Online electrochemical impedance spectroscopy detecting system and method of fuel cell

Abstract

The invention relates to internal resistance detection of a fuel cell, specially an online electrochemical impedance spectroscopy detecting system and method of the fuel cell. The excitation source of the system is integrated in a Boost circuit, the excitation source is unnecessary to generate triangular waves in the whole process, the Boost circuit controls the fuel cell current to generate the current formed by superimposing direct current and slight triangular waves not influencing the work of the cell, after the work of the fuel cell is stabilized, Fourier analysis is carried out to the voltage and the current of the fuel cell; the internal resistance value of the fuel cell under every frequency is obtained, and the electrochemical impedance spectroscopy of the cell is obtained. With respect to the given triangular waves of the system, the triangular waves of three frequencies are given successively by a selection mode so as to be convenient in measurement; with respect to the control of the current, the current of the cell is controlled by prediction control; the whole system overcomes the defect of the design of the excitation source and the defect that the frequency scanning time of using sine waves is long.

Description

technical field [0001] The invention relates to the detection of internal resistance of a fuel cell, in particular to an online electrochemical impedance spectroscopy detection system and method for a fuel cell. Background technique [0002] Fuel cell, as a green and environmentally friendly new technology, is a research hotspot in the field of new energy today. Proton exchange membrane fuel cells have attracted much attention due to their advantages of cleanness, environmental protection, energy saving and high efficiency. Since the internal resistance can comprehensively reflect the internal humidity, temperature and health status of the fuel cell, monitoring the internal resistance of each single-chip fuel cell is the key to ensure the safe and efficient operation of the fuel cell. Therefore, the internal resistance is an important indicator to reflect the performance of the fuel cell. It is of great significance to design an online test system for the internal resistanc...

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Problems solved by technology

However, the general AC impedance method often needs to design an independent excitation source to generate a disturbance waveform applied to both ends of the fuel cell. During the test, it is necessary to change the frequency of the excitation source to scan from low to high frequency, and measure the internal resistance at each frequency. To obtain the impedance spectrum, the design of the excitation source is often difficult, and the scanning frequency of the frequency sweep method is more, and the test time is long, which increases the difficulty of the design of the internal resistance detection system

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