WO2019116815A1 - Device for monitoring secondary cell, device for computing state of secondary cell, and method for estimating state of secondary cell - Google Patents

Device for monitoring secondary cell, device for computing state of secondary cell, and method for estimating state of secondary cell Download PDF

Info

Publication number
WO2019116815A1
WO2019116815A1 PCT/JP2018/042226 JP2018042226W WO2019116815A1 WO 2019116815 A1 WO2019116815 A1 WO 2019116815A1 JP 2018042226 W JP2018042226 W JP 2018042226W WO 2019116815 A1 WO2019116815 A1 WO 2019116815A1
Authority
WO
WIPO (PCT)
Prior art keywords
temperature
internal resistance
battery
secondary battery
unit
Prior art date
Application number
PCT/JP2018/042226
Other languages
French (fr)
Japanese (ja)
Inventor
直行 五十嵐
亮平 中尾
大川　圭一朗
Original Assignee
日立オートモティブシステムズ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立オートモティブシステムズ株式会社 filed Critical 日立オートモティブシステムズ株式会社
Priority to JP2019558982A priority Critical patent/JP6895541B2/en
Publication of WO2019116815A1 publication Critical patent/WO2019116815A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a secondary battery monitoring device, a secondary battery state calculation device, and a secondary battery state estimation method.
  • the state of the secondary battery is the internal resistance of the secondary battery, the state of charge (SOC: State of Charge) or the remaining capacity indicating how much the battery is charged or to which the amount of charge that can be discharged remains.
  • SOC State of Charge
  • SOH state of health
  • Patent Document 1 describes that temperature correction is performed based on internal resistance-temperature characteristic data of a secondary battery and a temperature measured by a temperature sensor.
  • Patent Document 1 does not take measures against the expansion of the error of the internal resistance of the secondary battery in the low temperature region, the error of the internal resistance in the low temperature region is expanded, and thus the accuracy of the state estimation of the secondary battery Even worse.
  • the secondary battery monitoring device includes a temperature measurement unit that measures the temperature of the secondary battery, and a secondary battery state computing device.
  • the secondary battery state computing device includes the temperature and the internal resistance of the secondary battery.
  • a temperature correction unit that derives a correction temperature T ⁇ by adding a temperature correction value ⁇ to the battery temperature T measured by the temperature measurement unit, and a temperature correction unit that is derived by the temperature correction unit State estimation for performing the state estimation of the secondary battery based on an internal resistance calculating unit that obtains the internal resistance corresponding to the correction temperature T ⁇ with reference to the storage unit, and the internal resistance obtained by the internal resistance calculating unit And a control unit.
  • the secondary battery state calculation device adds the temperature correction value ⁇ to the measured battery temperature T and stores the correction temperature T ⁇ by the storage unit that stores the correspondence between the temperature of the secondary battery and the internal resistance.
  • a temperature correction unit to be derived an internal resistance calculation unit to obtain the internal resistance corresponding to the correction temperature T ⁇ derived by the temperature correction unit with reference to the storage unit, and an internal calculation obtained by the internal resistance calculation unit
  • a state estimation control unit that estimates the state of the secondary battery based on a resistance.
  • the secondary battery state estimation method stores the correspondence between the temperature of the secondary battery and the internal resistance, adds the temperature correction value ⁇ to the measured battery temperature T, and derives the correction temperature T ⁇ .
  • the internal resistance corresponding to the derived correction temperature T ⁇ is determined with reference to the stored correspondence relationship between the temperature of the secondary battery and the internal resistance, and the state of the secondary battery based on the determined internal resistance Make an estimate.
  • the error of the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
  • FIG. 1 is a block diagram of a secondary battery monitoring device 1000 in the present embodiment.
  • the secondary battery monitoring device 1000 includes a battery 100, a measurement unit 200, a battery state calculation device 300, and an output unit 400.
  • the charge stored in the battery 100 is supplied as power to an external device, and an electric vehicle, a hybrid car, a train, or the like can be considered as a target for supplying power.
  • the battery state computing device 300 outputs the state of charge SOC of the battery 100, the degree of deterioration SOH, and the like to the output unit 400.
  • the battery 100 is, for example, a rechargeable battery such as a lithium ion secondary battery.
  • the present embodiment can be applied to a device having a power storage function such as a nickel hydrogen battery, a lead battery, and an electric double layer capacitor.
  • the battery 100 may be a single battery cell, or may be a module structure in which a plurality of single battery cells are combined.
  • the measurement unit 200 is a functional unit that measures physical characteristics of the battery 100, for example, voltage V across the battery 100, current (battery current) I flowing to the battery 100, battery temperature T of the battery 100, etc. It consists of sensors, necessary electrical circuits, etc. Although measurement means such as a thermistor, thermocouple or infrared ray are used to measure the battery temperature T, in any measurement means, the battery temperature as the measurement result includes the device-specific measurement error value ⁇ .
  • the battery state calculation device 300 is a device that estimates the state of the battery 100, and includes a battery state estimation device 310 and a storage unit 320.
  • internal resistance value R of the battery 100 is required for state estimation of the battery 100 so that it may mention later, in this embodiment, in the battery state estimation apparatus 310, internal resistance value R is used using other measurement parameters. calculate.
  • the battery state estimation device 310 stores the battery 100 stored in the storage unit 320 based on the voltage V across the battery 100 measured by the measurement unit 200, the battery current I flowing to the battery 100, and the battery temperature T of the battery 100.
  • the SOC and SOH of the battery 100 are calculated with reference to the characteristic information of Calculation of the internal resistance R of the battery 100 and calculation of the SOC and SOH will be described later.
  • the battery state estimation device 310 can be configured using hardware such as a circuit device that realizes the function.
  • software that implements the function can be configured by execution by an arithmetic device such as a central processing unit (CPU).
  • the software is stored, for example, in the storage unit 320.
  • the storage unit 320 stores characteristic information of the battery 100 that can be known in advance, such as the internal resistance R of the battery 100, the polarization voltage, the charging efficiency, the allowable current, and the battery capacity.
  • the correspondence between the battery temperature and the internal resistance is stored in the form of a correspondence table, a functional expression, or the like. Further, as described later, the correspondence between the battery temperature and the temperature correction value is stored.
  • the characteristic information may store values individually for charge and discharge operations, or may store values individually for each state of the battery 100, such as charge state and battery temperature.
  • the storage unit 320 is configured using a storage device such as a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a magnetic disk, or the like.
  • the storage unit 320 may be provided outside the battery state estimation device 310, or may be realized as a memory device provided inside the battery state estimation device 310.
  • the storage unit 320 may be removable. If removable, replacing the storage unit 320 allows the characteristic information and software to be easily changed. Further, the characteristic information and the software can be updated for each small unit by distributing and storing the characteristic information and the software in the replaceable storage unit 320 having a plurality of the memory units 320.
  • the output unit 400 is a functional unit that outputs the output of the battery state calculation device 300 to an external device (for example, a host device such as a vehicle control device provided in an electric vehicle).
  • an external device for example, a host device such as a vehicle control device provided in an electric vehicle.
  • FIG. 2 is a block diagram of a battery state calculation device 300 including the battery state estimation device 310 and the storage unit 320.
  • the battery state estimation device 310 includes a temperature correction unit 311, an internal resistance calculation unit 312, an SOC calculation unit 313, and an SOH calculation unit 314.
  • the temperature correction unit 311 adds the temperature correction value ⁇ to the battery temperature T measured by the measurement unit 200 when the temperature of the battery 100 is equal to or lower than the predetermined value, and sends the correction temperature T ⁇ to the internal resistance calculation unit 312. Output.
  • the temperature correction value ⁇ is a value within the range of the measurement error value ⁇ of the temperature measurement by the sensor of the measurement unit 200.
  • the measurement error value ⁇ is a unique value corresponding to the sensor used in the measurement unit 200, and is a value known in advance. The derivation of the optimal temperature correction value ⁇ will be described later.
  • temperature correction unit 311 When the temperature of battery 100 is not equal to or lower than the predetermined value, temperature correction unit 311 outputs battery temperature T measured by measurement unit 200 to internal resistance calculation unit 312 as it is.
  • the internal resistance calculation unit 312 corresponds the internal resistance corresponding to the corrected temperature T ⁇ determined by the temperature correction unit 311 to the temperature in the storage unit 320 and the internal resistance. Find by referring to the relationship. Further, when the temperature of battery 100 is not equal to or lower than a predetermined value, internal resistance calculation unit 312 sets the internal resistance corresponding to battery temperature T measured by measurement unit 200 to the internal resistance of temperature in storage unit 320 and the internal resistance. Determine by referring to the correspondence. The calculated internal resistance is output to SOC calculation unit 313 and SOH calculation unit 314.
  • temperature correction unit 311 and internal resistance calculation unit 312 convert the value of internal resistance with less error, as described later, so this value was used.
  • the calculation of the SOC calculation unit 313 and the SOH calculation unit 314 also reduces the error.
  • the SOC operation unit 313 obtains the SOC, but there are various methods for the method, and the first method will be described below.
  • the SOC calculation unit 313 receives the voltage V across the battery 100, the current (battery current) I flowing through the battery 100, the battery temperature T of the battery 100, and the like.
  • the SOC calculation unit 313 calculates and outputs an SOC based on the integrated value of the current based on the input current and the previous value (calculation result of one cycle earlier) of the SOC calculation result by the SOC calculation unit 313.
  • the SOC is calculated, for example, by the following equation (1).
  • SOCold is the previous value of SOC.
  • ⁇ SOC is a change amount of SOC due to the current I flowing from the previous calculation time to the current calculation time
  • Qmax is a full charge capacity of the battery 100
  • ts is a control cycle (sampling cycle such as current or voltage) It is.
  • SOC operation unit 313 integrates the discharge current from full charge based on equation (1), and the charge amount remaining in battery 100 with respect to the charge amount (total capacity) that can be charged to the maximum. The ratio of (remaining capacity) is calculated to determine the SOC.
  • battery 100 can be represented by a series connection of an impedance Z and a capacitance component C in parallel, an internal resistance R, and an open circuit voltage OCV.
  • a closed circuit voltage CCV which is a voltage between terminals of the battery 100 is expressed by the following equation (2).
  • Vp is a polarization voltage, which corresponds to the voltage across the parallel-connected pair of impedance Z and capacitance component C.
  • CCV OCV + I ⁇ R + Vp (2)
  • SOC operation unit 313 obtains open circuit voltage OCV by subtracting IR drop and polarization voltage Vp from closed circuit voltage CCV as in the following equation (3).
  • OCV CCV-I-R-Vp (3)
  • the internal resistance R and the polarization voltage Vp are stored in advance in the storage unit 120 as characteristic information of the battery 100. Since the internal resistance R and the polarization voltage Vp differ depending on the charge state of the battery 100, the battery temperature, and the like, individual values are stored in the storage unit 120 for each combination of these. In the present embodiment, the storage unit 120 is referred to using the internal resistance R obtained by the internal resistance calculation unit 312. Then, using the internal resistance R determined by the internal resistance calculation unit 312, an IR drop is determined.
  • the correspondence between the open circuit voltage OCV of the battery 100 and the SOC is determined by the characteristics of the battery 100, and in the storage unit 120, data defining the correspondence is stored in advance as an SOC table.
  • SOC operation unit 313 calculates open circuit voltage OCV using equation (3) described above, and uses this as a key to calculate the SOC of battery 100 by referring to the SOC table.
  • the current SOC can be obtained by the first method and the second method. Furthermore, the SOC may be determined by weighted addition to the SOC determined by these methods.
  • the SOH calculator 314 calculates SOH, for example, according to the following equation (4), based on the initial internal resistance value R0 corresponding to the SOC and the temperature, and the internal resistance value R at the present time.
  • the value of the internal resistance R determined by the internal resistance calculation unit 312 is used.
  • SOH 100 ⁇ R / R 0 (4)
  • the initial internal resistance value R0 is stored in advance in storage unit 320 corresponding to battery 100.
  • the SOH calculator 314 updates the calculation based on the equation (4) for each predetermined cycle such as a control cycle (sampling cycle of current, voltage or the like) and outputs it.
  • the SOC calculating part 313 and the SOH calculating part 314 show the typical example utilized in the secondary battery control apparatus in this embodiment, it is not restricted to these and another calculation is added. It may be other configurations.
  • FIG. 3 is a diagram showing the relationship between the battery temperature of the battery 100 and the internal resistance.
  • the horizontal axis represents temperature
  • the vertical axis represents internal resistance.
  • R THIGH the internal resistance
  • R TLOW the internal resistance
  • FIG. 4 is a diagram showing the relationship between the battery temperature and the internal resistance error, and shows the degree of influence of the measurement error of the battery temperature T on the calculation result of the internal resistance R.
  • the battery temperature T is a value measured by the measurement unit 200, but the measurement result includes the measurement error ⁇ .
  • the measurement error ⁇ by the measurement unit 200 is added, and the range is from T H1 to T H2 .
  • the possible range of the internal resistance R is R TH1 to R TH2 .
  • the measurement error ⁇ by the measurement unit 200 is added, and the range is from T L1 to T L2 .
  • the possible range of the internal resistance R is R TL1 to R TL2 .
  • FIG. 5 is a diagram showing the relationship between the battery temperature, the correction temperature, and the internal resistance error.
  • Figure 5 shows an example, and the internal R T resistor corresponding to the battery temperature T, and an internal resistance R T [alpha corresponding to the temperature T alpha performing the correction of adding temperature correction value alpha to the battery temperature T.
  • the battery temperature T measured by the measuring unit 200 includes a measurement error ⁇ . Therefore, the temperature range when considering the measurement error ⁇ is in the range of T 1 of the T 2. That is, the range of T 1 to T 2 is within the range of the measurement error ⁇ . At this time, although the original internal resistance is RT , the internal resistance calculated under the influence of the temperature measurement error is in the range from RT1 to RT2 .
  • the temperature correction unit 311 adds the temperature correction value ⁇ to the battery temperature T, and the added battery temperature is T ⁇ .
  • the temperature correction value ⁇ is a value within the range of the measurement error value ⁇ of the temperature measurement by the sensor of the measurement unit 200. At this time, although the internal resistance becomes R T [alpha, internal resistance calculated by the influence of the temperature measurement error in the range of R T [alpha] 1 of R T ⁇ 2.
  • the temperature correction value ⁇ a value that satisfies this condition is set.
  • Storage unit 320 stores the correspondence between temperature and internal resistance, and based on the correspondence between temperature and internal resistance, temperature correction value ⁇ for reducing the internal resistance error as described above is stored in advance. ing.
  • the temperature correction unit 311 reads the temperature correction value ⁇ , adds the temperature correction value ⁇ to the battery temperature T measured by the measurement unit 200, and outputs the correction temperature T ⁇ to the internal resistance calculation unit 312.
  • the temperature correction value ⁇ corrected by the temperature correction unit 311 will be described with reference to FIGS. 6 to 8.
  • the temperatures of the battery 100 are 25 ° C., 35 ° C., and 45 ° C.
  • the battery temperature T measured by the measuring unit 200 is 25 ° C., 35 ° C., and 45 ° C.
  • the graph shows the internal resistance error when the temperature correction value ⁇ is performed from 0 to 2.0 when the temperature includes the errors of 0 ° C., 1 ° C., 2 ° C., and 3 ° C., respectively.
  • FIG. 6 is a diagram showing the relationship between the temperature correction value ⁇ and the internal resistance error when the temperature of the battery 100 is 25 ° C.
  • the actual temperature T c of the battery 100 is 25 ° C.
  • the temperature T measured by the measuring unit 200 is T C + 3 ° C.
  • the temperature correction value ⁇ has a range in which the internal resistance error is minimized.
  • the broken line of the black triangle mark in FIG. 6 is a case where the temperature T measured by the measurement unit 200 is T C + 2 ° C., that is, a measurement error of 2 ° C. is included.
  • the broken line in the black square in FIG. 6 is a case where the temperature T measured by the measurement unit 200 is T C + 1 ° C., that is, a measurement error of 1 ° C. is included.
  • the broken line in the black rhombus in FIG. 6 is a case where the temperature T measured by the measurement unit 200 is T C ° C., that is, a measurement error of 0 ° C. is included. That is, it can be seen that the internal resistance error can be reduced by increasing the temperature correction value ⁇ as the measurement error increases.
  • FIG. 7 is a diagram showing the relationship between the temperature correction value ⁇ and the internal resistance error when the temperature of the battery 100 is 35 ° C.
  • the temperature correction value ⁇ is represented by a line graph of black circles. The internal resistance error is minimized when the temperature is set to 1.5.degree.
  • FIG. 8 is a diagram showing the relationship between the temperature correction value ⁇ and the internal resistance error when the temperature of the battery 100 is 45 ° C.
  • the internal resistance error is increased by performing the temperature correction. This is because, as described with reference to FIG. 4, the higher the battery temperature, the smaller the influence on the error of the internal resistance due to the temperature measurement error. Therefore, the effect of the expansion of the internal resistance error due to the temperature correction Because it is larger.
  • the temperature correction value ⁇ is 1 ° C.
  • the temperature correction value ⁇ is 1.
  • the temperature is 5 ° C.
  • the temperature correction value ⁇ is set to 0 ° C., or the temperature correction is not performed. Thereby, the reduction of the internal resistance error due to the temperature correction can be effectively used.
  • the storage unit 320 stores the correspondence between the battery temperature T and the temperature correction value ⁇ .
  • the temperature correction unit 311 refers to the correspondence between the battery temperature T and the temperature correction value ⁇ stored in the storage unit 320, and uses the temperature correction value ⁇ corresponding to the battery temperature T of the battery 100 measured by the measurement unit 200. Read out, the temperature correction value ⁇ is added to the battery temperature T, and the result is output to the internal resistance calculation unit 312.
  • the threshold of the temperature or the like exemplified in the present embodiment is not limited to that value, and an optimal value may be selected according to the characteristics of the device involved in the calculation, such as the characteristics of the battery 100 and the measurement error of the measuring unit 200. It shall be selected.
  • the internal resistance calculated by the internal resistance calculation unit 312 can be obtained.
  • the error can be reduced. Furthermore, the errors in the calculations of the SOC calculation unit 313 and the SOH calculation unit 314 using the internal resistance also decrease.
  • the secondary battery monitoring device 1000 includes a measurement unit 200 that measures the temperature of the battery 100, and a secondary battery state calculation device 300 that calculates the state of the battery 100.
  • the secondary battery state arithmetic unit 300 adds the temperature correction value ⁇ to the battery temperature T measured by the measurement unit 200 and the storage unit 320 that stores the correspondence between the temperature of the battery 100 and the internal resistance, and corrects the correction temperature T
  • a temperature correction unit 311 for deriving ⁇ an internal resistance calculation unit 312 for obtaining an internal resistance corresponding to the correction temperature T ⁇ derived by the temperature correction unit 311 with reference to the storage unit 320, and an internal resistance calculation unit 312
  • the SOC calculation unit 313 and the SOH calculation unit 314 that estimate the state of the battery 100 based on the calculated internal resistance are provided.
  • the SOC calculation unit 313 and the SOH calculation unit 314 are elements constituting the battery state estimation device 310. Thereby, the error of the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
  • the storage unit 320 stores the correspondence between the battery temperature T and the temperature correction value ⁇ , and the temperature correction unit 311 corresponds to the battery temperature T measured by the measurement unit 200.
  • the temperature correction value ⁇ to be calculated is determined with reference to the correspondence between the battery temperature T stored in the storage unit 320 and the temperature correction value ⁇ .
  • the battery temperature T can be associated with the temperature correction value ⁇ , the error in the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
  • the temperature correction unit 311 sets the battery temperature T measured by the measurement unit 200 and the resistance value RT corresponding to the battery temperature T calculated by the internal resistance calculation unit 312 as the temperature correction value ⁇ , and the battery temperature T
  • Two temperatures obtained by T ⁇ 1, T ⁇ 2 and the internal resistance calculator 312 A temperature correction value
  • the temperature correction value ⁇ is within the range of the temperature measurement error of the measurement unit 200. Therefore, the error of the internal resistance of the secondary battery in the low temperature range can be reduced within the range of the temperature measurement error of the measurement unit 200, and the accuracy of the state estimation of the secondary battery can be improved.
  • the secondary battery state computing device 300 includes the storage unit 320 that stores the correspondence between the temperature of the secondary battery and the internal resistance, and the battery state estimation device 310.
  • Battery state estimating unit 310 includes a temperature compensation unit 311 for deriving the correction temperature T alpha by adding the temperature correction value alpha to the measured battery temperature T, corresponding to the correction temperature T alpha derived by the temperature correction unit 311
  • An internal resistance calculating unit 312 for obtaining the internal resistance with reference to the storage unit; an SOC calculating unit 313 for estimating the state of the secondary battery based on the internal resistance obtained by the internal resistance calculating unit 312; Equipped with
  • the internal resistance calculation unit 312 measures the internal resistance corresponding to the measured battery temperature T, the temperature T of the secondary battery stored in the storage unit 320, and the internal resistance. Determine by referring to the correspondence of.
  • the secondary battery state estimation method stores the correspondence between the temperature of the battery 100 and the internal resistance, adds the temperature correction value ⁇ to the measured battery temperature T, and derives the correction temperature T ⁇ to derive the correction temperature T ⁇ .
  • the internal resistance corresponding to the corrected temperature T ⁇ is determined with reference to the stored correspondence relationship between the temperature of the battery 100 and the internal resistance, and the state of the battery 100 is estimated based on the determined internal resistance. Thereby, the error of the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
  • the internal resistance corresponding to the measured battery temperature T is a correspondence between the stored secondary battery temperature and the internal resistance. See and ask for.
  • the present invention can be implemented with the following modifications of the embodiment described above.
  • (1) The embodiment has been described using an example in which the temperature range for temperature correction and the temperature correction value ⁇ are predetermined and stored in the storage unit 320. However, these are not determined in advance, and the battery state estimation device 310 calculates the temperature correction value ⁇ which reduces the internal resistance error most while changing the temperature correction value ⁇ variously, and determines it in real time. It may be

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Tests Of Electric Status Of Batteries (AREA)
  • Secondary Cells (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

If no measures are taken against increases in errors in the internal resistance of a secondary cell in a low-temperature region, not only will errors in the internal resistance increase in the low-temperature region, but also precision of estimating the state of the secondary cell will deteriorate. When the temperature of a cell 100 is equal to or less than a prescribed value, a temperature correction unit 311 refers to a correlation between cell temperatures T and temperature correction values α that is stored in a storage unit 320, reads out a temperature correction value α that corresponds to the cell temperature T of the cell 100 as measured by a measurement unit 200, adds the temperature correction value α to the cell temperature T, and outputs the result to an internal resistance computation unit 312.

Description

二次電池監視装置、二次電池状態演算装置および二次電池状態推定方法Secondary battery monitoring device, secondary battery state computing device and secondary battery state estimating method
　本発明は、二次電池監視装置、二次電池状態演算装置および二次電池状態推定方法に関する。 The present invention relates to a secondary battery monitoring device, a secondary battery state calculation device, and a secondary battery state estimation method.
　リチウムニ次電池やニッケル水素電池、鉛電池、電気二重層キャパシタなどの二次電池を用いた電源装置、分散型電力貯蔵装置、電気自動車では、二次電池を安全に、且つ有効に使用するために、二次電池の状態を推定している。二次電池の状態としては、二次電池の内部抵抗、どの程度まで充電されているか、あるいはどの程度放電可能な電荷量が残っているのかを示す充電状態（ＳＯＣ：Ｓｔａｔｅ ｏｆ Ｃｈａｒｇｅ）又は残存容量、どの程度まで劣化もしくは弱っているのかを示す健康状態（ＳＯＨ：Ｓｔａｔｅ ｏｆ Ｈｅａｌｔｈ）又は劣化度などがある。これらの二次電池の状態に基づいて、二次電池からどの程度の出力を出せるのかの指標となる許容電力や許容電流などが導出される。 Power supply device using a secondary battery such as a lithium secondary battery, a nickel hydrogen battery, a lead battery, an electric double layer capacitor, a distributed power storage device, and an electric vehicle, for using the secondary battery safely and effectively , Have estimated the state of the secondary battery. The state of the secondary battery is the internal resistance of the secondary battery, the state of charge (SOC: State of Charge) or the remaining capacity indicating how much the battery is charged or to which the amount of charge that can be discharged remains. There is a state of health (SOH) or a degree of deterioration, which indicates how much the body is deteriorated or weakened. Based on the state of these secondary batteries, an allowable power, an allowable current, and the like, which are indicators of how much power can be output from the secondary battery, are derived.
　そして、二次電池の状態の推定には、二次電池の内部抵抗が用いられているため、これを正確に検知、推定することが重要である。一般に内部抵抗と温度との関係においては、低温ほど内部抵抗が高くなる傾向があり、より低温になるほど内部抵抗の上昇率も上がり、温度から内部抵抗を検索する場合、内部抵抗の誤差が拡大する傾向にある。特許文献１には、二次電池の内部抵抗‐温度特性データと温度センサで測定された温度とに基づいて温度補正することが記載されている。 And since the internal resistance of the secondary battery is used to estimate the state of the secondary battery, it is important to detect and estimate this accurately. Generally, in the relationship between internal resistance and temperature, the lower the temperature, the higher the internal resistance tends to be, and the lower the temperature, the higher the rate of increase in internal resistance, and when searching for internal resistance from temperature, the error in internal resistance increases There is a tendency. Patent Document 1 describes that temperature correction is performed based on internal resistance-temperature characteristic data of a secondary battery and a temperature measured by a temperature sensor.
特開２００１－２２８２２６号公報JP, 2001-228226, A
　特許文献１に記載の技術は、低温域における二次電池の内部抵抗の誤差の拡大について対策を取っておらず、低温域における内部抵抗の誤差が拡大し、ひいては二次電池の状態推定の精度も悪化する。 The technique described in Patent Document 1 does not take measures against the expansion of the error of the internal resistance of the secondary battery in the low temperature region, the error of the internal resistance in the low temperature region is expanded, and thus the accuracy of the state estimation of the secondary battery Even worse.
　本発明による二次電池監視装置は、二次電池の温度を測定する温度測定部、および二次電池状態演算装置を備え、二次電池状態演算装置は、前記二次電池の温度と内部抵抗との対応関係を記憶する記憶部と、前記温度測定部で測定された電池温度Ｔに温度補正値αを加算して補正温度Tαを導出する温度補正部と、前記温度補正部で導出された前記補正温度Tαに対応する内部抵抗を前記記憶部を参照して求める内部抵抗演算部と、前記内部抵抗演算部で求められた内部抵抗に基づいて前記二次電池の状態推定を行う状態推定制御部と、を備える。
　本発明による二次電池状態演算装置は、二次電池の温度と内部抵抗との対応関係を記憶する記憶部と、測定された電池温度Ｔに温度補正値αを加算して補正温度Tαを導出する温度補正部と、前記温度補正部で導出された前記補正温度Tαに対応する内部抵抗を前記記憶部を参照して求める内部抵抗演算部と、前記内部抵抗演算部で求められた内部抵抗に基づいて前記二次電池の状態推定を行う状態推定制御部と、を備える。
　本発明による二次電池状態推定方法は、二次電池の温度と内部抵抗との対応関係を記憶し、測定された電池温度Ｔに温度補正値αを加算して補正温度Tαを導出し、導出された前記補正温度Tαに対応する内部抵抗を前記記憶された二次電池の温度と内部抵抗との対応関係を参照して求め、求められた内部抵抗に基づいて前記二次電池の状態推定を行う。 The secondary battery monitoring device according to the present invention includes a temperature measurement unit that measures the temperature of the secondary battery, and a secondary battery state computing device. The secondary battery state computing device includes the temperature and the internal resistance of the secondary battery. And a temperature correction unit that derives a correction temperature T α by adding a temperature correction value α to the battery temperature T measured by the temperature measurement unit, and a temperature correction unit that is derived by the temperature correction unit State estimation for performing the state estimation of the secondary battery based on an internal resistance calculating unit that obtains the internal resistance corresponding to the correction temperature T α with reference to the storage unit, and the internal resistance obtained by the internal resistance calculating unit And a control unit.
The secondary battery state calculation device according to the present invention adds the temperature correction value α to the measured battery temperature T and stores the correction temperature T α by the storage unit that stores the correspondence between the temperature of the secondary battery and the internal resistance. A temperature correction unit to be derived, an internal resistance calculation unit to obtain the internal resistance corresponding to the correction temperature T α derived by the temperature correction unit with reference to the storage unit, and an internal calculation obtained by the internal resistance calculation unit And a state estimation control unit that estimates the state of the secondary battery based on a resistance.
The secondary battery state estimation method according to the present invention stores the correspondence between the temperature of the secondary battery and the internal resistance, adds the temperature correction value α to the measured battery temperature T, and derives the correction temperature T α . The internal resistance corresponding to the derived correction temperature T α is determined with reference to the stored correspondence relationship between the temperature of the secondary battery and the internal resistance, and the state of the secondary battery based on the determined internal resistance Make an estimate.
　本発明によれば、低温域における二次電池の内部抵抗の誤差を低減させ、二次電池の状態推定の精度を向上することができる。 According to the present invention, the error of the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
二次電池監視装置のブロック構成図である。It is a block block diagram of a secondary battery monitoring device. 二次電池状態演算装置のブロック構成図である。It is a block block diagram of a secondary battery state arithmetic unit. 電池温度と内部抵抗の関係を示す図である。It is a figure which shows the relationship between battery temperature and internal resistance. 電池温度と内部抵抗誤差の関係を示す図である。It is a figure which shows the relationship between battery temperature and an internal resistance error. 電池温度と補正温度と内部抵抗誤差の関係を示す図である。It is a figure which shows the relationship between a battery temperature, correction | amendment temperature, and an internal resistance error. 電池温度２５℃における温度補正値と内部抵抗誤差の関係を示す図である。It is a figure which shows the relationship between the temperature correction value in 25 degreeC of battery temperatures, and an internal resistance difference | error. 電池温度３５℃における温度補正値と内部抵抗誤差の関係を示す図である。It is a figure which shows the relationship between the temperature correction value in 35 degreeC of battery temperatures, and an internal resistance difference | error. 電池温度４５℃における温度補正値と内部抵抗誤差の関係を示す図である。It is a figure which shows the relationship between the temperature correction value in 45 degreeC of battery temperatures, and an internal resistance difference | error.
　図１は、本実施形態における二次電池監視装置１０００のブロック構成図である。二次電池監視装置１０００は、電池１００、計測部２００、電池状態演算装置３００、出力部４００を備える。電池１００が蓄積している電荷は外部装置に電力として供給され、電力を供給する対象としては、例えば電気自動車やハイブリッド自動車、電車などが考えられる。電池状態演算装置３００は、電池１００の充電状態ＳＯＣおよび劣化度ＳＯＨなどを出力部４００へ出力する。 FIG. 1 is a block diagram of a secondary battery monitoring device 1000 in the present embodiment. The secondary battery monitoring device 1000 includes a battery 100, a measurement unit 200, a battery state calculation device 300, and an output unit 400. The charge stored in the battery 100 is supplied as power to an external device, and an electric vehicle, a hybrid car, a train, or the like can be considered as a target for supplying power. The battery state computing device 300 outputs the state of charge SOC of the battery 100, the degree of deterioration SOH, and the like to the output unit 400.
　電池１００は、例えばリチウムイオン二次電池などの充電可能な電池である。その他、ニッケル水素電池、鉛電池、電気２重層キャパシタなどの電力貯蔵機能を有するデバイスに対しても、本実施形態を適用することができる。電池１００は、単電池セルであっても良いし、単電池セルを複数組み合わせたモジュール構造でも良い。 The battery 100 is, for example, a rechargeable battery such as a lithium ion secondary battery. In addition, the present embodiment can be applied to a device having a power storage function such as a nickel hydrogen battery, a lead battery, and an electric double layer capacitor. The battery 100 may be a single battery cell, or may be a module structure in which a plurality of single battery cells are combined.
　計測部２００は、電池１００の物理特性、例えば電池１００の両端電圧Ｖ、電池１００に流れる電流（電池電流）Ｉ、電池１００の電池温度Ｔなどを計測する機能部であり、各値を計測するセンサ、必要な電気回路などによって構成されている。なお、電池温度Ｔの測定にはサーミスタ、熱電対、赤外線などの計測手段が用いられるが、いずれの計測手段の場合も、その測定結果の電池温度にはデバイス固有の測定誤差値βが含まれる。 The measurement unit 200 is a functional unit that measures physical characteristics of the battery 100, for example, voltage V across the battery 100, current (battery current) I flowing to the battery 100, battery temperature T of the battery 100, etc. It consists of sensors, necessary electrical circuits, etc. Although measurement means such as a thermistor, thermocouple or infrared ray are used to measure the battery temperature T, in any measurement means, the battery temperature as the measurement result includes the device-specific measurement error value β .
　電池状態演算装置３００は、電池１００の状態推定を行う装置であり、電池状態推定装置３１０と記憶部３２０とを備える。なお、後述するように電池１００の状態推定には電池１００の内部抵抗値Ｒが必要であるが、本実施形態では、電池状態推定装置３１０において、内部抵抗値Ｒをその他の計測パラメータを用いて算出する。 The battery state calculation device 300 is a device that estimates the state of the battery 100, and includes a battery state estimation device 310 and a storage unit 320. In addition, although internal resistance value R of the battery 100 is required for state estimation of the battery 100 so that it may mention later, in this embodiment, in the battery state estimation apparatus 310, internal resistance value R is used using other measurement parameters. calculate.
　電池状態推定装置３１０は、計測部２００により計測された電池１００の両端電圧Ｖ、電池１００に流れる電池電流Ｉ、及び電池１００の電池温度Ｔに基づいて、記憶部３２０に格納されている電池１００の特性情報を参照して、電池１００のＳＯＣやＳＯＨを算出する。電池１００の内部抵抗Ｒの演算、ＳＯＣやＳＯＨの演算については後述する。 The battery state estimation device 310 stores the battery 100 stored in the storage unit 320 based on the voltage V across the battery 100 measured by the measurement unit 200, the battery current I flowing to the battery 100, and the battery temperature T of the battery 100. The SOC and SOH of the battery 100 are calculated with reference to the characteristic information of Calculation of the internal resistance R of the battery 100 and calculation of the SOC and SOH will be described later.
　電池状態推定装置３１０は、その機能を実現する回路デバイスなどのハードウェアを用いて構成することができる。また、その機能を実装したソフトウェアを、ＣＰＵ（Central Processing Unit）などの演算装置が実行することによって構成することもできる。後者の場合は、当該ソフトウェアは例えば記憶部３２０に格納される。 The battery state estimation device 310 can be configured using hardware such as a circuit device that realizes the function. Alternatively, software that implements the function can be configured by execution by an arithmetic device such as a central processing unit (CPU). In the latter case, the software is stored, for example, in the storage unit 320.
　記憶部３２０は、電池１００の内部抵抗Ｒ、分極電圧、充電効率、許容電流、電池容量などの、あらかじめ知ることができる電池１００の特性情報を記憶している。本実施形態では、電池温度と内部抵抗との対応関係を対応テーブル、関数式などの形式で記憶している。さらに、後述するように電池温度と温度補正値との対応関係を記憶している。これらの特性情報は、充電・放電の動作別に値を個別に記憶するようにしてもよいし、充電状態や電池温度など、電池１００の状態毎に値を個別に記憶するようにしてもよい。 The storage unit 320 stores characteristic information of the battery 100 that can be known in advance, such as the internal resistance R of the battery 100, the polarization voltage, the charging efficiency, the allowable current, and the battery capacity. In the present embodiment, the correspondence between the battery temperature and the internal resistance is stored in the form of a correspondence table, a functional expression, or the like. Further, as described later, the correspondence between the battery temperature and the temperature correction value is stored. The characteristic information may store values individually for charge and discharge operations, or may store values individually for each state of the battery 100, such as charge state and battery temperature.
　記憶部３２０は、フラッシュメモリ、ＥＥＰＲＯＭ（Electrically Erasable Programmable Read-Only Memory）、磁気ディスクなどの記憶装置を用いて構成される。記憶部３２０は、電池状態推定装置３１０の外部に設けてもよいし、電池状態推定装置３１０の内部に備えるメモリ装置として実現してもよい。記憶部３２０は、取り外し可能にしてもよい。取り外し可能にした場合、記憶部３２０を取り替えることによって、特性情報とソフトウェアを簡単に変更することができる。また、記憶部３２０を複数有し、特性情報とソフトウェアを取り替え可能な記憶部３２０に分散させて格納することにより、特性情報とソフトウェアを小単位毎に更新することができる。 The storage unit 320 is configured using a storage device such as a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a magnetic disk, or the like. The storage unit 320 may be provided outside the battery state estimation device 310, or may be realized as a memory device provided inside the battery state estimation device 310. The storage unit 320 may be removable. If removable, replacing the storage unit 320 allows the characteristic information and software to be easily changed. Further, the characteristic information and the software can be updated for each small unit by distributing and storing the characteristic information and the software in the replaceable storage unit 320 having a plurality of the memory units 320.
　出力部４００は、電池状態演算装置３００の出力を外部装置（例えば電気自動車が備える車両制御装置などの上位装置）に対して出力する機能部である。 The output unit 400 is a functional unit that outputs the output of the battery state calculation device 300 to an external device (for example, a host device such as a vehicle control device provided in an electric vehicle).
　図２は、電池状態推定装置３１０と記憶部３２０とよりなる電池状態演算装置３００のブロック構成図である。
　電池状態推定装置３１０は、温度補正部３１１、内部抵抗演算部３１２、ＳＯＣ演算部３１３、ＳＯＨ演算部３１４を備える。 FIG. 2 is a block diagram of a battery state calculation device 300 including the battery state estimation device 310 and the storage unit 320.
The battery state estimation device 310 includes a temperature correction unit 311, an internal resistance calculation unit 312, an SOC calculation unit 313, and an SOH calculation unit 314.
　温度補正部３１１は、電池１００の温度が所定値以下の場合に、計測部２００により計測された電池温度Ｔに対して温度補正値αを加算して補正温度Ｔαを内部抵抗演算部３１２へ出力する。なお、この温度補正値αは、計測部２００のセンサによる温度測定の測定誤差値βの範囲内の値である。測定誤差値βは、計測部２００に用いられるセンサに応じた固有の値であり、予め判明している値である。最適な温度補正値αの導出については後述する。また、温度補正部３１１は、電池１００の温度が所定値以下でない場合は、計測部２００により計測された電池温度Ｔをそのまま内部抵抗演算部３１２へ出力する。 The temperature correction unit 311 adds the temperature correction value α to the battery temperature T measured by the measurement unit 200 when the temperature of the battery 100 is equal to or lower than the predetermined value, and sends the correction temperature T α to the internal resistance calculation unit 312. Output. The temperature correction value α is a value within the range of the measurement error value β of the temperature measurement by the sensor of the measurement unit 200. The measurement error value β is a unique value corresponding to the sensor used in the measurement unit 200, and is a value known in advance. The derivation of the optimal temperature correction value α will be described later. When the temperature of battery 100 is not equal to or lower than the predetermined value, temperature correction unit 311 outputs battery temperature T measured by measurement unit 200 to internal resistance calculation unit 312 as it is.
　内部抵抗演算部３１２は、電池１００の温度が所定値以下の場合には、温度補正部３１１求められた補正温度Ｔαに対応する内部抵抗を、記憶部３２０内の温度と内部抵抗との対応関係を参照して求める。また、内部抵抗演算部３１２は、電池１００の温度が所定値以下でない場合には、計測部２００により計測された電池温度Ｔに対応する内部抵抗を、記憶部３２０内の温度と内部抵抗との対応関係を参照して求める。求められた内部抵抗はＳＯＣ演算部３１３およびＳＯＨ演算部３１４へ出力される。 When the temperature of the battery 100 is equal to or lower than a predetermined value, the internal resistance calculation unit 312 corresponds the internal resistance corresponding to the corrected temperature T α determined by the temperature correction unit 311 to the temperature in the storage unit 320 and the internal resistance. Find by referring to the relationship. Further, when the temperature of battery 100 is not equal to or lower than a predetermined value, internal resistance calculation unit 312 sets the internal resistance corresponding to battery temperature T measured by measurement unit 200 to the internal resistance of temperature in storage unit 320 and the internal resistance. Determine by referring to the correspondence. The calculated internal resistance is output to SOC calculation unit 313 and SOH calculation unit 314.
　電池１００の温度が所定値以下の場合には、温度補正部３１１および内部抵抗演算部３１２により、後述するように、より誤差の少ない内部抵抗の値に変換されているので、この値を用いたＳＯＣ演算部３１３およびＳＯＨ演算部３１４の演算も誤差が少なくなる。 When the temperature of battery 100 is lower than a predetermined value, temperature correction unit 311 and internal resistance calculation unit 312 convert the value of internal resistance with less error, as described later, so this value was used. The calculation of the SOC calculation unit 313 and the SOH calculation unit 314 also reduces the error.
　以下に、ＳＯＣ演算部３１３およびＳＯＨ演算部３１４の演算の一例について説明する。
　ＳＯＣ演算部３１３は、ＳＯＣを求めるが、その手法には種々の手法があり、以下に、第一の手法について説明する。 Hereinafter, an example of the calculation of the SOC calculation unit 313 and the SOH calculation unit 314 will be described.
The SOC operation unit 313 obtains the SOC, but there are various methods for the method, and the first method will be described below.
　ＳＯＣ演算部３１３には、電池１００の両端電圧Ｖ、電池１００に流れる電流（電池電流）Ｉ、電池１００の電池温度Ｔなどが入力される。ＳＯＣ演算部３１３は、入力された電流と、ＳＯＣ演算部３１３によるＳＯＣ演算結果の前回値（一周期前の演算結果）とに基づいて、電流の積算値に基づくＳＯＣを演算して出力する。ＳＯＣは、例えば、次式（１）で算出される。式（１）において、ＳＯＣoldは、ＳＯＣの前回値である。また、ΔＳＯＣは、前回の演算時から今回の演算時までに流れた電流ＩによるＳＯＣの変化量であり、Ｑmaxは電池１００の満充電容量、ｔsは制御周期(電流や電圧等のサンプリング周期)である。
　　ＳＯＣ＝ＳＯＣold＋ΔＳＯＣ　　…（１）
　ただし、ΔＳＯＣ＝１００×Ｉ×ｔs／Ｑmaxである。 The SOC calculation unit 313 receives the voltage V across the battery 100, the current (battery current) I flowing through the battery 100, the battery temperature T of the battery 100, and the like. The SOC calculation unit 313 calculates and outputs an SOC based on the integrated value of the current based on the input current and the previous value (calculation result of one cycle earlier) of the SOC calculation result by the SOC calculation unit 313. The SOC is calculated, for example, by the following equation (1). In equation (1), SOCold is the previous value of SOC. Further, ΔSOC is a change amount of SOC due to the current I flowing from the previous calculation time to the current calculation time, Qmax is a full charge capacity of the battery 100, and ts is a control cycle (sampling cycle such as current or voltage) It is.
SOC = SOCold + ΔSOC (1)
However, it is ΔSOC = 100 × I × ts / Qmax.
　このように、ＳＯＣ演算部３１３は、式（１）に基づいて、満充電からの放電電流を積算し、最大限充電可能な電荷量（全容量）に対し、電池１００に残っている電荷量（残存容量）の比を算出してＳＯＣを求める。 Thus, SOC operation unit 313 integrates the discharge current from full charge based on equation (1), and the charge amount remaining in battery 100 with respect to the charge amount (total capacity) that can be charged to the maximum. The ratio of (remaining capacity) is calculated to determine the SOC.
　次に、ＳＯＣ演算部３１３によるＳＯＣを求める第二の手法について説明する。
　一般に、電池１００は、インピーダンスＺとキャパシタンス成分Ｃの並列接続対、内部抵抗Ｒ、開回路電圧ＯＣＶの直列接続によって表すことができる。電池１００に電池電流Ｉを印加すると、電池１００の端子間電圧である閉回路電圧ＣＣＶは次式（２）で表される。式（２）において、Ｖｐは分極電圧であり、インピーダンスＺとキャパシタンス成分Ｃの並列接続対の両端電圧に相当する。
　　ＣＣＶ＝ＯＣＶ＋Ｉ・Ｒ＋Ｖｐ　・・・（２） Next, a second method of obtaining the SOC by the SOC calculation unit 313 will be described.
In general, battery 100 can be represented by a series connection of an impedance Z and a capacitance component C in parallel, an internal resistance R, and an open circuit voltage OCV. When a battery current I is applied to the battery 100, a closed circuit voltage CCV which is a voltage between terminals of the battery 100 is expressed by the following equation (2). In equation (2), Vp is a polarization voltage, which corresponds to the voltage across the parallel-connected pair of impedance Z and capacitance component C.
CCV = OCV + I · R + Vp (2)
　ＳＯＣの算出には開回路電圧ＯＣＶが用いられるが、電池１００が充放電している間は直接測定することができない。そこで、ＳＯＣ演算部３１３は、次式（３）のように閉回路電圧ＣＣＶからＩＲドロップと分極電圧Ｖｐを差し引くことにより、開回路電圧ＯＣＶを求める。
　　ＯＣＶ＝ＣＣＶ－Ｉ・Ｒ－Ｖｐ　・・・（３） Although the open circuit voltage OCV is used to calculate the SOC, it can not be measured directly while the battery 100 is charging and discharging. Therefore, SOC operation unit 313 obtains open circuit voltage OCV by subtracting IR drop and polarization voltage Vp from closed circuit voltage CCV as in the following equation (3).
OCV = CCV-I-R-Vp (3)
　内部抵抗Ｒと分極電圧Ｖｐは、記憶部１２０に予め電池１００の特性情報として格納されている。内部抵抗Ｒと分極電圧Ｖｐは、電池１００の充電状態や電池温度などに応じて異なるので、これらの組合せ毎に個別の値が記憶部１２０に格納されている。本実施形態では、内部抵抗演算部３１２で求められ内部抵抗Ｒを用いて、記憶部１２０を参照する。そして、内部抵抗演算部３１２で求められた内部抵抗Ｒを用いて、ＩＲドロップを求める。 The internal resistance R and the polarization voltage Vp are stored in advance in the storage unit 120 as characteristic information of the battery 100. Since the internal resistance R and the polarization voltage Vp differ depending on the charge state of the battery 100, the battery temperature, and the like, individual values are stored in the storage unit 120 for each combination of these. In the present embodiment, the storage unit 120 is referred to using the internal resistance R obtained by the internal resistance calculation unit 312. Then, using the internal resistance R determined by the internal resistance calculation unit 312, an IR drop is determined.
　また、電池１００の開回路電圧ＯＣＶとＳＯＣとの対応関係は電池１００の特性によって定まるものであり、記憶部１２０には、その対応関係を定義するデータがＳＯＣテーブルとして予め格納されている。ＳＯＣ演算部３１３は、上述の式（３）を用いて開回路電圧ＯＣＶを算出し、これをキーにしてＳＯＣテーブルを参照することにより、電池１００のＳＯＣを算出する。 Further, the correspondence between the open circuit voltage OCV of the battery 100 and the SOC is determined by the characteristics of the battery 100, and in the storage unit 120, data defining the correspondence is stored in advance as an SOC table. SOC operation unit 313 calculates open circuit voltage OCV using equation (3) described above, and uses this as a key to calculate the SOC of battery 100 by referring to the SOC table.
　以上のように、第一の手法、第二の手法により、現在のＳＯＣを求めることができる。さらには、これらの手法で求められたＳＯＣに重み付け加算してＳＯＣを求めてもよい。 As described above, the current SOC can be obtained by the first method and the second method. Furthermore, the SOC may be determined by weighted addition to the SOC determined by these methods.
　ＳＯＨ演算部３１４は、ＳＯＣおよび温度、に対応した初期の内部抵抗値Ｒ0と、現時点の内部抵抗値Ｒとに基づき、例えば、次式（４）によりＳＯＨを算出する。本実施形態では、内部抵抗演算部３１２で求められ内部抵抗Ｒの値を用いる。
　　ＳＯＨ＝１００×Ｒ/Ｒ0　　　…（４）
　初期の内部抵抗値Ｒ0は電池１００に対応して記憶部３２０へ予め記憶されている。ＳＯＨ演算部３１４は、通常は、式（４）に基づく演算を制御周期(電流や電圧等のサンプリング周期)などの所定周期毎に更新して出力する。 The SOH calculator 314 calculates SOH, for example, according to the following equation (4), based on the initial internal resistance value R0 corresponding to the SOC and the temperature, and the internal resistance value R at the present time. In the present embodiment, the value of the internal resistance R determined by the internal resistance calculation unit 312 is used.
SOH = 100 × R / R 0 (4)
The initial internal resistance value R0 is stored in advance in storage unit 320 corresponding to battery 100. In general, the SOH calculator 314 updates the calculation based on the equation (4) for each predetermined cycle such as a control cycle (sampling cycle of current, voltage or the like) and outputs it.
　なお、ＳＯＣ演算部３１３、ＳＯＨ演算部３１４は、本実施形態における二次電池制御装置において利用される代表的な例を示しているが、これらに限られたものではなく、他の演算が加わってもよいし、その他の構成であってもよい。 In addition, although the SOC calculating part 313 and the SOH calculating part 314 show the typical example utilized in the secondary battery control apparatus in this embodiment, it is not restricted to these and another calculation is added. It may be other configurations.
　次に電池１００の内部抵抗について図３、図４を参照して説明する。
　図３は、電池１００の電池温度と内部抵抗の関係を示す図である。図３では、横軸に温度を、縦軸に内部抵抗を示す。図３に示すように、電池の温度が高いＴＨＩＧＨほど内部抵抗は小さくＲＴＨＩＧＨ、温度が低いＴＬＯＷほど内部抵抗は大きくＲ ＴＬＯＷなる。 Next, the internal resistance of the battery 100 will be described with reference to FIGS. 3 and 4.
FIG. 3 is a diagram showing the relationship between the battery temperature of the battery 100 and the internal resistance. In FIG. 3, the horizontal axis represents temperature, and the vertical axis represents internal resistance. As shown in FIG. 3, as the battery temperature is higher T HIGH, the internal resistance is smaller R THIGH , and as the temperature is lower T LOW the internal resistance is larger R TLOW .
　図４は、電池温度と内部抵抗誤差の関係を示す図であり、電池温度Ｔの測定誤差が内部抵抗Ｒの演算結果に与える影響の度合いを示す。電池温度Ｔは計測部２００により測定された値が用いられるが、その測定結果には測定誤差βが含まれる。電池１００の温度が高いＴＨＩＧＨである場合、計測部２００による測定誤差βを加味するとＴＨ１からＴＨ２の範囲となる。この時に内部抵抗Ｒの取りうる範囲はＲＴＨ１からＲＴＨ２となる。一方、電池１００の温度が低いＴＬＯＷである場合、計測部２００による測定誤差βを加味するとＴＬ１からＴＬ２の範囲となる。この時に内部抵抗Ｒの取りうる範囲はＲＴＬ１からＲＴＬ２となる。 FIG. 4 is a diagram showing the relationship between the battery temperature and the internal resistance error, and shows the degree of influence of the measurement error of the battery temperature T on the calculation result of the internal resistance R. The battery temperature T is a value measured by the measurement unit 200, but the measurement result includes the measurement error β. When the temperature of the battery 100 is high T HIGH , the measurement error β by the measurement unit 200 is added, and the range is from T H1 to T H2 . At this time, the possible range of the internal resistance R is R TH1 to R TH2 . On the other hand, when the temperature of the battery 100 is low T LOW , the measurement error β by the measurement unit 200 is added, and the range is from T L1 to T L2 . At this time, the possible range of the internal resistance R is R TL1 to R TL2 .
　電池温度Ｔが高いＴＨＩＧＨの場合の内部抵抗Ｒの演算誤差ＥＲＴＨＩＧＨは、ＥＲＴＨＩＧＨ＝ＲＴＨ１－ＲＴＨ２となり、電池温度Ｔが低いＴＬＯＷの場合の内部抵抗Ｒの演算誤差ＥＲＴＬＯＷは、ＥＲＴＬＬＯＷ＝ＲＴＬ１－ＲＴＬ２となる。このとき２つの演算誤差の関係はＥＲＴＬＯＷ＞ＥＲＴＨＩＧＨとなり電池温度Ｔがより低温になるほど内部抵抗Ｒの演算誤差が大きいことが分かる。 The calculation error E RTHIGH of the internal resistance R when the battery temperature T is high T HIGH is E RTHIGH = R TH1- R TH2 , and the calculation error E RTLOW of the internal resistance R when the battery temperature T is low T LOW is E RTLLOW = R TL1- R TL2 At this time, the relationship between the two calculation errors is E RTLOW > E RT HIGH , and it is understood that the calculation error of the internal resistance R is larger as the battery temperature T becomes lower.
　次に、温度補正部３１１による温度補正について、図５を参照して説明する。
　図５は、電池温度と補正温度と内部抵抗誤差の関係を示す図である。図５は一例として、電池温度Ｔに対応する内部抵抗ＲＴと、電池温度Ｔに温度補正値αを加算する補正を行った温度Ｔαに対応する内部抵抗ＲＴαとを示す。 Next, temperature correction by the temperature correction unit 311 will be described with reference to FIG.
FIG. 5 is a diagram showing the relationship between the battery temperature, the correction temperature, and the internal resistance error. Figure 5 shows an example, and the internal R T resistor corresponding to the battery temperature T, and an internal resistance R T [alpha corresponding to the temperature T alpha performing the correction of adding temperature correction value alpha to the battery temperature T.
　さらに、電池１００の実際の電池温度がＴＣである場合、計測部２００により測定される電池温度Ｔには測定誤差βが含まれる。したがって、測定誤差βを加味すると温度範囲はＴ１からＴ２の範囲となる。すなわち、Ｔ１からＴ２の範囲は測定誤差βの範囲内である。このとき、本来の内部抵抗はＲＴであるが、温度測定誤差の影響で演算される内部抵抗はＲＴ１からＲＴ２の範囲となる。 Furthermore, when the actual battery temperature of the battery 100 is T C , the battery temperature T measured by the measuring unit 200 includes a measurement error β. Therefore, the temperature range when considering the measurement error β is in the range of T 1 of the T 2. That is, the range of T 1 to T 2 is within the range of the measurement error β. At this time, although the original internal resistance is RT , the internal resistance calculated under the influence of the temperature measurement error is in the range from RT1 to RT2 .
　本実施形態では、あえて温度補正部３１１において、電池温度Ｔに温度補正値αを加算し、加算された電池温度がＴαであるとする。なお、この温度補正値αは、計測部２００のセンサによる温度測定の測定誤差値βの範囲内の値とする。このとき、内部抵抗はＲＴαとなるが、温度測定誤差の影響で演算される内部抵抗はＲＴα１からＲＴα２の範囲となる。 In the present embodiment, it is assumed that the temperature correction unit 311 adds the temperature correction value α to the battery temperature T, and the added battery temperature is T α . The temperature correction value α is a value within the range of the measurement error value β of the temperature measurement by the sensor of the measurement unit 200. At this time, although the internal resistance becomes R T [alpha, internal resistance calculated by the influence of the temperature measurement error in the range of R T [alpha] 1 of R Tα2.
　図４を用いて説明したように、電池温度Ｔが高いほど内部抵抗Ｒの誤差は小さくなる。よって、図５に示すように、電池温度Ｔにおける内部抵抗Ｒの誤差のとりうる範囲ＥＲＴと、温度Ｔαにおける内部抵抗誤差のとりうる範囲ＥＲＴαを比較した場合ＥＲＴ＞ＥＲＴαとなり、電池温度Ｔに温度補正値αを加算することで内部抵抗Ｒの誤差が小さくなる。しかし、温度補正部３１１において、実際に測定された電池温度Ｔに対して温度補正値αを加算する補正をしているため、本来のＲＴに対してＤＲ０（＝ＲＴ－ＲＴα）だけ内部抵抗誤差が拡大する。
　よって温度補正を行ったことによって小さくなる内部抵抗誤差ＤＲ１（＝ＥＲＴ－ＥＲＴα）と大きくなる内部抵抗誤差ＤＲ０を比較してＤＲ１のほうが大きくなる範囲で温度補正を行うことで内部抵抗誤差を小さくすることができる。温度補正値αには、この条件を満たす値を設定する。 As described with reference to FIG. 4, the higher the battery temperature T, the smaller the error of the internal resistance R. Therefore, as shown in FIG. 5, when the possible range E RT of the error of the internal resistance R at the battery temperature T and the possible range E RTα of the internal resistance error at the temperature T α are compared, E RT > E RT α , By adding the temperature correction value α to the battery temperature T, the error of the internal resistance R is reduced. However, since the temperature correction unit 311 performs correction to add the temperature correction value α to the battery temperature T actually measured, D R0 (= R T −R Tα ) with respect to the original R T Only the internal resistance error is magnified.
Therefore, the internal resistance error D R1 (= E RT -E RTα ), which decreases due to the temperature correction, is compared with the internal resistance error D R0 that increases and temperature correction is performed in a range where D R1 is larger. Resistance error can be reduced. As the temperature correction value α, a value that satisfies this condition is set.
　記憶部３２０には、温度と内部抵抗との対応関係が記憶されており、この温度と内部抵抗との対応関係に基づいて上述のように内部抵抗誤差を小さくする温度補正値αが予め記憶されている。温度補正部３１１は、この温度補正値αを読み出し、計測部２００により計測された電池温度Ｔに対して温度補正値αを加算して補正温度Ｔαを内部抵抗演算部３１２へ出力する。 Storage unit 320 stores the correspondence between temperature and internal resistance, and based on the correspondence between temperature and internal resistance, temperature correction value α for reducing the internal resistance error as described above is stored in advance. ing. The temperature correction unit 311 reads the temperature correction value α, adds the temperature correction value α to the battery temperature T measured by the measurement unit 200, and outputs the correction temperature T α to the internal resistance calculation unit 312.
　次に、温度補正部３１１で補正する温度補正値αについて、図６乃至図８を参照して説明する。
　図６乃至図８に示す４つの折れ線グラフは、電池１００の温度が２５℃、３５℃、４５℃であり、計測部２００により測定される電池温度Ｔが２５℃、３５℃、４５℃の各温度に対しそれぞれ０℃、１℃、２℃、３℃の誤差を含んだ場合において、温度補正値αを０～２．０まで行った場合の内部抵抗誤差を示している。 Next, the temperature correction value α corrected by the temperature correction unit 311 will be described with reference to FIGS. 6 to 8.
In the four line graphs shown in FIGS. 6 to 8, the temperatures of the battery 100 are 25 ° C., 35 ° C., and 45 ° C., and the battery temperature T measured by the measuring unit 200 is 25 ° C., 35 ° C., and 45 ° C. The graph shows the internal resistance error when the temperature correction value α is performed from 0 to 2.0 when the temperature includes the errors of 0 ° C., 1 ° C., 2 ° C., and 3 ° C., respectively.
　図６は、電池１００の温度が２５℃である場合における、温度補正値αと内部抵抗誤差の関係を示す図である。電池１００の実際の温度ＴＣが２５℃で、計測部２００により測定される温度ＴがＴＣ＋３℃である場合、すなわち３℃の測定誤差が含まれる場合、図６の黒丸印の折れ線グラフで表されるように、温度補正を行わない場合（α＝０）に比べ、温度補正値αを０．５℃、１℃と大きくするにしたがって内部抵抗誤差を小さくできる。しかし温度補正値αを１．０℃からさらに大きくすると、こんどは逆に内部抵抗誤差が大きくなる。このように、温度補正値αには内部抵抗誤差を最も小さくする範囲が存在する。 FIG. 6 is a diagram showing the relationship between the temperature correction value α and the internal resistance error when the temperature of the battery 100 is 25 ° C. In FIG. When the actual temperature T c of the battery 100 is 25 ° C. and the temperature T measured by the measuring unit 200 is T C + 3 ° C., that is, when the measurement error of 3 ° C. is included, the broken line graph in FIG. As expressed by the following equation, the internal resistance error can be reduced as the temperature correction value α is increased to 0.5 ° C. and 1 ° C., as compared with the case where the temperature correction is not performed (α = 0). However, if the temperature correction value α is further increased from 1.0 ° C., the internal resistance error increases conversely at this time. As described above, the temperature correction value α has a range in which the internal resistance error is minimized.
　図６の黒三角印の折れ線は、計測部２００により測定される温度ＴがＴＣ＋２℃である場合、すなわち２℃の測定誤差が含まれる場合である。図６の黒四角印の折れ線は、計測部２００により測定される温度ＴがＴＣ＋１℃である場合、すなわち１℃の測定誤差が含まれる場合である。図６の黒菱形印の折れ線は、計測部２００により測定される温度ＴがＴＣ℃である場合、すなわち０℃の測定誤差が含まれる場合である。すなわち、測定誤差が大きくなるほど温度補正値αを大きくした方が内部抵抗誤差を小さくできることが分かる。 The broken line of the black triangle mark in FIG. 6 is a case where the temperature T measured by the measurement unit 200 is T C + 2 ° C., that is, a measurement error of 2 ° C. is included. The broken line in the black square in FIG. 6 is a case where the temperature T measured by the measurement unit 200 is T C + 1 ° C., that is, a measurement error of 1 ° C. is included. The broken line in the black rhombus in FIG. 6 is a case where the temperature T measured by the measurement unit 200 is T C ° C., that is, a measurement error of 0 ° C. is included. That is, it can be seen that the internal resistance error can be reduced by increasing the temperature correction value α as the measurement error increases.
　図７は、電池１００の温度が３５℃である場合における、温度補正値αと内部抵抗誤差の関係を示す図である。この場合も、電池１００の実際の温度ＴＣが３５℃で、計測部２００により測定される温度ＴがＴＣ＋３℃である場合、黒丸印の折れ線グラフで表されるように温度補正値αを１．５℃としたときに内部抵抗誤差が最も小さくなる。 FIG. 7 is a diagram showing the relationship between the temperature correction value α and the internal resistance error when the temperature of the battery 100 is 35 ° C. In FIG. Also in this case, when the actual temperature T c of the battery 100 is 35 ° C., and the temperature T measured by the measuring unit 200 is T C + 3 ° C., the temperature correction value α is represented by a line graph of black circles. The internal resistance error is minimized when the temperature is set to 1.5.degree.
　図８は、電池１００の温度が４５℃である場合における、温度補正値αと内部抵抗誤差の関係を示す図である。この場合、電池１００の実際の温度ＴＣと、計測部２００により測定される温度Ｔとの誤差の大小にかかわらず、温度補正を行うことによって、内部抵抗誤差が大きくなっている。これは図４を参照して説明してように、電池温度が高いほど、温度測定誤差に対する内部抵抗の誤差への影響が小さくなるため、温度補正を行うことによる内部抵抗誤差の拡大の影響の方が大きい為である。 FIG. 8 is a diagram showing the relationship between the temperature correction value α and the internal resistance error when the temperature of the battery 100 is 45 ° C. In FIG. In this case, regardless of the magnitude of the error between the actual temperature T C of the battery 100 and the temperature T measured by the measurement unit 200, the internal resistance error is increased by performing the temperature correction. This is because, as described with reference to FIG. 4, the higher the battery temperature, the smaller the influence on the error of the internal resistance due to the temperature measurement error. Therefore, the effect of the expansion of the internal resistance error due to the temperature correction Because it is larger.
　これらのことから、例えば、測定される電池温度Ｔが３０℃以下の場合は、温度補正値αを１℃とし、電池温度Ｔが３０℃から４０℃の場合は、温度補正値αを１．５℃とする。電池温度Ｔが４０℃以上の場合は、温度補正値αを０℃とする、もしくは温度補正を行わない。これにより、温度補正による内部抵抗誤差の低減を効果的に利用することができる。記憶部３２０は、これらの電池温度Ｔと温度補正値αとの対応関係を記憶している。 From these things, for example, when the battery temperature T to be measured is 30 ° C. or less, the temperature correction value α is 1 ° C., and when the battery temperature T is 30 ° C. to 40 ° C., the temperature correction value α is 1. The temperature is 5 ° C. When the battery temperature T is 40 ° C. or more, the temperature correction value α is set to 0 ° C., or the temperature correction is not performed. Thereby, the reduction of the internal resistance error due to the temperature correction can be effectively used. The storage unit 320 stores the correspondence between the battery temperature T and the temperature correction value α.
　温度補正部３１１は、記憶部３２０に記憶されている電池温度Ｔと温度補正値αとの対応関係を参照し、計測部２００で測定した電池１００の電池温度Ｔに対応した温度補正値αを読み出し、電池温度Ｔに温度補正値αを加算して内部抵抗演算部３１２へ出力する。なお、本実施形態で例示した温度等の閾値は、その値に限定されることはなく、電池１００の特性、計測部２００の測定誤差など、演算に関わるデバイスの特性に合わせて最適な値を選択するものとする。 The temperature correction unit 311 refers to the correspondence between the battery temperature T and the temperature correction value α stored in the storage unit 320, and uses the temperature correction value α corresponding to the battery temperature T of the battery 100 measured by the measurement unit 200. Read out, the temperature correction value α is added to the battery temperature T, and the result is output to the internal resistance calculation unit 312. Note that the threshold of the temperature or the like exemplified in the present embodiment is not limited to that value, and an optimal value may be selected according to the characteristics of the device involved in the calculation, such as the characteristics of the battery 100 and the measurement error of the measuring unit 200. It shall be selected.
　本実施形態によれば、計測部２００により測定される電池温度Ｔに対して、その電池温度Ｔに応じた温度補正値αを加算することにより、内部抵抗演算部３１２により導出される内部抵抗の誤差を小さくすることができる。さらに、内部抵抗を用いたＳＯＣ演算部３１３およびＳＯＨ演算部３１４の演算も誤差が少なくなる。 According to the present embodiment, by adding the temperature correction value α according to the battery temperature T to the battery temperature T measured by the measurement unit 200, the internal resistance calculated by the internal resistance calculation unit 312 can be obtained. The error can be reduced. Furthermore, the errors in the calculations of the SOC calculation unit 313 and the SOH calculation unit 314 using the internal resistance also decrease.
　以上説明した実施形態によれば、次の作用効果が得られる。
（１）二次電池監視装置１０００は、電池１００の温度を測定する計測部２００、および電池１００の状態を演算する二次電池状態演算装置３００を備える。二次電池状態演算装置３００は、電池１００の温度と内部抵抗との対応関係を記憶する記憶部３２０と、計測部２００で測定された電池温度Ｔに温度補正値αを加算して補正温度Ｔαを導出する温度補正部３１１と、温度補正部３１１で導出された補正温度Ｔαに対応する内部抵抗を記憶部３２０を参照して求める内部抵抗演算部３１２と、内部抵抗演算部３１２で求められた内部抵抗に基づいて電池１００の状態推定を行うＳＯＣ演算部３１３およびＳＯＨ演算部３１４と、を備える。ＳＯＣ演算部３１３およびＳＯＨ演算部３１４は電池状態推定装置３１０を構成する要素である。これにより、低温域における二次電池の内部抵抗の誤差を低減させ、二次電池の状態推定の精度を向上することができる。 According to the embodiment described above, the following effects can be obtained.
(1) The secondary battery monitoring device 1000 includes a measurement unit 200 that measures the temperature of the battery 100, and a secondary battery state calculation device 300 that calculates the state of the battery 100. The secondary battery state arithmetic unit 300 adds the temperature correction value α to the battery temperature T measured by the measurement unit 200 and the storage unit 320 that stores the correspondence between the temperature of the battery 100 and the internal resistance, and corrects the correction temperature T A temperature correction unit 311 for deriving α , an internal resistance calculation unit 312 for obtaining an internal resistance corresponding to the correction temperature T α derived by the temperature correction unit 311 with reference to the storage unit 320, and an internal resistance calculation unit 312 The SOC calculation unit 313 and the SOH calculation unit 314 that estimate the state of the battery 100 based on the calculated internal resistance are provided. The SOC calculation unit 313 and the SOH calculation unit 314 are elements constituting the battery state estimation device 310. Thereby, the error of the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
（２）二次電池監視装置１０００において、記憶部３２０は、電池温度Ｔと温度補正値αとの対応関係を記憶し、温度補正部３１１は、計測部２００で測定された電池温度Ｔに対応する温度補正値αを記憶部３２０に記憶されている電池温度Ｔと温度補正値αとの対応関係を参照して求める。これにより、電池温度Ｔと温度補正値αとを対応づけ、低温域における二次電池の内部抵抗の誤差を低減させ、二次電池の状態推定の精度を向上することができる。 (2) In the secondary battery monitoring device 1000, the storage unit 320 stores the correspondence between the battery temperature T and the temperature correction value α, and the temperature correction unit 311 corresponds to the battery temperature T measured by the measurement unit 200. The temperature correction value α to be calculated is determined with reference to the correspondence between the battery temperature T stored in the storage unit 320 and the temperature correction value α. Thus, the battery temperature T can be associated with the temperature correction value α, the error in the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
（３）温度補正部３１１は、温度補正値αとして、計測部２００で測定された電池温度Ｔと内部抵抗演算部３１２にて求めた電池温度Ｔに対応する抵抗値ＲＴと、電池温度Ｔよりも温度補正値α分高い補正温度Ｔαと内部抵抗演算部３１２から求めた電池温度Ｔよりも温度補正値α分高い温度に対応する抵抗値ＲＴαとの差分ＤＲ０（＝ＲＴ－ＲＴα）よりも、電池温度Ｔから上下に所定値（計測部２００の温度測定誤差）だけずらした２つの温度Ｔ1、Ｔ2と、内部抵抗演算部３１２で求めた２つの温度Ｔ1、Ｔ2に対応する２つの抵抗値の差分ＥＲＴと、電池温度Ｔよりも温度補正値α分高い補正温度Ｔαから上下に所定値（計測部２００の温度測定誤差）だけずらした２つの温度Ｔα1、Ｔα2と内部抵抗演算部３１２で求めた２つの温度Ｔα1、Ｔα2に対応する２つの抵抗値の差分ＥＲＴαとの差分ＤＲ１（＝ＥＲＴ－ＥＲＴα）の方が大きくなる温度補正値αを用いる。これにより、最適な温度補正値αを設定して、低温域における二次電池の内部抵抗の誤差を低減させ、二次電池の状態推定の精度を向上することができる。 (3) The temperature correction unit 311 sets the battery temperature T measured by the measurement unit 200 and the resistance value RT corresponding to the battery temperature T calculated by the internal resistance calculation unit 312 as the temperature correction value α, and the battery temperature T The difference D R0 between the correction temperature T α higher by the temperature correction value α than the resistance value R Tα corresponding to the temperature higher by the temperature correction value α than the battery temperature T obtained from the internal resistance calculator 312 (= R T − R T [alpha) than a temperature measurement error) two temperatures T 1 obtained by shifting, T 2 of the predetermined value (measurement unit 200 from the battery temperature T in the vertical, two temperatures T 1 determined by the internal resistance computing unit 312, A difference E RT between two resistance values corresponding to T 2 and two temperatures shifted up and down from the correction temperature T α higher by a temperature correction value α than the battery temperature T by a predetermined value (temperature measurement error of the measuring unit 200) Two temperatures obtained by T α1, T α2 and the internal resistance calculator 312 A temperature correction value α is used, which makes the difference D R1 (= E RT −E RTα ) between the difference E RTα of the two resistance values corresponding to the degrees T α1 and T α2 larger. As a result, an optimum temperature correction value α can be set to reduce an error in the internal resistance of the secondary battery in the low temperature range, and improve the accuracy of state estimation of the secondary battery.
（４）二次電池監視装置１０００において、温度補正値αは、計測部２００の温度測定誤差の範囲内である。これにより、計測部２００の温度測定誤差の範囲内で、低温域における二次電池の内部抵抗の誤差を低減させ、二次電池の状態推定の精度を向上することができる。 (4) In the secondary battery monitoring device 1000, the temperature correction value α is within the range of the temperature measurement error of the measurement unit 200. Thereby, the error of the internal resistance of the secondary battery in the low temperature range can be reduced within the range of the temperature measurement error of the measurement unit 200, and the accuracy of the state estimation of the secondary battery can be improved.
（５）二次電池状態演算装置３００は、二次電池の温度と内部抵抗との対応関係を記憶する記憶部３２０と、電池状態推定装置３１０とを有する。電池状態推定装置３１０は、測定された電池温度Ｔに温度補正値αを加算して補正温度Ｔαを導出する温度補正部３１１と、温度補正部３１１で導出された補正温度Ｔαに対応する内部抵抗を前記記憶部を参照して求める内部抵抗演算部３１２と、内部抵抗演算部３１２で求められた内部抵抗に基づいて二次電池の状態推定を行うＳＯＣ演算部３１３およびＳＯＨ演算部３１４とを備える。 (5) The secondary battery state computing device 300 includes the storage unit 320 that stores the correspondence between the temperature of the secondary battery and the internal resistance, and the battery state estimation device 310. Battery state estimating unit 310 includes a temperature compensation unit 311 for deriving the correction temperature T alpha by adding the temperature correction value alpha to the measured battery temperature T, corresponding to the correction temperature T alpha derived by the temperature correction unit 311 An internal resistance calculating unit 312 for obtaining the internal resistance with reference to the storage unit; an SOC calculating unit 313 for estimating the state of the secondary battery based on the internal resistance obtained by the internal resistance calculating unit 312; Equipped with
（６）内部抵抗演算部３１２は、電池温度Ｔが所定値以下でない場合は、測定された電池温度Ｔに対応する内部抵抗を記憶部３２０に記憶された二次電池の温度Ｔと内部抵抗との対応関係を参照して求める。 (6) If the battery temperature T is not equal to or lower than the predetermined value, the internal resistance calculation unit 312 measures the internal resistance corresponding to the measured battery temperature T, the temperature T of the secondary battery stored in the storage unit 320, and the internal resistance. Determine by referring to the correspondence of.
（７）二次電池状態推定方法は、電池１００の温度と内部抵抗との対応関係を記憶し、測定された電池温度Ｔに温度補正値αを加算して補正温度Ｔαを導出し、導出された補正温度Ｔαに対応する内部抵抗を、記憶された電池１００の温度と内部抵抗との対応関係を参照して求め、求められた内部抵抗に基づいて電池１００の状態推定を行う。これにより、低温域における二次電池の内部抵抗の誤差を低減させ、二次電池の状態推定の精度を向上することができる。
（８）二次電池状態推定方法において、電池温度Ｔが所定値以下でない場合は、測定された電池温度Ｔに対応する内部抵抗を、記憶された二次電池の温度と内部抵抗との対応関係を参照して求める。 (7) The secondary battery state estimation method stores the correspondence between the temperature of the battery 100 and the internal resistance, adds the temperature correction value α to the measured battery temperature T, and derives the correction temperature T α to derive the correction temperature T α. The internal resistance corresponding to the corrected temperature T α is determined with reference to the stored correspondence relationship between the temperature of the battery 100 and the internal resistance, and the state of the battery 100 is estimated based on the determined internal resistance. Thereby, the error of the internal resistance of the secondary battery in the low temperature range can be reduced, and the accuracy of the state estimation of the secondary battery can be improved.
(8) In the secondary battery state estimating method, when the battery temperature T is not lower than a predetermined value, the internal resistance corresponding to the measured battery temperature T is a correspondence between the stored secondary battery temperature and the internal resistance. See and ask for.
（変形例）
　本発明は、以上説明した実施形態を次のように変形して実施することができる。
（１）実施形態では、温度補正を行う温度範囲や温度補正値αを予め定めて記憶部３２０に記憶した例で説明した。しかし、これらを予め定めるのではなく、電池状態推定装置３１０が温度補正値αを種々変更しながらもっとも内部抵抗誤差が小さくなる温度補正値αをリアルタイムに演算して求め、これを温度補正値αとしてもよい。 (Modification)
The present invention can be implemented with the following modifications of the embodiment described above.
(1) The embodiment has been described using an example in which the temperature range for temperature correction and the temperature correction value α are predetermined and stored in the storage unit 320. However, these are not determined in advance, and the battery state estimation device 310 calculates the temperature correction value α which reduces the internal resistance error most while changing the temperature correction value α variously, and determines it in real time. It may be
　本発明は、上記の実施形態に限定されるものではなく、本発明の特徴を損なわない限り、本発明の技術思想の範囲内で考えられるその他の形態についても、本発明の範囲内に含まれる。 The present invention is not limited to the above-described embodiment, and other forms considered within the scope of the technical idea of the present invention are also included in the scope of the present invention as long as the features of the present invention are not impaired. .
１００…電池
２００…計測部
３００…電池状態演算装置
３１０…電池状態推定装置
３１１…温度補正部
３１２…内部抵抗演算部
３１３…ＳＯＣ演算部
３１４…ＳＯＨ演算部
３２０…記憶部
４００…出力部
１０００…二次電池監視装置 100 battery 200 measuring unit 300 battery state computing device 310 battery state estimating device 311 temperature correction unit 312 internal resistance computing unit 313 SOC computing unit 314 SOH computing unit 320 storage unit 400 output unit 1000 Secondary battery monitoring device

Claims (9)

  1. 　二次電池の温度を測定する温度測定部、および前記二次電池の状態を演算する二次電池状態演算装置を有する二次電池監視装置であって、
    　前記二次電池状態演算装置は、
    　前記二次電池の温度と内部抵抗との対応関係を記憶する記憶部と、
    　前記温度測定部で測定された電池温度Ｔに温度補正値αを加算して補正温度Ｔαを導出する温度補正部と、
    　前記温度補正部で導出された前記補正温度Ｔαに対応する内部抵抗を前記記憶部を参照して求める内部抵抗演算部と、
    　前記内部抵抗演算部で求められた内部抵抗に基づいて前記二次電池の状態推定を行う状態推定制御部と、
    　を備えた二次電池監視装置。     A secondary battery monitoring device comprising: a temperature measurement unit that measures a temperature of a secondary battery; and a secondary battery state calculation device that calculates a state of the secondary battery,
    The secondary battery state computing device
    A storage unit that stores the correspondence between the temperature of the secondary battery and the internal resistance;
    A temperature correction unit that adds a temperature correction value α to the battery temperature T measured by the temperature measurement unit to derive a correction temperature T α ;
    An internal resistance calculating unit which obtains the internal resistance corresponding to the correction temperature T α derived by the temperature correction unit with reference to the storage unit;
    A state estimation control unit that estimates the state of the secondary battery based on the internal resistance obtained by the internal resistance calculation unit;
    Secondary battery monitoring device equipped with.
  2. 　請求項１に記載の二次電池監視装置において、
    　前記記憶部は、前記電池温度Ｔと温度補正値αとの対応関係を記憶し、
    　前記温度補正部は、前記温度測定部で測定された前記電池温度Ｔに対応する温度補正値αを前記記憶部に記憶されている前記電池温度Ｔと温度補正値αとの対応関係を参照して求める二次電池監視装置。     In the secondary battery monitoring device according to claim 1,
    The storage unit stores the correspondence between the battery temperature T and the temperature correction value α,
    The temperature correction unit refers to the correspondence between the battery temperature T and the temperature correction value α stored in the storage unit, the temperature correction value α corresponding to the battery temperature T measured by the temperature measurement unit. And a secondary battery monitoring device.
  3. 　請求項１または請求項２に記載の二次電池監視装置において、
    　前記温度補正部は、前記温度補正値αとして、
    　前記温度測定部で測定された電池温度Ｔと前記内部抵抗演算部にて求めた前記電池温度Ｔに対応する抵抗値ＲＴと、前記電池温度Ｔよりも温度補正値α分高い補正温度Ｔαと前記内部抵抗演算部から求めた前記電池温度Ｔよりも温度補正値α分高い温度に対応する抵抗値ＲＴαとの差分ＤＲ０（＝ＲＴ－ＲＴα）よりも、
    　前記電池温度Ｔから上下に所定値だけずらした２つの温度Ｔ1、Ｔ2と、前記内部抵抗演算部で求めた前記２つの温度Ｔ1、Ｔ2に対応する２つの抵抗値の差分ＥＲＴと、前記電池温度Ｔよりも温度補正値α分高い補正温度Ｔαから上下に所定値だけずらした２つの温度Ｔα1、Ｔα2と前記内部抵抗演算部で求めた前記２つの温度Ｔα1、Ｔα2に対応する２つの抵抗値の差分ＥＲＴαとの差分ＤＲ１（＝ＥＲＴ－ＥＲＴα）の方が大きくなる温度補正値αを用いる二次電池監視装置。     In the secondary battery monitoring device according to claim 1 or 2,
    The temperature correction unit sets the temperature correction value α as
    The battery temperature T measured by the temperature measurement unit and the resistance value RT corresponding to the battery temperature T determined by the internal resistance calculation unit, and the correction temperature T α higher than the battery temperature T by the temperature correction value α Than a difference D R0 (= R T −R Tα ) between the resistance value R Tα corresponding to a temperature higher by the temperature correction value α than the battery temperature T obtained from the internal resistance calculation unit,
    The difference E RT between the two resistance values corresponding to the two temperatures T 1 and T 2 shifted by the predetermined value up and down from the battery temperature T and the two temperatures T 1 and T 2 determined by the internal resistance calculation unit When the battery temperature temperature correction value than T alpha content higher compensation temperature T 2 one temperature shifted by a predetermined value from the alpha vertically T [alpha] 1, the obtained by the and T [alpha] 2 internal resistance calculation section two temperatures T [alpha] 1, A secondary battery monitoring device using a temperature correction value α in which a difference D R1 (= E RT −E RTα ) between a difference E RTα of two resistance values corresponding to T α2 is larger.
  4. 　請求項１から請求項３のいずれか一項に記載の二次電池監視装置において、
    　前記温度補正値αは、前記温度測定部の温度測定誤差の範囲内である二次電池監視装置。     The secondary battery monitoring device according to any one of claims 1 to 3.
    The secondary battery monitoring device, wherein the temperature correction value α is within a range of a temperature measurement error of the temperature measurement unit.
  5. 　請求項１から４までのいずれか１項に記載の二次電池監視装置において、
    　前記内部抵抗演算部は、前記電池温度Ｔが所定値以下でない場合は、前記測定された電池温度Ｔに対応する内部抵抗を前記記憶部に記憶された二次電池の温度と内部抵抗との対応関係を参照して求める二次電池監視装置。     The secondary battery monitoring device according to any one of claims 1 to 4.
    When the battery temperature T is not equal to or less than a predetermined value, the internal resistance calculating unit corresponds the internal resistance corresponding to the measured battery temperature T to the temperature of the secondary battery stored in the storage unit and the internal resistance. Secondary battery monitoring device to obtain by referring to the relationship.
  6. 　二次電池の温度と内部抵抗との対応関係を記憶する記憶部と、
    　測定された電池温度Ｔに温度補正値αを加算して補正温度Ｔαを導出する温度補正部と、
    　前記温度補正部で導出された前記補正温度Ｔαに対応する内部抵抗を前記記憶部を参照して求める内部抵抗演算部と、
    　前記内部抵抗演算部で求められた内部抵抗に基づいて前記二次電池の状態推定を行う状態推定制御部と、
    　を備えた二次電池状態演算装置。     A storage unit that stores the correspondence between the temperature of the secondary battery and the internal resistance;
    A temperature correction unit that adds a temperature correction value α to the measured battery temperature T to derive a correction temperature T α ;
    An internal resistance calculating unit which obtains the internal resistance corresponding to the correction temperature T α derived by the temperature correction unit with reference to the storage unit;
    A state estimation control unit that estimates the state of the secondary battery based on the internal resistance obtained by the internal resistance calculation unit;
    A secondary battery state computing device equipped with
  7. 　請求項６に記載の二次電池状態演算装置において、
    　前記内部抵抗演算部は、前記電池温度Ｔが所定値以下でない場合は、前記測定された電池温度Ｔに対応する内部抵抗を前記記憶部に記憶された二次電池の温度と内部抵抗との対応関係を参照して求める、二次電池状態演算装置。     In the secondary battery state computing device according to claim 6,
    When the battery temperature T is not equal to or less than a predetermined value, the internal resistance calculating unit corresponds the internal resistance corresponding to the measured battery temperature T to the temperature of the secondary battery stored in the storage unit and the internal resistance. The secondary battery state arithmetic unit to obtain by referring to the relationship.
  8. 　二次電池の温度と内部抵抗との対応関係を記憶し、
    　測定された電池温度Ｔに温度補正値αを加算して補正温度Ｔαを導出し、
    　導出された前記補正温度Ｔαに対応する内部抵抗を前記記憶された二次電池の温度と内部抵抗との対応関係を参照して求め、
    　求められた内部抵抗に基づいて前記二次電池の状態推定を行う、
    　二次電池状態推定方法。     Remember the correspondence between the temperature of the secondary battery and the internal resistance,
    A temperature correction value α is added to the measured battery temperature T to derive a correction temperature T α ,
    The internal resistance corresponding to the derived correction temperature T α is determined with reference to the stored correspondence relationship between the temperature of the secondary battery and the internal resistance,
    State estimation of the secondary battery based on the determined internal resistance,
    Secondary battery state estimation method.
  9. 　請求項８に記載の二次電池状態推定方法において、
    　前記電池温度Ｔが所定値以下でない場合は、前記測定された電池温度Ｔに対応する内部抵抗を前記記憶された二次電池の温度と内部抵抗との対応関係を参照して求める二次電池状態推定方法。     In the secondary battery state estimation method according to claim 8,
    If the battery temperature T is not equal to or lower than a predetermined value, a secondary battery state is obtained by referring to the correspondence between the stored secondary battery temperature and the internal resistance corresponding to the measured battery temperature T Estimation method.
PCT/JP2018/042226 2017-12-11 2018-11-15 Device for monitoring secondary cell, device for computing state of secondary cell, and method for estimating state of secondary cell WO2019116815A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2019558982A JP6895541B2 (en) 2017-12-11 2018-11-15 Secondary battery monitoring device, secondary battery status calculation device and secondary battery status estimation method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017237264 2017-12-11
JP2017-237264 2017-12-11

Publications (1)

Publication Number Publication Date
WO2019116815A1 true WO2019116815A1 (en) 2019-06-20

Family

ID=66820242

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/042226 WO2019116815A1 (en) 2017-12-11 2018-11-15 Device for monitoring secondary cell, device for computing state of secondary cell, and method for estimating state of secondary cell

Country Status (2)

Country Link
JP (1) JP6895541B2 (en)
WO (1) WO2019116815A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111366863A (en) * 2020-03-13 2020-07-03 上海应用技术大学 Lithium ion battery service life acceleration pre-judging method based on low-temperature circulation
WO2021065231A1 (en) * 2019-09-30 2021-04-08 株式会社デンソー Battery state estimation device
JP6918433B1 (en) * 2020-03-10 2021-08-11 三菱電機株式会社 Deterioration degree diagnostic device
JP2023515658A (en) * 2020-10-05 2023-04-13 エルジー エナジー ソリューション リミテッド BATTERY DEVICE AND BATTERY OUTPUT PREDICTION METHOD
CN115993552A (en) * 2023-03-23 2023-04-21 杭州科工电子科技有限公司 Method for estimating internal resistance of battery

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004271342A (en) * 2003-03-10 2004-09-30 Shin Kobe Electric Mach Co Ltd Charging and discharging control system
JP2006292565A (en) * 2005-04-12 2006-10-26 Furukawa Electric Co Ltd:The Method for discriminating secondary cell degradation condition and secondary cell degradation condition discriminating device
JP2007108063A (en) * 2005-10-14 2007-04-26 Furukawa Electric Co Ltd:The Method and device for determining secondary battery degradation, and power supply system
JP2010249770A (en) * 2009-04-20 2010-11-04 Nissan Motor Co Ltd Internal resistance operation method of secondary battery
JP2016005304A (en) * 2014-06-13 2016-01-12 トヨタ自動車株式会社 vehicle

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004271342A (en) * 2003-03-10 2004-09-30 Shin Kobe Electric Mach Co Ltd Charging and discharging control system
JP2006292565A (en) * 2005-04-12 2006-10-26 Furukawa Electric Co Ltd:The Method for discriminating secondary cell degradation condition and secondary cell degradation condition discriminating device
JP2007108063A (en) * 2005-10-14 2007-04-26 Furukawa Electric Co Ltd:The Method and device for determining secondary battery degradation, and power supply system
JP2010249770A (en) * 2009-04-20 2010-11-04 Nissan Motor Co Ltd Internal resistance operation method of secondary battery
JP2016005304A (en) * 2014-06-13 2016-01-12 トヨタ自動車株式会社 vehicle

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021065231A1 (en) * 2019-09-30 2021-04-08 株式会社デンソー Battery state estimation device
JP2021056095A (en) * 2019-09-30 2021-04-08 株式会社デンソー Battery condition estimation device
JP7124812B2 (en) 2019-09-30 2022-08-24 株式会社デンソー Battery state estimation device
JP6918433B1 (en) * 2020-03-10 2021-08-11 三菱電機株式会社 Deterioration degree diagnostic device
WO2021181536A1 (en) * 2020-03-10 2021-09-16 三菱電機株式会社 Deterioration degree diagnosis device
CN111366863A (en) * 2020-03-13 2020-07-03 上海应用技术大学 Lithium ion battery service life acceleration pre-judging method based on low-temperature circulation
CN111366863B (en) * 2020-03-13 2022-04-05 上海应用技术大学 Lithium ion battery service life acceleration pre-judging method based on low-temperature circulation
JP2023515658A (en) * 2020-10-05 2023-04-13 エルジー エナジー ソリューション リミテッド BATTERY DEVICE AND BATTERY OUTPUT PREDICTION METHOD
JP7436078B2 (en) 2020-10-05 2024-02-21 エルジー エナジー ソリューション リミテッド Battery device and battery output prediction method
CN115993552A (en) * 2023-03-23 2023-04-21 杭州科工电子科技有限公司 Method for estimating internal resistance of battery
CN115993552B (en) * 2023-03-23 2023-07-18 杭州科工电子科技有限公司 Method for estimating internal resistance of battery

Also Published As

Publication number Publication date
JPWO2019116815A1 (en) 2021-01-14
JP6895541B2 (en) 2021-06-30

Similar Documents

Publication Publication Date Title
WO2019116815A1 (en) Device for monitoring secondary cell, device for computing state of secondary cell, and method for estimating state of secondary cell
JP5863603B2 (en) Battery state estimation device, battery control device, battery system, battery state estimation method
ES2917177T3 (en) Method and apparatus for determining the state of health and state of charge of lithium sulfur batteries
JP5287844B2 (en) Secondary battery remaining capacity calculation device
CN108369258B (en) State estimation device and state estimation method
US10845417B2 (en) Battery state estimation device, battery control device, battery system, battery state estimation method
CN109669131B (en) SOC estimation method of power battery under working condition environment
JP6183336B2 (en) Charge rate calculation device
JP2015524048A (en) Estimating battery charge
JP2015090342A (en) Battery characteristics learning apparatus
WO2020026509A1 (en) Cell state estimation device and cell control device
JP2022044172A (en) Determination device, power storage system, determination method, and determination program for multiple batteries
JP6834849B2 (en) Impedance estimator
US20240094303A1 (en) Battery state estimation device, battery state estimation system, and battery state estimation method
JP6580784B2 (en) Battery state estimation device
WO2006057469A1 (en) Method and system for joint battery stateand parameter estimation
CN112189143B (en) Device for estimating the state of charge of a battery
JP6827527B2 (en) Battery control device
WO2020075503A1 (en) Battery control device
JP2013253857A (en) Cell state estimation device of battery pack
JP2021144886A (en) Battery management device, battery management system and battery management method
KR20190102814A (en) Apparatus and method for managing battery
JP7468939B2 (en) Discharge voltage graph prediction method and battery system using the same
JP6895537B2 (en) Battery state estimator
JP6834397B2 (en) Battery monitoring system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18888334

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2019558982

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18888334

Country of ref document: EP

Kind code of ref document: A1