High Power DC-DC Converter For Fast Activation Of Fuel Cells

In the production process of proton exchange membrane fuel cell(PEMFC),rapid activation is a crucial step.This step requires an electronic load composed of a DC-DC converter to perform rapid activation discharge on PEMFC to improve its performance.Currently,the power of the DC-DC converter in the electronic load for fuel cell activation is small,the input ripple is large,and the activation start time cannot be set,which cannot meet the requirements of high power,low ripple,and high accuracy for rapid activation of fuel cell stack.To address these issues,this paper mainly conducts the following work on the high-power DC-DC converter used for fuel cell rapid activation.Firstly,according to the requirements of rapid activation of fuel cell stack,the system scheme was designed,the working principle of DC-DC converter was analyzed,and the working mode of the converter was introduced.The advantages of the selected four-phase interleaved parallel Buck main circuit topology structure were explained,the working principle of the main circuit in different modes and the working waveform in continuous mode(CCM)were analyzed,and the component parameters were calculated and selected.Secondly,the circuit model of DC-DC converter is established by using Matlab/Simulink software,and three control strategy simulation models of traditional PID,BP neural network PID and seagull algorithm(SOA)-BP neural network PID are established on the circuit model.The simulation experiments were carried out for the above control strategies,and their performances were compared.The simulation results showed that the traditional PID control strategy had longer system response time and larger current ripple.The current ripple of the BP neural network PID control strategy was 50%of that of the traditional PID control strategy,and the control parameters could be adjusted in real-time online,but the response speed was significantly reduced.The current ripple of the SOA-BP neural network PID control strategy was almost the same as that of the BP neural network algorithm control strategy,but the system response time was only 7.9%of that of the BP neural network algorithm control strategy.Finally,a prototype of the high-power DC-DC converter used for rapid activation of fuel cell was built and tested.The performance of the prototype was mainly tested from six aspects:driving signal,working mode,control accuracy,current ripple,response speed,and efficiency.The test results showed that the prototype could operate normally in four modes of constant current,constant power,constant resistance,and custom activation curve.Its input power could reach 60 kW with an efficiency of 93.74%,and it had the advantages of high control accuracy,low input current ripple,and fast response speed.