Gm Global Technolgoy Operations, Inc.

Matthew K Hortop

Abdullah Basar Alp

Bruce Jeffrey Clingerman

Matthew C Kirklin

Akbar Chowdhury

Derek S Kilmer

William S Wheat

William Henry Pettit

Balasubramanian Lakshmanan

John P Salvador

Manish Sinha

David S Mathews

David A Arthur

Pinkhas A Rapaport

Kengo Ikeya

Robert S Foley

Jason R Kolodziej

Clark G Hochgraf

Patricia J Nelson

David John Keyes

Kristian M Whitehouse

Ellen Greifenstein

Kazuyuki Izawa

Shyam Kocha

A fuel cell system is provided that includes a fuel cell stack and an air compressor in communication with a cathode inlet, a hydrogen source in communication with an anode inlet, and a start-up battery adapted to power the air compressor. The start-up battery is at least one of a low-voltage battery and a high-voltage battery. A pressure sensor is in communication with the air compressor and adapted to measure a compressor outlet pressure. A power conversion module is in electrical communication with the start-up battery and the air compressor. A controller is in communication with the power conversion module and adapted to set an air compressor speed based on an available electrical energy. A closed-loop method of operating the fuel cell system at start-up is also provided, wherein an anode purge is scheduled based on an air flow rate calculated from the compressor outlet pressure and the actual speed.

Closed-loop method for fuel cell system start-up with low voltage source

A fuel cell system is provided that includes a fuel cell stack and an air compressor in communication with a cathode inlet, a hydrogen source in communication with an anode inlet, and a start-up battery adapted to power the air compressor. The start-up battery is at least one of a low-voltage battery and a high-voltage battery. A power conversion module is in electrical communication with the start-up battery and the air compressor. The power conversion module is adapted to boost a voltage of the start-up battery as desired and power the air compressor at start-up. A controller is in communication with the power conversion module and is adapted to set an air compressor speed based on an available electrical energy. An open-loop method of operating the fuel cell system at start-up is also provided, wherein an anode purge is scheduled based on the available electrical energy from the battery.

Open-loop system and method for fuel cell stack start-up with low-voltage source

A fuel cell system that employs a method for determining the potential that a freeze condition will exist after the system is shut-down based on predetermined input, such as ambient temperature, geographical location, user usage profile, date, weather reports, etc. If the system determines that a freeze condition is probable, then the system initiates a purge shut-down of the fuel cell system where water is purged out of the reactant gas flow channels. If the system determines that a freeze condition is unlikely, then it will initiate a normal shut-down procedure without purging the flow channels. The system will then periodically determine if the conditions have changed, and will initiate the purge if a freeze condition subsequently becomes probable.

Fuel cell system water management strategy for freeze capability

A fuel cell system is provided that includes a fuel cell stack with a plurality of fuel cells and a power converter in electrical communication with the fuel cell stack. The power converter is configured to selectively regulate a power of the fuel cell stack and short circuit the fuel cell stack, as desired. A method for starting the fuel cell stack is also described, including the steps of causing a short circuit of the fuel cell stack by placing the power converter in a short circuit mode; introducing a hydrogen to the anodes of the fuel cell stack to displace a quantity of air on the anodes; and placing the power converter in a power regulation mode. A degradation of the fuel cell stack during start-up is thereby militated against.

System and method for shorting a fuel cell stack

A hybrid fuel cell system that employs a fuel cell stack and an ultracapacitor. A diode is provided on a high voltage electrical bus between the fuel cell stack and the ultracapacitor so that high voltage from the ultracapacitor does not affect the operation of the fuel cell stack. During system start-up, a by-pass switch is closed to by-pass the ultracapacitor so that power from the ultracapacitor can be used to start various system loads, such as a cathode side air compressor that provides air to the fuel cell stack. A 12 volt-to-high voltage converter is employed to provide a low power, high voltage supply from a low voltage battery to the system loads at start-up when the by-pass switch is opened, but before a fuel cell stack switch is closed.

Method and apparatus for starting a fuel cell engine in a vehicle equipped with an ultracapacitor

A system and method for providing dynamic cathode stoichiometry control in a fuel cell during stack load transients to minimize relative humidity excursions. Particularly, changes in the cathode stoichiometry is controlled as a function of time in response to a decrease or increase in stack current density. Thus, if the stack current density drops to a predetermined current density, the dynamic stoichiometry logic will monitor the low power condition and determine if the condition is sustained, i.e., for an extended period of time. If the low power condition is not sustained, then the cathode stoichiometry does not change, but if it is sustained, then the cathode stoichiometry is increased. The same delay in changing the cathode stoichiometry can be provided for a transition from a low power condition to a high power condition.

System and method for controlling cathode stoichiometry to minimize RH excursions during transients

A printed circuit board that enables electrical communication between a fuel cell stack and measuring electronics includes a substrate having first and second sides and a plurality of pad sets formed in the substrate. Each of the pad sets includes a plurality of conductive pads that enable electrical communication between the first and second sides and a plurality of fusable links that enable electrical communication between the conductive pads on the first side. Each of the pad sets aligns with a corresponding separator plate to enable electrical communication between the separator plate and the measuring electronics.

Method of establishing connections between measuring electronics and fuel cell stack

A fuel cell monitor connector electrically connects a fuel cell monitor to a fuel cell stack. The fuel cell monitor connector includes a non-conductive housing. First connectors on the housing align with second connectors located on fuel cell plates of the fuel cell stack. A third connector on the housing mates with a fourth connector coupled to the monitor. Conductors connect the first connectors to the third connector. A clamping device includes a lever and has locked and released positions. When the clamping device is in the locked position, the first connectors retain the second connectors. When the clamping device is in the released position, the first connectors release the second connectors. The clamping device is a zero insertion force connector.

Fuel cell monitor connector

A gas flow control system for a fuel cell includes a gas supply and a humidifier. A fuel cell stack includes a cathode flow line with an inlet and an outlet. The inlet of the cathode flow line is connected to the outlet of the humidifier. A combustor includes an inlet that receives gas from the outlet of the cathode flow line. A valve and a bypass line bypass gas around the humidifier and the fuel cell stack to the combustor. The valve is preferably one of a gas restriction valve, a throttle valve, and a directional valve. A gas flow sensor generates a gas flow signal based on gas flowing through at least one of the humidifier, the cathode flow line of the fuel cell stack, and the bypass line. A flow controller that is connected to the gas flow sensor and the valve controls the valve based on the gas flow signal.

Electronic by-pass of fuel cell cathode gas to combustor

A method and apparatus for detecting leakage current in the coolant of a fuel cell stack. The invention eliminates the use of a conductivity sensor by using a voltmeter to measure the voltage across the coolant. If the coolant voltage is at or below a predetermined level, an excessive level of conductivity in the coolant exists, and the presence of leakage current is reported. The invention can also compare the coolant voltage to two different predetermined voltage levels, the second one higher than the first. A coolant voltage at or below the lower voltage level could signal a shut down of the stack, while a coolant voltage at or below the higher voltage level could signal an alarm or another diagnostic. The invention can optionally use a second voltmeter to measure the voltage across the stack and calculate the resistivity and conductivity of the coolant.

Growing community of inventors

Rochester, NY, United States of America

Matthew K Hortop