摘要:
A system and method for controlling the voltage on a high voltage bus in a fuel cell system in response to a failed high voltage battery. The method includes determining if the high voltage battery has failed, and disconnecting the battery from the high voltage bus in response to a failure. The method measures the voltage of the fuel cell stack by a DC boost circuit and converts the measured voltage to a voltage set-point value that sets the voltage on the high voltage bus, where the voltage set-point value changes as the measured voltage changes. A supervisory controller sets the media flow to the fuel cell stack and determines a minimum stack voltage limit value based on the stack maximum current draw that is used to determine a high voltage bus lower limit value.
摘要:
A method for revising a reference polarization curve of a fuel cell stack that identifies the relationship between the voltage and the current of the stack over time. When the stack is operating at a low load where kinetic voltage losses of the stack dominate, a first adaptation value is revised as the difference between the actual stack voltage and the stack voltage of the reference polarization curve. When the stack is operating at higher loads where ohmic voltage losses of the stack dominate, a second adaptation value is revised as the difference between the actual stack voltage and the stack voltage of the reference polarization curve.
摘要:
A heating system for optimizing execution of heating tasks in a fuel cell vehicle is disclosed, the system including a stack coolant loop with a fuel cell stack, a primary pump, and a radiator module. A bypass coolant loop is disposed parallel with and is connected to the stack coolant loop between the fuel cell stack and the radiator module. The bypass loop including a cabin heat exchanger and a coolant heater, along with a secondary pump for pumping coolant through the heaters when desired.
摘要:
A system and method for controlling a bleed valve and a compressor in a fuel cell system during an anode exhaust gas bleed so as to maintain the concentration of hydrogen within a mixed cathode exhaust gas and anode gas below a predetermined percentage. The system uses a valve orifice model to calculate the flow rate of the anode exhaust gas through the bleed valve to identify how much airflow from the compressor is required to dilute the hydrogen in the anode gas to be below the predetermined percentage. The system also uses sensor inaccuracies and production tolerances in the valve orifice model to ensure that the concentration of hydrogen in the mixed anode and cathode exhaust gas is below the determined percentage.
摘要:
An assembly (10) for achieving and maintaining a desired battery operating temperature. A positive thermal coefficient (PTC) resistive element (18) is disposed adjacent a battery (12) in a position to heat the battery.
摘要:
A fuel cell system includes a fuel cell stack, an anode reactant source and a shut-off valve that selectively prohibits anode reactant flow from the anode reactant source to the fuel cell stack through a conduit. A control module initiates closure of the shut-off valve to prohibit anode reactant flow through the conduit and determines a shutdown schedule based on a residual mass of the anode reactant within the conduit. The control module operates the fuel cell system using the residual mass and based on the shutdown schedule.
摘要:
A method for revising a reference polarization curve of a fuel cell stack that identifies the relationship between the voltage and the current of the stack over time. When the stack is operating at a low load where kinetic voltage losses of the stack dominate, a first adaptation value is revised as the difference between the actual stack voltage and the stack voltage of the reference polarization curve. When the stack is operating at higher loads where ohmic voltage losses of the stack dominate, a second adaptation value is revised as the difference between the actual stack voltage and the stack voltage of the reference polarization curve.
摘要:
A device and method to predict and regulate nitrogen concentration in a flow shifting system. In one aspect of the system, a bleed valve fluidly coupled to multiple fuel cell stacks is used to reduce the presence of nitrogen in an anode flowpath. One or more sensors can be used to measure voltage within one or both of the fuel cell stacks. By assessing fuel cell voltage changes within the anode flowpath and equating such changes with nitrogen fraction buildup, the system can manipulate the bleed valve at appropriate times to improve system operability. In one form of equating the sensed voltage changes with the nitrogen fraction buildup, a predictive algorithm can be used by a logic device in a controller to compare the sensed voltage so that the controller instructs the bleed valve when to open and close. In a variation, the controller can compare the sensed voltages against stored data rather than rely on a formula or related algorithm.
摘要:
A fuel cell stack that includes cascaded stack stages and tube bundle flow restrictions for providing a cathode input gas to each stage in the stack. The stack includes a first flow pipe for providing cathode gas flow to a first stage of the plurality of stages of the fuel cell stack. The fuel cell stack also includes a second flow pipe that receives a cathode exhaust gas flow from the first stage and fresh cathode gas flow, where the cathode exhaust gas flow and the fresh cathode gas flow are combined and sent to a second stage of the plurality of stages of the fuel cell stack. The tube bundle flow restriction is positioned within the second flow pipe and controls the flow of the cathode gas flow to the second stage, where the flow restriction provides a laminar flow through the control valve to the second stage.
摘要:
A fuel cell system that does not include a high voltage battery in combination with a fuel cell stack. The fuel cell stack and a bi-directional power module are electrically coupled to a high voltage bus. A first larger capacity 12 volt battery is electrically coupled to the power module opposite to the high voltage bus and a second smaller capacity 12 volt battery is electrically coupled to the first 12 volt battery, where a diode is electrically coupled between the first and second 12 volt batteries and only allows current flow from the first 12 volt battery to the second 12 volt battery. 12 volt battery loads are electrically coupled to the second 12 volt battery.