Study On Topology And Control Method For Multiplying-inductor Converters

Multiplying-inductor converters have the advantages of small size,high efficiency,multiple output,etc.They have received extensive attention from experts and scholars in related fields at home and abroad.These converters provide an ideal solution to meet the requirements of multiple levels of voltage supply and small size for modern electronic equipment and mobile terminals,and have important research value.This article has conducted in-depth research on the topological structure and control method of the multiplying-inductor converter.The specific work is as follows:(1)Based on the analysis of the inductor voltage state of the BUCK,BOOST or BUCKBOOST converter,this paper sum up an inductor voltage state sequencing method which is suitable for deriving single inductor converters.That is,the inductor voltage state of the converter is first sorted.Then based on the voltage state of the inductor,speculate the position of the input voltage source and output voltage source relative to inductor and the status of switch tubes.By this method,multiplying-inductor converters of parallel type,two-stage type are derived.In particular,traditional single-inductor multiple output(SIMO)power factor correction converter is parallel type and cannot simultaneously satisfy high power factor and low output ripple.The paper proposes a two-stage SIMO power factor correction converter.This structure contains a bus capacitor that can absorb the second-pass frequency ripple,so that the high power factor and low output ripple of the switching power supply can be satisfied at the same time.The inductor voltage state sequencing method is also applicable to the combination of the FLYBACK converter and the basic topology.Through the multiplying of the transformer secondary winding of the FLYBACK converter,a new two-stage structure of the FLYBACK converter and the basic converter is derived.Inductor voltage state sequencing method proposed in this paper is not only used in non-isolated converters,but also extended to isolated converters.(2)Single-inductor Two-stage BOOST-BUCK Converter is proposed for large size of the traditional Two-stage BOOST-BUCK Converter.Comparison simulations have found that a Single-inductor Two-stage BOOST-BUCK Converter can achieve the same output performance as a conventional Two-stage BOOST-BUCK Converter with a reduced inductor and no overvoltage at startup.For Single-inductor Two-stage BOOST-BUCK Power Factor Correction Converter under constant duty cycle control,the increase of the effective value of the input AC voltage will cause the problem of power factor reduction.This paper applies the control method of the fitting duty cycle to the control of Single-inductor Two-stage BOOST-BUCK Converter,so that the converter can still maintain a high power factor over a wide input voltage range,and the simulation is performed to verify it.(3)For disadvantage of one switch arm of Single-inductor Two-stage BOOST-BUCK Converter is not grounded,a Single-inductance Two-stage BOOST-BOOST Converter is proposed.The theoretical analysis,simulation and experiment of the converter are performed.The experimental results verify the correctness of the basic logic of the converter.According to the experimental results,some problems need to be further studied,such as the cross-regulation of single-inductor two-stage converter and the parameter of inductor of single-inductor two-stage converter under working conditions.