(1)High-gain DC/DC converter topology is built with coupled inductance.By replacing the inductance in the Boost converter with a coupled inductor,a high output voltage gain is achieved.The working principle of the designed converter is analyzed,in which the parameters,such as the ratio of output to input and the voltage stress on the switch,are calculated.Simulations on the converter are implemented with PSIM package.(2)Main circuit design for the high gain converter is realized.Circuit parameters for the DC/DC converter are calculated are selected.The inductance value for coupling inductance is calculated and the winding method is designed.RCD clamping circuit is also designed.The power circuit is verified with simulations based on PSIM.(3)Control loop for the high gain converter is desiged.The controllability of output in the converter with one cycle control is proved.To avoid the large overshoot in the starting process of converter,its small signal model is deduced by using the switching flow graph method,and the compensation network is designed.Finally,the simulation results indicate that the compensation network can work properly.(4)Experimental verifications on the high gain DC/DC converter are realized.Based on the previous design,the IR1155 chip from Infineon is selected as the controller,and the corresponding prototype converter is developed.Testing results show that the output ripple of the converter is small and its stability is high,which can meet the requirements of applying in DC micro-grid.