Research And Design Of Low Ripple High Efficiency Fuel Cell DCDC

In recent years,the rise of clean energy has continuously impacted the traditional fossil fuel industry.Among them,fuel cells have attracted attention because of their advantages such as sufficient fuel,large power density,and low noise,but the fuel cell has a slow dynamic response and cannot directly supply energy to the load.This paper proposes a low ripple high efficiency fuel cell DC/DC converter to improve the output conversion efficiency of the fuel cell and suppress the influence of the ripple of the downstream DC converter on the fuel cell.This paper first analyzes the development status of the fuel cell market at home and abroad,summarizes the various components of the fuel cell power supply system,and selects the hybrid fuel cell power system as the research object of this paper.Using MATLAB/SIMULINK simulation tools to simulate the steady-state and dynamic characteristics of the fuel cell empirical model,according to the simulation results and output characteristics of four-phase interleaved parallel Boost circuit topology,and the main circuit inductors,filter capacitors,power switches and Diodes and other devices for parameter design and selection.In order to improve the conversion efficiency of the DC converter,the control algorithm design of the multiphase interleaved parallel system needs to be based on the converter efficiency model.According to Kirchhoff's voltage and current law,the efficiency equations of the relevant parameters are derived by measuring the power loss of each device of the converter.The efficiency equation is a function of the efficiency and the output current of the fuel cell.Here,the appropriate online work is selected according to the different power load.Phase number.In order to avoid the excessive impact of the branch current in the phase number adjustment process,this paper establishes the Boost circuit small signal model and uses the amplitude-frequency characteristic curve of the controlled object to design an appropriate PI controller.Finally,the hardware design and software analysis of the DC converter are introduced;this includes the flow chart of the hardware acquisition circuit,the power transistor driver circuit,the minimum control system chip,and each control program.The circuit simulation and experimental results show that the shortcomings of the slow dynamic response of the fuel cell can be greatly improved by staggering and paralleling technology to achieve the peak-to-peak filling of the input voltage and current ripple;the DC at different working phases is simulated according to the established efficiency model.The efficiency curve of the converter and the adjustment of the phase number can achieve efficient operation under partial load,and the efficiency of the four-phase operation under full load has been significantly improved.