Abstract
The development of fuel cell hybrid vehicles (FCHV) started in 1990s and they are currently being improved to resolve the issues for commercialization. This research focused on one of the main issues of a fuel cell (FC), namely the water content of the electrolyte membrane, to develop an FC water content control system based on the measurement of AC impedance. Adopting this control system in an actual FCHV resolved the issue of reduced efficiency caused by the membrane drying up, and it became possible to start up the FCHV in temperatures of -30°C by performing the appropriate water content control for freezing environments.
