Research On Their Control In Three-Level DC-DC Converters With Coupeld Wingdings

Along with the rapid development of power generation such as solar energy,the DC-DC converters with high voltage gain which uses it to complete the function have become the focus of researchers at home and abroad.In this paper,after comparing and analyzing existing boost converters,three-level DC-DC converters with coupled wingdings is proposed.And establish its signal modeling to achieve closed-loop control.Compared with the traditional DC-DC converters,three-level DC-DC converters with coupled wingdings which is proposed in this paper adds a unit of coupled-inductor to realize the double degree of freedom adjustment of the switching tube duty cycle D and the coupled-inductor turns ratio n to increase the voltage gain,and this advantage can avoid the existence of extreme duty cycles;The clamp diode is added to clamp the voltage spike caused by the leakage inductance in the coupled windings,effectively reducing the peak to the components such as the switch;three-level transformation of the topology,so that the stress of the switch,diode and capacitor in the converter is reduced to half of the original,which is beneficial to the selection of the device and the overall cost control.Firstly,several existing boost converters are introduced and analyzed in this paper,Aiming at the existence of each converter problem,three-level DC-DC converters with coupled wingdings is proposed.Secondly,the working process of the five converters in this family is described in detail,and the overall output voltage gain and efficiency are quantitatively analyzed.Then it analyzes the typical topology—the three-level Sepic converter based on the coupled winding(CITLSC),under the influence of parasitic parameters,the operating mode of the converter and its influence on the performance of the converter,and According to this,the transfer function of the input and output signals of the converter is derived,the small signal model is established,and the PID compensation system is designed to provide a theoretical basis for the closed-loop control of the whole system.Finally,according to the theoretical analysis,the parameters of the relevant unit modules of the converter are calculated and selected,and the voltage and current waveforms of the key components in the converter are simulated by Saber simulation software.Then a 100 W experimental prototype is built closed-loop control is achieved to carry out the experiment.The experimental results are consistent with the results of theoretical analysis and simulation design.Through the verification of typical topology,the correctness and feasibility of the proposed topological family are fully explained: under the condition of avoiding the limit duty cycle,it can be greatly improved the voltage gain,and the voltage spike caused by the leakage inductance is effectively controlled and reused by the clamp diode to improve the overall efficiency of the converter.The three-level conversion structure is introduced to reduce the stress of the corresponding device in the converter,and the overall output efficiency is around 90%.Its performance is excellent.