| As the problems of energy consumption and environmental pollution become more and more prominent,Electric vehicles have become an important development in the modern transportation industry.Although electric vehicles use power batteries instead of traditional gasoline fuel as the on-board energy source,the charging and discharging performance of power batteries is still the biggest obstacle in the development of electric vehicles.Therefore the combination of battery and supercapacitor as hybrid energy storage system(HESS)for electric vehicles is considered as a good way to improve the overall efficiency and battery life of the electric vehicles.One challenge of HESS is that the terminal voltage of supercapacitor is low and the voltage varies in a wide range when charging or discharging.Therefore,HESS requires a bi-directional DC-DC converter with a wide voltage gain range to connect the low-voltage supercapacitor to the high-voltage DC bus.To address the above problems,two new non-isolated bidirectional DC-DC converters are proposed in this paper,one based on the conventional Boost circuit and the other based on a dual-inductor quadratic gain boost circuit,which is combined with a switched-capacitor structure to form the main circuit topology.This thesis analyzes in detail the operating principles of the two bidirectional DC-DC converters operating in two operating modes.A small-signal model is established to determine the component parameters of the topologies,and the simulation software MATLAB/Simulink is used to build the simulation models of the two bidirectional DC-DC converters.Finally,based on the design of TMS320F28335 type DSP and Xilinx XC6SLX9 type FPGA controller,the system block diagram of the bidirectional DC-DC converter is given.The scheme is experimentally verified on the Star Sim HIL hardware-in-the-loop experimental platform.The experimental results further verify the feasibility of the proposed scheme. |
