Patent ID: 7862944
Filing Date: 2011-01-04
Classification: B60L,G01R,H01M,Y02E,Y02T

Abstract:
1. A system for detecting isolation faults, said system comprising: a fuel cell stack including a positive terminal and a negative terminal; a battery including a positive terminal and a negative terminal; a system bus including a positive rail electrically coupled to the positive terminals of the fuel cell stack and the battery and a negative rail electrically coupled to the negative terminals of the fuel cell stack and the battery, wherein system loads are electrically coupled in parallel to the positive rail and the negative rail; and a ground rail and a plurality of comparators, wherein a plurality of isolation resistances are defined in the system, and wherein the system measures a plurality of voltage potentials in the system relative to the isolation resistances and compares the measured voltage potentials to predetermined voltage potentials by one or more of the comparators to determine whether any of the isolation resistances have fallen below a predetermined minimum value where an output of one or more of the comparators identifies whether an isolation fault has occurred.