摘要:
A method and system for controlling temperature in an electric vehicle battery pack such that battery pack longevity is preserved, while vehicle driving range is maximized. A controller prescribes a maximum allowable temperature in the battery pack as a function of state of charge, reflecting evidence that lithium-ion battery pack temperatures can be allowed to increase as state of charge decreases, without having a detrimental effect on battery pack life. During vehicle driving, battery pack temperature is allowed to increase with decreasing state of charge, and a cooling system is only used as necessary to maintain temperature beneath the increasing maximum level. The decreased usage of the cooling system reduces energy consumption and increases vehicle driving range. During charging operations, the cooling system must remove enough heat from the battery pack to maintain temperatures below a decreasing maximum, but this has no impact on driving range.
摘要:
A system for cooling a fuel cell stack and a drive unit in a fuel cell vehicle is disclosed, wherein the system includes a drive unit and a fuel cell stack. An oil cooling loop for the drive unit includes a three way valve, a liquid to liquid heat exchanger, and a pump. The liquid to liquid heat exchanger may be used to transfer drive unit off heat into the stack coolant loop. By not using an oil to air heat exchanger overall heat exchanger arrangement air side pressure drop can be minimized and airflow increased. The three way valve allows decoupling of the cooling loops if needed to inhibit negative impact on the fuel cell stack.
摘要:
A method and system for controlling temperature in an electric vehicle battery pack such that battery pack longevity is preserved, while vehicle driving range is maximized. A controller prescribes a maximum allowable temperature in the battery pack as a function of state of charge, reflecting evidence that lithium-ion battery pack temperatures can be allowed to increase as state of charge decreases, without having a detrimental effect on battery pack life. During vehicle driving, battery pack temperature is allowed to increase with decreasing state of charge, and a cooling system is only used as necessary to maintain temperature beneath the increasing maximum level. The decreased usage of the cooling system reduces energy consumption and increases vehicle driving range. During charging operations, the cooling system must remove enough heat from the battery pack to maintain temperatures below a decreasing maximum, but this has no impact on driving range.
摘要:
A system for cooling a fuel cell stack and a drive unit in a fuel cell vehicle is disclosed, wherein the system includes a drive unit and a fuel cell stack. An oil cooling loop for the drive unit includes a three way valve, a liquid to liquid heat exchanger, and a pump. The liquid to liquid heat exchanger may be used to transfer drive unit off heat into the stack coolant loop. By not using an oil to air heat exchanger overall heat exchanger arrangement air side pressure drop can be minimized and airflow increased. The three way valve allows decoupling of the cooling loops if needed to inhibit negative impact on the fuel cell stack.
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:
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.
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.