Research On Topology Structure Of DC-DC Converter Based On Pt Control

With the popularization of distributed power system and the rapid development of mobile electronic devices,the application of DC-DC power module is more and more extensive.The microminiaturization of electronic equipment is also becoming more and more demanding for the appearance and performance of DC-DC converters.Starting from the topological structure of the circuit,based on the control strategy of pulse train(PT),the topology of the single voltage output circuit and the multi voltage output circuit in the DC-DC converter is studied.Firstly,Based on a traditional typial single output Buck converter,by changing the topology of the circuit,a new type of Buck converter is designed in this paper,and the low frequency fluctuation of the output voltage of the PT control Buck converter is effectively suppressed when the inductor current is continuous.Secondly,in order to further improve the precision of the output voltage of the DC converter,this paper applies the coupled inductor to the topology of the DC-DC converter.Taking the Boost converter as the research object,the coupling inductance is used to replace the old inductor,and the auxiliary current transformer is used to form a new Boost converter with coupled inductors.The mechanism of the low frequency fluctuation in the topology of the new Boost converter is analyzed theoretically.The study shows that the low frequency fluctuation is completely suppressed under the suitable coupling coefficient.The effect of coupling coefficient on low frequency fluctuation is simulated and experimentally studied.Finally,aiming at the problem of traditional multi output DC-DC converter,such as large volume,high cost and low power transmission efficiency,this paper takes a dual output Buck converter as an example,and studies a new interleaved dual output Buck converter.By reducing the number of switches,the topology of dual output circuit greatly reduces the volume of dual output converter,the current stress of switch tube is also greatly reduced,and the power transmission efficiency is significantly improved.The superiority of the converter is verified by simulation and experiment.