摘要 |
A fuel cell system that employs a start-up heater. The heater is coupled to a cold plate that warms a stack coolant during system start-up. A heater circuit measures the voltage at the output of the fuel cell stack and across the heater and the current through the fuel cell stack and through the heater. The heater circuit controls the amount heat that the heater generates by the measured voltage and current and the available power at the output of the fuel cell stack. In one embodiment, the heater includes field effect transistors (FETs) and planar resistors directly mounted to the cold plate. The FETs operate in their linear mode, allowing only the amount of current, which is required at a given voltage, to produce the power needed from the stack.
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