Search

CN-122029439-A - Battery state estimation system, battery state estimation method, battery state estimation program, and recording medium

CN122029439ACN 122029439 ACN122029439 ACN 122029439ACN-122029439-A

Abstract

The battery model generation unit generates an internal model of the battery including the OCV (Open Circuit Voltage: open circuit voltage) based on measured values at a plurality of times of the terminal voltage of the battery during a rest period after the charge and discharge of the battery. The prediction unit predicts the terminal voltage of the battery and the OCV of the battery after the first set time based on the generated internal model of the battery. When the error between the predicted value and the measured value of the terminal voltage of the battery after the lapse of the first set time from the predicted time point is smaller than a certain value, the battery state estimating unit determines the OCV predicted from the internal model of the battery as the estimated value of the OCV of the battery.

Inventors

  • TANIGAWA MASAHIRO

Assignees

  • 松下知识产权经营株式会社

Dates

Publication Date
20260512
Application Date
20240930
Priority Date
20231016

Claims (14)

  1. 1. A battery state estimation system is provided with: a battery model generation unit that generates an internal model of a battery including an open-circuit voltage based on measurement values at a plurality of times of a terminal voltage of the battery during a rest period after charging and discharging of the battery; a prediction unit for predicting the terminal voltage of the battery and the open circuit voltage of the battery after a first set time based on the generated internal model of the battery, and And an OCV estimation unit that determines an open-circuit voltage predicted from the internal model of the battery as an estimated value of the open-circuit voltage of the battery when an error between a predicted value and a measured value of the terminal voltage of the battery after the lapse of the first set time from a predicted time point is smaller than a certain value.
  2. 2. The battery state estimation system according to claim 1, wherein, The battery model generating unit generates an internal model of the battery at intervals of a second set time.
  3. 3. The battery state estimation system according to claim 1, wherein, The battery charging control device further includes a rest period setting unit configured to forcibly set the rest period before charging when a charging operation for the battery is performed at a timing after a predetermined time or more has elapsed since a timing at which the open-circuit voltage was last estimated.
  4. 4. The battery state estimation system according to claim 2, wherein, The second setting period is set longer as it approaches the start of the rest period.
  5. 5. The battery state estimation system according to claim 1, wherein, The closer to the start of the rest period, the longer the first setting period is set.
  6. 6. The battery state estimation system according to claim 2, wherein, The second setting period is set longer than the first setting period.
  7. 7. The battery state estimation system according to claim 2, wherein, The second setting period is set shorter than the first setting time.
  8. 8. The battery state estimation system according to claim 2, wherein, The length of the second setting period is set equal to the length of the first setting time.
  9. 9. The battery state estimation system according to claim 1, wherein, The predicting unit predicts the terminal voltage and the open circuit voltage of the battery at a plurality of times within a first set time, When the evaluation value based on the error between the predicted value and the measured value of the terminal voltage of the battery at a plurality of times within the first set time is smaller than a certain value, the OCV estimating unit determines the open-circuit voltage predicted from the internal model of the battery as the estimated value of the open-circuit voltage of the battery.
  10. 10. The battery state estimation system according to claim 2, wherein, The OCV estimating unit determines an estimated value of the open circuit voltage of the battery based on the open circuit voltages predicted from the plurality of internal models when an error between a predicted value and a measured value of the terminal voltage of the battery in the first set time period among the plurality of continuous internal models is smaller than a certain value.
  11. 11. The battery state estimation system according to claim 2, wherein, The battery model generating unit updates an initial value of a parameter of the internal model to be generated next based on an error between a predicted value and a measured value of the terminal voltage of the battery in the internal model to be generated this time.
  12. 12. A battery state estimation method comprising the steps of: generating an internal model of the battery including an open-circuit voltage based on measured values of a plurality of times of a terminal voltage of the battery during a rest period after charge and discharge of the battery; Predicting a terminal voltage of the battery and an open circuit voltage of the battery after a first set time based on the generated internal model of the battery, and When the error between the predicted value and the measured value of the terminal voltage of the battery after the lapse of the first set time from the predicted time point is smaller than a certain value, the open-circuit voltage predicted from the internal model of the battery is determined as the estimated value of the open-circuit voltage of the battery.
  13. 13. A battery state estimation program that causes a computer to execute: generating an internal model of the battery including an open-circuit voltage based on measured values of a plurality of times of a terminal voltage of the battery during a rest period after charge and discharge of the battery; Predicting a terminal voltage of the battery and an open circuit voltage of the battery after a first set time based on the generated internal model of the battery, and When the error between the predicted value and the measured value of the terminal voltage of the battery after the lapse of the first set time from the predicted time point is smaller than a certain value, the open-circuit voltage predicted from the internal model of the battery is determined as the estimated value of the open-circuit voltage of the battery.
  14. 14. A non-transitory recording medium recorded with the battery state estimation program according to claim 13.

Description

Battery state estimation system, battery state estimation method, battery state estimation program, and recording medium Technical Field The present disclosure relates to a battery state estimation system, a battery state estimation method, a battery state estimation program, and a recording medium that estimate an internal state of a battery. Background In order to estimate the internal states Of a battery such as SOC (State Of Charge), FCC (Full CHARGE CAPACITY: full Charge capacity), SOH (State Of Health) and the like with high accuracy, it is necessary to estimate OCV (Open Circuit Voltage: open circuit voltage) Of the battery with high accuracy. Patent document 1 discloses a method of estimating OCV without waiting for stabilization of the terminal voltage of the battery after switching from the energization period to the non-energization period. In fig. 6 of patent document 1, the charge and discharge of the battery unit 31 is stopped in the non-energization period P2 from time t C to time t D. The time t C1 belongs to the non-energization period P2, and is set to a time after a predetermined time has elapsed from the time t C. Time t C2 belongs to the non-energization period P2, and is set to a time subsequent to time t C1. The OCV at time t in the non-energization period P2 is estimated by equations (8) and (9). The time difference between the time t C1 and the time t C2 is substituted into t on the right side of equation (8). In patent document 1, the OCV is estimated based on the formulas (8) and (9), whereby the time required for estimating the OCV can be shortened. However, a specific setting method of the time t C2 as the end point of the estimated required time is not mentioned. Prior art literature Patent literature Patent document 1 International publication No. 13/141100 Disclosure of Invention When the estimated required time of the OCV is set longer than the minimum time actually required, the convenience of the user is reduced. Specifically, the delay of the subsequent processing (SOC calculation processing and the like) and the delay of the charge/discharge schedule are the main causes. Conversely, when the minimum time required for the estimation is set to be shorter than the actual time, the estimation accuracy of the OCV is lowered. The present disclosure has been made in view of such a situation, and an object thereof is to provide a technique for shortening the estimation time of OCV while ensuring a certain estimation accuracy. In order to solve the above problems, a battery state estimation system according to one embodiment of the present disclosure includes a battery model generation unit that generates an internal model of a battery including an OCV (Open Circuit Voltage: open-circuit voltage) based on measured values at a plurality of times of a terminal voltage of the battery during a rest period after charge and discharge of the battery, a prediction unit that predicts the terminal voltage of the battery and the OCV of the battery after a first set time has elapsed based on the generated internal model of the battery, and an OCV estimation unit that determines the OCV predicted from the internal model of the battery as an estimated value of the OCV of the battery when an error between a predicted value of the terminal voltage of the battery and the measured value after the first set time has elapsed from a predicted time point is smaller than a fixed value. Any combination of the above components, and a method of converting the expression of the present disclosure between devices, systems, methods, computer programs, and the like are effective as modes of the present disclosure. According to the present disclosure, it is possible to ensure a certain estimation accuracy and shorten the estimation time of the OCV. Drawings Fig. 1 is a diagram for explaining a battery-mounted device according to an embodiment. Fig. 2 is a diagram showing a configuration example of the battery state estimation system according to the embodiment. Fig. 3 is a diagram showing an example of an equivalent circuit model of each unit cell constituting the assembled battery in the assembled battery. Fig. 4 is a diagram showing a transition image of the terminal voltage of the unit cell in the rest period after the discharge is stopped. Fig. 5 is a flowchart showing a flow of OCV estimation processing of the battery state estimation system according to the embodiment. Fig. 6A is a diagram showing an example of transition of the SOC of the battery pack mounted on the battery-mounted device. Fig. 6B is a diagram showing an example of transition of the SOC of the battery pack mounted on the battery-mounted device. Fig. 7 is a diagram showing an example of setting the second setting time Δt in the rest period after discharge. Fig. 8 is a diagram showing an example of setting the first setting time Δs in the rest period after discharge. Fig. 9 is a diagram showing an example in which the first setting time Δ