Patents Assigned to Ballard Power Systems
  • Patent number: 6969561
    Abstract: An electrochemical power generation system includes a fuel cell stack having an oxidant delivery system, an oxygen sensor for measuring the oxygen concentration of ambient air in the vicinity of the power generation system, and a hydrogen concentration sensor for measuring a hydrogen concentration in the ambient air in the vicinity of the power generation system. A controller is configured to cease operation of the power generation system, for example ceasing delivery of fuel to the fuel cell stack, when either the hydrogen concentration measured by the hydrogen concentration sensor exceeding a hydrogen concentration threshold or the oxygen concentration measured by the oxygen sensor falling below an oxygen concentration threshold.
    Type: Grant
    Filed: July 14, 2004
    Date of Patent: November 29, 2005
    Assignee: Ballard Power Systems Inc.
    Inventors: Jake de Vaal, Harvindra Deo
  • Patent number: 6969493
    Abstract: A process for generating a high-hydrogen, low-carbon monoxide gas comprises generating a product gas in a gas generating device. The product gas contains hydrogen and carbon monoxide that are generated from catalytic water vapor reforming of a water/fuel mixture and/or from partial oxidation of an oxygen/fuel mixture. In a gas purification stage, the carbon monoxide fraction in the product gas is reduced by selective CO oxidation on an oxidation catalyst. During a starting phase, oxygen is admixed to the supplied fuel and the flow direction is reversed such that the flow first takes place through the gas purification stage and only then through the gas generating device.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: November 29, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Martin Schuessler, Barbara Strobel, Detlef zur Megede
  • Publication number: 20050242157
    Abstract: A reactor structure has a heat transfer layer stacking construction with a stack of heat-conductive plate elements which, alternating in the stacking direction, bound one catalyst-filled reactor layer and one tempering layer respectively, adjacent plate elements being connected in a fluid-tight manner on at least two closed side areas. The plate elements on the closed side areas are bent in a U-shape and are arranged with U-side flanks which rest against one another in the stack such that the reactor layers have a larger height than the tempering layers. In addition or as an alternative, heat-conductive corrugated ribs are inserted at least in the reactor layers which are higher than the tempering layers.
    Type: Application
    Filed: July 12, 2005
    Publication date: November 3, 2005
    Applicant: BALLARD POWER SYSTEM AG
    Inventors: Uwe Benz, Horst Michels, Alois Tischler, Marc Weisser
  • Patent number: 6960401
    Abstract: A purge system for fuel cell stack includes a purge valve to regulate exhaust from the fuel cell stack in response control signals from a controller in response to a voltage across a purge cell portion of a fuel cell stack. The purge valve is opened when the voltage across the purge cell portion falls below a defined percentage of a threshold voltage. The threshold voltage can be equal to an average cell voltage of some or all of the fuel cells of the fuel cell stack. The purge may include one or more successive openings of the purge valve of controlled purge durations.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: November 1, 2005
    Assignee: Ballard Power Systems Inc.
    Inventors: Russell Howard Barton, Tan Duc Uong, Charles Joseph Schembri, George Alexander Skinner
  • Patent number: 6953630
    Abstract: A respective bipolar junction transistor is coupled across pairs of fuel cells in a fuel cell stack to monitor the voltage across each fuel cell pairs for a drop in voltage below a threshold voltage. A respective optoisolator coupled to each of the transistors produces a digital signal corresponding to the status of the respective pair of fuel cells. An “AND” circuit produces a single digital signal corresponding to the status of one or more pairs of fuel cells.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: October 11, 2005
    Assignee: Ballard Power Systems Inc.
    Inventor: Brian Wells
  • Patent number: 6953100
    Abstract: Regulation of energy supplied to an electric motor from an energy supply system including a fuel cell and an energy storage buffer such as a battery, improves the dynamic response of the motor by adding current from the energy storage buffer to the current from the fuel cell during acceleration.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: October 11, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Markus Aberle, Joachim Blum, Mathias Boehmisch, Thomas Schetter
  • Patent number: 6953561
    Abstract: A device for selective oxidation of a substance stream comprises a selectively active catalyst. For improving the cold-starting characteristics, the device also has an oxidation catalyst that possesses high activity at low temperatures. The selectively active catalyst is applied as a coating onto one or more surfaces of interior walls of the device. A layer of oxidation catalyst is provided in at least the inlet region where the substance stream enters the device, between the layer of selectively active catalyst and the interior walls of the device.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: October 11, 2005
    Assignee: Ballard Power Systems AG
    Inventor: Matthias Wolfsteiner
  • Patent number: 6949229
    Abstract: A device having a plurality of chambers for carrying out a solid-catalyzed reaction includes a common evaporation unit for evaporating liquid starting materials. The evaporation unit is in thermally conductive contact with a plurality of chambers. An area of the evaporation unit in which the evaporation substantially takes place is at least partially surrounded by the plurality of chambers.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: September 27, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Andreas Ebert, Oskar Lamla, Martin Schüssler, Tomas Stefanovski
  • Patent number: 6946212
    Abstract: An electrochemical fuel cell stack with improved reactant manifolding and sealing includes a pair of separator plates interposed between adjacent membrane electrode assemblies. Passageways fluidly interconnecting the anodes to a fuel manifold and interconnecting the cathodes to an oxidant manifold are formed between adjoining non-active surfaces of the pairs of separator plates. The passageways extend through one or more ports penetrating the thickness of one of the plates thereby fluidly connecting the manifold to the opposite active surface of that plate, and the contacted electrode. The non-active surfaces of adjoining separator plates in a fuel cell stack cooperate to provide passageways for directing both reactants from respective stack fuel and oxidant supply manifolds to the appropriate electrodes. The fuel and oxidant reactant streams passageways are fluidly isolated from each other, although they both traverse adjoining non-active surfaces of the same pair of plates.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: September 20, 2005
    Assignee: Ballard Power Systems Inc.
    Inventors: Joel A. Ronne, Boguslaw M. Wozniczka, Clarence Y. Chow, Henry H. Voss
  • Patent number: 6942938
    Abstract: A system is used for cooling a fuel cell arrangement, particularly a fuel cell arrangement with a gas generating system in a motor vehicle. A coolant circuit for the system is connected to a cooler, a coolant delivery device, a fuel cell and at least another component to be cooled. The coolant circuit has at least two valve devices which are each assigned to the fuel cell and the at least another component to be cooled. By means of the valve devices, a flow rate of the coolant through the fuel cell or the another component to be cooled can be influenced as a function of the temperature in the region associated with the fuel cell or the another component.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: September 13, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Monika Derflinger, Isabel Haas, Hans-Frieder Walz
  • Patent number: 6940735
    Abstract: A power converter system advantageously employs a modular, bi-directionally symmetrical power converter assembly in a readily customizable configuration to interconnect a direct current power source to a three-phase alternating power grid. Connections external to the power converter assembly are selected to optimize the power converter system for a specific application, such as interconnecting a photovoltaic array to the three-phase electrical power grid. The electrical interconnections of various elements including isolation transformers, voltage sensors, and control switches are optimized to improve efficiency and reliability.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: September 6, 2005
    Assignee: Ballard Power Systems Corporation
    Inventors: Duo Deng, Vijay Bhavaraju
  • Patent number: 6936370
    Abstract: In a solid polymer fuel cell series, various circumstances can result in the fuel cell being driven into voltage reversal. For instance, cell voltage reversal can occur if that cell receives an inadequate supply of fuel (for example, fuel starvation). In order to pass current during fuel starvation, reactions other than fuel oxidation may take place at the fuel cell anode, including water electrolysis and oxidation of anode components. The latter may result in significant degradation of the anode. Such fuel cells can be made more tolerant to cell reversal by promoting water electrolysis over anode component oxidation at the anode. This can be accomplished by incorporating a catalyst composition at the anode to promote the water electrolysis reaction, in addition to the typical anode electrocatalyst for promoting fuel oxidation.
    Type: Grant
    Filed: August 22, 2000
    Date of Patent: August 30, 2005
    Assignees: Ballard Power Systems Inc., Johnson Matthey Public Limited Company
    Inventors: Shanna D. Knights, David P. Wilkinson, Stephen A. Campbell, Jared L. Taylor, John M. Gascoyne, Thomas R. Ralph
  • Patent number: 6937483
    Abstract: A device and method of commutation control for an isolated boost converter provides a unique commutation logic to limit voltage spikes by utilizing switches on the secondary side to minimize a mismatch between current in the inductor and current in the leakage inductance of the transformer when commutation takes places. To minimize this mismatch, the current in the leakage inductance is preset at a certain level that approaches the current in the inductor prior to the commutation, thus significantly reducing the power rating for a clamp circuit and enabling use of a simple passive clamp circuit. In addition, through unique timing of the turn-on of the secondary switches, soft switching conditions are created that eliminate turn-on losses and the reverse recovery problems of free-wheeling diodes.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: August 30, 2005
    Assignee: Ballard Power Systems Corporation
    Inventors: Lizhi Zhu, Xingyi Xu
  • Patent number: 6936991
    Abstract: A closed-loop permanent magnet motor control method and system optimally partitions torque and flux-weakening currents to produce a desired torque without exceeding the capability of the DC source. A maximum limit for allowable torque current and a minimum threshold for the maximum torque current are determined, and the flux current is varied based at least in part on whether the maximum torque current limit is above or below the minimum threshold while operating in a flux-weakening region to compensate for the variability of the DC source voltage.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: August 30, 2005
    Assignee: Ballard Power Systems Corporation
    Inventors: Li Chen, Roy I. Davis, Stephen Stella, Tod R. Tesch
  • Publication number: 20050187101
    Abstract: A device for the catalytic generation of hydrogen from hydrocarbons includes a catalytic converter having feed and distribution channels for starting materials and discharge and collection manifolds for products. The feed and distribution channels and the discharge and collection manifolds are formed from a plurality of identically structured channels. Inlet channels for supplying and distributing starting materials and outlet channels for collecting and discharging products are defined by, in each case, inversely arranged closed and open channel ends. The inlet and outlet channels extend substantially across the entire catalytic converter and are provided in an alternately intermeshing arrangement.
    Type: Application
    Filed: April 15, 2005
    Publication date: August 25, 2005
    Applicant: Ballard Power Systems AG
    Inventors: Joanna Bass, Roland Cwik, Tomas Stefanovski
  • Patent number: 6932949
    Abstract: A reactor structure has a heat transfer layer stacking construction with a stack of heat-conductive plate elements which, alternating in the stacking direction, bound one catalyst-filled reactor layer and one tempering layer respectively, adjacent plate elements being connected in a fluid-tight manner on at least two closed side areas. The plate elements on the closed side areas are bent in a U-shape and are arranged with U-side flanks which rest against one another in the stack such that the reactor layers have a larger height than the tempering layers. In addition or as an alternative, heat-conductive corrugated ribs are inserted at least in the reactor layers which are higher than the tempering layers.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: August 23, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Uwe Benz, Horst Michels, Alois Tischler, Marc Weisser
  • Patent number: 6932282
    Abstract: Apparatus for supplying water to a plurality of individually controllable water injectors, has a pump adapted to provide water under pressure to the water injectors. Each water injector has associated therewith a respective controllable solenoid valve to control the amount of water supplied to the water injector, in dependence upon a pulse modulated control signal supplied to the valve.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: August 23, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Gregory Herd, Michael Schroepel
  • Patent number: 6932948
    Abstract: A device for the catalytic generation of hydrogen from hydrocarbons includes a catalytic converter having feed and distribution channels for starting materials and discharge and collection manifolds for products. The feed and distribution channels and the discharge and collection manifolds are formed from a plurality of identically structured channels. Inlet channels for supplying and distributing starting materials and outlet channels for collecting and discharging products are defined by, in each case, inversely arranged closed and open channel ends. The inlet and outlet channels extend substantially across the entire catalytic converter and are provided in an alternately intermeshing arrangement.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: August 23, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Joanna Bass, Roland Cwik, Tomas Stefanovski
  • Patent number: 6926987
    Abstract: A fuel cell system and associated method allows for continuous operation of the fuel cell system with fuel recirculation, without the necessity for periodic purging. A portion of the anode exhaust is not recirculated but is continuously bled from the anode exhaust line. Preferably, less than 5% by volume of the anode exhaust is allowed to bleed continuously from the anode exhaust. The bleed line may be connected to a catalytic reactor which combusts the unused fuel. The cathode exhaust may be used as the oxidant for the catalytic reactor. The flow of exhaust to the catalytic reactor may be controlled to ensure that the concentration of hydrogen in the catalytic reactor is no higher than 50% of the lower limit of inflammability for hydrogen.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: August 9, 2005
    Assignee: Ballard Power Systems AG
    Inventors: Janusz Blaszczyk, Wolfram Fleck
  • Patent number: 6927988
    Abstract: A method for diagnosing faults using a load. In the method IGBTs are controlled such that certain currents are expected. If the currents are not as expected, a fault may be diagnosed.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: August 9, 2005
    Assignee: Ballard Power Systems Corporation
    Inventors: Bing Cheng, Kent M. Harmon