# US 9,435,865 B2 · Method for diagnosing fault of fuel cell stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,865 B2 - Document ID: US9435865B2 - Status: Granted - Kind: B2 - Application number: 14/135,300 - Filed: 2013-12-19 - Published: 2014-06-26 - Granted: 2016-09-06 - Earliest claimed: 2012-12-20 - Assignees: Hyundai Autron Co., Ltd. - Applicants: Hyundai Autron Co., Ltd. - Inventors: Hyun-Seok Park; Uck-Soo Kim; Sun-Doo Kang - Web page: https://patentgrep.com/patent/US9435865B2 ## CPC - B60L 3/0053: {relating to fuel cells} - B60L 3/04: Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) - B60L 3/12: Recording operating variables {; Monitoring of operating variables} - B60L 50/72: Constructional details of fuel cells specially adapted for electric vehicles - B60L 58/30: for monitoring or controlling fuel cells - G01R 31/382: Arrangements for monitoring battery or accumulator variables, e.g. SoC - H01M 8/04559: {of fuel cell stacks} - H01M 8/04649: {of fuel cell stacks} - H01M 8/04679: {of fuel cell stacks} - H01M 2008/1095: {Fuel cells with polymeric electrolytes} - Y02E 60/50: Fuel cells - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Disclosed herein is a method for diagnosing a fault of a fuel cell stack, including: applying a summed current obtained by summing currents of different frequency regions to the fuel cell stack; passing output voltages of the fuel cell stack through each of the different frequency filters to extract the respective diagnosis data; and diagnosing whether or not a fault has been generated in the fuel cell stack using the respective diagnosis data. Therefore, it is possible to further improve diagnosis analysis capability by applying the summed current obtained by summing the currents of the different frequency regions to the fuel cell stack and then rapidly diagnosing the fault of the fuel cell stack using the diagnosis data obtained by filtering the output voltages of the fuel cell stack. ## Claims ### Claim 1 A method for diagnosing a fault of a fuel cell stack performed by an apparatus for diagnosing a fault of a fuel cell stack, the method comprising: applying a summed current obtained by summing currents of different frequency regions including a frequency used to calculate at least one of a total harmonic distortion(THD) and an impedance to the fuel cell stack; passing output voltages of the fuel cell stack through each of different frequency filters including a high pass filter and a band pass filter to extract simultaneously the respective diagnosis data by passing the output voltages of the fuel cell stack through the high pass filter to extract a basic wave frequency to a harmonic frequency for calculating the total harmonic distortion and passing the output voltages of the fuel cell stack through the band pass filter to extract a specific frequency for calculating the impedance; and diagnosing whether or not the fault and wetting state of the fuel cell stack have been generated in the fuel cell stack using the respective diagnosis data. ### Claim 2 (depends on 1) The method of claim 1, wherein the diagnosing of whether or not the fault and wetting state of the fuel cell stack has been generated in the fuel cell stack using the respective diagnosis data includes diagnosing whether or not the fault has been generated in the fuel cell stack depending on a ratio of the harmonic frequency to the basic wave frequency extracted by the high pass filter. ### Claim 3 (depends on 2) The method of claim 2, wherein the diagnosing of whether or not the fault and wetting state of the fuel cell stack has been generated in the fuel cell stack using the respective diagnosis data includes diagnosing that the fault has been generated in the fuel cell stack when the ratio of the harmonic frequency to the basic wave frequency is a specific ratio or more. ### Claim 4 (depends on 1) The method of claim 1, wherein the diagnosing of whether or not the fault and wetting state of the fuel cell stack has been generated in the fuel cell stack using the respective diagnosis data includes diagnosing a wetting state of the fuel cell stack using an impedance for the specific frequency extracted by the band pass filter. ### Claim 5 (depends on 4) The method of claim 4, wherein the diagnosing of whether or not the fault and wetting state of the fuel cell stack has been generated in the fuel cell stack using the respective diagnosis data includes diagnosing that an electrolyte membrane of the fuel cell stack is in a dry state when the impedance for the specific frequency is a specific impedance or more. ### Claim 6 (depends on 4) The method of claim 4, wherein the diagnosing of whether or not the fault and wetting state of the fuel cell stack has been generated in the fuel cell stack using the respective diagnosis data includes diagnosing that an electrolyte membrane of the fuel cell stack is in a wet state when the impedance for the specific frequency is a specific impedance or less.