Patent ID: 7862943

Claim:
A method for starting a hybrid fuel cell system, said method comprising: providing a high voltage electrical bus; providing a fuel cell stack electrically coupled to the high voltage electrical bus; providing a high voltage DC power storage device electrically coupled to the high voltage electrical bus; providing a diode in the high voltage electrical bus that prevents voltage from the high voltage storage device from accessing the fuel cell stack; providing a by-pass line around the diode; providing a fuel cell stack switch between the fuel cell stack and the high voltage electrical bus; electrically coupling system loads to the high voltage electrical bus; electrically coupling a low voltage to high voltage boost converter to the high voltage electrical bus; closing a by-pass switch in the by-pass line so that electrical power from the high voltage DC storage device goes around the diode and is able to operate the system loads; starting the fuel cell stack using the system loads; determining if an output voltage of the fuel cell stack is stable; opening the by-pass switch if the fuel cell stack voltage is stable; and closing the fuel cell stack switch after the by-pass switch is opened.