Abstract: A computer-implemented method when executed by data processing hardware causes the data processing hardware to perform operations. The operations include estimating, via an adaptive algorithm, a balance of plant (BoP) power loss of a BoP of a fuel cell system (FCS), receiving, at the adaptive algorithm, an application power request, and executing, via the adaptive algorithm, a BoP degradation computation. The operations also include learning, via a plurality of sensors, a BoP loss error in the estimated BoP power loss based on a comparison with the BoP degradation computation, applying, based on the learned BoP loss error, an adaptation factor to the BoP degradation computation, and generating, via the adaptive algorithm, a stack power request based on the application power request and the estimated BoP power loss.

Abstract: A method of controlling a hydrogen fuel cell includes, with a controller of the fuel cell, measuring an anode leak rate for the fuel cell, modelling, using the measured anode leak rate, an effective electrolyte membrane orifice size, calculating, using the effective electrolyte membrane orifice size, an effective runtime anode leak rate during operation of the fuel cell, using the effective runtime anode leak rate as a low-side metric when calculating emissions and dilution requests, and initiating adaptations of a control strategy of the fuel cell based on the effective runtime anode leak rate and shutdown leak rate to extend the lifetime of the fuel cell.

Abstract: A method of controlling selective purging of reacted fuel gas at the anode of a hydrogen fuel cell includes initiating a selective purging of reacted fuel gas, initiating air flow through the fuel cell necessary to dilute a concentration of hydrogen present within the reacted fuel gas exhausted from the fuel cell, and opening an anode valve adapted to allow reacted fuel gas within the anode to vent from the fuel cell after the air flow through the fuel cell reaches an estimated required air flow rate necessary to dilute the level of hydrogen present within the reacted fuel gas exhausted from the fuel cell.

Abstract: A hybrid system including a high-voltage bus, a high-voltage battery electrically connected to the high-voltage bus, a fuel cell power device electrically connected to the high-voltage bus, and a drive unit electrically connected to the high-voltage bus. A controller is electrically connected to the drive unit, the fuel cell power device, and the high-voltage battery. The controller is configured to identify an application power request for the drive unit and determine a relationship between the application power request and an optimal membrane life power for the fuel cell power device. The controller is also configured to direct the fuel cell power device to operate between the optimal membrane life power and a second power. The application power request is at a power level between the optimal membrane life power and the second power.

Abstract: The present disclosure concerns using microstructural engineering techniques to remove or reduce impurity elements from molten aluminum alloys, such as scrap. The impurities are removed by cooling molten aluminum, resulting in the formation of impurity-rich intermetallic compounds containing only one or more impurity elements as solid inclusions. Subsequent removal of impurity-rich intermetallic sediments by decantation, centrifuge, and filtration techniques can provide an economical method for removing the desired amount of impurities to meet the product specifications.

Abstract: The present disclosure provides a method for stacking a plurality of optical fibre ribbons in an optical fibre cable. The method includes a step of arranging a plurality of optical fibre ribbon stacks in a hexagonal arrangement in the optical fibre cable. The method may further include stacking the plurality of optical fibre ribbons to form an optical fibre ribbon stack such that the optical fibre ribbon stack may have a parallelogram shape. Each optical fibre ribbon is placed at an offset from adjacent optical fibre ribbon. The optical fibre ribbon stack may have a stack height. In addition, each optical fibre ribbon of the plurality of optical fibre ribbons may have a ribbon height. The hexagonal arrangement may have the packaging density greater than 80%.

Abstract: Presented are intelligent fuel cell systems (FCS) with logic for evacuating water from anode headers of a fuel cell stack, methods for making/using such systems, and vehicles equipped with such systems. A method of operating an FCS includes a system controller confirming the FCS is running and, once confirmed, receiving a bleed request to remove exhaust gas from exhaust output by the anode. Responsive to the bleed request, the controller determines a total bleed valve use (TBVU) indicating prior bleed requests completed by an anode bleed valve, and thereafter determines if the TBVU is less than a maximum bleed valve use (MBVU). If so, the controller responsively commands the bleed valve to bleed the exhaust gas from the anode exhaust. If TBVU is not less than MBVU, the controller commands a header drain valve to bleed the exhaust gas from the anode exhaust and drain water from the anode header.

Abstract: A method for controlling a fuel cell system having a hydrogen fuel injector/ejector and a control system, includes determining a hydrogen fuel consumption rate associated with a selected power level at steady state, determining a modeled hydrogen fuel flow rate associated with the selected power level and the injector/ejector, determining a modeled effective flow area associated with the injector/ejector, determining a true effective flow area of the injector/ejector, and using the effective flow area to calculate or adjust a command signal, an estimation or an estimation error of at least one of a hydrogen fuel flow rate, an anode leak rate and an anode exhaust valve flow rate.

Abstract: A system for controlling purge operation of a fuel cell assembly includes a controller and one or more sensors configured to obtain respective sensor data. The fuel cell stack is configured to receive a stack coolant. The controller is configured to execute a first purge mode when at least one of a first enabling condition and a second enabling condition is met. The first purge mode defines a first group of setpoints, including a relatively low cathode stoichiometric ratio. The controller is configured to switch to a second purge mode when the coolant temperature is above a minimum warm-up temperature and a third mode when a relative humidity value of a stack cathode output falls below a threshold humidity. The second purge mode defines a second group of setpoints, including a relatively high cathode stoichiometric ratio.

Abstract: A method for controlling a fuel cell system having a hydrogen fuel injector/ejector and a control system, includes determining a hydrogen fuel consumption rate associated with a selected power level at steady state, determining a modeled hydrogen fuel flow rate associated with the selected power level and the injector/ejector, determining a modeled effective flow area associated with the injector/ejector, determining a true effective flow area of the injector/ejector, and using the effective flow area to calculate or adjust a command signal, an estimation or an estimation error of at least one of a hydrogen fuel flow rate, an anode leak rate and an anode exhaust valve flow rate.

Abstract: A system for controlling purge operation of a fuel cell assembly includes a controller and one or more sensors configured to obtain respective sensor data. The fuel cell stack is configured to receive a stack coolant. The controller is configured to execute a first purge mode when at least one of a first enabling condition and a second enabling condition is met. The first purge mode defines a first group of setpoints, including a relatively low cathode stoichiometric ratio. The controller is configured to switch to a second purge mode when the coolant temperature is above a minimum warm-up temperature and a third mode when a relative humidity value of a stack cathode output falls below a threshold humidity. The second purge mode defines a second group of setpoints, including a relatively high cathode stoichiometric ratio.

Abstract: The present disclosure provides a method for stacking a plurality of optical fibre ribbons in an optical fibre cable. The method includes a step of arranging a plurality of optical fibre ribbon stacks in a hexagonal arrangement in the optical fibre cable. The method may further include stacking the plurality of optical fibre ribbons to form an optical fibre ribbon stack such that the optical fibre ribbon stack may have a parallelogram shape. Each optical fibre ribbon is placed at an offset from adjacent optical fibre ribbon. The optical fibre ribbon stack may have a stack height. In addition, each optical fibre ribbon of the plurality of optical fibre ribbons may have a ribbon height. The hexagonal arrangement may have the packaging density greater than 80%.

Abstract: A method of operating a fuel cell stack is described. The fuel cell stack includes a cathode, an anode, a sump configured for collecting water from the anode, and a temporarily disabled drain valve that is otherwise configured to transition from a first position to a second position and thereby modulate water drained from the sump. The method includes increasing a first pressure in the anode via a controller. The method also includes, concurrent to increasing, decreasing a second pressure in the cathode via the controller and, concurrent to decreasing, maintaining a relative humidity of less than a threshold relative humidity in the cathode via the controller.

Abstract: A fuel cell reversal event is diagnosed by integrating current density via a controller in response to determine an accumulated charge density. The controller executes a control action when the accumulated charge density exceeds a threshold, including recording a diagnostic code indicative of event severity. The control action may include continuing stack operation at reduced power capability when the accumulated charge density exceeds a first threshold and shutting off the stack when the accumulated charge density exceeds a higher second threshold. The event may be detected by calculating a voltage difference between an average and a minimum cell voltage, and then determining if the difference exceeds a voltage difference threshold. The charge density thresholds may be adjusted based on age, state of health, and/or temperature of the fuel cell or stack. A fuel cell system includes the stack and controller.

Abstract: An anode system is arranged to supply pressurized hydrogen to the anode of a fuel cell, and includes a multi-injector system. A controller is executable to monitor, via a pressure sensor, pressure in the anode system and command actuations of the plurality of hydrogen injectors. The controller may detect a fault in the multi-injector system when the commanded actuations of the plurality of hydrogen injectors are greater than a first threshold and the pressure in the anode system cell is less than a second threshold. The controller may execute alternating actuation of the hydrogen injectors of the multi-injector system and monitor the pressure in the anode system to detect a fault in one of the hydrogen injectors based upon the pressure in the anode system.

Abstract: A method of operating a fuel cell stack is described. The fuel cell stack includes a cathode, an anode, and a temporarily disabled bleed valve that is otherwise configured to transition from a first position to a second position and thereby modulate nitrogen drained from the anode. The method includes increasing a first pressure in the anode via a controller and, concurrent to increasing, decreasing a second pressure in the cathode via the controller. A system and a device including the fuel cell stack are also described.

Abstract: A method of operating a fuel cell stack is described. The fuel cell stack includes a cathode, an anode, and a temporarily disabled bleed valve that is otherwise configured to transition from a first position to a second position and thereby modulate nitrogen drained from the anode. The method includes increasing a first pressure in the anode via a controller and, concurrent to increasing, decreasing a second pressure in the cathode via the controller. A system and a device including the fuel cell stack are also described.

Abstract: A method of operating a fuel cell stack is described. The fuel cell stack includes a cathode, an anode, a sump configured for collecting water from the anode, and a temporarily disabled drain valve that is otherwise configured to transition from a first position to a second position and thereby modulate water drained from the sump. The method includes increasing a first pressure in the anode via a controller. The method also includes, concurrent to increasing, decreasing a second pressure in the cathode via the controller and, concurrent to decreasing, maintaining a relative humidity of less than a threshold relative humidity in the cathode via the controller.

Abstract: A fuel cell stack, a method of operating a fuel cell stack and a fuel cell system. In one particular form, shutting down the stack upon detection of a leakage of fuel either within the stack or from the stack involves depressurizing and uniform consumption of hydrogen by catalytic consumption in the cathode of all cells. Upon consumption of oxygen in the cathode portion of the stack by chemical reaction, the remaining unreacted nitrogen from the air acts as an inerting fluid. After an indication of reaction cessation is established, at least some of the inerting fluid is conveyed from the cathode portion to the anode portion. One or more of a bleed valve, backpressure valve and bypass valve are manipulated to promote the anode portion depressurization, cathode portion inerting and subsequent conveyance of the inerting fluid to the stack anode portion.

Abstract: A fuel cell reversal event is diagnosed by integrating current density via a controller in response to determine an accumulated charge density. The controller executes a control action when the accumulated charge density exceeds a threshold, including recording a diagnostic code indicative of event severity. The control action may include continuing stack operation at reduced power capability when the accumulated charge density exceeds a first threshold and shutting off the stack when the accumulated charge density exceeds a higher second threshold. The event may be detected by calculating a voltage difference between an average and a minimum cell voltage, and then determining if the difference exceeds a voltage difference threshold. The charge density thresholds may be adjusted based on age, state of health, and/or temperature of the fuel cell or stack. A fuel cell system includes the stack and controller.