Nonlinear thermal control of a PEM fuel cell stack
AssigneeGeneral Motors Corporation
InventorJason Kolodziej
Life of this patent
Estimating the term…
Abstract
A temperature control scheme for a fuel cell stack thermal sub-system in a fuel cell system that uses a non-linear thermal model and disturbance rejection to provide an optimum stack temperature. The thermal sub-system includes a coolant loop directing a cooling fluid through the stack, a pump for pumping the cooling fluid through the coolant loop, and a radiator for cooling the cooling fluid outside of the fuel cell stack. The system includes a controller for controlling the speed of the pump so as to maintain the temperature of the stack at a desired temperature. The controller uses the thermal model to anticipate a temperature of the cooling fluid out of the fuel cell stack to control the speed of the pump.
Claims22
A method for controlling the temperature of a fuel cell stack in a fuel cell system, said method comprising:
- developing a thermal model of the fuel cell stack that employs non-linear equations;
- generating an error signal that is the difference between a desired stack temperature and a temperature of a cooling fluid out of the fuel cell stack;
- applying feedback control to the error signal to generate a control signal;
- modifying a disturbance signal to generate a modified disturbance signal;
- adding the control signal to the modified disturbance signal to generate a linearization variable;
- generating a mass flow rate signal using the linearization variable;
- and
- linearizing the thermal model using the mass flow rate signal to reject the disturbance in the modified disturbance signal.
A fuel cell system comprising:
- a fuel cell stack;
- a pump for pumping a cooling fluid through the stack;
- and
- a controller for controlling the speed of the pump so as to maintain the temperature of the stack at a desired temperature, said controller generating an error signal that is the difference between a desired stack temperature and a temperature of the cooling fluid out of the fuel cell stack, applying feedback control to the error signal to generate a control signal, modifying a disturbance signal to generate a modified disturbance signal, adding the control signal to the modified disturbance signal to generate a linearization variable, generating a mass flow rate signal using the linearization variable, and linearizing the thermal model using the mass flow rate signal to reject the disturbance in the modified disturbance signal, wherein the controller uses the mass flow rate signal to control the speed of the pump.
A fuel cell system comprising:
- a fuel cell stack;
- a pump for pumping a cooling fluid through the stack;
- and
- a controller for controlling the speed of the pump so as to maintain the temperature of the stack at a desired temperature, said controller using a thermal model to anticipate a temperature of the cooling fluid out of the fuel cell stack to control the speed of the pump.
Dependencies are inferred from the claim text.