Research On Dual Boost Integrated Dual Active Bridge Multiport DC/Dc Converter

In recent years, with the development and more application of renewable energyresources, distributed generation (DG) system has become a hot research topic today.Multiport converter can integrate different converters into one single converter withmultiple ports, its application in DG system can greatly simplify the control stragey of theDG system, and thus the multiport converter attracts more and more attention. Based onthe analysis and research of the characteristics of multiport converter, this paper proposestwo novel multiport DC/DC converters which can be applied in DG system.The two multiport DC/DC converters which possess the feature of boost converterand dual active bridge converter are derived from the integration of dual boost converterand dual active bridge (DAB) converter. The two converters are composed of threesections: Unidirectional renewable power source is the main power supply section; theenergy storage section is able to supplement the insufficient or storing excess energy; theisolated output section is used to providing a reliable electrical energy to the load.In this paper, the photovoltaic (PV)-battery hybrid energy system is adopted as atypical example to explore circuit operation principle and the analysis of ZVSsoft-switching implementation about dual boost integrated dual active bridge (DAB)three-port DC/DC converter, and the ralted simulation results are given. Then based onthis topology, it can be expanded to four-port converter to form the dual boost integrateddual active bridge four-port DC/DC converter, and take the Wind Turbine-Photovoltaichybrid energy system as a typical example to explore circuit operation principle and theanalysis of ZVS soft-switching implementation, the ralted simulation results are given aswell. Finally, from the dual boost integrated dual active bridge three-port and four-portDC/DC converter，it can conclude that dual boost integrated dual active bridge multiportDC/DC converter can be expanded to any number of input ports.For the two converters’ application on distributed generation,“PWM+phase shift”control strategy is adoped to implement a reliable and stable system work for differentconverters’ working modes, it’s verified by the simulation results that the two multiportconverters can work reliably in different working modes, and therefore the validity of the control strategy is also proved by the simulation results. Then, the system parameterscalculation and design considerations are presented. A100W laboratory prototype is builtto verify the two topology operation principle, ZVS soft switching implementation and theeffectiveness of the control strategy. The experimental results demonstrate the feasibilityand correctness of the two topologies.