Self-tuning thermal control of an automotive fuel cell propulsion system

摘要

A fuel cell system that employs an on-line self-tuning algorithm that provides temperature control of a fuel cell stack in response to disturbances on the system. The system includes a thermal sub-system having a cooling fluid pump that pumps a cooling fluid through the fuel cell stack, a temperature sensor that measures the temperature of the cooling fluid out of the stack, a radiator that cooling the cooling fluid from the fuel cell stack and a by-pass valve that selectively controls how much of the cooling fluid flows through the radiator or by-passes the radiator. A controller controls the position of the by-pass valve in response to a temperature signal from the temperature sensor. The controller calculates a plurality of variables and a dead-time value, and determines whether the dead-time value should be increased, decreased or kept the same based on an estimate of a dead-time plant model.

主权项

1. A fuel cell system comprising:
a fuel cell stack; a cooling fluid pump pumping a cooling fluid through the fuel cell stack; a temperature sensor measuring the temperature of the cooling fluid out of the fuel cell stack; a radiator for cooling the cooling fluid from the fuel cell stack before it is returned to the fuel cell stack; a by-pass valve that selectively allows a portion of the cooling fluid to by-pass the radiator; and a controller programmed to control the position of the by-pass valve, said controller receiving a temperature signal from the temperature sensor, said controller also programmed with a dead-time plant model to calculate a plurality of variables and a dead-time value that are used to set the position of the by-pass valve so that the temperature of the cooling fluid exiting the fuel cell stack moves towards a desired temperature set-point, wherein the plurality of variables include control parameters that are recalculated for new operating conditions and wherein the recalculated control parameters are used to estimate new plant model parameters, and wherein the controller estimates a first dead-time plant model having a time delay greater than a current estimate of the dead-time value, a second dead-time plant model including a time-delay less than the current estimate of the dead-time value and a third dead-time plant model including the current estimate of the dead-time value, wherein the first dead-time plant model is compared to the third dead-time plant model and the second dead-time plant model is compared to the third dead-time plant model by calculating variances in the estimates to determine whether the dead-time value should be increased or decreased.