Patent ID: 9331350
Filing Date: 2016-05-03
CPC Classification: F04C,F04D,H01M,H02H,Y02E,Y02P

Claim Text:
1. A fuel cell system comprising: a fuel cell stack; a compressor providing cathode air flow to a cathode side of the fuel cell stack, said compressor including a stator, a rotor shaft and a displacement sensor, said displacement sensor being positioned proximate the rotor shaft and providing a frequency signal indicative of the balance of the rotor shaft; and an analog electrical circuit for determining whether the rotor shaft is unbalanced, said analog electrical circuit including a first filter that filters the frequency signal to remove unwanted frequencies and a second filter that converts the filtered frequency signal to a DC signal whose amplitude is an indication of the balance of the rotor shaft, wherein a controller of the analog electrical circuit is programmed to compare the amplitude of the DC signal to at least one threshold to determine whether the rotor shaft is unbalanced, and is programmed to cause a system shut-down, a performance reduction, or a combination thereof if the amplitude of the DC signal is greater than the at least one threshold.