# US 11,307,261 B2 · Rechargeable battery state estimation device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,307,261 B2 - Document ID: US11307261B2 - Status: Granted - Kind: B2 - Application number: 16/491,194 - Filed: 2017-11-06 - Published: 2020-01-30 - Granted: 2022-04-19 - Earliest claimed: 2017-03-31 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Tomoki Takegami; Toshihiro Wada; Seigo Kadota - Web page: https://patentgrep.com/patent/US11307261B2 ## CPC - G01R 31/3828: using current integration - G01R 31/36: Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] - G01R 31/367: Software therefor, e.g. for battery testing using modelling or look-up tables - G01R 31/3842: combining voltage and current measurements - H01M 10/42: Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells (H01M10/60 takes precedence) - H01M 10/48: Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) - H02J 7/00: Circuit arrangements for charging or discharging batteries or for supplying loads from batteries - G01R 31/3648: {comprising digital calculation means, e.g. for performing an algorithm} - Y02E 60/10: Energy storage using batteries - 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 - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract In response to demands for stably and precisely estimating states, a rechargeable battery state estimation device includes a current detecting unit which detects a charge-discharge current of the rechargeable battery as a detected current; a voltage detecting unit which detects a voltage between terminals of the rechargeable battery as a detected voltage; an OCV estimation method SOC estimation unit which calculates an OCV estimation method state of charge, based on the detected current and the detected voltage; a current integration method parameter estimation unit which estimates a current integration method parameter including a capacity retention rate, based on the detected current and the OCV estimation method state of charge; and a corrected SOC estimation unit which calculates an estimated state of charge, based on the detected current, the OCV estimation method state of charge, and the current integration method parameter. ## Claims ### Claim 1 A rechargeable battery state estimation device which estimates a state of charge of a rechargeable battery as an estimated state of charge, the rechargeable battery state estimation device comprising: a current detector which detects a charge-discharge current of the rechargeable battery as a detected current, a voltage detector which detects a voltage between terminals of the rechargeable battery as a detected voltage, a low pass filter which outputs a value which is eliminated of high frequency components, and a processor configured to: calculate an open circuit voltage (OCV) estimation state of charge of the rechargeable battery, based on the detected current of the rechargeable battery and the detected voltage between the terminals of the rechargeable battery, estimate a current integration parameter including a capacity retention rate, based on the detected current of the rechargeable battery and the OCV estimation state of charge of the rechargeable battery, and calculate an estimated state of charge of the rechargeable battery by: calculating a current integration state of charge of the rechargeable battery, based on the detected current of the rechargeable battery and the current integration parameter of the rechargeable battery, wherein the estimated state of charge of the rechargeable battery is based, at least in part, on (a) the current integration state of charge of the rechargeable battery and (b) the value output from the low pass filter that receives an input comprising a difference value between the OCV estimation state of charge of the rechargeable battery and one of the current integration state of charge of the rechargeable battery or the estimated state of charge of the rechargeable battery. ### Claim 2 (depends on 1) The rechargeable battery state estimation device as set forth in claim 1, wherein the processor is configured to calculate a change in the state of charge of the rechargeable battery, based on the detected current and the current integration parameter, and wherein the processor is configured to correct an estimation error of the current integration parameter, and an estimation error for the current integration state of charge. ### Claim 3 (depends on 2) The rechargeable battery state estimation device as set forth in claim 2, wherein the processor is configured to: generate a first coefficient vector, based on the detected current, obtain a second coefficient vector, based on the first coefficient vector, obtain a reference signal, based on the OCV estimation state of charge, and estimate the current integration parameter, based on the second coefficient vector and the reference signal. ### Claim 4 (depends on 2) The rechargeable battery state estimation device as set forth in claim 2, wherein the processor is configured to: compute the difference value by subtracting the current integration state of charge from the OCV estimation state of charge, wherein the low pass filter receives as the input the difference value, and wherein the estimated state of charge of the rechargeable battery is calculated by adding the current integration state of charge and the output value of the low pass filter. ### Claim 5 (depends on 2) The rechargeable battery state estimation device as set forth in claim 2, wherein the processor is configured to: compute the difference value by subtracting the estimated state of charge from the OCV estimation state of charge, wherein the low pass filter receives as the input the difference value, the rechargeable battery state estimation device further comprises a gain multiplication part which outputs a value which is computed by multiplying a positive real gain, based on the value which the low pass filter outputs; and wherein the processor is configured to calculate the estimated state of charge, based on the detected current which the current detector outputs, the current integration parameter, and the value which the gain multiplication part outputs. ### Claim 6 (depends on 2) The rechargeable battery state estimation device as set forth in claim 2, wherein the processor is configured to: compute the difference value by subtracting the estimated state of charge from the OCV estimation state of charge, and wherein the low pass filter receives as the input the difference value, wherein the rechargeable battery state estimation device further comprises a gain multiplication part which outputs a value which is computed by multiplying a positive real gain, based on the value which the low pass filter outputs, and wherein the estimated state of charge is calculated by adding the current integration state of charge and the value which the gain multiplication part outputs. ### Claim 7 (depends on 2) The rechargeable battery state estimation device as set forth in claim 2, wherein the processor is configured to: determine an estimated open circuit voltage from a corresponding relation between a state of charge of the rechargeable battery and an open circuit voltage, based on the estimated state of charge, and estimate an OCV estimation parameter, based on the estimated open circuit voltage, the detected current and the detected voltage, and wherein the calculation of the OCV estimation state of charge is based on the OCV estimation parameter, the detected current and the detected voltage. ### Claim 8 (depends on 3) The rechargeable battery state estimation device as set forth in claim 3, wherein the processor is configured to: compute the difference value by subtracting the current integration state of charge from the OCV estimation state of charge, wherein the low pass filter receives as the input the difference value, and wherein the estimated state of charge of the rechargeable battery is calculated by adding the current integration state of charge and an output value of the low pass filter. ### Claim 9 (depends on 3) The rechargeable battery state estimation device as set forth in claim 3, wherein the processor is configured to: compute the difference value by subtracting the estimated state of charge from the OCV estimation state of charge, wherein the low pass filter receives as the input the difference value, wherein the rechargeable battery state estimation device further comprises a gain multiplication part which outputs a value which is computed by multiplying a positive real gain, based on the value which the low pass filter outputs; and wherein the processor is configured to calculate the estimated state of charge, based on the detected current which the current detector outputs, the current integration parameter, and the value which the gain multiplication part outputs. ### Claim 10 (depends on 3) The rechargeable battery state estimation device as set forth in claim 3, wherein the processor is configured to: compute the difference value by subtracting the estimated state of charge from the OCV estimation state of charge, and wherein the low pass filter receives as the input the difference value, wherein the rechargeable battery state estimation device further comprises a gain multiplication part which outputs a value which is computed by multiplying a positive real gain, based on the value which the low pass filter outputs, and wherein the estimated state of charge is calculated by adding the current integration state of charge and the value which the gain multiplication part outputs. ### Claim 11 (depends on 3) The rechargeable battery state estimation device as set forth in claim 3, wherein the processor is configured to: determine an estimated open circuit voltage from a corresponding relation between a state of charge of the rechargeable battery and an open circuit voltage, based on the estimated state of charge, and estimate an OCV estimation parameter, based on the estimated open circuit voltage, the detected current and the detected voltage, and wherein the calculation of the OCV estimation state of charge is based on the OCV estimation parameter, the detected current and the detected voltage. ### Claim 12 A rechargeable battery state estimation device which estimates a state of charge of a rechargeable battery as an estimated state of charge, the rechargeable battery state estimation device comprising: a current detector which detects a charge-discharge current of the rechargeable battery as a detected current, a voltage detector which detects a voltage between terminals of the rechargeable battery as a detected voltage, and a processor configured to: calculate an open circuit voltage (OCV) estimation state of charge of the rechargeable battery, based on the detected current of the rechargeable battery and the detected voltage between the terminals of the rechargeable battery, estimate a current integration parameter including a capacity retention rate, based on the detected current of the rechargeable battery and the OCV estimation state of charge of the rechargeable battery, calculate an estimated state of charge of the rechargeable battery by: calculating a current integration state of charge of the rechargeable battery, based on the detected current of the rechargeable battery and the current integration parameter of the rechargeable battery, calculate a change in the state of charge of the rechargeable battery, based on the detected current and the current integration parameter, correct an estimation error of the current integration parameter, and an estimation error for the current integration state of charge, generate a first coefficient vector, based on the detected current, obtain a second coefficient vector, based on the first coefficient vector, obtain a reference signal, based on the OCV estimation state of charge, and estimate the current integration parameter, based on the second coefficient vector and the reference signal. ### Claim 13 A rechargeable battery state estimation device which estimates a state of charge of a rechargeable battery as an estimated state of charge, the rechargeable battery state estimation device comprising: a current detector which detects a charge-discharge current of the rechargeable battery as a detected current, a voltage detector which detects a voltage between terminals of the rechargeable battery as a detected voltage, a low pass filter which outputs a value which is eliminated of high frequency components, and a processor configured to: calculate an open circuit voltage (OCV) estimation state of charge of the rechargeable battery, based on the detected current of the rechargeable battery and the detected voltage between the terminals of the rechargeable battery, estimate a current integration parameter including a capacity retention rate, based on the detected current of the rechargeable battery and the OCV estimation state of charge of the rechargeable battery, calculate an estimated state of charge of the rechargeable battery by: calculating a current integration state of charge of the rechargeable battery, based on the detected current of the rechargeable battery and the current integration parameter of the rechargeable battery, calculate a change in the state of charge of the rechargeable battery, based on the detected current and the current integration parameter, correct an estimation error of the current integration parameter, and an estimation error for the current integration state of charge, and compute a difference value by subtracting the current integration state of charge from the OCV estimation state of charge, wherein the low pass filter receives as the input the difference value, and wherein the estimated state of charge of the rechargeable battery is calculated by adding the current integration state of charge and the output value of the low pass filter. ### Claim 14 (depends on 12) The rechargeable battery state estimation device as set forth in claim 12, wherein the processor is configured to: compute a difference value by subtracting the current integration state of charge from the OCV estimation state of charge, and a low pass filter which outputs a value which is eliminated of high frequency components, wherein the low pass filter receives as the input the difference value, and wherein the estimated state of charge of the rechargeable battery is calculated by adding the current integration state of charge and an output value of the low pass filter. ### Claim 15 (depends on 12) The rechargeable battery state estimation device as set forth in claim 12, wherein the processor is configured to: compute a difference value by subtracting the estimated state of charge from the OCV estimation state of charge, a low pass filter which outputs a value which is eliminated of high frequency components, wherein the low pass filter receives as the input the difference value, wherein the rechargeable battery state estimation device further comprises a gain multiplication part which outputs a value which is computed by multiplying a positive real gain, based on the value which the low pass filter outputs; and wherein the processor is configured to calculate the estimated state of charge, based on the detected current which the current detector outputs, the current integration parameter, and the value which the gain multiplication part outputs. ### Claim 16 (depends on 12) The rechargeable battery state estimation device as set forth in claim 12, wherein the processor is configured to: compute a difference value by subtracting the estimated state of charge from the OCV estimation state of charge, and a low pass filter which outputs a value which is eliminated of high frequency components, wherein the low pass filter receives as the input the difference value, wherein the rechargeable battery state estimation device further comprises a gain multiplication part which outputs a value which is computed by multiplying a positive real gain, based on the value which the low pass filter outputs, and wherein the estimated state of charge is calculated by adding the current integration state of charge and the value which the gain multiplication part outputs. ### Claim 17 (depends on 12) The rechargeable battery state estimation device as set forth in claim 12, wherein the processor is configured to: determine an estimated open circuit voltage from a corresponding relation between a state of charge of the rechargeable battery and an open circuit voltage, based on the estimated state of charge, and estimate an OCV estimation parameter, based on the estimated open circuit voltage, the detected current and the detected voltage, and wherein the calculation of the OCV estimation state of charge is based on the OCV estimation parameter, the detected current and the detected voltage.