Battery Current Distribution Detection Method Based On The Finite Element Analysis And Research

In recent years, proton exchange membrane fuel cell (PEMFC) has been appliedas a new energy in many aspects, mostly as the main power source for fuel cell electricvehicles. As a power source, to ensure its stability during operation is extremelyimportant. Due to its own factors and impacts of various aspects like fuel supply and soon, there would be a variety of non-normal conditions, the most significant result is thatit could lead to uneven current density distribution of the fuel cell. To improve thissituation, the inner current distribution of the fuel cell need to be monitored in order toadjust its targeted operating state to make the fuel cell system running in its top workingcondition. Until now, scholars in this area has already got some achievements, but mostof the detection means still limited to contact measurement. To solve this problem, thispaper proposed a new method for non-contact monitoring of battery internal currentdistribution. The main contents and results are as follows:This paper described the working principle of PEMFC and analyzed its modelingstatus, then established its corresponding magnetic field model and mechanism model,simulated and analyzed the mechanism model of KW-level stack with MATLAB/SIMULINK software, the results showed that the KW-level stack model controlledwith PID responded fast, and its anti-interference ability is relatively good, this modelbasically meets the modeling requirements of the stack. At the same time this papersimulated and analyzed the relationship between current and voltage of the PEMFCusing the hardware platform based on this model, the results meet the requirements.To the established PEMFC single cell model of the magnetic field, this papersimulated its external magnetic field distribution with ANSOFT MAXWELL2Dsoftware. The simulation of the model cases including local hypoxia of the sub-units form the edge to the center, and normal operation circumstances of the PEMFC,thenthis paper analyzed each case simulated above. The simulation results showed that,the distribution of the PEMFC’s external magnetic field distribution is closely related toits internal current distribution, and its internal current distribution could be basicallyreflected by the strength and shape of the external magnetic field distribution. After thatthis paper presented the estimation algorithm that calculates the internal currentdistribution of the fuel cell using its external magnetic induction value, and achieved itwith the MATLAB software. Then calculated and verified each of the simulation casesmentioned above using the algorithm, and analyzed the calculation results individually.The results showed that the algorithm for calculating the current distribution inside thePEMFC has a certain referential. When the hypoxia zone is located in the fuel cell’sedge Bureau, the calculation results in an acceptable range of error; when the hypoxiazone is moving to the center of the fuel cell, the error is increasing but the results stillhave some informative. At the same time it is capable to infer the location of thehypoxia zone by the external magnetic field distribution of the fuel cell.Using existed laboratory equipment verified two cases involving PEMFC internalcurrent uniform and51sub-unit of the local low current density by experiments andanalysis, the results showed that the experimental results can be dependent, and theerror mainly from detection means and devices.At last this paper designed an interactive interface of the internal currentdistribution monitoring system using ECLIPSE web development platform, inputmethods included manual input and files parameter values extraction. Display methodusing a spreadsheet and graphics to be more intuitive and more clearly observe theresults. After testing, the system could satisfy the demand.