Patent ID: 7972749
Filing Date: 2011-07-05
Classification: B60L,H01M,H02M,Y02E,Y02T

Abstract:
1. A fuel cell system comprising: a fuel cell stack, said fuel cell stack including a plurality of electrically coupled fuel cells separated by electrical plates, said electrical plates being bipolar plates where each bipolar plate includes an anode side and a cathode side for the anode and cathode of adjacent fuel cells, said fuel cell stack further including a negative tap electrically coupled at a negative end of the stack and a positive tap electrically coupled at a positive end of the stack, wherein a stack potential is provided across the positive tap and the negative tap from all the fuel cells in the stack; a plurality of intermediate taps each being electrically coupled to a different intermediate plate of the electrical plates in the fuel cell stack and providing different voltage potentials that are less than the stack potential, wherein one of the intermediate taps is designated a reference potential tap, and wherein the intermediate taps between the reference potential tap and the positive tap are positive intermediate taps and the intermediate taps between the reference tap and the negative tap are negative intermediate taps; and a switching network, said switching network selectively switching the intermediate taps to generate an AC signal.