Abstract: An apparatus for heating a fuel cell stack in a cold start mode is provided. The apparatus comprises a fuel cell stack, a boost converter, and a controller. The fuel cell stack powers a vehicle. The boost converter includes a power switch that is thermally coupled to the fuel cell stack. The controller is configured to receive a signal indicative of a temperature during a vehicle startup and to compare the temperature to a predetermined temperature value. The controller is further configured to activate the power switch if the temperature is below the predetermined temperature value such that the power switch generates heat to apply to the fuel cell stack and generates a voltage for powering a power circuit to enable the vehicle to driveaway while the fuel cell stack receives the heat.

Abstract: An apparatus for heating a fuel cell stack in a cold start mode is provided. The apparatus comprises a fuel cell stack, a power converter, and a controller. The power converter may include a power switch and resistive heating element that is thermally coupled to the fuel cell stack. The controller is configured to activate the power converter, if a temperature is below a predetermined temperature value, to draw current from the fuel cell stack to cause the fuel cell stack to generate heat. Heat from the power converter is also applied to the fuel cell stack.

Abstract: A vehicle is disclosed having a traction battery and an electrical impedance connected by a contactor. A pre-charge circuit is disclosed that controls current flow from the traction battery through the pre-charge circuit to the electrical impedance to increase voltage at the electrical impedance such that as the voltage approaches a voltage of the traction battery, a duty cycle of the pre-charge circuit approaches a maximum value and a current through the pre-charge circuit approaches a minimum value. In response to current falling below a predetermined value, the contactor is closed. A current sensor is disclosed that is located in the pre-charge circuit. A method of operating the pre-charge circuit is disclosed.

Abstract: A vehicle starter assembly includes a switching circuit configured to operate in a charging state and a discharging state, and a first energy storage device and a second energy storage device electrically connected to the switching circuit. The first energy storage device and the second energy storage device are connected in parallel to one another in the charging state and in series with one another in the discharging state. The processor is programmed to detect an engine start request and output a switch control signal that toggles the switching circuit between the charging state and the discharging state to start an internal combustion engine of a host vehicle.

Abstract: A linear current regulator is provided for precharging a high voltage bus, such as within a hybrid electric vehicle, in a quick, efficient, and optimal manner. The linear current regulator can include a battery; a bus; a transistor having, a base, a collector coupled to the bus, and an emitter; a resistor coupled between a precharge switch and the base; the precharge switch coupled to the battery and the resistor; and a main contactor coupled to the battery, the emitter, and the bus. When the recharge switch is closed, the bus is connected to the battery through the resistor and the transistor so that the bus is charged. When the voltages of the bus and the battery are nearly equal, the transistor turns off, the precharge switch is opened, and the main contactor is closed for normal operation of the vehicle.

Abstract: A vehicle starter assembly includes a switching circuit configured to operate in a charging state and a discharging state, and a first energy storage device and a second energy storage device electrically connected to the switching circuit. The first energy storage device and the second energy storage device are connected in parallel to one another in the charging state and in series with one another in the discharging state. The processor is programmed to detect an engine start request and output a switch control signal that toggles the switching circuit between the charging state and the discharging state to start an internal combustion engine of a host vehicle.

Abstract: A controller timing system according to an exemplary aspect of the present disclosure includes, among other things, a master controller to generate a timing signal, a first slave controller configured to wake in response to the timing signal, and a second slave controller configured to wake in response to the timing signal. Timing of the first slave controller and timing of the second slave controller is coordinated based on the timing signal.

Abstract: An automotive vehicle includes an air conditioning system configured to selectively cool a cabin of the vehicle and at least one electrical component of the vehicle. The vehicle also includes one or more controllers configured to determine whether the air conditioning system is operating to cool the at least one electrical component, to determine whether cabin cooling is requested, and to enable the air conditioning system to cool the cabin if the air conditioning system is operating to cool the at least one electrical component and if cabin cooling is requested.

Abstract: An electric drive system for an electric vehicle has a DC power source and a contactor with an output coupled to a main bus and an input adapted to be connected to the DC power source. The contactor is selectably switched between an open state and a closed state. A link capacitor is coupled to the main bus. A precharge circuit is coupled between the DC power source and the link capacitor comprised of a controlled current source. The controlled current source is selectably activated with the contactor in the open state to charge the link capacitor to a predetermined voltage to before switching the contactor to the closed state.

Abstract: A vehicle includes a fuel cell system, and a controller configured to receive a first signal indicative of a predicted ambient temperature at a specified location, and command the fuel cell system to operate at a reduced relative humidity when the predicted ambient temperature is below a threshold value. A method for controlling a fuel cell system includes receiving a first signal at a controller indicative of a predicted ambient temperature for a specified location, and operating the fuel cell system at a reduced relative humidity when the predicted ambient temperature is below a threshold value. A fuel cell system includes a fuel cell stack, and a controller configured to, in response to receiving a predicted freezing condition, command the fuel cell stack to operate at a lower relative humidity level for a time period preceding a predicted time for system shut down.

Abstract: A fuel storage system includes a storage vessel including a dielectric liner, a voltage sensor formed by a pair of plates disposed on opposing surfaces of the liner, and a controller configured to determine a gas pressure in the storage vessel based on voltages measured by the sensor.

Abstract: A linear current regulator is provided for precharging a high voltage bus, such as within a hybrid electric vehicle, in a quick, efficient, and optimal manner. The linear current regulator can include a battery; a bus; a transistor having, a base, a collector coupled to the bus, and an emitter; a resistor coupled between a precharge switch and the base; the precharge switch coupled to the battery and the resistor; and a main contactor coupled to the battery, the emitter, and the bus. When the recharge switch is closed, the bus is connected to the battery through the resistor and the transistor so that the bus is charged. When the voltages of the bus and the battery are nearly equal, the transistor turns off, the precharge switch is opened, and the main contactor is closed for normal operation of the vehicle.

Abstract: An electric drive system for an electric vehicle has a DC power source and a contactor with an output coupled to a main bus and an input adapted to be connected to the DC power source. The contactor is selectably switched between an open state and a closed state. A link capacitor is coupled to the main bus. A precharge circuit is coupled between the DC power source and the link capacitor comprised of a controlled current source. The controlled current source is selectably activated with the contactor in the open state to charge the link capacitor to a predetermined voltage to before switching the contactor to the closed state.

Abstract: A vehicle includes a fuel cell system, and a controller configured to receive a first signal indicative of a predicted ambient temperature at a specified location, and command the fuel cell system to operate at a reduced relative humidity when the predicted ambient temperature is below a threshold value. A method for controlling a fuel cell system includes receiving a first signal at a controller indicative of a predicted ambient temperature for a specified location, and operating the fuel cell system at a reduced relative humidity when the predicted ambient temperature is below a threshold value. A fuel cell system includes a fuel cell stack, and a controller configured to, in response to receiving a predicted freezing condition, command the fuel cell stack to operate at a lower relative humidity level for a time period preceding a predicted time for system shut down.

Abstract: A vehicle is disclosed having a traction battery and an electrical impedance connected by a contactor. A pre-charge circuit is disclosed that controls current flow from the traction battery through the pre-charge circuit to the electrical impedance to increase voltage at the electrical impedance such that as the voltage approaches a voltage of the traction battery, a duty cycle of the pre-charge circuit approaches a maximum value and a current through the pre-charge circuit approaches a minimum value. In response to current falling below a predetermined value, the contactor is closed. A current sensor is disclosed that is located in the pre-charge circuit. A method of operating the pre-charge circuit is disclosed.

Abstract: A controller timing system according to an exemplary aspect of the present disclosure includes, among other things, a master controller to generate a timing signal, a first slave controller configured to wake in response to the timing signal, and a second slave controller configured to wake in response to the timing signal. Timing of the first slave controller and timing of the second slave controller is coordinated based on the timing signal.

Abstract: An apparatus for heating a fuel cell stack in a cold start mode is provided. The apparatus comprises a fuel cell stack, a power converter, and a controller. The power converter may include a power switch and resistive heating element that is thermally coupled to the fuel cell stack. The controller is configured to activate the power converter, if a temperature is below a predetermined temperature value, to draw current from the fuel cell stack to cause the fuel cell stack to generate heat. Heat from the power converter is also applied to the fuel cell stack.

Abstract: An apparatus for heating a fuel cell stack in a cold start mode is provided. The apparatus comprises a fuel cell stack, a boost converter, and a controller. The fuel cell stack powers a vehicle. The boost converter includes a power switch that is thermally coupled to the fuel cell stack. The controller is configured to receive a signal indicative of a temperature during a vehicle startup and to compare the temperature to a predetermined temperature value. The controller is further configured to activate the power switch if the temperature is below the predetermined temperature value such that the power switch generates heat to apply to the fuel cell stack and generates a voltage for powering a power circuit to enable the vehicle to driveaway while the fuel cell stack receives the heat.

Abstract: An automotive vehicle includes an electrical circuit capable of being electrically connected with an electrical grid, a propulsion electrical bus electrically connected with the circuit, a power conversion module electrically connected with the propulsion electrical bus, and a power storage unit electrically connected with the power conversion module.

Abstract: An automotive vehicle includes an air conditioning system configured to selectively cool a cabin of the vehicle and at least one electrical component of the vehicle. The vehicle also includes one or more controllers configured to determine whether the air conditioning system is operating to cool the at least one electrical component, to determine whether cabin cooling is requested, and to enable the air conditioning system to cool the cabin if the air conditioning system is operating to cool the at least one electrical component and if cabin cooling is requested.