Abstract: A fuel cell system and a method of operating same are provided. The fuel cell system includes a fuel cell for driving a load, at least one fuel cell peripheral, a device for measuring at least one fuel cell operation characteristic, and at least one controller for controlling the operation of at least one fuel cell peripheral based on the at least one fuel cell operation characteristic. The fuel cell operation characteristic is divided into at least two ranges, and operation of at least one fuel cell is controlled to provide it with a respective operational characteristic for each range of operation of the fuel cell system.

Abstract: The present invention relates to a fuel cell system and a method of operating same, The fuel cell has a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet. The invention involves (a) providing a first reactant incoming stream to the first reactant inlet; (b) providing a second reactant incoming stream to the second reactant inlet; (c) monitoring a fuel cell state variable indicative of flooding; (d) based on the fuel cell state variable, determining whether the fuel cell is flooded; and, (e) providing an additional amount of the first reactant to the fuel cell when the fuel cell is flooded.

Abstract: When a conventional fuel cell module is shutdown the conditions within the fuel cell stack change. The conditions change because elements that support and regulate the operation of the fuel cell stack switch to their respective shutdown states. For example, the input and output valves are closed, which cuts off the supply inflows and exhaust outflows. Moreover, when an element such as a flow control device switches to a shutdown state internal conditions, such as for example, the pressure within the anode electrodes change. When the internal conditions of the fuel cell stack change the reactants (e.g. hydrogen and oxygen) remaining in the fuel cell stack and the feed lines (between the fuel cell stack and the closed valves) are substantially consumed in combustion reactions as opposed to being consumed in electrochemical reactions yielding a useful form of energy.

Abstract: A system and method for monitoring cell voltages for a plurality of electrochemical cells connected in series forming a cell stack. The method includes dividing the cells into at least two cell groups, measuring the voltage across each cell group and estimating the minimum cell voltage for each group based on the average cell stack voltage and an estimated number of deficient cells in each group. The lowest minimum cell voltage for the entire cell stack is then determined.

Abstract: Aspects of the invention relate to a test station for a fuel cell power module (FCPM). The fuel cell power module has at least one fuel cell therein and a FCPM controller. The test station includes a test controller arranged to communicate with the FCPM controller to determine performance of the FCPM under a simulated load. The test station and FCPM may be arranged in various combinations and configurations for testing one or more FCPM's.

Abstract: A fuel cell system has: a fuel cell having a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet, and optionally a coolant inlet and coolant outlet. A first reactant supply subsystem supplies a first reactant incoming stream to the first reactant inlet of the fuel cell. A second reactant supply subsystem supplies a second reactant incoming stream to the second reactant inlet of the fuel cell. A first reactant recirculation subsystem recirculates at least a portion of the first reactant exhaust stream from the first reactant outlet to an enthalpy shifting subsystem in which one portion of the heat and moisture in first reactant exhaust stream is transferred to one of the first reactant incoming stream in the first reactant supply subsystem and the second reactant incoming stream in the second reactant supply subsystem. Another portion of the heat and moisture is transferred to the other stream.

Abstract: A system and method used to regulate the operation of fuel cell systems. In one embodiment, a fuel cell system comprises a fuel cell stack, the fuel cell stack comprising at least one fuel cell and electric outputs for driving a load; a balance of plant system for supplying and withdrawing process fluids to and from the fuel cell stack; and a controller that controls the operation of the fuel cell stack and the balance of plant system by measuring and setting process parameters; where the controller comprises a storage device adapted to, for at least one of the process parameters, store at least one baseline table of set values of the process parameter and to optionally store at least one correction table of correction values of the process parameter. Correction values are stored in real-time as changes are made to the process parameter during the operation of the fuel cell stack.

Abstract: A fuel cell power system has a plurality of fuel cell power modules, each module including a fuel cell and associated peripheral devices. Each fuel cell power module is controlled by its own local controller. A master controller controls each of the local controllers in accordance with overall system requirements. Optionally, a bypass allows the master controller to shut down and bypass a particular fuel cell power module, providing this system with greater flexibility, robustness and reliability. The modular system architecture also simplifies manufacturing, maintenance and repair.

Abstract: The present invention relates to a fuel cell system for producing electrical power and a method of operating same. The fuel cell has a first reactant inlet, a first reactant outlet, a second reactant inlet, and a second reactant outlet. The invention involves (a) providing a first reactant incoming stream to the first reactant inlet at a first reactant supply rate; (b) providing a second reactant incoming stream to the second reactant inlet at a second reactant supply rate; (c) conditioning at least one of the first reactant incoming stream and the second reactant incoming stream to a selected conditioning level; and, (d) selectably and temporarily reducing the selected conditioning level to increase at least one of the first reactant supply rate and the second reactant supply rate.

Abstract: The present invention relates to a fuel cell system and a method of operating same, The fuel cell has a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet. The invention involves (a) providing a first reactant incoming stream to the first reactant inlet; (b) providing a second reactant incoming stream to the second reactant inlet; (c) monitoring a fuel cell state variable indicative of flooding; (d) based on the fuel cell state variable, determining whether the fuel cell is flooded; and, (e) providing an additional amount of the first reactant to the fuel cell when the fuel cell is flooded.

Abstract: A system and method for monitoring cell voltages for a plurality of electrochemical cells connected in series forming a cell stack. The method includes dividing the cells into at least two cell groups, measuring the voltage across each cell group and estimating the minimum cell voltage for each group based on the average cell stack voltage and an estimated number of deficient cells in each group. The lowest minimum cell voltage for the entire cell stack is then determined.

Abstract: A fuel cell system and a method of operating same are provided. The fuel cell system includes a fuel cell for driving a load, at least one fuel cell peripheral, a device for measuring at least one fuel cell operation characteristic, and at least one controller for controlling the operation of at least one fuel cell peripheral based on the at least one fuel cell operation characteristic. The fuel cell operation characteristic is divided into at least two ranges, and operation of at least one fuel cell is controlled to provide it with a respective operational characteristic for each range of operation of the fuel cell system.

Abstract: A fuel cell system, comprising: a fuel cell for producing electrical energy; a load driven by the fuel cell; a first reactant supply line for supplying a first reactant to the fuel cell; a second reactant supply line for supplying a second reactant to the fuel cell; a first reactant buffer for storing first reactant and supplying an additional amount of first reactant to the fuel cell in response to an increase in a measured characteristic; a first flow regulating device that regulating the amount of the first reactant supplied from the first reactant buffer to the fuel cell; and a controller for controlling the first flow regulating device in response to the measured characteristic.

Abstract: A method and apparatus are provided for delivery and regulation of a process fluid to a multi-cell electrochemical device. A controller regulates the process fluid flow, after at least one of the process parameters indicates a drop in load current draw, based on the operating rate of the fuel cell and the rate of decrease in the load.

Abstract: A fuel cell system and a method of operating same. The fuel cell system comprises a fuel cell for driving a load, a first process delivery device for supplying a first process fluid to the fuel cell, and a controller for controlling an operation rate of the first process fluid delivery device based on an overriding signal received from a signal source external to the controller and the fuel cell.

Abstract: A method and apparatus are provided for delivery and regulation of process fluid flow of a multi-cell electrochemical device. A controller regulates the process fluid flow using pre-determined setpoints stored in the controller until at least one of the process parameters has reached a pre-determined value when the controller is switched to the open loop control mode, and the controller regulates the process fluid flow using at least one of the process parameter signals when the controller is switched to the closed loop control mode.

Abstract: A fuel cell system has: a fuel cell having a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet, and optionally a coolant inlet and coolant outlet. A first reactant supply subsystem supplies a first reactant incoming stream to the first reactant inlet of the fuel cell. A second reactant supply subsystem supplies a second reactant incoming stream to the second reactant inlet of the fuel cell. A first reactant recirculation subsystem recirculates at least a portion of the first reactant exhaust stream from the first reactant outlet to a regenerative dryer subsystem in which one portion of the heat and moisture in first reactant exhaust stream is transferred to one of the first reactant incoming stream in the first reactant supply subsystem and the second reactant incoming stream in the second reactant supply subsystem. Another portion of the heat and moisture is transferred to the other stream.

Abstract: A fuel cell system has: a fuel cell having a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet, and optionally a coolant inlet and coolant outlet. A first reactant supply subsystem supplies a first reactant incoming stream to the first reactant inlet of the fuel cell. A second reactant supply subsystem supplies a second reactant incoming stream to the second reactant inlet of the fuel cell. A first reactant recirculation subsystem recirculates at least a portion of the first reactant exhaust stream from the first reactant outlet to an enthalpy shifting subsystem in which one portion of the heat and moisture in first reactant exhaust stream is transferred to one of the first reactant incoming stream in the first reactant supply subsystem and the second reactant incoming stream in the second reactant supply subsystem. Another portion of the heat and moisture is transferred to the other stream.