Patent ID: 11923575
Assignee: HYUNDAI MOTOR COMPANY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC B  H  Y | IPC B  G  H

Claim 0:
1. A fault diagnostic apparatus for a fuel cell electric vehicle, the fault diagnostic apparatus comprising:
a main relay connected to a fuel cell stack;
a power converter connected to the main relay;
a heater relay connected to the fuel cell stack and the main relay at one end and connected to a cathode oxygen depletion (COD) heater at the other end; and
a fuel cell control unit (FCU) connected with the main relay, the power converter, and the heater relay,
wherein the FCU diagnoses a fault of the main relay based on an amount of change in stack voltage according to control to turn off and on the heater relay and a power of the power converter according to variable control of a voltage of the power converter, when the vehicle enters a shutdown sequence, and outputs the diagnosed result.