# US 11,909,081 B2 · Control device for a fuel cells stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,081 B2 - Document ID: US11909081B2 - Status: Granted - Kind: B2 - Application number: 17/841,638 - Filed: 2022-06-15 - Published: 2022-12-15 - Granted: 2024-02-20 - Earliest claimed: 2021-06-15 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Antonius Bader - Web page: https://patentgrep.com/patent/US11909081B2 ## CPC - H01M 8/04589: {of fuel cell stacks} - H01M 8/04559: {of fuel cell stacks} - H01M 8/04992: characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence - H01M 8/04679: {of fuel cell stacks} - H01M 8/0491: {of fuel cell stacks} - H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane - Y02E 60/50: Fuel cells - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - 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 The invention relates to a control device (10) for a fuel cell stack (14), the control device being set up to actuate the fuel cell stack (14) using a predetermined current (IV) and to measure the resulting voltage (U) and to compare this with a reference voltage (UR). The predetermined current (IV) depends on the reference voltage (UR) by means of a sum of at least two exponential functions whose argument in each case contains the reference voltage (UR). The control device (10) is designed to ascertain the reference voltage (UR) by approximately reversing the correlation between the predetermined current and the reference voltage (UR) using an iterative approximation algorithm. ## Claims ### Claim 1 A fuel cell stack comprising: a control device being configured to actuate the fuel cell stack in accordance with a desired predetermined current (IV), to measure a resulting voltage (U), and to compare the resulting voltage (U) with a reference voltage (UR), the predeteiztiined current (IV) being dependent on the reference voltage (UR) via a sum of at least two exponential functions whose argument in each case contains the reference voltage (UR), and the control device being configured to ascertain the reference voltage (UR) by approximately reversing a correlation between the predetermined current (IV) and the reference voltage (UR) using an iterative approximation algorithm. ### Claim 2 (depends on 1) The fuel cell stack of claim 1, wherein the control device is configured to ascertain the reference voltage (UR) by applying arithmetic operations of addition, subtraction, multiplication, division, and exponentiation and to retrieve values of logarithms from a table. ### Claim 3 (depends on 1) The fuel cell stack of claim 1, wherein the control device is configured to ascertain a malfunction and/or degradation of the fuel cell stack from a deviation between the resulting voltage (U) and the reference voltage (UR). ### Claim 4 (depends on 3) The fuel cell stack of claim 3, wherein the control device is configured to change actuation of the fuel cell stack to reduce the deviation between the resulting voltage (U) and the reference voltage (UR). ### Claim 5 (depends on 1) The fuel cell stack of claim 1, wherein the control device is configured to operate the fuel cell stack using the predetermined current (IV) at an operating point at which degradation of the fuel cell stack is minimized. ### Claim 6 (depends on 3) The fuel cell stack of claim 3, wherein the control device is configured to change actuation of the fuel cell stack in such a way that an electrical power that is output by the fuel cell stack remains constant at a same specification, irrespective of the degradation. ### Claim 7 (depends on 1) A fuel cell vehicle comprising the fuel cell stack of claim 1. ### Claim 8 (depends on 1) A fuel cell vehicle comprising the fuel cell stack of claim 1. ### Claim 9 A control device configured: to actuate a fuel cell stack in accordance with a desired predetermined current (IV), to measure the resulting voltage (U), and to compare the resulting voltage (U) with a reference voltage (UR), the predetermined current (IV) being dependent on the reference voltage (UR) via a sum of at least two exponential functions whose argument in each case contains the reference voltage (UR), and to ascertain the reference voltage (UR) by approximately reversing a correlation between the predetermined current (IV) and the reference voltage (UR) using an iterative approximation algorithm, the control device being a fuel cell control device. ### Claim 10 (depends on 9) The control device of claim 9, wherein the control device is configured to ascertain the reference voltage (UR) by applying arithmetic operations of addition, subtraction, multiplication, division, and exponentiation and to retrieve values of logarithms from a table. ### Claim 11 (depends on 9) The control device of claim 9, wherein the control device is configured to ascertain a malfunction and/or degradation of the fuel cell stack from a deviation between the resulting voltage (U) and the reference voltage (UR). ### Claim 12 (depends on 11) The control device of claim 11, wherein the control device is configured to change actuation of the fuel cell stack to reduce the deviation between the resulting voltage (U) and the reference voltage (UR). ### Claim 13 (depends on 9) The control device of claim 9, wherein the control device is configured to operate the fuel cell stack using the predetermined current (IV) at an operating point at which degradation of the fuel cell stack is minimized. ### Claim 14 (depends on 11) The control device of claim 11, wherein the control device is configured to change actuation of the fuel cell stack in such a way that an electrical power that is output by the fuel cell stack remains constant at a same specification, irrespective of the degradation.