Research On Quadratic Interleaved DC-DC Converter For Fuel Cell Vehicles

With the rapid development of the transportation industry,the consumption of non-renewable energy sources is increasing day by day,which leads to the problems of excessive energy consumption and serious environmental pollution.The emergence of new energy vehicles has provided a new direction for the development of the traditional transportation industry,and among the new energy vehicles,fuel cell vehicles have been favored by major domestic and foreign automakers due to their zero pollution and zero emission advantages.However,due to the inherent characteristics of fuel cells(weak output characteristics,low output voltage level,and poor voltage-and-ampere characteristic curve),it is difficult to meet the requirements of fuel cell vehicle power system directly.Therefore,it is significant to research DCDC converters that can realize power matching and voltage decoupling for fuel cell vehicle system to promote the development of fuel cell vehicles.In this paper,non-isolated boost basic cells are divided into several types according to the different combinations of energy storage elements in the topologies,and the basic characteristics of the different structures are analyzed.According to the demand index of DC-DC converter for fuel cell vehicle,the basic unit suitable for fuel cell vehicle is summarized.On this basis,a topology structure of DC-DC converter based on the general structure of front and rear stage is proposed for fuel cell vehicle,and the general expression of voltage gain of front and rear stage structure is given.Secondly,a quadratic interleaved DC-DC converter with a voltage multiplier structure is proposed based on the proposed topology formulation.The proposed converter has the advantages of high voltage gain,low voltage stress,low input ripple,wide operating range and common ground.The operating principle of the proposed converter is analyzed,and the calculation methods of voltage gain,voltage and current stress,inductor and capacitor parameters and input current ripple are given.The proposed converter is compared with other common non isolated DC-DC converters according to the demand index.Then,the dynamic modeling of the proposed converter is carried out by using state space averaging method and small signal modeling method,and the PI controller is designed.Thirdly,the hardware and software design of the proposed converter is carried out according to the design specifications,and the design process and working principle of the main circuit,voltage sampling circuit,drive circuit,auxiliary power supply circuit,and the software design flow chart are presented.In addition,the C language is used to program each part of the software program in the CCS software environment.Finally,the simulation model of the proposed converter is built by using Simulink simulation software,and the experimental prototype and test platform with rated power of 100 W are built.The steady-state characteristics,dynamic characteristics and efficiency of the proposed converter are measured,and the experimental results and loss are analyzed.The experimental results show that the proposed converter can meet the requirements of fuel cell vehicle for DC-DC converter.