Research On EIS Frequency Secant Angle Methodology Of PEMFC About Status Diagnosis Method Of Water Management

Proton Exchange Membrane Fuel Cell?PEMFC?with zero pollution,zero noise and low operating temperature,has a bright prospect.However,in the real practice,unreasonable operation of PEMFC leads to water-fault condition of the reactor and variation of reactor resistance,resulting in significant effects on the output performance.So that this article explores PEMFC output performance diagnosis caused by variation of stack resistance,early warning and treatment methods under water-fault condition.Firstly,combined with the current domestic and international research status of PEMFCand investigated on the diagnosis of fuel cell output performance,Based on the equivalent model of the fuel cell,the internal resistance of the reactor is analyzed and the model of the impedance spectrum is obtained,and it is verified by the EIS experiment.Secondly,based on the operating conditions due to change of stack impedance changes,we propose a frequency EIS method based on the secant angle method,namely through two specific frequency calculation of fuel cell electrochemical impedance spectra and real axis angle size?Abbreviation as?Frequency Secant Methodology??,access the operating conditions change,the secant angle changes.At the same time,the simulation model of operation conditions and mechanism of stack resistance based on changing the operating conditions to obtain the optimal output performance of the frequency of secant angle.Lastly,the mechanism model of pile internal resistance and the operating conditions and the frequency of secant angle and stack resistance calculation formula is established.Secant angle?_t?current secant angle?corresponding to the model is calculated under present current density and known operating conditions.UnderCurrent density with the optimal output performance,?₀ measured?optimal secant angle?and compares to?_t to obtain frequency secant angle difference??.Based on analysis of regulation of??under water-fault conditions,the internal stack working condition can be judged,and the accuracy is verified by the experiment method.