Research On Bidirectional DC/DC Converter Applied To DC Microgrid System

With the continuous development of science and social economy,energy has gradually become the foundation of modern society.Promoting new renewable energy has become the focus of the entire world.In order to maximize the renewable energy of distributed energy and other advantages,some scholars have proposed the development of DC microgrid concept,DC microgrid does not exist frequency,phase synchronization and skin effect during power transmission.The number of transformations required for grid integration of distributed energy sources is small,making the overall system highly efficient and easy to control.In this paper,Isolated Bidirectional Full-bridge DC-DC Converter(IBDC)has become a bidirectional DC / DC converter under the direct current microgrid system because of its advantages of electrical isolation,bidirectional energy transmission and zero voltage switch.The preferred topology of the converter.The paper introduces the design of single-phase-shifting(SPS),dual-phaseshifting(DPS)the operating principle,power transmission characteristics and the range of the soft-switching of the isolated bidirectional DC / DC converter under the triplephase-shifting(TPS)mode are analyzed in detail.By optimizing the phase shifting control method,Power return and peak current,thereby increasing the efficiency and power density of the converter system.The single-voltage loop feedback control method,the single-voltage feedback control method based on the phase-shift model and the voltage and current feedback control method based on the phase-shifting model are simulated and analyzed.The appropriate feedback control method is selected and optimized to meet the requirements of the DC microgrid System input voltage fluctuations and changes in load plug converter dynamic response speed and stability requirements.Simulink is used to simulate the optimized phase shift control method and feedback control method.Finally,DSP is used as control chip to build an experimental platform to verify the feasibility and effectiveness of the optimized control method.