AC impedance measurement method for a fuel cell system

摘要

An AC impedance measurement method for a fuel cell system equipped with a fuel cell and a battery device connected so that the battery device can be charged with output power from the fuel cell, the method comprising the steps of: applying (S1) a predetermined AC signal an output voltage of the fuel cell; Detecting (S2) an output voltage value of the battery device, the output voltage value varying as the output power value of the fuel cell over which the AC signal has been applied varies; Comparing (S3) the detected output voltage value of the battery device with a predetermined threshold voltage; and determining (S4) whether or not the measurement of the AC impedance is permitted depending on whether the output voltage value of the battery device exceeds the threshold voltage or not, and it is determined that the measurement of the AC impedance is not allowed if the output voltage value of the battery device is at or below a threshold voltage lower limit, and ...