Abstract
In the second report, a method for measuring the spatial distribution of the electric current generated in a PEFC from the frequency shift of the Nuclear Magnetic Resonance (NMR) signal of water acquired by eight planar surface coils inserted into the PEFC was described. In this paper, a newly-developed technique to calculate the current density distribution from the measured frequency shifts using inversion analysis is presented. In this technique, the PEFC is divided into eight elements, and the current which flows through the eight elements is searched so that the frequency shift calculated by magnetic field analysis and the frequency shift obtained by experiment come into agreement. In order to shorten the computation time consumed in this technique, an efficient algorithm was developed in which the current is searched by an iterative calculation using the equation between that relates the current and the spatial gradient of the frequency shift. The spatial distribution of the current density could be obtained using eight iterations of the inversion analysis algorithm.
