Research On High Gain And Low Ripple Bidirectional DC/DC Converter Based On Coupled Inductor

The bidirectional DC/DC converter can realize the bidirectional energy transmission between the energy storage device and the DC bus,and it is an indispensable part in the field of new energy power generation.The huge voltage gap between the energy storage device and the DC bus requires the bidirectional DC/DC converter to have the characteristics of high voltage gain.Therefore,how to improve the voltage gain of the converter has become one of the hotspots of academic research.In addition,the low-voltage side current ripple is also a problem to be solved urgently for the bidirectional DC/DC converter,and its performance will directly affect the efficiency of the converter and the service life of the energy storage device.Therefore,the research on suppressing current ripple is also of great significance.In view of the above problems,this paper studies three new types of bidirectional DC/DC converter topologies,the main contents are as follows:First of all,this article introduces the research background and significance of the subject,and summarizes the research status of high voltage gain bidirectional DC/DC converters,and at the same time expounds the common current ripple suppression methods.Secondly,in view of the limited voltage gain of the traditional bidirectional Boost/Buck converter,a voltage doubler unit based on a coupled inductor is introduced on the basis of it,and a high-gain bidirectional DC/DC converter with a coupled inductor voltage doubler unit is formed.The working principle and steady-state performance of the converter are analyzed in detail.The feasibility of the converter is verified by simulation and experiment.The results prove that the converter has the advantages of high voltage gain,low voltage stress of the switch and zero voltage turnon.Then,in order to solve the problem of large current ripple on the low-voltage side of the converter mentioned in the previous chapter,a passive ripple injection circuit was introduced on the basis of it,and the topology was further simplified,thereby proposing a three-winding coupled inductor with high gain and zero ripple.bidirectional DC/DC converter.The converter retains the advantages of the original converter with high gain,low stress,and zero voltage turn-on,and at the same time,it uses the passive ripple injection method to achieve the goal of zero ripple on the low-voltage side current.The working principle and steady-state characteristics of the converter are analyzed in detail,and the feasibility and superiority of the proposed topology are verified through simulation and experiments.Finally,in order to suppress the current ripple on the low-voltage side while reducing the current stress,using the interleaved technology,another interleaved highgain low-ripple bidirectional DC/DC converter with coupled inductor is proposed.The two coupled inductors form an interleaved structure in the low-voltage side circuit,which not only effectively suppresses the current ripple,but also reduces the current stress.On the high-voltage side,two coupled inductor windings are connected in series,so that the converter has a higher voltage gain.The working principle and performance of the converter are analyzed in detail,and finally the feasibility and superiority of the proposed topology are verified through simulation and experiments.The paper has 79 pictures,9 tables,and 82 references.