Patent ID: 8277993
Filing Date: 2012-10-02
Classification: H01M,Y02E,Y02T

Abstract:
1. A fuel cell system comprising: a fuel cell that generates electric power through an electrochemical reaction between a fuel gas and an oxidant gas; an insulation resistance measurement unit that measures an insulation resistance between the fuel cell and an outer conductor; and a control unit programmed to control a power generation state of the fuel cell, wherein the control unit is programmed to carry out a high-potential prevention control that avoids a voltage of the fuel cell becoming equal to or higher than a predetermined high-potential prevention voltage threshold lower than an open circuit voltage of the fuel cell, and to change the high-potential prevention voltage threshold during an insulation resistance detection performed by the insulation resistance measurement unit; and the control unit is programmed to perform a voltage maintenance oxidant-gas blowing operation in which an oxidant gas is supplied to the fuel cell when the voltage of the fuel cell decreases to a predetermined lower-limit voltage threshold lower than the high-potential prevention voltage threshold during the high-potential prevention control, and to change the high-potential prevention voltage threshold such that an interval between voltage maintenance oxidant-gas blowing operations is longer than an insulation resistance detectable time during the insulation resistance detection.