Research Of High Power DC/DC Converter Based On The Energy Of The Doubly-fed High-precision

Bi-directional DC/DC converter allows the transfer of power between two DC sources in either direction as needed.It has a very wide range of applications in aerospace power systems,electric vehicles,photovoltaic power systems,uninterruptible power systems,distributed generation systems and so on.With the continuous expansion of the scope of application of the converter,the power level and current are also increasing,the choice of the device has become more stringent.The method of interleaved parallel not only can increase the stress of the device,also can increase the power level at the same time.Therefore,this article focuses on staggered parallel bi-directional DC/DC converter,both can satisfy the requirement of high power rating and can reduce the voltage ripple current,and improve power quality.First of all,the basic principle of the bi-directional DC/DC converter was expounded,the basic structure and related characteristics of isolated and non-isolated bi-directional DC/DC converters were summarized.According to the Buck and Boost modes of bidirectional DC/DC converters,the correlation functions are deduced.According to the principle of interleaving parallel technology and mathematical analysis of the ripple suppression,the parallel module number and duty ratio on ripple suppression effect was studied,a six-staggered parallel bi-directional DC/DC converter was designed.According to the converter topology structure,the main circuit parameters,the control circuit,IGBT drive circuit,sampling and communication circuit were designed.Through the analysis of flow technology,the current flow control method of voltage and current double closed-loop was determined.Finally a power rating of 800 kW staggered parallel DC/DC converter was set up.The staggered parallel scheme of the converter,voltage and current double closed-loop control scheme were simulated through the Matlab simulation software,the flow effect,ripple suppression effect and the dynamic response speed and stability were verified.