| Traditional fuel vehicles not only consume a lot of energy,but also emit serious pollution to the ecological environment.Compared with the fuel cell vehicle with the proton exchange membrane fuel cell as the power source,it has the characteristics of no pollution and high efficiency,and the fuel cell vehicle has the advantages of short hydrogenation time and long mileage of the vehicle compared with the pure electric vehicle.The output characteristics of the fuel cell are soft and the single cell voltage is low,so the DC/DC converter is required to match the bus voltage level.In this paper,the multi-phase interleaved parallel DC/DC converter is studied,and its power loop,control strategy and application scenarios are researched and designed.The main one is divided into the following three parts:(1)Research on fuel cell vehicle power system: Firstly,the characteristics of fuel cell,lithium battery and super capacitor are analyzed.Then the structure of fuel cell power system is studied,and the structure of several common fuel cell power system is compared and analyzed.Disadvantages,and selected fuel cell system structure.Finally,the energy flow in different working modes of the power system is analyzed.(2)Study on the two-phase staggered parallel BOOST converter: Firstly,the working principle and characteristics of the two-phase staggered parallel BOOST converter are studied,and the parameters of the main circuit inductance,output capacitance and other components are designed.Secondly,the two-phase staggered parallel BOOST converter is modeled by small signal,and the transfer function of the controlled object is obtained.The current loop and voltage loop controller in the double loop control structure are designed.Then the simulation model of the two-phase staggered parallel BOOST converter is built and the simulation results are analyzed.The simulation results show that the interleaved parallel BOOST converter can effectively reduce the input current ripple.Finally,based on dSPACE controller and hardware power loop experiments,the experimental results verify the effectiveness of the designed circuit parameters and control strategy.(3)Designing the fuel cell vehicle power simulation system: Firstly,the overall structure of the simulation system is introduced,and then the working principle of the analog system components is studied.Then the simulation model of the simulation system is built and simulated.The simulation results show that the simulation system can maintain the stability of the DC bus voltage when the power of the DC/DC variator fluctuates.Finally,the hardware platform of the simulation system is built and experiments are carried out.The experimental results show that the simulation system can simulate the average power mode and peak power mode of the fuel cell vehicle power system,and verify the effectiveness of the simulation system. |
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