Patent ID: 11870113
Assignee: HYUNDAI MOTOR COMPANY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B  Y | IPC B  H

Claim 0:
1. A method for measuring impedance of a fuel cell stack in a vehicle, the method comprising:
a first step of receiving instructions at a fuel cell controller to determine whether measuring the impedance of the fuel cell stack is requested during driving of the vehicle driven by using power of a fuel cell stack;
a second step of switching a DC-DC converter connecting the fuel cell stack to a battery to a buck mode when measuring the impedance is requested, thereby blocking output current of the fuel cell stack from flowing to the battery through the DC-DC converter such that when the impedance of the fuel cell stack is measured, influence of components connected to the DC-DC converter through a second junction box is removed;
a third step of determining a first current value of the fuel cell stack for measuring the impedance;
a fourth step of controlling a resistance value of a COD variable resistor consuming the output current of the fuel cell stack according to the first current value, wherein, when a requested current of stack peripheral devices changes, a requested current of the COD variable resistor is recalculated by subtracting the changed requested current of the stack peripheral devices from the first current value and then the resistance value of the COD variable resistor is re-determined in accordance with the recalculated requested current of the COD variable resistor; and
a fifth step of measuring the impedance of the fuel cell stack while the output current of the fuel cell stack is maintained at the first current value.