Propulsion system for an electric vehicle powered by fuel cells started using abattery

摘要

A motor vehicle propulsion system includes a fuel cell 10 and a traction motor 14 fed by inverter 16 coupled to the fuel cell 10 on a first bus 11. A second bus 24 of relatively lower voltage is connected to the first bus 11 via a bidirectional DC to DC converter 23 which allows the fuel cell 10 to supply energy to the second bus 24. The second bus contains a standard 12 volt vehicle battery 30, low voltage loads such as those present in the vehicle 26 and those required to operate the fuel cell 28. At start up the battery 30 is used to supply power via the converter 23 to an electrically driven compressor 18 which feeds reaction gas to the fuel cell 10 until it can supply enough power to maintain the operation of the compressor 18 itself. During regenerative braking of the motor 14 the power is returned to the battery 30 with a diode 12 to prevent reverse voltage at the fuel cell 10. Also if the motor 14 requires more power than is being supplied from the fuel cell 10 the battery 30 power can be utilised.