Study On The Internal Resistance Detection System Of Fuel Cell Based On DC/DC Converter

As a new renewable and clean energy with the characteristics of high efficiency,energy conservation and environmental protection,fuel cell is a hot research topic in the field of energy in the world today.The impedance of fuel cell can reflect its internal humidity,temperature and the state of health,and the design of the real-time on-line detection system of fuel cell is the key to ensure its safe and efficient operation.In contrast to the traditional method of using an incentive source to applying a sine wave to the internal resistance,in this article,a new method and a new way of thinking will be used to modulate the DC/DC circuit,and then the ripple of the circuit will be introduced into the fuel cell as an incentive signal.In this paper,an online detection method for fuel cell internal resistance based on DC/DC circuit is designed.By using the equivalent internal resistance model of fuel cell,the ripple of DC/DC circuit is modulated,which is used as the excitation source signal will be introduced to fuel cell,so as to analyze the output signal of fuel cell and obtain its internal resistance parameters.In this paper,the concrete research content is as follows:The equivalent model of fuel cell will be analyzed,and the principle of internal resistance teste will be introduced.To analyze the characteristic curve of the selected internal resistance model,and how to analyze the internal resistance parameters from the characteristic curve.According to the theory of internal resistance test,a complete set of internal resistance detection scheme is designed by using the small value triangular wave instead of sine wave as the disturbance signal.In MATLAB,simulation circuit model and the parameters of fuel cell model will be designed,and the Nyquist characteristic of internal resistance will be analyzed.The parameter design on that main topology circuit will be carried out,a simulation platform will be designed in Simulink to carry out internal resistance detection by triangular wave,and analyze the result obtained by the analysis,and judge the feasibility of the test method based on the experimental result.Modeling and analysis of the system,and lays the theoretical foundation for the whole detection system by analyzing the feasibility of the scheme in theory.The influence of the triangular wave disturbance signal on the system will be analyaed,and selection principle of triangle wave will be introduced.The software for the control system will be designed,and the advantages of using triangular wave instead of sine wave will be introduced.The physical object detection platform will be built,and analyzing the data of the physical platform by FFT,then get the internal resistance result.At the same time,the results will be chosen,and the accuracy of the results should be ensured as far as possible.And according to the principle of nonlinear fit to curve fitting the result of the internal resistance,compare the internal resistance curve obtained by fitting to the simulation result,the cause of the error will be analyzed,and verify the guidance and feasibility of the test plan in the engineering application by using triangular wave instead of sinusoidal wave.