Patent ID: 8268495
Filing Date: 2012-09-18
Classification: H01M,Y02E,Y02T

Abstract:
1. A fuel cell system, comprising: a DC/DC converter for increasing and lowering an output voltage of a fuel cell stack formed by laminating a plurality of cells; a controller programmed to drive the DC/DC converter to apply an AC signal to the fuel cell stack; and a detector for detecting a response voltage of the cell upon applying the AC signal to the fuel cell stack, wherein the controller is programmed to measure AC impedance of the cell from the detected response voltage of the cell upon applying the AC signal to the fuel cell stack when the DC/DC converter operates outside of a lowered response capability region, and wherein the controller is programmed to inhibit measurement of the AC impedance of the cell when the DC/DC converter operates inside of the lowered response capability region, and wherein the lowered response capability region corresponds to an operating region of the DC/DC converter where a dead time compensation value varies greatly as a function of power passing through the DC/DC converter.