JP2023137389A - Battery state estimation device and battery state estimation method - Google Patents

Battery state estimation device and battery state estimation method Download PDF

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JP2023137389A
JP2023137389A JP2022043579A JP2022043579A JP2023137389A JP 2023137389 A JP2023137389 A JP 2023137389A JP 2022043579 A JP2022043579 A JP 2022043579A JP 2022043579 A JP2022043579 A JP 2022043579A JP 2023137389 A JP2023137389 A JP 2023137389A
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健二 福田
Kenji Fukuda
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Sawafuji Electric Co Ltd
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Abstract

To provide a battery state estimation device of a secondary batter and a battery state estimation method thereof that distinguish capacity reduction in the secondary battery, and a gain error of current acquisition means and offset error thereof to compute a correction value, and enable computing a more accurate estimation charge rate.SOLUTION: The present battery state estimation device and battery state estimation method are configured to compute a charge side correction value K(+) and discharge side correction value K(-) on the basis of a ratio of an amount of change in a charge rate based on open circuit voltages of at least three or more points of a reference point, a charge point and a discharge point, and an amount of change in the charge rate based on current integrated values ΔAh (+) and ΔAh (-) of at least two or more sections corresponding to these reference point, charge point and discharge point. Then, in cases where both correction values are less than 1, where both are greater than 1, and where only one of both correction values is less than 1, the correction is made by the method corresponding to respective cases. Therefor, corrections to reduction in a battery capacity of a secondary battery 10 and gain error of current acquisition means can be discriminated from a correction to offset error of the current acquisition means.SELECTED DRAWING: Figure 1

Description

本発明は、二次電池の状態を推定する電池状態推定装置およびその推定方法に関する。 The present invention relates to a battery state estimation device and estimation method for estimating the state of a secondary battery.

近年、充電が可能なリチウムイオン電池が携帯用通信端末や携帯用電動工具等の比較的小型の機器から、住宅設備用途等の大型の機器まで幅広い分野で使用されている。そして、特に大型の接続機器で使用するリチウムイオン電池では二次電池の状態情報としてのSOC(充電率:State of Charge)を、二次電池の電流値等から推定充電率SOC’として間接的に算出することが行われている。この推定充電率SOC’の算出方法としては、二次電池の電流積算値ΔAhと、二次電池の新品時の電池容量(BOL:Beginning of Life:基準総容量Ah(0))とから、下記(A)式に基づいて充電率の変化量ΔSOCを算出し、この充電率の変化量ΔSOCから下記(A’)式に基づいて推定充電率SOC’を算出することが一般的に用いられている。尚、SOC(0)は基準点となる充電率であり、システムの起動時点の二次電池の電圧を開回路電圧OCVとしてOCV-SOC特性に基づいて取得される。
ΔSOC=ΔAh/Ah(0)・・・(A)
SOC’=SOC(0)+ΔSOC ・・・(A’)
In recent years, rechargeable lithium ion batteries have been used in a wide range of fields, from relatively small devices such as portable communication terminals and portable power tools to large devices such as housing equipment. In particular, for lithium-ion batteries used in large connected devices, the SOC (State of Charge) as state information of the secondary battery is indirectly calculated as the estimated charging rate SOC' from the current value of the secondary battery, etc. Calculation is being carried out. The estimated charging rate SOC' is calculated as follows from the integrated current value ΔAh of the secondary battery and the battery capacity when new of the secondary battery (BOL: Beginning of Life: standard total capacity Ah (0)). It is generally used to calculate the amount of change ΔSOC in the charging rate based on formula (A), and calculate the estimated charging rate SOC' from the amount of change ΔSOC in the charging rate based on formula (A') below. There is. Note that SOC(0) is a charging rate serving as a reference point, and is obtained based on the OCV-SOC characteristic, with the voltage of the secondary battery at the time of system startup as the open circuit voltage OCV.
ΔSOC=ΔAh/Ah(0)...(A)
SOC'=SOC(0)+ΔSOC...(A')

しかしながら、二次電池の電池容量は劣化により減少するため、劣化を考慮していない基準総容量Ah(0)を用いてΔSOCを算出すると、ΔSOCは真の値よりも小さくなる。この場合、推定充電率SOC’は真値よりもSOC(0)からの変化幅が小さな値となり、このような誤った状態情報に基づいて二次電池の充放電の制御を行うと二次電池の劣化を速める他、様々な不具合の原因となる。 However, since the battery capacity of the secondary battery decreases due to deterioration, when ΔSOC is calculated using the reference total capacity Ah (0) that does not take deterioration into account, ΔSOC becomes smaller than the true value. In this case, the estimated charging rate SOC' has a smaller variation range from SOC (0) than the true value, and if the charging and discharging of the secondary battery is controlled based on such erroneous status information, the secondary battery In addition to accelerating deterioration, it can also cause various problems.

この問題点に関し、下記[特許文献1]には2点の開回路電圧OCV(Open Circuit Voltage)に対応した充電率SOCと、この2点間の電流積算値ΔAhとから、劣化により減少した二次電池の電池容量を推定する発明が開示されている。 Regarding this problem, the following [Patent Document 1] describes the charge rate SOC corresponding to the open circuit voltage OCV (Open Circuit Voltage) at two points and the current integrated value ΔAh between these two points, and calculates An invention for estimating the battery capacity of a secondary battery is disclosed.

特開2003-224901号公報Japanese Patent Application Publication No. 2003-224901

ただし、ΔSOCが変化する要因には電池容量の低下に加え、電流積算値ΔAhの基となる電流取得手段(電流センサ等)の測定誤差(主にゲイン誤差及びオフセット誤差)が考えられる。しかしながら、[特許文献1]に記載の発明のように2点間の開回路電圧OCVに基づいた推定方法では、電池容量の低下及び電流取得手段のゲイン誤差と電流取得手段のオフセット誤差とが判別できず、全て電池容量の低下として算出される。しかしながら、特にオフセット誤差が電池容量の低下として算出された場合、二次電池の充電時と放電時とで補正値が異なることとなり、動作安定性と連続性に問題が生じる可能性が有る。また、正確な推定充電率SOC’を得ることができないという問題点がある。 However, in addition to a decrease in battery capacity, factors that may cause the ΔSOC to change include measurement errors (mainly gain errors and offset errors) of the current acquisition means (current sensor, etc.) that is the basis of the current integrated value ΔAh. However, in the estimation method based on the open circuit voltage OCV between two points as in the invention described in [Patent Document 1], it is possible to distinguish between a decrease in battery capacity, a gain error of the current acquisition means, and an offset error of the current acquisition means. This is not possible, and the entire amount is calculated as a decrease in battery capacity. However, especially when the offset error is calculated as a decrease in battery capacity, the correction value will be different when charging and discharging the secondary battery, which may cause problems in operational stability and continuity. Further, there is a problem that an accurate estimated charging rate SOC' cannot be obtained.

本発明は上記事情に鑑みてなされたものであり、二次電池の容量低下及び電流取得手段のゲイン誤差と電流取得手段のオフセット誤差とを区別して補正値を算出し、より正確な推定充電率SOC’を算出することが可能な二次電池の電池状態推定装置及び電池状態推定方法の提供を目的とする。 The present invention has been made in view of the above circumstances, and calculates a correction value by distinguishing between a decrease in the capacity of the secondary battery, a gain error of the current acquisition means, and an offset error of the current acquisition means, thereby providing a more accurate estimated charging rate. It is an object of the present invention to provide a battery state estimating device and a battery state estimating method for a secondary battery that are capable of calculating SOC'.

本発明は、
(1)システムに電力供給を行う充電可能な二次電池10の推定充電率SOC’を算出する電池状態推定装置であって、
前記二次電池10の電流値を取得する電流取得部30と、前記電流取得部30が取得した電流値に基づいて前記二次電池10の電流積算値ΔAhを算出する電流積算値算出部32と、前記二次電池10の電圧値を取得する電圧取得部34と、
前記電圧取得部34が取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得し、さらに少なくとも1つの前記基準点の開回路電圧、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)と対応した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得するOCV-SOC取得部42と、
前記電流積算値算出部32から入力した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得するとともに、取得した充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、取得した放電点の電流積算値ΔAh(-)に基づいて第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、また、前記OCV-SOC取得部42から取得した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)に基づいて、第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、第2の放電側の充電率の変化量としてのΔSOC2(-)を算出するΔSOC算出部52と、
前記ΔSOC算出部52が算出した前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出部54と、
前記補正係数算出部54が算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定部56と、
前記判定部56で、充電側補正値K(+)と放電側補正値K(-)の双方が1未満もしくは、充電側補正値K(+)と放電側補正値K(-)の双方が1より大きいと判定された場合、前記充電側補正値K(+)と前記放電側補正値K(-)とに基いて補正値K’(n)を算出するとともに、前記補正値K’(n)に基づいて容量補正値K(n)を設定する補正係数設定部57と、
前記補正係数設定部57が設定した容量補正値K(n)に基づいて二次電池10の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量補正部58と、
前記容量補正部58が算出した総容量Ah(n)に基づいて前記推定充電率SOC’を算出する推定充電率算出部60と、を有することを特徴とする電池状態推定装置80を提供することにより、上記課題を解決する。
(2)ΔSOC算出部52が、二次電池10の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池10の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
また、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出部54が、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする上記(1)記載の電池状態推定装置80を提供することにより、上記課題を解決する。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
(3)システムに電力供給を行う充電可能な二次電池10の推定充電率SOC’を算出する電池状態推定装置であって、
前記二次電池10の電流値を取得する電流取得部30と、前記電流取得部30が取得した電流値に基づいて前記二次電池10の電流積算値ΔAhを算出する電流積算値算出部32と、前記二次電池10の電圧値を取得する電圧取得部34と、
前記電圧取得部34が取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得し、さらに少なくとも1つの前記基準点の開回路電圧、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)と対応した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得するOCV-SOC取得部42と、
前記電流積算値算出部32から入力した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得するとともに、取得した充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、取得した放電点の電流積算値ΔAh(-)に基づいて第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、また、前記OCV-SOC取得部42から取得した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)に基づいて、第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、第2の放電側の充電率の変化量としてのΔSOC2(-)を算出するΔSOC算出部52と、
前記ΔSOC算出部52が算出した前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出部54と、
前記補正係数算出部54が算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定部56と、
前記判定部56で、充電側補正値K(+)と放電側補正値K(-)の一方が1より小さく、他方が1より大きいと判定された場合、過去の容量補正値K(n-1)を容量補正値K(n)に設定する補正係数設定部57と、
前記補正係数設定部57が設定した容量補正値K(n)に基づいて二次電池の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量補正部58と、
前記ΔSOC1(+)、SOC1(-)、ΔSOC2(+)、ΔSOC2(-)の値に基づいてSOC補正値K(soc)を設定するSOC補正部59と、
前記総容量Ah(n)と前記SOC補正値K(soc)に基づいて前記推定充電率SOC’を算出する推定充電率算出部60と、を有することを特徴とする電池状態推定装置80を提供することにより、上記課題を解決する。
(4)ΔSOC算出部52が、二次電池10の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池10の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
また、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出部54が、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする上記(3)記載の電池状態推定装置80を提供することにより、上記課題を解決する。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
(5)補正係数設定部57が、1よりも小さい補正下限値K(min)を有し、補正値K’(n)が補正下限値K(min)よりも小さい場合には、補正下限値K(min)を容量補正値K(n)として設定することを特徴とする上記(1)または上記(2)に記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(6)補正係数設定部57が軽減係数Aを有し、前記軽減係数Aと1つ前の容量補正値K(n-1)とから下記(4’)式に基づいて容量補正値K(n)を算出することを特徴とする上記(1)または上記(2)に記載の電池状態推定装置80を提供することにより、上記課題を解決する。
K(n)=(1-A×(1-K’(n)))×K(n-1)・・・(4’)
(7)SOC補正部59が、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値に基づいてSOC補正値K(soc)を設定することを特徴とする上記(3)または上記(4)記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(8)SOC補正部59が、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値の平均値をSOC補正値K(soc)とすることを特徴とする上記(7)記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(9)基準点の開回路電圧OCV(0)、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)のうち少なくとも1つに、システム起動時の二次電池10の開回路電圧を用いることを特徴とする上記(1)乃至上記(8)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(10)判定部56が充電側補正値K(+)と放電側補正値K(-)の双方が1よりも大きいと判定した場合、補正係数設定部57が下記(4’’)式に基づいて、前記充電側補正値K(+)と前記放電側補正値K(-)との平均値に1つ前の容量補正値K(n-1)を乗じた値を容量補正値K(n)として設定することを特徴とする上記(1)乃至上記(9)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
K(n)=((K(+)+K(-))/2)×K(n-1)・・・(4’’)
(11)容量補正部58が、下記(5)式に基づいて総容量Ah(n-1)を補正し総容量Ah(n)を算出することを特徴とする上記(1)乃至上記(10)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
Ah(n)=Ah(n-1)×K(n)・・・(5)
(12)複数の充電点もしくは複数の放電点を取得した場合に、
OCV-SOC取得部42はそれぞれの充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得するとともに、
ΔSOC算出部52は、それぞれの充電点もしくは放電点に対して個別にΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)を算出し、
補正係数算出部54は、前記(3)式、(3’)式に基づいて、それぞれの充電点もしくは放電点の暫定充電側補正値、暫定放電側補正値を個別に算出した上で、これら暫定充電側補正値、暫定放電側補正値の充電点もしくは放電点ごとの平均値を充電側補正値K(+)、放電側補正値K(-)とすることを特徴とする上記(1)乃至上記(11)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(13)OCV-SOC取得部42が取得した充電点もしくは放電点が、基準点の上下に設定された所定の閾値の範囲を超えた場合に、この点を充電点もしくは放電点として設定することを特徴とする上記(1)乃至上記(12)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(14)電流取得部30からの電流値が予め設定された所定の時間、ゼロ近傍の予め設定された所定の電流ゼロ状態を継続した場合に、OCV-SOC取得部42に対し開回路電圧の取得を許可する緩和状態判定部56をさらに有することを特徴とする上記(1)乃至上記(13)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(15)補正後の総容量Ah(n)を適用した後、再度、容量補正値K(n+1)を算出することを特徴とする上記(1)乃至上記(14)のいずれかに記載の電池状態推定装置80。
(16)1回のシステムの稼働期間における容量補正値K(n)の算出動作の回数に上限を設けることを特徴とする上記(15)記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(17)システムオフ時点に適用されていた容量補正値K(n-1)を少なくとも記録する記録部55をさらに有し、
システムの起動時には、前記記録部55に記録されている前記容量補正値K(n-1)を読み出して、前記容量補正値K(n-1)を容量補正値K(n)とし、下記(5’)式に基づいて初回の総容量Ah(n)を算出することを特徴とする上記(1)乃至上記(16)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
Ah(n)=Ah(0)×K(n)・・・(5’)
(18)システムオフ時点に適用されていた容量補正値K(n-1)とそのときの基準点の充電率SOC(0)’と前回のシステム起動からシステムオフ時点までの全ての期間の電流積算値ΔAh(total)とを少なくとも記録する記録部55をさらに有し、
システムの起動時には、起動時の開回路電圧OCV(0)から充電率SOC(0)を取得するとともに、前記記録部55に記録されている基準点の充電率SOC(0)’と前記電流積算値ΔAh(total)とを読み出して、
前記電流積算値ΔAh(total)がシステムオフ時点の基準点に対して充電側に位置するか放電側に位置するかを判別した上で前記ΔAh(total)に基づいてΔSOC1(+)もしくはΔSOC1(-)を算出し、
前記充電率SOC(0)’と充電率SOC(0)とに基づいてΔSOC2(+)もしくはΔSOC2(-)を算出し、充電側補正値K(+)もしくは放電側補正値K(-)のいずれか一方を算出することを特徴とする上記(1)乃至上記(16)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(19)二次電池10の内部抵抗と電池容量の関係を記録したデータマッピングをさらに有し、
電圧取得部34の取得した電圧値と電流取得部30が取得した電流値とから二次電池10の推定内部抵抗値を算出し、前記推定内部抵抗値と対応する電池容量を前記データマッピングから取得して、前記電池容量が容量低下を示し且つ、判定部56が充電側補正値K(+)と放電側補正値K(-)の双方が1未満と判定した場合に総容量Ah(n)を算出することを特徴とする上記(1)乃至上記(18)のいずれかに記載の電池状態推定装置80を提供することにより、上記課題を解決する。
(20)システムに電力供給を行う充電可能な二次電池10の推定充電率SOC’を算出する電池状態推定方法であって、
前記二次電池10の電流値を取得する電流取得ステップと、
前記電流取得ステップで取得した電流値に基づいて前記二次電池10の電流積算値ΔAhを算出する電流積算値算出ステップと、
前記二次電池10の電圧値を取得する電圧取得ステップと、
前記電圧取得ステップで取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得する開回路電圧取得ステップと、
前記開回路電圧取得ステップで取得した少なくとも1つの基準点の開回路電圧と、充電点の開回路電圧OCV(+)と、放電点の開回路電圧OCV(-)とにそれぞれ対応した少なくとも1つの基準点の充電率と、充電点の充電率SOC(+)と、放電点の充電率SOC(-)とを取得する充電率取得ステップと、
前記電流積算値算出ステップで取得した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得する充放電電流積算値取得ステップと、
前記充放電電流積算値取得ステップで得られた充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、放電点の電流積算値ΔAh(-)に基づいて、第1の放電側の充電率の変化量としてのΔSOC1(-)を算出する第1の充電率変化量算出ステップと、
前記充電率取得ステップで得られた少なくとも1つの基準点の充電率と充電点の充電率SOC(+)とに基づいて第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて第2の放電側の充電率の変化量としてのΔSOC2(-)を算出する第2の充電率変化量算出ステップと、
前記第1の充電率変化量算出ステップと前記第2の充電率変化量算出ステップにより得られた前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出ステップと、
前記補正係数算出ステップで算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定ステップと、
前記判定ステップで充電側補正値K(+)と放電側補正値K(-)の双方が1未満もしくは、充電側補正値K(+)と放電側補正値K(-)の双方が1より大きいと判定された場合、前記充電側補正値K(+)と前記放電側補正値K(-)とに基いて補正値K’(n)を算出するとともに、前記補正値K’(n)に基づいて容量補正値K(n)を設定する補正係数設定ステップと、
前記補正係数設定ステップで設定された容量補正値K(n)に基づいて二次電池の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量値補正ステップと、
前記容量値補正ステップで算出された総容量Ah(n)に基づいて前記推定充電率SOC’を算出する推定充電率算出ステップと、を有することを特徴とする電池状態推定方法を提供することにより、上記課題を解決する。
(21)第1の充電率変化量算出ステップが、二次電池10の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池10の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
第2の充電率変化量算出ステップが、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出ステップが、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする上記(20)記載の電池状態推定方法を提供することにより、上記課題を解決する。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
(22)システムに電力供給を行う充電可能な二次電池10の推定充電率SOC’を算出する電池状態推定方法であって、
前記二次電池10の電流値を取得する電流取得ステップと、
前記電流取得ステップで取得した電流値に基づいて前記二次電池10の電流積算値ΔAhを算出する電流積算値算出ステップと、
前記二次電池10の電圧値を取得する電圧取得ステップと、
前記電圧取得ステップで取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得する開回路電圧取得ステップと、
前記開回路電圧取得ステップで取得した少なくとも1つの基準点の開回路電圧と、充電点の開回路電圧OCV(+)と、放電点の開回路電圧OCV(-)とにそれぞれ対応した少なくとも1つの基準点の充電率と、充電点の充電率SOC(+)と、放電点の充電率SOC(-)とを取得する充電率取得ステップと、
前記電流積算値算出ステップで取得した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得する充放電電流積算値取得ステップと、
前記充放電電流積算値取得ステップで得られた充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、放電点の電流積算値ΔAh(-)に基づいて、第1の放電側の充電率の変化量としてのΔSOC1(-)を算出する第1の充電率変化量算出ステップと、
前記充電率取得ステップで得られた少なくとも1つの基準点の充電率と充電点の充電率SOC(+)とに基づいて第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて第2の放電側の充電率の変化量としてのΔSOC2(-)を算出する第2の充電率変化量算出ステップと、
前記第1の充電率変化量算出ステップと前記第2の充電率変化量算出ステップにより得られた前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出ステップと、
前記補正係数算出ステップで算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定ステップと、
前記判定ステップで、充電側補正値K(+)と放電側補正値K(-)の一方が1より小さく、他方が1より大きいと判定された場合、
過去の容量補正値K(n-1)に基づいて容量補正値K(n)を設定する補正係数設定ステップと、
前記補正係数設定ステップで設定された容量補正値K(n)に基づいて二次電池10の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量値補正ステップと、
前記ΔSOC1(+)、SOC1(-)、ΔSOC2(+)、ΔSOC2(-)の値に基づいてSOC補正値K(soc)を設定するSOC補正値設定ステップと、
前記容量値補正ステップで算出された総容量Ah(n)と前記SOC補正値設定ステップで設定されたSOC補正値K(soc)に基づいて前記推定充電率SOC’を算出する推定充電率算出ステップと、を有することを特徴とする電池状態推定方法を提供することにより、上記課題を解決する。
(23)第1の充電率変化量算出ステップが、二次電池10の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池10の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
第2の充電率変化量算出ステップが、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出ステップが、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする上記(22)記載の電池状態推定方法を提供することにより、上記課題を解決する。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
(24)補正係数設定ステップが、1よりも小さい補正下限値K(min)よりも補正値K’(n)が小さい場合には、補正下限値K(min)を容量補正値K(n)として設定することを特徴とする上記(20)または上記(21)に記載の電池状態推定方法を提供することにより、上記課題を解決する。
(25)補正係数設定ステップが、1よりも小さい軽減係数Aと1つ前の容量補正値K(n-1)とから下記(4’)式に基づいて容量補正値K(n)を算出することを特徴とする上記(20)または上記(21)に記載の電池状態推定方法を提供することにより、上記課題を解決する。
K(n)=(1-A×(1-K’(n)))×K(n-1)・・・(4’)
(26)SOC補正値設定ステップが、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値に基づいてSOC補正値K(soc)を設定することを特徴とする上記(22)または上記(23)に記載の電池状態推定方法を提供することにより、上記課題を解決する。
(27)SOC補正値設定ステップが、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値の平均値をSOC補正値K(soc)とすることを特徴とする上記(26)に記載の電池状態推定方法を提供することにより、上記課題を解決する。
(28)開回路電圧取得ステップが、基準点の開回路電圧OCV(0)、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)のうち少なくとも1つに、システム起動時の二次電池10の開回路電圧を用いることを特徴とする上記(20)乃至上記(27)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
(29)判定ステップで、充電側補正値K(+)と放電側補正値K(-)の双方が1よりも大きいと判定された場合、補正係数設定ステップが下記(4’’)式に基づいて、前記充電側補正値K(+)と前記放電側補正値K(-)との平均値に1つ前の容量補正値K(n-1)を乗じた値を容量補正値K(n)として設定することを特徴とする上記(20)乃至上記(28)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
K(n)=((K(+)+K(-))/2)×K(n-1)・・・(4’’)
(30)容量値補正ステップが、下記(5)式に基づいて総容量Ah(n-1)を補正し総容量Ah(n)を算出することを特徴とする上記(20)乃至上記(29)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
Ah(n)=Ah(n-1)×K(n)・・・(5)
(31)開回路電圧取得ステップが、複数の充電点もしくは複数の放電点を取得した場合に、充電率取得ステップはそれぞれの充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得し、
充電率変化量算出ステップは、それぞれの充電点もしくは放電点に対して個別にΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)を算出し、
補正係数算出ステップは、前記(3)式、(3’)式に基づいて、それぞれの充電点もしくは放電点の暫定充電側補正値、暫定放電側補正値を個別に算出した上で、これら暫定充電側補正値、暫定放電側補正値の充電点もしくは放電点ごとの平均値を充電側補正値K(+)、放電側補正値K(-)とすることを特徴とする上記(20)乃至上記(30)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
(32)開回路電圧取得ステップが、取得した充電点もしくは放電点が基準点の上下に設定された所定の閾値の範囲を超えた場合に、この点を充電点もしくは放電点として設定することを特徴とする上記(20)乃至上記(31)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
(33)開回路電圧取得ステップが、電流取得部30からの電流値が予め設定された所定の時間、ゼロ近傍の予め設定された所定の電流ゼロ状態を継続した場合に、開回路電圧を取得する緩和状態待機ステップをさらに有することを特徴とする上記(20)乃至上記(32)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
(34)補正後の総容量Ah(n)を適用した後、再度、容量補正値K(n+1)を算出することを特徴とする上記(20)乃至上記(33)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
(35)1回のシステムの稼働期間における容量補正値K(n)の算出動作の回数に上限を設けることを特徴とする上記(34)記載の電池状態推定方法を提供することにより、上記課題を解決する。
(36)システムオフ時点で適用中の容量補正値K(n-1)を少なくとも記録する記録ステップと、
システムの起動時に実行される初期補正値算出ステップと、をさらに有し、
前記初期補正値算出ステップは、前記記録ステップで記録された前記容量補正値K(n-1)を読み出して、前記容量補正値K(n-1)を容量補正値K(n)とし、下記(5’)式に基づいて初回の総容量Ah(n)を算出することを特徴とする上記(20)乃至上記(35)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
Ah(n)=Ah(0)×K(n)・・・(5’)
(37)システムオフ時点に適用されていた容量補正値K(n-1)とそのときの基準点の充電率SOC(0)’と前回のシステム起動からシステムオフ時点までの全ての期間の電流積算値ΔAh(total)とを少なくとも記録する記録ステップをさらに有し、
システムの起動時には、起動時の開回路電圧OCV(0)から充電率SOC(0)を取得するとともに、前記記録部55に記録されている基準点の充電率SOC(0)’と前記電流積算値ΔAh(total)とを読み出して、
前記電流積算値ΔAh(total)がシステムオフ時点の基準点に対して充電側に位置するか放電側に位置するかを判別した上で前記ΔAh(total)に基づいてΔSOC1(+)もしくはΔSOC1(-)を算出し、
前記充電率SOC(0)’と充電率SOC(0)とに基づいてΔSOC2(+)もしくはΔSOC2(-)を算出し、充電側補正値K(+)もしくは放電側補正値K(-)のいずれか一方を算出することを特徴とする上記(20)乃至上記(35)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
(38)二次電池10の内部抵抗と電池容量の関係を記録したデータマッピングを備えるとともに、
電圧取得ステップで取得した電圧値と電流取得ステップで取得した電流値とから二次電池10の推定内部抵抗値を算出する内部抵抗算出ステップと、
前記内部抵抗算出ステップで算出した推定内部抵抗値と対応する電池容量を前記データマッピングから取得する電池容量取得ステップと、
前記電池容量取得ステップが取得した電池容量が容量低下を示すか否かを判定する容量低下判定ステップと、をさらに有し、
前記容量低下判定ステップにて前記電池容量取得ステップで取得した電池容量が容量低下を示し、且つ判定ステップにて充電側補正値K(+)と放電側補正値K(-)の双方が1未満と判定した場合に総容量Ah(n)を算出することを特徴とする上記(20)乃至上記(37)のいずれかに記載の電池状態推定方法を提供することにより、上記課題を解決する。
The present invention
(1) A battery state estimation device that calculates an estimated charging rate SOC' of a rechargeable secondary battery 10 that supplies power to the system,
a current acquisition unit 30 that acquires the current value of the secondary battery 10; a current cumulative value calculation unit 32 that calculates the current cumulative value ΔAh of the secondary battery 10 based on the current value acquired by the current acquisition unit 30; , a voltage acquisition unit 34 that acquires the voltage value of the secondary battery 10;
An open circuit voltage OCV (+) of at least one reference point based on the voltage value acquired by the voltage acquisition unit 34 and an open circuit voltage OCV (+) of a charging point located in the charging direction with respect to at least one reference point. , obtain the open circuit voltage OCV(-) of a discharge point located in the discharge direction relative to at least one reference point, and further obtain the open circuit voltage OCV(+) of the at least one reference point and the open circuit voltage OCV(+) of a charging point. ), OCV-SOC acquisition that acquires the charging rate of at least one reference point corresponding to the open circuit voltage OCV (-) of the discharge point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharge point Section 42 and
Based on the current integrated value ΔAh input from the current integrated value calculation unit 32, a current integrated value ΔAh (+) of the charging point based on the current integrated value of at least one of the reference points, and at least one of the reference points. The integrated current value ΔAh(-) at the discharging point is obtained based on the integrated current value of ΔSOC1(+) as a quantity is calculated, ΔSOC1(-) is calculated as a change in the charging rate on the first discharging side based on the acquired current integrated value ΔAh(-) of the discharge point, and The charging rate of the second charging side is determined based on the charging rate of at least one reference point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharging point acquired from the OCV-SOC acquisition unit 42. a ΔSOC calculation unit 52 that calculates ΔSOC2(+) as the amount of change and calculates ΔSOC2(-) as the amount of change in the charging rate on the second discharge side;
The charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) calculated by the ΔSOC calculation unit 52, and a correction coefficient calculation unit 54 that calculates a discharge side correction value K(-) based on the
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated by the correction coefficient calculation unit 54 are each larger or smaller than 1, and the estimated charging rate SOC' is determined according to the determination result. a determination unit 56 that selects a calculation method;
The determination unit 56 determines whether both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, or both the charging side correction value K(+) and the discharging side correction value K(-). If it is determined to be larger than 1, a correction value K'(n) is calculated based on the charging side correction value K(+) and the discharging side correction value K(-), and the correction value K'( a correction coefficient setting unit 57 that sets a capacitance correction value K(n) based on
a capacity correction unit 58 that calculates the total capacity Ah(n) by correcting the total capacity Ah(n-1) of the secondary battery 10 based on the capacity correction value K(n) set by the correction coefficient setting unit 57; ,
To provide a battery state estimation device 80, comprising: an estimated charging rate calculation unit 60 that calculates the estimated charging rate SOC′ based on the total capacity Ah(n) calculated by the capacity correction unit 58. This solves the above problem.
(2) The ΔSOC calculation unit 52 performs charging on the first charging side based on the total capacity Ah (n-1) of the secondary battery 10 and the integrated current value ΔAh (+) at the charging point according to the following formula (1). Calculate ΔSOC1 (+) as the amount of change in the rate, and use the following formula (1') based on the total capacity Ah (n-1) of the secondary battery 10 and the integrated current value ΔAh (-) at the discharge point. Calculate ΔSOC1 (-) as the amount of change in the charging rate on the first discharge side,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
In addition, based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point, ΔSOC2(+ ), or calculate the following formula (2'') based on the charging rate SOC (0') of another reference point different from the charging rate SOC (0) and the charging rate SOC (+) of the charging point. Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
The correction coefficient calculation unit 54 calculates a charging side correction value K(+) based on the ΔSOC1(+) and ΔSOC2(+) using the following equation (3), and calculates the charging side correction value K(+) based on the ΔSOC1(-) and ΔSOC2(-). The above problem is solved by providing the battery state estimation device 80 described in the above (1), which is characterized in that the discharge side correction value K(-) is calculated by the following equation (3') based on the above equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
(3) A battery state estimation device that calculates the estimated charging rate SOC' of the rechargeable secondary battery 10 that supplies power to the system,
a current acquisition unit 30 that acquires the current value of the secondary battery 10; a current cumulative value calculation unit 32 that calculates the current cumulative value ΔAh of the secondary battery 10 based on the current value acquired by the current acquisition unit 30; , a voltage acquisition unit 34 that acquires the voltage value of the secondary battery 10;
An open circuit voltage OCV (+) of at least one reference point based on the voltage value acquired by the voltage acquisition unit 34 and an open circuit voltage OCV (+) of a charging point located in the charging direction with respect to at least one reference point. , obtain the open circuit voltage OCV(-) of a discharge point located in the discharge direction relative to at least one reference point, and further obtain the open circuit voltage OCV(+) of the at least one reference point and the open circuit voltage OCV(+) of a charging point. ), OCV-SOC acquisition that acquires the charging rate of at least one reference point corresponding to the open circuit voltage OCV (-) of the discharge point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharge point Section 42 and
Based on the current integrated value ΔAh input from the current integrated value calculation unit 32, a current integrated value ΔAh (+) of the charging point based on the current integrated value of at least one of the reference points, and at least one of the reference points. The integrated current value ΔAh(-) at the discharging point is obtained based on the integrated current value of ΔSOC1(+) as a quantity is calculated, ΔSOC1(-) is calculated as a change in the charging rate on the first discharging side based on the acquired current integrated value ΔAh(-) of the discharge point, and The charging rate of the second charging side is determined based on the charging rate of at least one reference point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharging point acquired from the OCV-SOC acquisition unit 42. a ΔSOC calculation unit 52 that calculates ΔSOC2(+) as the amount of change and calculates ΔSOC2(-) as the amount of change in the charging rate on the second discharge side;
The charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) calculated by the ΔSOC calculation unit 52, and a correction coefficient calculation unit 54 that calculates a discharge side correction value K(-) based on the
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated by the correction coefficient calculation unit 54 are each larger or smaller than 1, and the estimated charging rate SOC' is determined according to the determination result. a determination unit 56 that selects a calculation method;
If the determination unit 56 determines that one of the charging side correction value K(+) and the discharging side correction value K(-) is smaller than 1 and the other is larger than 1, the past capacity correction value K(n- 1) as a capacity correction value K(n);
a capacity correction unit 58 that calculates the total capacity Ah (n) by correcting the total capacity Ah (n-1) of the secondary battery based on the capacity correction value K (n) set by the correction coefficient setting unit 57;
an SOC correction unit 59 that sets an SOC correction value K (soc) based on the values of ΔSOC1 (+), SOC1 (-), ΔSOC2 (+), and ΔSOC2 (-);
Provided is a battery state estimation device 80 characterized by having an estimated charging rate calculation unit 60 that calculates the estimated charging rate SOC' based on the total capacity Ah (n) and the SOC correction value K (soc). By doing so, the above problem is solved.
(4) The ΔSOC calculation unit 52 performs charging on the first charging side according to the following formula (1) based on the total capacity Ah (n-1) of the secondary battery 10 and the integrated current value ΔAh (+) at the charging point. Calculate ΔSOC1 (+) as the amount of change in the rate, and use the following formula (1') based on the total capacity Ah (n-1) of the secondary battery 10 and the integrated current value ΔAh (-) at the discharge point. Calculate ΔSOC1 (-) as the amount of change in the charging rate on the first discharge side,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
In addition, based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point, ΔSOC2(+ ), or calculate the following formula (2'') based on the charging rate SOC (0') of another reference point different from the charging rate SOC (0) and the charging rate SOC (+) of the charging point. Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
The correction coefficient calculation unit 54 calculates a charging side correction value K(+) based on the ΔSOC1(+) and ΔSOC2(+) using the following equation (3), and calculates the charging side correction value K(+) based on the ΔSOC1(-) and ΔSOC2(-). The above problem is solved by providing the battery state estimation device 80 described in the above (3), which is characterized in that the discharge side correction value K(-) is calculated by the following equation (3') based on the above equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
(5) When the correction coefficient setting unit 57 has a correction lower limit value K (min) smaller than 1 and the correction value K' (n) is smaller than the correction lower limit value K (min), the correction lower limit value The above problem is solved by providing the battery state estimating device 80 described in (1) or (2) above, which is characterized in that K(min) is set as the capacity correction value K(n).
(6) The correction coefficient setting unit 57 has a reduction coefficient A, and the capacity correction value K( The above problem is solved by providing the battery state estimating device 80 described in the above (1) or (2), which is characterized by calculating n).
K(n)=(1-A×(1-K'(n)))×K(n-1)...(4')
(7) The SOC correction unit 59 sets the SOC correction value K (soc) based on the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| The above problem is solved by providing the battery state estimation device 80 described in (3) or (4) above, which is characterized by the following.
(8) The SOC correction unit 59 sets the average value of the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| as the SOC correction value K(soc). The above problem is solved by providing the battery state estimation device 80 described in (7) above, which is characterized by the following.
(9) At least one of the open circuit voltage OCV (0) at the reference point, the open circuit voltage OCV (+) at the charging point, and the open circuit voltage OCV (-) at the discharge point is set to the secondary battery 10 at the time of system startup. The above problem is solved by providing the battery state estimating device 80 according to any one of (1) to (8) above, which uses an open circuit voltage of .
(10) When the determining unit 56 determines that both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1, the correction coefficient setting unit 57 calculates the following equation (4''). Based on this, a value obtained by multiplying the average value of the charging side correction value K(+) and the discharging side correction value K(-) by the previous capacity correction value K(n-1) is calculated as the capacity correction value K( The above problem is solved by providing the battery state estimating device 80 according to any one of (1) to (9) above, which is set as n).
K(n)=((K(+)+K(-))/2)×K(n-1)...(4'')
(11) The capacity correction unit 58 corrects the total capacity Ah (n-1) based on the following equation (5) to calculate the total capacity Ah (n). ) The above problem is solved by providing the battery state estimation device 80 according to any one of the above.
Ah(n)=Ah(n-1)×K(n)...(5)
(12) When multiple charging points or multiple discharging points are acquired,
The OCV-SOC acquisition unit 42 acquires the charging rate SOC (+) of each charging point and the charging rate SOC (-) of the discharging point,
The ΔSOC calculation unit 52 individually calculates ΔSOC1(+), ΔSOC1(-), ΔSOC2(+), and ΔSOC2(-) for each charging point or discharging point,
The correction coefficient calculation unit 54 individually calculates a provisional charging side correction value and a provisional discharge side correction value for each charging point or discharge point based on equations (3) and (3'), and then calculates these values. (1) above, characterized in that the average value of the temporary charging side correction value and the temporary discharging side correction value for each charging point or discharging point is used as the charging side correction value K (+) and the discharging side correction value K (-). The above problem is solved by providing the battery state estimation device 80 according to any one of (11) above.
(13) When the charging point or discharging point acquired by the OCV-SOC acquisition unit 42 exceeds the range of predetermined threshold values set above and below the reference point, set this point as the charging point or discharging point. The above problem is solved by providing the battery state estimation device 80 according to any one of the above (1) to (12), which is characterized by the following.
(14) When the current value from the current acquisition unit 30 continues in a preset zero current state near zero for a preset time, the open circuit voltage is determined by the OCV-SOC acquisition unit 42. The above problem is solved by providing the battery state estimation device 80 according to any one of (1) to (13) above, which further includes a relaxation state determination unit 56 that permits acquisition.
(15) The battery according to any one of (1) to (14) above, characterized in that after applying the corrected total capacity Ah(n), the capacity correction value K(n+1) is calculated again. State estimation device 80.
(16) By providing the battery state estimating device 80 described in (15) above, which is characterized in that an upper limit is set for the number of times the capacity correction value K(n) is calculated during one system operation period, solve problems.
(17) further comprising a recording unit 55 for recording at least the capacitance correction value K(n-1) applied at the time the system was turned off;
When the system is started, the capacitance correction value K(n-1) recorded in the recording section 55 is read out, the capacitance correction value K(n-1) is set as the capacitance correction value K(n), and the following ( By providing the battery state estimating device 80 according to any one of (1) to (16) above, which calculates the initial total capacity Ah(n) based on equation 5'), solve problems.
Ah(n)=Ah(0)×K(n)...(5')
(18) Capacity correction value K(n-1) applied at the time the system was turned off, charging rate SOC(0)' at the reference point at that time, and current during the entire period from the previous system startup to the time the system was turned off. further comprising a recording unit 55 for recording at least the integrated value ΔAh (total),
When the system is started, the charging rate SOC(0) is obtained from the open circuit voltage OCV(0) at the time of startup, and the charging rate SOC(0)' at the reference point recorded in the recording unit 55 and the current integration are obtained. Read out the value ΔAh (total),
After determining whether the current integrated value ΔAh (total) is located on the charging side or discharging side with respect to the reference point at the time of system off, ΔSOC1 (+) or ΔSOC1 ( -) is calculated,
ΔSOC2(+) or ΔSOC2(-) is calculated based on the charging rate SOC(0)' and the charging rate SOC(0), and the charging side correction value K(+) or the discharging side correction value K(-) is calculated. The above problem is solved by providing the battery state estimating device 80 according to any one of the above (1) to (16), which is characterized by calculating either one of the above.
(19) further includes data mapping that records the relationship between the internal resistance and battery capacity of the secondary battery 10;
An estimated internal resistance value of the secondary battery 10 is calculated from the voltage value acquired by the voltage acquisition unit 34 and a current value acquired by the current acquisition unit 30, and a battery capacity corresponding to the estimated internal resistance value is acquired from the data mapping. Then, when the battery capacity shows a capacity decrease and the determination unit 56 determines that both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, the total capacity Ah(n) The above problem is solved by providing the battery state estimating device 80 according to any one of (1) to (18) above, which is characterized by calculating the above.
(20) A battery state estimation method for calculating an estimated charging rate SOC' of a rechargeable secondary battery 10 that supplies power to the system, comprising:
a current acquisition step of acquiring a current value of the secondary battery 10;
a current integrated value calculation step of calculating an integrated current value ΔAh of the secondary battery 10 based on the current value obtained in the current obtaining step;
a voltage acquisition step of acquiring a voltage value of the secondary battery 10;
an open circuit voltage of at least one or more reference points based on the voltage value acquired in the voltage acquisition step; and an open circuit voltage OCV (+) of a charging point located in the charging direction than the at least one reference point; an open circuit voltage obtaining step of obtaining an open circuit voltage OCV(-) of a discharge point located in the discharge direction with respect to at least one reference point;
At least one open circuit voltage corresponding to the at least one reference point open circuit voltage obtained in the open circuit voltage obtaining step, the charging point open circuit voltage OCV (+), and the discharging point open circuit voltage OCV (−), respectively. a charging rate acquisition step of acquiring a charging rate at a reference point, a charging rate SOC (+) at a charging point, and a charging rate SOC (-) at a discharging point;
Based on the current integrated value ΔAh obtained in the current integrated value calculation step, calculate the current integrated value ΔAh (+) of the charging point based on the current integrated value of at least one of the reference points, and the current integrated value ΔAh (+) of the at least one of the reference points. a charging/discharging current integrated value acquisition step of respectively obtaining a current integrated value ΔAh(-) at a discharge point based on the current integrated value;
Based on the integrated current value ΔAh(+) at the charging point obtained in the charging/discharging current integrated value acquisition step, ΔSOC1(+) as the amount of change in the charging rate on the first charging side is calculated, and the current at the discharging point is calculated. a first charge rate change amount calculation step of calculating ΔSOC1(-) as a change amount in the charge rate on the first discharging side based on the integrated value ΔAh(-);
Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side based on the charging rate of at least one reference point obtained in the charging rate acquisition step and the charging rate SOC(+) of the charging point. and a second charging rate that calculates ΔSOC2(-) as the amount of change in the charging rate on the second discharge side based on the charging rate SOC(0) at the reference point and the charging rate SOC(-) at the discharge point. a step of calculating the amount of change;
A charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) obtained by the first charging rate change amount calculating step and the second charging rate change amount calculating step. a correction coefficient calculation step of calculating a discharge side correction value K(-) based on the ratio of the ΔSOC1(-) and ΔSOC2(-);
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated in the correction coefficient calculation step are each larger or smaller than 1, and the estimated charging rate SOC' is calculated according to the judgment result. a determination step of selecting a calculation method;
In the determination step, both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, or both the charging side correction value K(+) and the discharging side correction value K(-) are greater than 1. If it is determined that the correction value K'(n) is large, a correction value K'(n) is calculated based on the charging side correction value K(+) and the discharging side correction value K(-), and the correction value K'(n) a correction coefficient setting step of setting a capacity correction value K(n) based on;
a capacity value correction step of calculating the total capacity Ah(n) by correcting the total capacity Ah(n-1) of the secondary battery based on the capacity correction value K(n) set in the correction coefficient setting step;
By providing a battery state estimation method, comprising: an estimated charging rate calculation step of calculating the estimated charging rate SOC' based on the total capacity Ah (n) calculated in the capacity value correction step. , solve the above problems.
(21) The first charge rate change calculation step is performed using the following equation (1) based on the total capacity Ah (n-1) of the secondary battery 10 and the integrated current value ΔAh (+) at the charging point. ΔSOC1 (+) as the amount of change in the charging rate on the charging side is calculated, and the following ( 1') Calculate ΔSOC1(-) as the amount of change in the charging rate on the first discharge side,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
The second charging rate change calculation step calculates the charging rate on the second charging side using the following formula (2) based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point. Calculate ΔSOC2 (+) as the amount of change in the charging rate, or calculate the charging rate SOC (0') at another reference point different from the charging rate SOC (0) and the charging rate SOC (+) at the charging point. Based on the following formula (2''), calculate ΔSOC2 (+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
The correction coefficient calculating step calculates a charging side correction value K(+) based on the above-mentioned ΔSOC1(+) and ΔSOC2(+) using the following equation (3), and calculates the charging-side correction value K(+) based on the above-mentioned ΔSOC1(-) and ΔSOC2(-). The above problem is solved by providing the battery state estimation method described in the above (20), which is characterized in that the discharge side correction value K(-) is calculated by the following equation (3') based on the above.
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
(22) A battery state estimation method for calculating an estimated charging rate SOC' of a rechargeable secondary battery 10 that supplies power to the system, comprising:
a current acquisition step of acquiring a current value of the secondary battery 10;
a current integrated value calculation step of calculating an integrated current value ΔAh of the secondary battery 10 based on the current value obtained in the current obtaining step;
a voltage acquisition step of acquiring a voltage value of the secondary battery 10;
an open circuit voltage of at least one or more reference points based on the voltage value acquired in the voltage acquisition step; and an open circuit voltage OCV (+) of a charging point located in the charging direction than the at least one reference point; an open circuit voltage obtaining step of obtaining an open circuit voltage OCV(-) of a discharge point located in the discharge direction with respect to at least one reference point;
At least one open circuit voltage corresponding to the at least one reference point open circuit voltage obtained in the open circuit voltage obtaining step, the charging point open circuit voltage OCV (+), and the discharging point open circuit voltage OCV (−), respectively. a charging rate acquisition step of acquiring a charging rate at a reference point, a charging rate SOC (+) at a charging point, and a charging rate SOC (-) at a discharging point;
Based on the current integrated value ΔAh obtained in the current integrated value calculation step, calculate the current integrated value ΔAh (+) of the charging point based on the current integrated value of at least one of the reference points, and the current integrated value ΔAh (+) of the at least one of the reference points. a charging/discharging current integrated value acquisition step of respectively obtaining a current integrated value ΔAh(-) at a discharge point based on the current integrated value;
Based on the integrated current value ΔAh(+) at the charging point obtained in the charging/discharging current integrated value acquisition step, ΔSOC1(+) as the amount of change in the charging rate on the first charging side is calculated, and the current at the discharging point is calculated. a first charge rate change amount calculation step of calculating ΔSOC1(-) as a change amount in the charge rate on the first discharging side based on the integrated value ΔAh(-);
Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side based on the charging rate of at least one reference point obtained in the charging rate acquisition step and the charging rate SOC(+) of the charging point. and a second charging rate that calculates ΔSOC2(-) as the amount of change in the charging rate on the second discharge side based on the charging rate SOC(0) at the reference point and the charging rate SOC(-) at the discharge point. a step of calculating the amount of change;
A charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) obtained by the first charging rate change amount calculating step and the second charging rate change amount calculating step. a correction coefficient calculation step of calculating a discharge side correction value K(-) based on the ratio of the ΔSOC1(-) and ΔSOC2(-);
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated in the correction coefficient calculation step are each larger or smaller than 1, and the estimated charging rate SOC' is calculated according to the judgment result. a determination step of selecting a calculation method;
If it is determined in the determination step that one of the charging side correction value K(+) and the discharging side correction value K(-) is smaller than 1 and the other is larger than 1,
a correction coefficient setting step of setting a capacity correction value K(n) based on a past capacity correction value K(n-1);
a capacity value correction step of calculating the total capacity Ah(n) by correcting the total capacity Ah(n-1) of the secondary battery 10 based on the capacity correction value K(n) set in the correction coefficient setting step; ,
an SOC correction value setting step of setting an SOC correction value K (soc) based on the values of the ΔSOC1(+), SOC1(-), ΔSOC2(+), and ΔSOC2(-);
An estimated charging rate calculation step of calculating the estimated charging rate SOC' based on the total capacity Ah (n) calculated in the capacity value correction step and the SOC correction value K (soc) set in the SOC correction value setting step. The above problem is solved by providing a battery state estimation method characterized by having the following.
(23) The first charge rate change calculation step is performed using the following equation (1) based on the total capacity Ah (n-1) of the secondary battery 10 and the integrated current value ΔAh (+) at the charging point. ΔSOC1 (+) as the amount of change in the charging rate on the charging side is calculated, and the following ( 1') Calculate ΔSOC1(-) as the amount of change in the charging rate on the first discharge side,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
The second charging rate change calculation step calculates the charging rate on the second charging side using the following formula (2) based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point. Calculate ΔSOC2 (+) as the amount of change in the charging rate, or calculate the charging rate SOC (0') at another reference point different from the charging rate SOC (0) and the charging rate SOC (+) at the charging point. Based on the following formula (2''), calculate ΔSOC2 (+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
The correction coefficient calculating step calculates a charging side correction value K(+) based on the above-mentioned ΔSOC1(+) and ΔSOC2(+) using the following equation (3), and calculates the charging-side correction value K(+) based on the above-mentioned ΔSOC1(-) and ΔSOC2(-). The above problem is solved by providing the battery state estimation method described in the above (22), which is characterized in that the discharge side correction value K(-) is calculated by the following equation (3') based on the above equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
(24) In the correction coefficient setting step, if the correction value K'(n) is smaller than the correction lower limit value K(min) which is smaller than 1, the correction lower limit value K(min) is set to the capacity correction value K(n). The above problem is solved by providing the battery state estimation method described in (20) or (21) above, which is characterized in that the battery condition estimation method is set as follows.
(25) The correction coefficient setting step calculates the capacity correction value K(n) based on the following formula (4') from the reduction coefficient A smaller than 1 and the previous capacity correction value K(n-1). The above problem is solved by providing the battery state estimation method described in (20) or (21) above, which is characterized in that:
K(n)=(1-A×(1-K'(n)))×K(n-1)...(4')
(26) The SOC correction value setting step sets the SOC correction value K (soc) based on the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| The above problem is solved by providing the battery state estimation method described in (22) or (23) above, which is characterized by the following.
(27) The SOC correction value setting step sets the average value of the values of |ΔSOC2(+)−ΔSOC1(+)| and the values of |ΔSOC2(−)−ΔSOC1(−)| as the SOC correction value K(soc). The above problem is solved by providing the battery state estimation method described in the above (26), which is characterized in that:
(28) The open circuit voltage acquisition step is performed when the system The above problem is solved by providing the battery state estimation method according to any one of (20) to (27) above, which uses the open circuit voltage of the secondary battery 10 at startup.
(29) If it is determined in the determination step that both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1, the correction coefficient setting step is performed using the following formula (4''). Based on this, a value obtained by multiplying the average value of the charging side correction value K(+) and the discharging side correction value K(-) by the previous capacity correction value K(n-1) is calculated as the capacity correction value K( The above problem is solved by providing the battery state estimation method according to any one of (20) to (28) above, characterized in that the battery condition estimation method is set as n).
K(n)=((K(+)+K(-))/2)×K(n-1)...(4'')
(30) The capacitance value correction step is characterized in that the total capacitance Ah (n-1) is corrected based on the following equation (5) to calculate the total capacitance Ah (n). ) The above problem is solved by providing the battery state estimation method according to any one of the above.
Ah(n)=Ah(n-1)×K(n)...(5)
(31) When the open circuit voltage acquisition step acquires a plurality of charging points or a plurality of discharge points, the charging rate acquisition step acquires the charging rate SOC (+) of each charging point, the charging rate SOC (-) of the discharging point, ) and
The charging rate change calculation step calculates ΔSOC1(+), ΔSOC1(-), ΔSOC2(+), ΔSOC2(-) for each charging point or discharging point individually,
In the correction coefficient calculation step, the provisional charging side correction value and the provisional discharging side correction value for each charging point or discharging point are individually calculated based on equations (3) and (3'), and then these provisional correction values are calculated. (20) above, characterized in that the average value of the charging side correction value and provisional discharging side correction value for each charging point or discharging point is used as the charging side correction value K (+) and the discharging side correction value K (-). The above problem is solved by providing the battery state estimation method according to any one of (30) above.
(32) In the open circuit voltage acquisition step, if the acquired charging point or discharging point exceeds the range of predetermined threshold values set above and below the reference point, set this point as the charging point or discharging point. The above problem is solved by providing the battery state estimation method according to any one of features (20) to (31) above.
(33) In the open circuit voltage acquisition step, the open circuit voltage is acquired when the current value from the current acquisition unit 30 continues in a preset zero current state near zero for a preset time. The above problem is solved by providing the battery state estimation method according to any one of (20) to (32) above, which further includes a relaxing state standby step.
(34) The battery according to any one of (20) to (33) above, characterized in that after applying the corrected total capacity Ah(n), the capacity correction value K(n+1) is calculated again. The above problem is solved by providing a state estimation method.
(35) The above problem can be solved by providing the battery state estimation method according to (34) above, which is characterized in that an upper limit is set on the number of times the capacity correction value K(n) is calculated during one system operation period. Solve.
(36) a recording step of recording at least the capacitance correction value K(n-1) being applied at the time the system is turned off;
further comprising an initial correction value calculation step executed at system startup;
The initial correction value calculation step reads the capacitance correction value K(n-1) recorded in the recording step, sets the capacitance correction value K(n-1) to the capacitance correction value K(n), and performs the following process. By providing the battery state estimation method according to any one of (20) to (35) above, which is characterized in that the initial total capacity Ah(n) is calculated based on equation (5'), solve problems.
Ah(n)=Ah(0)×K(n)...(5')
(37) Capacity correction value K(n-1) applied at the time the system was turned off, charging rate SOC(0)' at the reference point at that time, and current during all periods from the previous system startup to the time the system was turned off. further comprising a recording step of recording at least the integrated value ΔAh (total),
When the system is started, the charging rate SOC(0) is obtained from the open circuit voltage OCV(0) at the time of startup, and the charging rate SOC(0)' at the reference point recorded in the recording unit 55 and the current integration are obtained. Read out the value ΔAh (total),
After determining whether the current integrated value ΔAh (total) is located on the charging side or discharging side with respect to the reference point at the time of system off, ΔSOC1 (+) or ΔSOC1 ( -) is calculated,
ΔSOC2(+) or ΔSOC2(-) is calculated based on the charging rate SOC(0)' and the charging rate SOC(0), and the charging side correction value K(+) or the discharging side correction value K(-) is calculated. The above problem is solved by providing the battery state estimation method according to any one of (20) to (35) above, which is characterized in that either one of the above is calculated.
(38) Includes data mapping that records the relationship between the internal resistance and battery capacity of the secondary battery 10, and
an internal resistance calculation step of calculating an estimated internal resistance value of the secondary battery 10 from the voltage value acquired in the voltage acquisition step and the current value acquired in the current acquisition step;
a battery capacity acquisition step of acquiring a battery capacity corresponding to the estimated internal resistance value calculated in the internal resistance calculation step from the data mapping;
further comprising a capacity reduction determination step of determining whether the battery capacity acquired in the battery capacity acquisition step indicates a decrease in capacity;
In the capacity decrease determination step, the battery capacity acquired in the battery capacity acquisition step indicates a decrease in capacity, and in the determination step, both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1. The above problem is solved by providing the battery state estimation method according to any one of (20) to (37) above, which is characterized in that when it is determined that the total capacity Ah(n) is calculated.

本発明に係る電池状態推定装置及び電池状態推定方法は、基準点、充電点、放電点の少なくとも3点以上の開回路電圧に基づく充電率SOC(0)、SOC(+)、SOC(-)の変化量と、これら基準点、充電点、放電点に対応した少なくとも2区間以上の電流積算値ΔAh(+)、ΔAh(-)とに基づく充電率の変化量との比率に基づいて充電側補正値K(+)、放電側補正値K(-)を算出する。そして、充電側補正値K(+)、放電側補正値K(-)の双方がともに1未満の場合、ともに1よりも大きい場合、一方のみが1未満の場合、のそれぞれに対応した方法で補正を行う。これにより、二次電池の電池容量の低下及び電流取得手段のゲイン誤差に対する補正と、電流取得手段のオフセット誤差に対する補正とを区別して行うことが可能であり、双方に対応した補正を適切に行うことができる。そして、より正確な推定充電率SOC’を算出することができる。 The battery state estimation device and the battery state estimation method according to the present invention provide charging rates SOC(0), SOC(+), and SOC(-) based on open circuit voltages at at least three points: a reference point, a charging point, and a discharging point. and the amount of change in the charging rate based on the integrated current values ΔAh (+) and ΔAh (-) for at least two sections corresponding to these reference points, charging points, and discharging points. A correction value K(+) and a discharge side correction value K(-) are calculated. Then, in the case where both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, when both are greater than 1, and when only one is less than 1, Make corrections. As a result, it is possible to distinguish between correction for the decrease in battery capacity of the secondary battery and the gain error of the current acquisition means, and correction for the offset error of the current acquisition means, and appropriately perform correction corresponding to both. be able to. Then, a more accurate estimated charging rate SOC' can be calculated.

本発明に係る電池状態推定装置の概略構成を示すブロック図である。FIG. 1 is a block diagram showing a schematic configuration of a battery state estimation device according to the present invention. 本発明に係る電池状態推定方法のフローチャートである。3 is a flowchart of a battery state estimation method according to the present invention. 本発明に係る電池状態推定方法のフローチャートである。3 is a flowchart of a battery state estimation method according to the present invention. 本発明に係る電池状態推定方法のフローチャートである。3 is a flowchart of a battery state estimation method according to the present invention. 基準点を複数有する場合の本発明に係る電池状態推定方法を説明する図である。It is a figure explaining the battery state estimation method based on this invention when it has multiple reference points. 電流値と電流積算値を説明する図である。It is a figure explaining a current value and a current integrated value. オフセット誤差とΔSOC1、ΔSOC2の関係を説明する図である。FIG. 3 is a diagram illustrating the relationship between offset error and ΔSOC1 and ΔSOC2.

本発明に係る電池状態推定装置80及び電池状態推定方法について図面に基づいて説明する。図1は本発明に係る電池状態推定装置80の概略構成を示すブロック図である。先ず、本発明に係る電池状態推定装置80は、負荷1の電力源として用いる二次電池10の状態を推定するものであり、この二次電池10の電池電圧Vや電流値I等の情報を取得する電池情報取得部20と、この電池情報取得部20からの情報に基づいて充電率SOCを取得する充電率取得部40と、この充電率取得部40が取得した少なくとも3点の充電率SOC(SOC(0)、SOC(+)、SOC(-))と電池情報取得部20から取得した電流積算値ΔAh(ΔAh(+)、ΔAh(-))とに基づいて容量補正値K(n)もしくはSOC補正値K(soc)を設定するとともに、この容量補正値K(n)に基づいて総容量Ah(n)を算出する補正値設定部50と、この補正値設定部50が算出した総容量Ah(n)とSOC補正値K(soc)とに基づいて推定充電率SOC’を算出する推定充電率算出部60と、を有している。尚、本発明に係る電池状態推定装置80は、上記の構成の他に、SOP(充放電許容電力:State of Power)、SOH(劣化率:State of Health)等の他の電池状態情報を取得もしくは算出する周知の構成を有していても良い。 A battery state estimation device 80 and a battery state estimation method according to the present invention will be explained based on the drawings. FIG. 1 is a block diagram showing a schematic configuration of a battery condition estimating device 80 according to the present invention. First, the battery state estimation device 80 according to the present invention estimates the state of the secondary battery 10 used as a power source for the load 1, and uses information such as the battery voltage V and current value I of the secondary battery 10. A battery information acquisition unit 20 that acquires battery information, a charging rate acquisition unit 40 that acquires a charging rate SOC based on information from the battery information acquiring unit 20, and at least three charging rate SOCs acquired by this charging rate acquisition unit 40. (SOC(0), SOC(+), SOC(-)) and the capacity correction value K(n ) or a correction value setting section 50 that sets the SOC correction value K (soc) and calculates the total capacity Ah (n) based on this capacity correction value K (n), and the correction value setting section 50 that calculates the total capacity Ah (n). It has an estimated charging rate calculation section 60 that calculates an estimated charging rate SOC' based on the total capacity Ah (n) and the SOC correction value K (soc). In addition to the above-described configuration, the battery state estimation device 80 according to the present invention acquires other battery state information such as SOP (Charge/Discharge Allowable Power: State of Power) and SOH (Deterioration Rate: State of Health). Alternatively, it may have a known configuration for calculating.

次に、本発明に係る電池状態推定装置80の各部の詳細な構成と動作及び本発明に係る電池状態推定方法に関して説明を行う。ここで、図2~図4は本発明に係る電池状態推定方法のフローチャートである。尚、ここでは二次電池10を備え太陽光パネルを外部電力源7として有する太陽光発電システムと、二次電池10を備え使用時にのみシステムを起動する電気機械機器を例に説明を行うが、本発明はこれに限定される訳ではなく、二次電池10を有する全ての機械機器、設備等に適用が可能である。 Next, the detailed configuration and operation of each part of the battery state estimation device 80 according to the present invention and the battery state estimation method according to the present invention will be explained. Here, FIGS. 2 to 4 are flowcharts of the battery state estimation method according to the present invention. Note that here, explanation will be given using as an example a solar power generation system including a secondary battery 10 and a solar panel as an external power source 7, and an electromechanical device including a secondary battery 10 and starting the system only when in use. The present invention is not limited to this, but can be applied to all mechanical equipment, equipment, etc. that include the secondary battery 10.

先ず、本発明に係る電池状態推定装置80を備えたシステムは、電池状態推定装置80と、充電可能な二次電池10と、システム全体を制御するシステム制御部5と、例えば太陽光パネルや商用電力等の外部電力源7と、二次電池10もしくは外部電力源7からの電力供給によって動作する接続機器としての負荷1と、二次電池10への充電や負荷1への電力供給を双方に適した電力に変換して行う電力変換器3と、電池状態推定装置80が出力する推定充電率SOC’等の電池状態情報に基づいて所定の動作を行う図示しない動作部と、を有している。 First, a system equipped with a battery state estimating device 80 according to the present invention includes a battery state estimating device 80, a rechargeable secondary battery 10, a system control unit 5 that controls the entire system, and a solar panel or commercial An external power source 7 such as electric power, a secondary battery 10 or a load 1 as a connected device that operates with power supplied from the external power source 7, and charging the secondary battery 10 and supplying power to the load 1 to both. It has a power converter 3 that performs conversion into suitable power, and an operation unit (not shown) that performs a predetermined operation based on battery state information such as the estimated charging rate SOC' outputted by the battery state estimation device 80. There is.

また、電池状態推定装置80の電池情報取得部20は、二次電池10に設置された電流センサ等の周知の電流取得手段30aと、この電流取得手段30aの出力から二次電池10の充放電時の電流値Iを取得する電流取得部30と、この電流取得部30が取得した電流値Iに基づいて二次電池10の電流積算値ΔAhを算出する電流積算値算出部32と、二次電池10に設置された電圧センサ等の周知の電圧取得手段34aと、この電圧取得手段34aの出力から二次電池10の電池電圧Vを取得する電圧取得部34と、を有している。尚、電流取得手段30aとしては、非接触で電流値の測定が可能なホール素子を用いた電流センサの他、周知の電流取得手段を用いることができる。また、電圧取得部34は二次電池10が組電池の場合、電圧取得手段34aを組電池の両端に設置して直接電池電圧Vを取得するようにしても良いし、電圧取得手段34aを組電池を構成する各セルに設置して各セルの電圧値を個別に取得し電圧取得部34がこれらを合算して二次電池10の電池電圧Vとしても良い。また、電池情報取得部20はサーミスタなどの周知の温度取得手段12aを介して二次電池10の電池温度Tを取得する温度取得部12をさらに有していても良い。尚、この温度取得部12は二次電池10の異常な発熱を感知する保護装置のものと兼用するようにしても良い。そして、電池情報取得部20は基本的にシステムの稼働中には常時動作して、二次電池10の電池電圧V、電流積算値ΔAh(電流値I)、電池温度Tを取得し充電率取得部40に出力する。 Further, the battery information acquisition unit 20 of the battery state estimating device 80 uses a well-known current acquisition means 30a such as a current sensor installed in the secondary battery 10, and the charging/discharging of the secondary battery 10 based on the output of this current acquisition means 30a. A current acquisition unit 30 that acquires the current value I at the time of It has a well-known voltage acquisition means 34a such as a voltage sensor installed on the battery 10, and a voltage acquisition section 34 that acquires the battery voltage V of the secondary battery 10 from the output of the voltage acquisition means 34a. In addition, as the current acquisition means 30a, other than a current sensor using a Hall element that can measure a current value without contact, a known current acquisition means can be used. Further, when the secondary battery 10 is an assembled battery, the voltage acquisition unit 34 may install the voltage acquisition means 34a at both ends of the assembled battery to directly acquire the battery voltage V, or the voltage acquisition means 34a may be installed at both ends of the assembled battery. It may be installed in each cell constituting the battery to obtain the voltage value of each cell individually, and the voltage obtaining unit 34 may add these together to obtain the battery voltage V of the secondary battery 10. Further, the battery information acquisition section 20 may further include a temperature acquisition section 12 that acquires the battery temperature T of the secondary battery 10 via a well-known temperature acquisition means 12a such as a thermistor. Note that this temperature acquisition section 12 may also be used as a protection device that detects abnormal heat generation of the secondary battery 10. The battery information acquisition unit 20 basically operates all the time while the system is in operation, and acquires the battery voltage V, integrated current value ΔAh (current value I), and battery temperature T of the secondary battery 10, and acquires the charging rate. output to section 40.

また、充電率取得部40は、二次電池10の開回路電圧OCVと対応した充電率SOCが例えばテーブルデータとして記録されているSOC記憶部44と、二次電池10の開回路電圧OCVを得るとともにSOC記憶部44を参照してこの開回路電圧OCVと対応した充電率SOCを取得するOCV-SOC取得部42と、を有している。 The charging rate acquisition unit 40 also acquires the SOC storage unit 44 in which the charging rate SOC corresponding to the open circuit voltage OCV of the secondary battery 10 is recorded, for example, as table data, and the open circuit voltage OCV of the secondary battery 10. It also includes an OCV-SOC acquisition section 42 that refers to the SOC storage section 44 and acquires the charging rate SOC corresponding to this open circuit voltage OCV.

また、補正値設定部50は、充電率取得部40から入力する少なくとも3点の充電率SOC(SOC(0)、SOC(+)、SOC(-))と2区間の電流積算値ΔAh(+)、ΔAh(-)とから後述のΔSOC1(+)、ΔSOC1(-)及び、ΔSOC2(+)、ΔSOC2(-)を算出するΔSOC算出部52と、これらΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)から充電側補正値K(+)、放電側補正値K(-)を算出する補正係数算出部54と、これら充電側補正値K(+)、放電側補正値K(-)に基づいて補正方法を選択する判定部56と、この判定部56の判定結果に応じて容量補正値K(n)を設定する補正係数設定部57と、この補正係数設定部57が設定した容量補正値K(n)に基づいて総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量補正部58と、判定部56の判定結果に応じてSOC補正値K(soc)を設定するSOC補正部59と、を有している。また、推定充電率算出部60は(オフセット誤差が生じていない状態では)、容量補正部58が算出した総容量Ah(n)と、電流積算値算出部32が出力する現在の電流積算値ΔAhと、基準点の充電率SOC(0)とから上記の(A)、(A’)式をまとめた下記(A’’)式に基づいて、推定充電率SOC’を算出する。
SOC’=ΔAh/Ah(n)+SOC(0)・・・(A’’)
In addition, the correction value setting unit 50 inputs at least three charging rates SOC (SOC(0), SOC(+), SOC(−)) from the charging rate obtaining unit 40 and the current integrated value ΔAh(+ ), ΔAh(-), and a ΔSOC calculation unit 52 that calculates ΔSOC1(+), ΔSOC1(-), ΔSOC2(+), ΔSOC2(-), which will be described later, from ΔSOC1(+), ΔSOC1(-), A correction coefficient calculation unit 54 that calculates a charging side correction value K(+) and a discharging side correction value K(-) from ΔSOC2(+) and ΔSOC2(-), and these charging side correction value K(+) and discharging side correction. A determination section 56 that selects a correction method based on the value K(-), a correction coefficient setting section 57 that sets a capacitance correction value K(n) according to the determination result of this determination section 56, and this correction coefficient setting section. A capacity correction unit 58 that calculates the total capacity Ah (n) by correcting the total capacity Ah (n-1) based on the capacity correction value K (n) set by the unit 57; It has an SOC correction section 59 that sets an SOC correction value K (soc). In addition, the estimated charging rate calculation unit 60 calculates the total capacity Ah(n) calculated by the capacity correction unit 58 and the current integrated current value ΔAh outputted by the current integrated value calculation unit 32 (in a state where no offset error occurs). The estimated charging rate SOC' is calculated from the charging rate SOC(0) at the reference point based on the following equation (A'') which is a combination of the above equations (A) and (A').
SOC'=ΔAh/Ah(n)+SOC(0)...(A'')

尚、補正値設定部50には、システムの電源オフ時の各値を記録する記録部55を設けることが好ましい。この記録部55としては、電源がオフとなっても記録内容が消去しない例えばEEPROM(Electrically Erasable and Programmable Read Only Memory)等の周知の記録手段を用いることができる。尚、ここでは補正値設定部50が記録部55を有し、システムの起動時には後述の初期補正値算出ステップS120を行う例を用いて説明を行う。また、システムの起動直後には、二次電池10に電流が流れない例を用いて説明を行う。 Note that it is preferable that the correction value setting section 50 is provided with a recording section 55 that records each value when the system is powered off. As the recording unit 55, a well-known recording means such as an EEPROM (Electrically Erasable and Programmable Read Only Memory), which does not erase recorded contents even when the power is turned off, can be used. Note that the explanation will be given using an example in which the correction value setting section 50 has a recording section 55 and performs an initial correction value calculation step S120, which will be described later, at the time of system startup. Further, the explanation will be given using an example in which no current flows through the secondary battery 10 immediately after the system is started.

先ず、システム全体が起動すると(ステップS001)、電池状態推定装置80の図示しない制御部は記録部55から初期の容量補正値K(n)の算出に必要なデータを読み出して取得する(ステップS012)。このとき読み出すデータとしては、前回のシステムのオフ時点で適用されていた容量補正値K(n-1)とそのときの基準点の充電率SOC(0)’及びシステムオフ時点の電流積算値ΔAh’等である。 First, when the entire system is started (step S001), the control section (not shown) of the battery state estimation device 80 reads and acquires data necessary for calculating the initial capacity correction value K(n) from the recording section 55 (step S012). ). The data to be read at this time includes the capacity correction value K(n-1) that was applied when the system was turned off last time, the charging rate SOC(0)' at the reference point at that time, and the integrated current value ΔAh when the system was turned off. ' etc.

次に、起動直後に二次電池10に電流が流れていない状態では、電圧取得手段34aが二次電池10の例えば正極、負極の電位をそれぞれ取得して電圧取得部34に出力する。そして、電圧取得部34はこれらの電位の値から二次電池10の電池電圧Vを算出し、充電率取得部40のOCV-SOC取得部42に出力する(ステップS102:電圧取得ステップ)。また、このとき電池状態推定装置80の制御部は、このシステムの起動時を基準点として設定する(ステップS103)。ここで、システムがオフの状態では二次電池10には電流が流れておらず、二次電池10は分極電圧が解消された緩和状態にある。このため、システムの起動直後に二次電池10に電流が流れない構成では、二次電池10の電池電圧Vから直ちに開回路電圧OCVを取得することができる。よって、OCV-SOC取得部42は、このときの電池電圧Vを基準点の開回路電圧OCV(0)とする(ステップS112:開回路電圧取得ステップ)。そして、OCV-SOC取得部42はSOC記憶部44を参照し、この開回路電圧OCV(0)と対応した基準点の充電率SOC(0)を取得する(ステップS114:充電率取得ステップ)。そして、補正値設定部50のΔSOC算出部52に出力する。 Next, in a state where no current is flowing through the secondary battery 10 immediately after startup, the voltage acquisition means 34a acquires the potentials of, for example, the positive electrode and the negative electrode of the secondary battery 10, and outputs them to the voltage acquisition unit 34. Then, the voltage acquisition unit 34 calculates the battery voltage V of the secondary battery 10 from these potential values, and outputs it to the OCV-SOC acquisition unit 42 of the charging rate acquisition unit 40 (step S102: voltage acquisition step). Also, at this time, the control unit of the battery state estimating device 80 sets the time of startup of this system as a reference point (step S103). Here, when the system is off, no current flows through the secondary battery 10, and the secondary battery 10 is in a relaxed state in which the polarization voltage is eliminated. Therefore, in a configuration in which current does not flow through the secondary battery 10 immediately after the system is started, the open circuit voltage OCV can be immediately obtained from the battery voltage V of the secondary battery 10. Therefore, the OCV-SOC acquisition unit 42 sets the battery voltage V at this time as the reference point open circuit voltage OCV(0) (step S112: open circuit voltage acquisition step). Then, the OCV-SOC acquisition unit 42 refers to the SOC storage unit 44 and acquires the charging rate SOC(0) of the reference point corresponding to this open circuit voltage OCV(0) (step S114: charging rate acquisition step). Then, it is output to the ΔSOC calculation section 52 of the correction value setting section 50.

また、電池状態推定装置80の制御部が基準点を設定すると、電流積算値算出部32はこの基準点における電流積算値ΔAh(0)をΔSOC算出部52に出力する(ステップS116)。 Further, when the control unit of the battery state estimating device 80 sets a reference point, the current integrated value calculation unit 32 outputs the current integrated value ΔAh(0) at this reference point to the ΔSOC calculation unit 52 (step S116).

そして、電池状態推定装置80は、この基準点(起動時)の充電率SOC(0)と電流積算値ΔAh(0)と、記録部55から読み出したデータとを適宜使用して、初回の補正後総容量Ah(n)を算出する(初期補正値算出ステップS120)。尚、この初期補正値算出ステップS120に関しては後に詳述する。そして、この初期補正値算出ステップS120で算出された総容量Ah(n)に基づいて推定充電率SOC’が導出され、二次電池10の状態判定や電力変換器3の制御等に用いられる。また、補正値設定部50が記録部55を有さない場合には、基準点、充電点、放電点の3点のデータが揃った時点で容量補正値K(n)及び推定充電率SOC’の算出を行う。尚、このようにして得られた推定充電率SOC’は電流積算値ΔAhが時々刻々更新するため、この電流積算値ΔAhの更新に応じて随時更新がなされる。勿論、電流積算値ΔAh以外の総容量Ah(n)やSOC補正値K(soc)が更新されることでも推定充電率SOC’は更新される。 Then, the battery state estimating device 80 uses the charging rate SOC (0) at this reference point (at startup), the current integrated value ΔAh (0), and the data read from the recording unit 55 as appropriate to perform the initial correction. The total rear capacity Ah(n) is calculated (initial correction value calculation step S120). Note that this initial correction value calculation step S120 will be described in detail later. Then, the estimated charging rate SOC' is derived based on the total capacity Ah(n) calculated in this initial correction value calculation step S120, and is used for determining the state of the secondary battery 10, controlling the power converter 3, etc. In addition, when the correction value setting section 50 does not have the recording section 55, the capacity correction value K(n) and the estimated charging rate SOC' are set at the time when the data of the three points of the reference point, the charging point, and the discharging point are collected. Calculate. Incidentally, the estimated charging rate SOC' obtained in this way is updated at any time in accordance with the update of the current integrated value ΔAh, because the current integrated value ΔAh is updated every moment. Of course, the estimated charging rate SOC' is also updated by updating the total capacity Ah(n) other than the current integrated value ΔAh and the SOC correction value K(soc).

また、起動直後に二次電池10に電流が流れている状態の場合、記録部55にはシステムオフ時点の推定充電率SOC’を記録しておき、システム起動時にはこの推定充電率SOC’を読み出して起動時の充電率SOC(0)とし、初期補正値算出ステップS120を行うようにしても良い。尚、このシステムでは起動時を基準点と出来ないため、例えばOCV-SOC取得部42が最初に開回路電圧OCVを取得した点を基準点とすることが好ましい。 In addition, when current is flowing through the secondary battery 10 immediately after startup, the estimated charging rate SOC' at the time the system is turned off is recorded in the recording unit 55, and this estimated charging rate SOC' is read out at the time of system startup. Alternatively, the charging rate SOC (0) at startup may be set, and the initial correction value calculation step S120 may be performed. Note that in this system, since startup cannot be used as a reference point, it is preferable to use, for example, the point at which the OCV-SOC acquisition unit 42 first acquires the open circuit voltage OCV as the reference point.

次に、システムが二次電池10の電力を用いて負荷1を動作させる場合、システム制御部5が二次電池10を電源とした電力供給を指示する。これにより、二次電池10は放電し電力供給を開始する。そして、二次電池10が出力した電力は電力変換器3によって負荷1に適した電力に変換されて供給され、負荷1は目的の動作を行う。また、例えば外部電力源7としての太陽光パネルが発電して二次電池10からの電力供給が不要になると、システム制御部5は電力変換器3を制御して二次電池10からの電力供給を停止する。これにより、二次電池10の電流値Iはゼロとなる。さらに、外部電力源7からの電力の供給量が負荷1の使用量を上回ると、システム制御部5は余剰な電力を二次電池10に充電するよう指示する。これにより、電力変換器3は外部電力源7からの電力を適切な電圧に変換して二次電池10に出力する。これにより、二次電池10に充電電流が流れ二次電池10は充電される。 Next, when the system operates the load 1 using the power of the secondary battery 10, the system control unit 5 instructs power supply using the secondary battery 10 as a power source. As a result, the secondary battery 10 discharges and starts supplying power. Then, the power output by the secondary battery 10 is converted by the power converter 3 into power suitable for the load 1 and supplied, so that the load 1 performs the intended operation. For example, when the solar panel as the external power source 7 generates power and the power supply from the secondary battery 10 becomes unnecessary, the system control unit 5 controls the power converter 3 to start supplying power from the secondary battery 10. stop. As a result, the current value I of the secondary battery 10 becomes zero. Further, when the amount of power supplied from the external power source 7 exceeds the amount used by the load 1, the system control unit 5 instructs the secondary battery 10 to be charged with the excess power. Thereby, the power converter 3 converts the power from the external power source 7 into an appropriate voltage and outputs it to the secondary battery 10. As a result, a charging current flows to the secondary battery 10 and the secondary battery 10 is charged.

そして、このときの二次電池10に流れる電流値は電流取得手段30aが取得して電流取得部30に出力する。電流取得部30はこの放電時、充電時の電流値Iを例えば正負の符号で区別して電流積算値算出部32に出力する(電流取得ステップS200)。そして、電流積算値算出部32は電流取得部30から入力した電流値Iを現在の電流積算値ΔAhに積算する(電流積算値算出ステップS202)。このとき、放電時の電流値Iを負(-)、充電時の電流値Iを正(+)とした場合、放電時の電流積算値ΔAhは減少し、充電時の電流積算値ΔAhは増加する。 The current value flowing through the secondary battery 10 at this time is acquired by the current acquisition means 30a and output to the current acquisition section 30. The current acquisition unit 30 outputs the current value I during discharging and charging to the current integrated value calculation unit 32 by distinguishing it, for example, with a positive or negative sign (current acquisition step S200). Then, the current integrated value calculation unit 32 integrates the current value I input from the current acquisition unit 30 into the current integrated current value ΔAh (current integrated value calculation step S202). At this time, if the current value I during discharging is negative (-) and the current value I during charging is positive (+), the integrated current value ΔAh during discharging decreases, and the integrated current value ΔAh during charging increases. do.

また、電圧取得部34は二次電池10の電池電圧VをOCV-SOC取得部42に出力し続ける(ステップS203:電圧取得ステップ)。ただし、ここで必要となる開回路電圧OCVは、二次電池10に電流が流れていない状態における二次電池10の電圧であるため、二次電池10が充放電動作を行っている間はOCV-SOC取得部42は開回路電圧OCVを取得せず待機状態をとる。またさらに二次電池10の電流値Iがゼロとなった直後には分極電圧が残留しており、正確な開回路電圧OCVを取得することができない。よって、本願発明の充電率取得部40には緩和状態判定部46を設けることが好ましい。尚、ノイズなどの影響がある場合、電流取得手段30aが出力する電流値が完全なゼロとはならない可能性が有る。また、直前まで大きな電流が流れていた場合、完全なゼロ電流ではなく、わずかな電流が流れている場合でも分極電圧は緩和されていく。よって、緩和状態判定部46は、例えば電流取得部30から二次電池10の電流値Iを取得し、この二次電池10の電流値Iがゼロもしくはゼロ近傍の予め設定された規定の値以下、例えばCレートの±0.1C以下、即ち電流値Iが -0.1C相当電流値 ≦ I ≦+0.1C相当電流値の場合に、この状態を電流値Iがゼロの状態(以後、電流ゼロ状態とする)と判断する。そして、緩和状態判定部46は分極電圧が解消する十分な分極緩和時間、電流ゼロ状態を維持したときにOCV-SOC取得部42に対し開回路電圧OCVの取得を許可する。これにより、OCV-SOC取得部42は分極電圧が解消した正確な開回路電圧OCVを取得することができる。尚、電流ゼロ状態の閾値に関しては、システム側が利用を想定する電流値(二次電池10の放電時の電流値)等によって適切に設計、設定される。また、二次電池10の充放電が間断なく繰り返されるシステム等では、例えばシステム制御部5が充放電の切り替え時等に分極電圧が解消する十分な時間、二次電池10の充放電動作を停止させ、OCV-SOC取得部42が開回路電圧OCVを取得可能とするようにしても良い。 Further, the voltage acquisition unit 34 continues to output the battery voltage V of the secondary battery 10 to the OCV-SOC acquisition unit 42 (step S203: voltage acquisition step). However, the open circuit voltage OCV required here is the voltage of the secondary battery 10 in a state where no current flows through the secondary battery 10, so while the secondary battery 10 is performing charging/discharging operation, the OCV - The SOC acquisition unit 42 does not acquire the open circuit voltage OCV and takes a standby state. Further, immediately after the current value I of the secondary battery 10 becomes zero, a polarization voltage remains, making it impossible to obtain an accurate open circuit voltage OCV. Therefore, it is preferable to provide the relaxation state determination section 46 in the charging rate acquisition section 40 of the present invention. Note that if there is an influence of noise or the like, there is a possibility that the current value output by the current acquisition means 30a will not be completely zero. Furthermore, if a large current was flowing just before, the polarization voltage will be relaxed even if a small current is flowing, rather than completely zero current. Therefore, the relaxation state determination unit 46 acquires the current value I of the secondary battery 10 from the current acquisition unit 30, for example, and determines whether the current value I of the secondary battery 10 is equal to or less than a preset prescribed value of zero or near zero. , for example, when the C rate is ±0.1C or less, that is, when the current value I is -0.1C equivalent current value ≦ I ≦ +0.1C equivalent current value, this state is defined as the state where the current value I is zero (hereinafter referred to as current (zero state). Then, the relaxation state determination section 46 allows the OCV-SOC acquisition section 42 to acquire the open circuit voltage OCV when the zero current state is maintained for a sufficient polarization relaxation time for the polarization voltage to disappear. Thereby, the OCV-SOC acquisition section 42 can acquire an accurate open circuit voltage OCV in which the polarization voltage has been eliminated. Note that the threshold value for the current zero state is appropriately designed and set based on the current value (current value when the secondary battery 10 is discharged) that the system side assumes to use. In addition, in a system where charging and discharging of the secondary battery 10 is repeated without interruption, for example, the system control unit 5 stops the charging and discharging operation of the secondary battery 10 for a sufficient period of time to eliminate the polarization voltage when switching between charging and discharging. The OCV-SOC acquisition unit 42 may be configured to be able to acquire the open circuit voltage OCV.

また、分極緩和時間は、二次電池10の能力、仕様、システム側の動作、システム側の二次電池10の運用状態等の他、二次電池10の電池温度T、そのときの充電率、二次電池10の劣化状態、直前までの充放電電流の大きさや通電時間等の要因により変化する。ただし、条件変化に対する分極緩和時間の変化量が比較的小さい場合には、分極緩和時間を固定値として良い。また、分極緩和時間が条件によって大きく変化する場合には、変化の大きい主要な条件のいずれか、もしくは変化の大きな複数の条件に対して予め実験を行い、これらの分極緩和時間のテーブルデータを作成して、緩和状態判定部46が二次電池10の状態に応じた分極緩和時間を適宜選択して設定するようにしても良い。 In addition, the polarization relaxation time is determined based on the capacity and specifications of the secondary battery 10, the operation on the system side, the operation status of the secondary battery 10 on the system side, the battery temperature T of the secondary battery 10, the charging rate at that time, etc. It changes depending on factors such as the state of deterioration of the secondary battery 10, the magnitude of the previous charging/discharging current, and the energization time. However, if the amount of change in the polarization relaxation time with respect to a change in conditions is relatively small, the polarization relaxation time may be set to a fixed value. In addition, if the polarization relaxation time changes significantly depending on the conditions, perform experiments in advance for one of the major conditions that change significantly, or for multiple conditions that change significantly, and create table data of these polarization relaxation times. Then, the relaxation state determination unit 46 may appropriately select and set the polarization relaxation time according to the state of the secondary battery 10.

そして、この電流ゼロ状態の電流値Iは電流取得部30が取得して緩和状態判定部46と電流積算値算出部32とに出力される。このとき、電流積算値算出部32は、電流値Iが電流ゼロ状態である場合には、電流積算値ΔAhへの電流値Iの積算を停止するようにしても良い。この構成では、電流ゼロ状態の閾値を最適化することで、電流ゼロ状態時におけるノイズの影響や電流取得手段30aのオフセット誤差等による僅かな検出誤差が電流積算値ΔAhに積算することを防ぐことができる。これにより、電流積算値ΔAhの誤差を低減することが可能となる。また、緩和状態判定部46が電流ゼロ状態を検出し(ステップS204:Yes)、この電流ゼロ状態が所定の分極緩和時間、例えば1分間継続すると(ステップS206:Yes)、緩和状態判定部46はOCV-SOC取得部42に対し開回路電圧OCVの取得を許可する(ステップS207)。 The current value I in the current zero state is acquired by the current acquisition section 30 and output to the relaxation state determination section 46 and the current integrated value calculation section 32. At this time, the current integrated value calculation unit 32 may stop integrating the current value I into the current integrated value ΔAh when the current value I is in a current zero state. In this configuration, by optimizing the threshold value of the current zero state, it is possible to prevent slight detection errors due to the influence of noise during the current zero state, offset errors of the current acquisition means 30a, etc. from being integrated into the current integrated value ΔAh. I can do it. This makes it possible to reduce the error in the current integrated value ΔAh. Further, when the relaxation state determination unit 46 detects a zero current state (step S204: Yes) and this current zero state continues for a predetermined polarization relaxation time, for example, one minute (step S206: Yes), the relaxation state determination unit 46 detects a zero current state (step S204: Yes). The OCV-SOC acquisition unit 42 is permitted to acquire the open circuit voltage OCV (step S207).

OCV-SOC取得部42が開回路電圧OCVを取得可能な状態になると、電池状態推定装置80の制御部は、電流積算値算出部32の現在の電流積算値ΔAhが電流積算値ΔAh(0)を基準としたときの放電側(負)に位置するか、充電側(正)に位置するかを判別する。そして、電流積算値ΔAhが放電側に位置している、即ち ΔAh<ΔAh(0)の場合には(ステップS208:Yes)、この点を放電点として設定する(ステップS210A)。また、電流積算値ΔAhが電流積算値ΔAh(0)よりも充電側に位置している、即ち ΔAh>ΔAh(0)の場合には(ステップS208:No、ステップS209:Yes)、この点を充電点として設定する(ステップS210B)。また、電流積算値ΔAhと電流積算値ΔAh(0)とが同一の場合には(ステップS208:No、ステップS209:No)、充電点にも放電点にも設定せずに、電流取得ステップS200に帰還する。 When the OCV-SOC acquisition unit 42 is in a state where it can acquire the open circuit voltage OCV, the control unit of the battery state estimation device 80 changes the current integrated current value ΔAh of the current integrated value calculation unit 32 to the current integrated value ΔAh(0). It is determined whether it is located on the discharging side (negative) or on the charging side (positive) with reference to . If the current integrated value ΔAh is located on the discharge side, that is, ΔAh<ΔAh(0) (step S208: Yes), this point is set as the discharge point (step S210A). In addition, if the current integrated value ΔAh is located on the charging side than the current integrated value ΔAh(0), that is, ΔAh>ΔAh(0) (step S208: No, step S209: Yes), this point is It is set as a charging point (step S210B). Further, if the current integrated value ΔAh and the current integrated value ΔAh(0) are the same (step S208: No, step S209: No), the current acquisition step S200 is performed without setting the charging point or the discharging point. to return to.

尚、図2~図4のフローチャートでは基準点が1つの例を説明しているが、基準点は必ずしも一つでなくとも良く、以下の例に示すように少なくとも1つ以上の基準点が存在していても良い。例えば、電流積算値ΔAh(0)の基準点が設定されて、この基準点の電流積算値ΔAh(0)を基に充電点もしくは放電点のいずれか一方を設定した後に、図5(a)、(b)に示すように、電流積算値ΔAh(0)とは異なる点(値)の電流積算値ΔAh(0’)の新たな基準点が設定され、この新たな基準点を基に残りの放電点もしくは充電点を設定しても良い。この構成の手順としては、例えばステップS207で開回路電圧OCVが取得された際に、予め設定された所定の条件を満たした場合、これを新たな基準点に設定する。そして、この新たな基準点の開回路電圧OCV(0’)、充電率SOC(0’)、電流積算値ΔAh(0’)を取得して、ステップS200へと移行することが挙げられる。 Note that although the flowcharts in FIGS. 2 to 4 explain an example in which there is one reference point, the number of reference points does not necessarily have to be one, and there may be at least one reference point as shown in the example below. It's okay to do so. For example, after a reference point for the current integrated value ΔAh(0) is set and either the charging point or the discharging point is set based on the current integrated value ΔAh(0) at this reference point, as shown in FIG. , (b), a new reference point is set for the current integrated value ΔAh(0') at a point (value) different from the current integrated value ΔAh(0), and the remaining current is calculated based on this new reference point. Alternatively, a discharge point or a charging point may be set. As a procedure for this configuration, for example, when the open circuit voltage OCV is acquired in step S207 and a predetermined condition set in advance is satisfied, this is set as a new reference point. Then, the open circuit voltage OCV (0'), charging rate SOC (0'), and current integrated value ΔAh (0') of this new reference point are acquired, and the process proceeds to step S200.

また、電流積算値ΔAh(0)の基準点を基に充電点もしくは放電点のいずれか一方が設定された後に、この設定された充電点もしくは放電点を新たな基準点としても良い。例えば、図5(c)、(d)に示すように、電流積算値ΔAh(0)の基準点を基に放電点の充電率SOC(-)が設定された後に、この放電点の充電率SOC(-)、電流積算値ΔAhを、新たな基準点の充電率SOC(0’)、電流積算値ΔAh(0’)として再設定する。そして、この新たな基準点を基に残りの充電点を設定する。尚、このときの充電点は、図5(c)に示すように、最初の基準点の電流積算値ΔAh(0)よりも充電側(正側)に位置していても良いし、図5(d)に示すように、放電側(負側)に位置していても良い。また、この構成の手順としては、例えば、後述のステップS240でNo判定とされ、且つ予め設定された所定の条件が満たされた場合に、直前に設定された充電点もしくは放電点を新たな基準点とし、ステップS200へと移行することが挙げられる。 Furthermore, after either the charging point or the discharging point is set based on the reference point of the current integrated value ΔAh(0), this set charging point or discharging point may be used as the new reference point. For example, as shown in FIGS. 5(c) and 5(d), after the charging rate SOC(-) of the discharge point is set based on the reference point of the current integrated value ΔAh(0), the charging rate of this discharge point is The SOC (-) and the current integrated value ΔAh are reset as the new reference point charging rate SOC (0') and the current integrated value ΔAh (0'). Then, the remaining charging points are set based on this new reference point. Note that the charging point at this time may be located on the charging side (positive side) of the current integrated value ΔAh(0) at the first reference point, as shown in FIG. As shown in (d), it may be located on the discharge side (negative side). In addition, as a procedure for this configuration, for example, when a No determination is made in step S240 described later and a predetermined condition set in advance is satisfied, the charging point or discharging point set immediately before is set as a new standard. An example of this is to select a point and proceed to step S200.

そして、これらの1以上の基準点を用いる構成では、例えば基準点が二次電池10の満充電の近くや電池残量無しの近辺に位置するなどして、充電点と放電点の双方が長時間揃わない状態を解消することができる。 In a configuration using one or more of these reference points, both the charging point and the discharging point are long, for example, the reference point is located near the fully charged state of the secondary battery 10 or near the battery with no remaining battery power. It is possible to resolve the situation where the time is not set.

また、ステップS210A、S210Bで設定された充電点、放電点がそれぞれの基準点の近傍に位置する場合、後述の(2)、(2’)式、もしくは(2’’)、(2’’’)式で算出されるΔSOC2(+)、ΔSOC2(-)の値が小さくなり、(3)、(3’)式での充電側補正値K(+)、放電側補正値K(-)が著しく大きな値となる可能性が有る。よって、充電点、放電点がそれぞれの基準点の近傍に位置する場合には充電点、放電点として設定しないことが好ましい。この近傍位置の判定方法としては、例えばOCV-SOC取得部42が基準点の電流積算値ΔAh(0)(ΔAh(0’))を中心とした上下に所定の閾値αの範囲を設け、ステップS208、ステップS209は、電流積算値ΔAhがそれぞれの基準点の閾値αを超えた ΔAh<(ΔAh(0)-α) もしくは ΔAh<(ΔAh(0’)-α)の場合に放電点とし、ΔAh>(ΔAh(0)+α) もしくは ΔAh>(ΔAh(0’)+α)の場合に充電点とし、(ΔAh(0)-α)≦ΔAh≦(ΔAh(0)+α) もしくは (ΔAh(0’)-α)≦ΔAh≦(ΔAh(0’)+α)の場合には充電点、放電点としないことが挙げられる。 In addition, if the charging point and discharging point set in steps S210A and S210B are located near the respective reference points, the equations (2) and (2') described below, or (2'') and (2'' The values of ΔSOC2(+) and ΔSOC2(-) calculated by formula ') become smaller, and the charging side correction value K(+) and discharging side correction value K(-) in formulas (3) and (3') become smaller. may become a significantly large value. Therefore, when the charging point and the discharging point are located near the respective reference points, it is preferable not to set them as the charging point and the discharging point. As a method for determining this nearby position, for example, the OCV-SOC acquisition unit 42 sets a range of predetermined threshold values α above and below the current integrated value ΔAh(0) (ΔAh(0′)) of the reference point, and steps In S208 and Step S209, when the current integrated value ΔAh exceeds the threshold value α of each reference point, ΔAh<(ΔAh(0)−α) or ΔAh<(ΔAh(0′)−α), the discharge point is determined. When ΔAh>(ΔAh(0)+α) or ΔAh>(ΔAh(0')+α), it is considered as a charging point, and when (ΔAh(0)-α)≦ΔAh≦(ΔAh(0)+α) or (ΔAh(0) ')-α)≦ΔAh≦(ΔAh(0′)+α), the point may not be set as a charging point or a discharging point.

そして、上記のステップS210Aにより放電点が設定された場合、OCV-SOC取得部42はこのときの二次電池10の電池電圧Vを放電点の開回路電圧OCV(-)とする(ステップS214A:開回路電圧取得ステップ)。そして、OCV-SOC取得部42はSOC記憶部44を参照し、開回路電圧OCV(-)と対応した放電点の充電率SOC(-)を取得し(ステップS216A:充電率取得ステップ)、ΔSOC算出部52に出力する。またこのとき、電流積算値算出部32は放電点の電流積算値ΔAhをΔSOC算出部52に出力する(ステップS218A)。 Then, when the discharge point is set in step S210A above, the OCV-SOC acquisition unit 42 sets the battery voltage V of the secondary battery 10 at this time to the open circuit voltage OCV (-) of the discharge point (step S214A: open circuit voltage acquisition step). Then, the OCV-SOC acquisition unit 42 refers to the SOC storage unit 44, acquires the charging rate SOC(-) of the discharge point corresponding to the open circuit voltage OCV(-) (step S216A: charging rate acquisition step), and obtains the ΔSOC It is output to the calculation unit 52. At this time, the current integrated value calculation section 32 outputs the current integrated value ΔAh at the discharge point to the ΔSOC calculation section 52 (step S218A).

また、上記のステップS210Bにより充電点が設定された場合、OCV-SOC取得部42はこのときの二次電池10の電池電圧Vを充電点の開回路電圧OCV(+)とする(ステップS214B:開回路電圧取得ステップ)。そして、OCV-SOC取得部42はSOC記憶部44を参照し、開回路電圧OCV(+)と対応した充電点の充電率SOC(+)を取得し(ステップS216B:充電率取得ステップ)、ΔSOC算出部52に出力する。またこのとき、電流積算値算出部32はこの充電点の電流積算値ΔAhをΔSOC算出部52に出力する(ステップS218B)。 Further, when the charging point is set in step S210B above, the OCV-SOC acquisition unit 42 sets the battery voltage V of the secondary battery 10 at this time to the open circuit voltage OCV (+) of the charging point (step S214B: open circuit voltage acquisition step). Then, the OCV-SOC acquisition unit 42 refers to the SOC storage unit 44, acquires the charging rate SOC (+) of the charging point corresponding to the open circuit voltage OCV (+) (step S216B: charging rate acquisition step), and obtains the ΔSOC It is output to the calculation unit 52. At this time, the current integrated value calculation unit 32 outputs the current integrated value ΔAh of this charging point to the ΔSOC calculation unit 52 (step S218B).

尚、基準点、放電点、充電点の充電率SOCの取得は、上記のように各点の開回路電圧の取得時に随時行っても良いし、基準点、放電点、放電点の開回路電圧が全て揃った時点で行っても良い。また、上記の例では初めに基準点を設定し、次いで放電点、充電点を設定しているが、特にシステムの起動直後に二次電池10に電流が流れ基準点の開回路電圧OCV(0)が取得できない構成では、必ずしも最初に基準点を設定する必要はなく、例えば、開回路電圧OCVを取得した点の電流積算値ΔAhを比較して、その大小によって放電点、基準点、充電点を割り当てるようにしても良い。 Note that the charging rate SOC at the reference point, discharge point, and charging point may be obtained at any time when obtaining the open circuit voltage at each point as described above, or when the open circuit voltage at the reference point, discharge point, and discharge point is obtained. You can go when you have everything ready. Furthermore, in the above example, the reference point is first set, and then the discharging point and the charging point. ), it is not necessary to set a reference point first; for example, by comparing the current integrated value ΔAh at the point where the open circuit voltage OCV is obtained, the discharge point, reference point, or charging point can be determined depending on the magnitude. You may also assign .

また、電池状態推定装置80が温度取得部12を備え、電池温度Tを考慮した充電率SOC(0)、(SOC(0’))、SOC(+)、SOC(-)を取得する場合には、SOC記憶部44は電池温度TごとのOCV-SOCデータテーブルを備え、OCV-SOC取得部42は各開回路電圧取得時の電池温度Tと対応したOCV-SOCのデータテーブルから充電率SOC(0)、(SOC(0’))、SOC(+)、SOC(-)をそれぞれ取得する。この構成によれば、OCV-SOC取得部42は電池温度Tをも考慮した、より正確な充電率を取得することができる。 Furthermore, when the battery state estimating device 80 includes the temperature acquisition unit 12 and acquires the charging rate SOC(0), (SOC(0')), SOC(+), and SOC(-) in consideration of the battery temperature T, In this case, the SOC storage unit 44 includes an OCV-SOC data table for each battery temperature T, and the OCV-SOC acquisition unit 42 obtains the charging rate SOC from the OCV-SOC data table corresponding to the battery temperature T at the time of each open circuit voltage acquisition. (0), (SOC(0')), SOC(+), and SOC(-) are obtained, respectively. According to this configuration, the OCV-SOC acquisition unit 42 can acquire a more accurate charging rate that also takes into consideration the battery temperature T.

また、ΔSOC算出部52は電流積算値算出部32から放電点の電流積算値ΔAhが入力すると、これと対応する基準点の電流積算値ΔAh(0)もしくは電流積算値ΔAh(0’)からの差分、即ち、|ΔAh-ΔAh(0)|もしくは|ΔAh-ΔAh(0’)|を算出し、これを放電点の電流積算値ΔAh(-)とする(ステップS220A:充放電電流積算値取得ステップ)。また、充電点の電流積算値ΔAhが入力すると、これと対応する基準点の電流積算値ΔAh(0)もしくは電流積算値ΔAh(0’)からの差分、即ち、|ΔAh-ΔAh(0)|もしくは|ΔAh-ΔAh(0’)|を算出し、これを充電点の電流積算値ΔAh(+)とする(ステップS220B:充放電電流積算値取得ステップ)。 Further, when the current integrated value ΔAh at the discharge point is input from the current integrated value calculation unit 32, the ΔSOC calculation unit 52 calculates the current integrated value ΔAh (0) or current integrated value ΔAh (0′) at the corresponding reference point. Calculate the difference, that is, |ΔAh-ΔAh(0)| or |ΔAh-ΔAh(0')|, and set this as the current integrated value ΔAh(-) at the discharge point (Step S220A: Obtain the charging/discharging current integrated value step). Furthermore, when the current integrated value ΔAh at the charging point is input, the difference from the current integrated value ΔAh(0) or current integrated value ΔAh(0') at the corresponding reference point, that is, |ΔAh-ΔAh(0)| Alternatively, |ΔAh−ΔAh(0′)| is calculated, and this is set as the current integrated value ΔAh(+) at the charging point (step S220B: charge/discharge current integrated value acquisition step).

そして、ΔSOC算出部52はこれらの値の入力により、充電点、放電点の開回路電圧OCV(+)、OCV(-)と基準点の開回路電圧OCV(0)、(OCV(0’))及び、これと対応した電流積算値ΔAh(+)、ΔAh(-)が全て揃ったか否かを判別する。そして、これらのデータが未だ揃っていない場合(ステップS240:No)、電流取得ステップS200に帰還する。 Then, by inputting these values, the ΔSOC calculation unit 52 calculates the open circuit voltages OCV(+), OCV(-) at the charging point and the discharging point, and the open circuit voltages OCV(0), (OCV(0')) at the reference point. ) and the corresponding current integrated values ΔAh(+) and ΔAh(−) are all determined. If these data are not yet complete (step S240: No), the process returns to current acquisition step S200.

また、これらのデータが全て揃った場合(ステップS240:Yes)、充電点の電流積算値ΔAh(+)と後述の二次電池10の総容量Ah(n-1)とから、下記(1)式に基づいて、第1の充電側の充電率の変化量としてのΔSOC1(+)を算出する。また、放電点の電流積算値ΔAh(-)と二次電池10の総容量Ah(n-1)とから、下記(1’)式に基づいて、第1の放電側の充電率の変化量としてのΔSOC1(-)を算出する(第1の充電率変化量算出ステップS300)。尚、ここでの総容量Ah(n-1)とは、記録部55を有する場合には、記録部55が記録していた一つ前の容量補正値K(n-1)に基準総容量Ah(0)を乗算したもの、即ち Ah(n-1)=Ah(0)×K(n-1)を用いる。また、一つ前の容量補正値K(n-1)の値が存在しない場合には、基準総容量Ah(0)をそのまま用いる。尚、基準総容量Ah(0)は前述のように新品時の二次電池10の電池容量であり、この値は予め取得され記録部55等に記録されている。
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
In addition, when all of these data are collected (step S240: Yes), the following (1) is calculated from the integrated current value ΔAh (+) at the charging point and the total capacity Ah (n-1) of the secondary battery 10, which will be described later. Based on the formula, ΔSOC1(+) as the amount of change in the charging rate on the first charging side is calculated. Also, from the current integrated value ΔAh(-) at the discharge point and the total capacity Ah(n-1) of the secondary battery 10, the amount of change in the charging rate on the first discharge side is calculated based on the following formula (1'). ΔSOC1(-) is calculated (first charge rate change amount calculation step S300). In addition, the total capacity Ah (n-1) here means, when the recording unit 55 is included, the reference total capacity is added to the previous capacity correction value K (n-1) recorded by the recording unit 55. The value multiplied by Ah(0), ie Ah(n-1)=Ah(0)×K(n-1), is used. Furthermore, if the previous capacitance correction value K(n-1) does not exist, the reference total capacitance Ah(0) is used as is. Note that the reference total capacity Ah(0) is the battery capacity of the secondary battery 10 when new, as described above, and this value is obtained in advance and recorded in the recording unit 55 or the like.
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')

ここで、図6に電流取得部30が出力する電流値Iと電流積算値算出部32が出力する電流積算値ΔAhの関係を示す。尚、図6中の横軸が時間で、上段が電流値I、下段が電流積算値ΔAhを示している。ここで、図6中のA点を仮に基準点とすると、このA点での電流積算値ΔAhが基準点の電流積算値ΔAh(0)となる。次に、システムが稼働し、二次電池10は充放電を繰り返す、これにより二次電池10の電流値Iは図6の上段に示すように充電領域と放電領域とを行き来する。このとき、電流積算値ΔAhは図6の下段に示すように電流値Iが積算値されながら充電領域と放電領域とを行き来する。そして、仮に図6中のB点で電流ゼロ状態となり、且つ開回路電圧OCVを取得可能な状態になると、電池状態推定装置80の制御部はこのB点での電流積算値ΔAhが充電側(正)に位置するか放電側(負)に位置するかを判別する。尚、図6ではB点での電流積算値ΔAhは充電側(正)にあるため、電池状態推定装置80の制御部はB点を充電点と設定する。そして、図6中の矢印で表す電流積算値ΔAhと基準点の電流積算値ΔAh(0)との差ΔAh-ΔAh(0)が充電点の電流積算値ΔAh(+)となる。尚、この充電点の電流積算値ΔAh(+)は、上記(1)式に示すようにΔSOC1(+)とは比例関係にある。 Here, FIG. 6 shows the relationship between the current value I output by the current acquisition section 30 and the current integrated value ΔAh outputted by the current integrated value calculation section 32. In addition, the horizontal axis in FIG. 6 is time, the upper row shows the current value I, and the lower row shows the current integrated value ΔAh. Here, if point A in FIG. 6 is assumed to be a reference point, the current integrated value ΔAh at this point A becomes the current integrated value ΔAh(0) at the reference point. Next, the system starts operating, and the secondary battery 10 repeats charging and discharging, so that the current value I of the secondary battery 10 goes back and forth between the charging region and the discharging region as shown in the upper part of FIG. At this time, the current integrated value ΔAh moves back and forth between the charging region and the discharging region while the current value I is integrated as shown in the lower part of FIG. If the current becomes zero at point B in FIG. 6 and the open circuit voltage OCV can be obtained, the control section of the battery condition estimating device 80 determines that the current integrated value ΔAh at point B is on the charging side ( (positive) or discharge side (negative). In addition, in FIG. 6, since the current integrated value ΔAh at point B is on the charging side (positive), the control unit of the battery state estimation device 80 sets point B as the charging point. Then, the difference ΔAh−ΔAh(0) between the current integrated value ΔAh indicated by the arrow in FIG. 6 and the current integrated value ΔAh(0) at the reference point becomes the current integrated value ΔAh(+) at the charging point. Note that the current integrated value ΔAh(+) at this charging point is in a proportional relationship with ΔSOC1(+) as shown in the above equation (1).

尚、ΔSOC1(+)、ΔSOC1(-)の値が著しく小さい場合、後述の充電側補正値K(+)、放電側補正値K(-)が小さな値となり異常な容量補正値K(n)が算出される可能性が有る。よって、ΔSOC1(+)、ΔSOC1(-)が所定の値よりも小さい値、例えばΔSOC1(+)、ΔSOC1(-)が充電率SOC(+)、SOC(-)の10%に満たない場合には、充電点、放電点としての設定を取り消し、電流取得ステップS200に帰還させるようにしても良い。 Note that if the values of ΔSOC1(+) and ΔSOC1(-) are extremely small, the charging side correction value K(+) and discharging side correction value K(-), which will be described later, will become small values, resulting in an abnormal capacity correction value K(n). may be calculated. Therefore, when ΔSOC1(+) and ΔSOC1(-) are smaller than a predetermined value, for example, when ΔSOC1(+) and ΔSOC1(-) are less than 10% of the charging rate SOC(+) and SOC(-), Alternatively, the setting as the charging point and the discharging point may be canceled and the process may be returned to the current acquisition step S200.

また、ΔSOC算出部52は、対応する基準点の充電率SOC(0)もしくはSOC(0’)と充電点の充電率SOC(+)とから下記(2)式もしくは(2’’)式に基づいて第2の充電側の充電率の変化量としてのΔSOC2(+)を算出する。また、対応する基準点の充電率SOC(0)もしくはSOC(0’)と放電点の充電率SOC(-)とから下記(2’)式もしくは(2’’’)式に基づいて第2の放電側の充電率の変化量としてのΔSOC2(-)を算出する(第2の充電率変化量算出ステップS302)。
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
Further, the ΔSOC calculation unit 52 calculates the following formula (2) or (2'') from the charging rate SOC (0) or SOC (0') of the corresponding reference point and the charging rate SOC (+) of the charging point. Based on this, ΔSOC2(+) as the amount of change in the charging rate on the second charging side is calculated. In addition, a second calculation is performed based on the following equation (2') or (2''') from the charging rate SOC (0) or SOC (0') of the corresponding reference point and the charging rate SOC (-) of the discharge point. ΔSOC2(-) is calculated as the amount of change in the charging rate on the discharging side (second charging rate change amount calculation step S302).
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')

尚、充電点、放電点の設定時に電流積算値ΔAh(0)に対する閾値αを設けない構成では、充電点、放電点が基準点の近傍に位置した場合、(2)式~(2’’’)式で算出されるΔSOC2(+)、ΔSOC2(-)の値が小さくなり、以下の(3)、(3’)式での充電側補正値K(+)、放電側補正値K(-)が著しく大きな値となる可能性が有る。よって、ΔSOC算出部52が算出した、ΔSOC2(+)、ΔSOC2(-)が所定の値よりも小さい値、例えば充電率SOC(+)、SOC(-)の10%に満たない場合には充電点、放電点としての設定を取り消し、電流取得ステップS200に帰還させるようにしても良い。 In addition, in a configuration in which the threshold value α for the current integrated value ΔAh(0) is not provided when setting the charging point and the discharging point, when the charging point and the discharging point are located near the reference point, equations (2) to (2'' The values of ΔSOC2(+) and ΔSOC2(-) calculated by the equation (3) and (3') become smaller, and the charging side correction value K(+) and the discharging side correction value K( -) may become a significantly large value. Therefore, if ΔSOC2(+) and ΔSOC2(-) calculated by the ΔSOC calculation unit 52 are smaller than a predetermined value, for example, less than 10% of the charging rate SOC(+) and SOC(-), charging is stopped. The setting as a point or discharge point may be canceled and the process may be returned to the current acquisition step S200.

そして、ΔSOC算出部52は、これらΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)を補正係数算出部54に出力する。また、補正係数算出部54は、入力したΔSOC1(+)とΔSOC2(+)との比率、即ち下記(3)式に基づいて充電側補正値K(+)を算出する。また、入力したΔSOC1(-)とΔSOC2(-)との比率、即ち下記(3’)式に基づいて放電側補正値K(-)を算出する(補正係数算出ステップS304)。そして、これらの充電側補正値K(+)と放電側補正値K(-)とを判定部56に出力する。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
Then, the ΔSOC calculation unit 52 outputs these ΔSOC1(+), ΔSOC1(−), ΔSOC2(+), and ΔSOC2(−) to the correction coefficient calculation unit 54. Further, the correction coefficient calculation unit 54 calculates a charging side correction value K(+) based on the ratio of the input ΔSOC1(+) and ΔSOC2(+), that is, the following equation (3). Further, a discharge side correction value K(-) is calculated based on the ratio of the input ΔSOC1(-) and ΔSOC2(-), ie, the following equation (3') (correction coefficient calculation step S304). Then, these charging side correction value K(+) and discharging side correction value K(-) are output to the determination section 56.
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')

尚、基準点、充電点、放電点が複数存在する場合には、対応する基準点を基にそのそれぞれに対して暫定充電側補正値K(+)’もしくは暫定放電側補正値K(-)’を個別に算出し、これら暫定充電側補正値K(+)’、暫定放電側補正値K(-)’の充電側、放電側ごとの平均値を充電側補正値K(+)、放電側補正値K(-)として判定部56に出力することが好ましい。 If there are multiple reference points, charging points, and discharge points, the provisional charging side correction value K(+)' or the provisional discharging side correction value K(-) is calculated for each of them based on the corresponding reference point. ' is calculated separately, and the average value for each charging side and discharging side of these provisional charging side correction value K(+)' and provisional discharging side correction value K(-)' is calculated as charging side correction value K(+)' and discharging side correction value K(+)'. It is preferable to output the side correction value K(-) to the determination unit 56.

また、判定部56は、充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかの判定を行う。そして、充電側補正値K(+)と放電側補正値K(-)の双方がともに1未満の場合、即ち、K(+)<1 で且つ K(-)<1 の場合(ステップS306:Yes:判定ステップ)、判定部56はその判定結果とともに充電側補正値K(+)、放電側補正値K(-)を補正係数設定部57に出力する。補正係数設定部57はこの判定結果を受けると、充電側補正値K(+)と放電側補正値K(-)の平均値を補正値K’(n)とする。 Further, the determining unit 56 determines whether the charging side correction value K(+) and the discharging side correction value K(-) are each larger than or smaller than 1. Then, when both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, that is, when K(+)<1 and K(-)<1 (step S306: Yes: determination step), the determination unit 56 outputs the determination result as well as the charging side correction value K(+) and the discharging side correction value K(−) to the correction coefficient setting unit 57. Upon receiving this determination result, the correction coefficient setting unit 57 sets the average value of the charging side correction value K(+) and the discharging side correction value K(-) as the correction value K'(n).

そして、すでに容量補正値の算出された状態で1つ前の容量補正値K(n-1)が存在する場合では、この容量補正値K(n-1)を用いて補正された総容量Ah(n-1)、即ちAh(n-1)=Ah(0)×K(n-1)が(1)式、(1’)式に適用されて、ΔSOC1(+)、ΔSOC1(-)が算出されている。また、このΔSOC1(+)、ΔSOC1(-)に基づいて補正値K’(n)が算出されている。この場合、1つ前の容量補正値K(n-1)を考慮して、下記(4)式に基づいて容量補正値K(n)を算出することが好ましい。
K(n)=K’(n)×K(n-1)・・・(4)
また、1つ前の容量補正値K(n-1)が存在せず、(1)式、(1’)式においてAh(n-1)の代わりに基準総容量Ah(0)が用いられてΔSOC1(+)とΔSOC1(-)が算出されている場合には、この補正値K’(n)をそのまま容量補正値K(n)として設定しても良い。
If the previous capacitance correction value K(n-1) exists in a state where the capacitance correction value has already been calculated, the total capacitance Ah corrected using this capacitance correction value K(n-1) (n-1), that is, Ah (n-1) = Ah (0) × K (n-1), is applied to equations (1) and (1'), and ΔSOC1 (+), ΔSOC1 (-) has been calculated. Further, the correction value K'(n) is calculated based on ΔSOC1(+) and ΔSOC1(-). In this case, it is preferable to calculate the capacitance correction value K(n) based on the following equation (4) in consideration of the previous capacitance correction value K(n-1).
K(n)=K'(n)×K(n-1)...(4)
In addition, the previous capacitance correction value K(n-1) does not exist, and the reference total capacitance Ah(0) is used instead of Ah(n-1) in equations (1) and (1'). If ΔSOC1(+) and ΔSOC1(-) have been calculated, this correction value K'(n) may be directly set as the capacitance correction value K(n).

また、例えばノイズ等により電池情報取得部20の測定値に突発的な測定誤差が生じている場合、異常な補正値K’(n)が算出され、システムの動作全体に悪影響を及ぼす虞が有る。よって、本発明に係る電池状態推定装置80では突発的で異常な補正値K’(n)の影響を軽減するために、例えば、頻繁に補正値K’(n)が算出可能なシステムでは、補正値K’(n)の平均値もしくは移動平均値を容量補正値K(n)としても良い。また、予め設定された回数(例えば10回等)補正値K’(n)が算出されるごとにその平均値を容量補正値K(n)としても良い。また、任意の時間間隔(例えば10分間)で区切りを設け、その時間間隔内で最新の補正値K’(n)もしくは、その時間間隔内で得られた補正値K’(n)の平均値を容量補正値K(n)としても良い。そして、これらの構成によって突発的な補正値K’(n)の異常値の影響を軽減することができる。 Furthermore, if a sudden measurement error occurs in the measured value of the battery information acquisition unit 20 due to noise or the like, for example, an abnormal correction value K'(n) may be calculated, which may adversely affect the overall operation of the system. . Therefore, in order to reduce the influence of the sudden and abnormal correction value K'(n), in the battery state estimation device 80 according to the present invention, for example, in a system where the correction value K'(n) can be calculated frequently, The average value or moving average value of the correction values K'(n) may be used as the capacity correction value K(n). Furthermore, each time the correction value K'(n) is calculated a preset number of times (for example, 10 times, etc.), the average value thereof may be used as the capacity correction value K(n). Also, set a break at an arbitrary time interval (for example, 10 minutes), and use the latest correction value K'(n) within that time interval or the average value of the correction values K'(n) obtained within that time interval. may be set as the capacitance correction value K(n). These configurations can reduce the influence of sudden abnormal values of the correction value K'(n).

さらに、補正係数設定部57に1よりも小さい補正下限値K(min)を予め設定し、算出された容量補正値K(n)が補正下限値K(min)よりも小さい場合には、補正下限値K(min)を容量補正値K(n)として設定するようにしても良い。 Further, a correction lower limit value K (min) smaller than 1 is preset in the correction coefficient setting section 57, and when the calculated capacity correction value K (n) is smaller than the correction lower limit value K (min), the correction The lower limit value K(min) may be set as the capacitance correction value K(n).

また、1よりも小さな値の軽減係数Aを設定しておき、下記(4’)式により、容量補正値K(n)を設定するようにしても良い。
K(n)=(1-A×(1-K’(n)))×K(n-1)・・・(4’)
これらの補正下限値K(min)を設定した構成、軽減係数Aを設定した構成でも、異常に小さな補正値K’(n)が算出されたときの影響を軽減することができる。そして、補正係数設定部57はこの算出もしくは設定した容量補正値K(n)を容量補正部58に出力する。以上が充電側補正値K(+)と放電側補正値K(-)の双方がともに1未満の場合の補正係数設定ステップ(ステップS310A)に相当する。
Alternatively, the reduction coefficient A may be set to a value smaller than 1, and the capacitance correction value K(n) may be set using the following equation (4').
K(n)=(1-A×(1-K'(n)))×K(n-1)...(4')
Even with the configuration in which the lower correction limit value K (min) is set and the configuration in which the reduction coefficient A is set, the influence when an abnormally small correction value K'(n) is calculated can be reduced. Then, the correction coefficient setting section 57 outputs the calculated or set capacitance correction value K(n) to the capacitance correction section 58. The above corresponds to the correction coefficient setting step (step S310A) when both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1.

ここで、ΔSOC1(+)、(-)とΔSOC2(+)、(-)との間に差が生じる主な原因としては次の3つが考えられる。1つ目は前述の二次電池10の劣化による電池容量の減少である。2つ目は、電池情報取得部20の測定誤差、即ち、電流取得手段30aのゲイン誤差、オフセット誤差、電圧取得手段34aの測定誤差の影響である。また、3つ目は二次電池10の充放電動作停止直後の分極電圧の開回路電圧OCVへの影響である。このうち、電圧取得手段34aの測定誤差は設置時等の調整により除去することができる。また、充放電動作停止直後の分極電圧に関しては、前述の緩和状態判定部46を設置することで対処が可能である。しかしながら、電流取得手段30aのゲイン誤差、オフセット誤差に関しては経時によって誤差の値が変化する可能性があり恒久的な対応が困難である。よって、対応すべきは電池容量の減少と電流取得手段30aのゲイン誤差、オフセット誤差のこれら3つの要因となる。 Here, the following three are considered to be the main causes of the difference between ΔSOC1(+), (-) and ΔSOC2(+), (-). The first is a decrease in battery capacity due to the aforementioned deterioration of the secondary battery 10. The second is the influence of measurement errors of the battery information acquisition section 20, that is, gain errors and offset errors of the current acquisition means 30a, and measurement errors of the voltage acquisition means 34a. The third factor is the influence of the polarization voltage on the open circuit voltage OCV immediately after the charging/discharging operation of the secondary battery 10 is stopped. Among these, the measurement error of the voltage acquisition means 34a can be removed by adjustment at the time of installation or the like. Furthermore, the polarization voltage immediately after the charging/discharging operation is stopped can be dealt with by installing the above-mentioned relaxation state determining section 46. However, regarding the gain error and offset error of the current acquisition means 30a, the error values may change over time, making it difficult to permanently deal with them. Therefore, the three factors that need to be addressed are the reduction in battery capacity, the gain error of the current acquisition means 30a, and the offset error.

そして、電池容量の減少は前述のようにΔSOC1(+)、ΔSOC1(-)の低下として現れる。また、電流取得手段30aのゲイン誤差により電流値Iの値(絶対値)が真値よりも小さく取得される場合にもΔSOC1(+)、ΔSOC1(-)の低下が現れる。このため、二次電池10の電池容量が減少している状態、もしくは電流取得手段30aのゲイン誤差により電流値Iの絶対値が真値よりも小さく取得されている状態では、充電側補正値K(+)、放電側補正値K(-)の双方はともに1未満の値をとる。この場合、1未満の充電側補正値K(+)、放電側補正値K(-)に基づいて算出される容量補正値K(n)も基本的に1未満の値を取り、この1未満の容量補正値K(n)によって補正される補正後の総容量Ah(n)は基準総容量Ah(0)から減少した値となる。これにより、二次電池10の電池容量が減少している状態でも適正な推定充電率SOC’の算出が可能となる。尚、ゲイン誤差によって電流値Iの絶対値が真値よりも小さく取得され、総容量Ah(n)が基準総容量Ah(0)から減少する補正処理では、電流値Iの大きさそのものに対する補正は行われない。ただし、ゲイン誤差を含む電流値Iによって得られた電流積算値ΔAhを後述の(6)式に適用する際に、(6)式における総容量Ah(n)が基準総容量Ah(0)から減少するため、ゲイン誤差により電流値Iの絶対値が真値よりも小さく取得され電流積算値ΔAhが小さくなる影響は解消され、適正なΔSOC(=ΔAh/Ah(n))を算出することができる。これにより、(6)式による適正な推定充電率SOC’の算出が可能となる。尚、ゲイン誤差によるΔSOC1(+)、ΔSOC1(-)の低下と、電池容量の減少によるΔSOC1(+)、ΔSOC1(-)の低下とは区別することはできないが、補正手法は同じであるため特に区別する必要は無く、上記の手法で一括して補正することができる。 As described above, the decrease in battery capacity appears as a decrease in ΔSOC1(+) and ΔSOC1(-). Furthermore, a decrease in ΔSOC1(+) and ΔSOC1(-) also appears when the value (absolute value) of the current value I is acquired smaller than the true value due to a gain error of the current acquisition means 30a. Therefore, in a state in which the battery capacity of the secondary battery 10 is decreasing or in a state in which the absolute value of the current value I is obtained smaller than the true value due to a gain error of the current obtaining means 30a, the charging side correction value K (+) and the discharge side correction value K(-) both take values less than 1. In this case, the capacity correction value K(n) calculated based on the charging side correction value K(+) and the discharging side correction value K(-), which are less than 1, also basically takes a value less than 1; The total capacitance Ah(n) after correction corrected by the capacitance correction value K(n) becomes a value decreased from the reference total capacitance Ah(0). This makes it possible to calculate an appropriate estimated charging rate SOC' even when the battery capacity of the secondary battery 10 is decreasing. In addition, in the correction process in which the absolute value of the current value I is obtained smaller than the true value due to gain error and the total capacity Ah (n) decreases from the reference total capacity Ah (0), the magnitude of the current value I itself is corrected. will not be carried out. However, when applying the current integrated value ΔAh obtained from the current value I including the gain error to the equation (6) described below, the total capacity Ah (n) in the equation (6) is changed from the reference total capacity Ah (0). Therefore, the effect of the gain error resulting in the absolute value of the current value I being obtained smaller than the true value and the current integrated value ΔAh becoming smaller is eliminated, and it is possible to calculate an appropriate ΔSOC (=ΔAh/Ah(n)). can. This makes it possible to calculate an appropriate estimated charging rate SOC' using equation (6). Although it is not possible to distinguish between a decrease in ΔSOC1(+) and ΔSOC1(-) due to gain error and a decrease in ΔSOC1(+) and ΔSOC1(-) due to a decrease in battery capacity, the correction method is the same. There is no particular need to distinguish between them, and they can be corrected all at once using the above method.

また、充電側補正値K(+)と放電側補正値K(-)の双方がともに1よりも大きい場合、即ち、K(+)>1 で且つ K(-)>1 の場合(ステップS306:No、ステップS308:Yes:判定ステップ)、これは1つ前に算出した容量補正値K(n-1)の値が過小で、1つ前に算出した容量補正値K(n-1)による補正が過剰であることを示している。これは、実際の電池容量の減少よりも1つ前に算出した容量補正値K(n-1)が過剰に容量を低減する値となっているか、もしくは電流取得手段30aのゲイン誤差によって電流値Iの絶対値が真値よりも大きな値で取得されていることを意味する。よって、補正係数設定部57はこの判定結果を受けた場合、充電側補正値K(+)と放電側補正値K(-)の平均値に1つ前の容量補正値K(n-1)を乗じた下記(4’’)式に基づいて容量補正値K(n)を算出する。
K(n)=((K(+)+K(-))/2)×K(n-1)・・・(4’’)
ただし、(4’’)式によって算出されたK(n)が1を超える場合、補正係数設定部57はK(n)を「1」としても良い。
Further, when both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1, that is, when K(+)>1 and K(-)>1 (step S306 : No, Step S308: Yes: Determination step), this means that the value of the capacitance correction value K (n-1) calculated one time ago is too small, and the value of the capacitance correction value K (n-1) calculated one time ago is too small. This indicates that the correction is excessive. This is because the capacity correction value K(n-1) calculated one time before the actual decrease in battery capacity is a value that reduces the capacity excessively, or the current value is due to a gain error of the current acquisition means 30a. This means that the absolute value of I is obtained as a value larger than the true value. Therefore, when the correction coefficient setting unit 57 receives this determination result, it adds the previous capacity correction value K(n-1) to the average value of the charging side correction value K(+) and the discharging side correction value K(-). The capacitance correction value K(n) is calculated based on the following equation (4'') multiplied by .
K(n)=((K(+)+K(-))/2)×K(n-1)...(4'')
However, if K(n) calculated by equation (4'') exceeds 1, the correction coefficient setting unit 57 may set K(n) to "1".

さらに、電流取得手段30aのゲイン誤差によって電流値Iの絶対値が真値よりも大きな値で取得されている場合を考慮して、上記の(4’’)式によって算出された容量補正値K(n)が予め設定した1以上の上限値K(lim)を超える場合、補正係数設定部57は容量補正値K(n)を上限値であるK(lim)としても良い。そして、補正係数設定部57はこの容量補正値K(n)を容量補正部58に出力する。尚、充電側補正値K(+)と放電側補正値K(-)の双方がともに1よりも大きい場合においても、この原因が電流取得手段30aのゲイン誤差によって電流値Iの絶対値が真値よりも大きな値で取得されているためなのか、電池容量の補正が過剰であるのかは区別することはできない。しかしながら、補正手法は同じであるため特に区別する必要は無く、上記の手法で一括して補正することができる。以上が充電側補正値K(+)と放電側補正値K(-)の双方がともに1よりも大きい場合の補正係数設定ステップ(ステップS310B)に相当する。 Furthermore, in consideration of the case where the absolute value of the current value I is acquired as a value larger than the true value due to the gain error of the current acquisition means 30a, the capacitance correction value K is calculated by the above equation (4''). If (n) exceeds one or more preset upper limit values K(lim), the correction coefficient setting unit 57 may set the capacitance correction value K(n) to the upper limit value K(lim). Then, the correction coefficient setting section 57 outputs this capacitance correction value K(n) to the capacitance correction section 58. Note that even if both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1, the absolute value of the current value I may not be true due to the gain error of the current acquisition means 30a. It is not possible to distinguish whether this is because the value is larger than the actual value, or whether the battery capacity is overcorrected. However, since the correction methods are the same, there is no particular need to distinguish between them, and the above-mentioned method can be used to correct them all at once. The above corresponds to the correction coefficient setting step (step S310B) when both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1.

また、充電側補正値K(+)と放電側補正値K(-)のいずれか一方が1よりも大きく他方が1未満の場合、即ち、K(+)<1 で且つ K(-)>1 の場合、もしくは、K(+)>1 で且つ K(-)<1 の場合(ステップS306:No、ステップS308:No、ステップS309:Yes:判定ステップ)、判定部56はこの判定結果を補正係数設定部57に出力するとともに、ΔSOC算出部52がΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)をSOC補正部59に出力する。また、補正係数設定部57はこの判定結果を受けた場合、新たな容量補正値K(n)を算出せず、1つ前の容量補正値K(n-1)をそのまま容量補正値K(n)とする(ステップS310C:補正係数設定ステップ)。そして、補正係数設定部57はこの容量補正値K(n)を容量補正部58に出力する。 Furthermore, if either the charging side correction value K(+) or the discharging side correction value K(-) is greater than 1 and the other is less than 1, that is, K(+)<1 and K(-)> 1, or if K(+)>1 and K(-)<1 (step S306: No, step S308: No, step S309: Yes: determination step), the determination unit 56 uses this determination result. At the same time, the ΔSOC calculation unit 52 outputs ΔSOC1(+), ΔSOC1(−), ΔSOC2(+), and ΔSOC2(−) to the SOC correction unit 59. In addition, when the correction coefficient setting unit 57 receives this determination result, it does not calculate a new capacity correction value K(n) and uses the previous capacity correction value K(n-1) as it is. n) (step S310C: correction coefficient setting step). Then, the correction coefficient setting section 57 outputs this capacitance correction value K(n) to the capacitance correction section 58.

ここで、K(+)<1 で且つ K(-)>1 の場合とは、図7(a)に示すように、|ΔSOC1(+)|<|ΔSOC2(+)| で且つ |ΔSOC2(-)|<|ΔSOC1(-)|を意味しており、電流積算値ΔAh(+)、ΔAh(-)から算出したΔSOC1(+)、ΔSOC1(-)が、開回路電圧OCVに基づいて取得したΔSOC2(+)、ΔSOC2(-)に対して全体的に放電側(マイナス方向)にオフセットしていることを意味している。これは、電流値Iが電流取得手段30aのオフセット誤差により全体的に負の方向(放電方向)にズレているためと考えられる。また、K(+)>1 で且つ K(-)<1 の場合とは、図7(b)に示すように、|ΔSOC1(+)|>|ΔSOC2(+)| で且つ |ΔSOC2(-)|>|ΔSOC1(-)|を意味しており、電流積算値ΔAh(+)、ΔAh(-)から算出したΔSOC1(+)、ΔSOC1(-)が、開回路電圧OCVに基づいて取得したΔSOC2(+)、ΔSOC2(-)に対して全体的に充電側(プラス方向)にオフセットしていることを意味している。これは、電流値Iが電流取得手段30aのオフセット誤差により全体的に正の方向(充電方向)にズレているためと考えられる。 Here, the case where K(+)<1 and K(-)>1 means that |ΔSOC1(+)|<|ΔSOC2(+)| and |ΔSOC2( -) | < | ΔSOC1(-) | means that ΔSOC1(+) and ΔSOC1(-) calculated from the current integrated values ΔAh(+) and ΔAh(-) are obtained based on the open circuit voltage OCV. This means that it is offset in the discharge side (minus direction) as a whole with respect to ΔSOC2(+) and ΔSOC2(-). This is considered to be because the current value I is generally shifted in the negative direction (discharge direction) due to the offset error of the current acquisition means 30a. Furthermore, the case where K(+)>1 and K(-)<1 means that |ΔSOC1(+)|>|ΔSOC2(+)| and |ΔSOC2(- )|>|ΔSOC1(-)| means that ΔSOC1(+) and ΔSOC1(-) calculated from the current integrated values ΔAh(+) and ΔAh(-) are obtained based on the open circuit voltage OCV. This means that it is offset in the charging side (positive direction) as a whole with respect to ΔSOC2(+) and ΔSOC2(-). This is considered to be because the current value I is generally shifted in the positive direction (charging direction) due to the offset error of the current acquisition means 30a.

よって、判定結果がK(+)<1 で且つ K(-)>1 の場合、SOC補正部59は例えば、|ΔSOC2(+)|-|ΔSOC1(+)|の値、及び、|ΔSOC1(-)|-|ΔSOC2(-)|の値をそれぞれ算出し、双方を比較して小さい方の値、もしくは双方の値の平均値を「正」(充電方向)のSOC補正値K(soc)とする。また、判定結果がK(+)>1 で且つ K(-)<1 の場合、SOC補正部59は例えば、|ΔSOC1(+)|-|ΔSOC2(+)|の値、及び、|ΔSOC2(-)|-|ΔSOC1(-)|の値をそれぞれ算出し、双方を比較して小さい方の値、もしくは双方の値の平均値を「負」(放電方向)のSOC補正値K(soc)とする。 Therefore, when the determination result is K(+)<1 and K(-)>1, the SOC correction unit 59 calculates, for example, the value of |ΔSOC2(+)|-|ΔSOC1(+)| and |ΔSOC1( -) | - | ΔSOC2 (-) | are calculated respectively, and both are compared and the smaller value or the average value of both values is determined as the "positive" (charging direction) SOC correction value K (soc). shall be. Further, when the determination result is K(+)>1 and K(-)<1, the SOC correction unit 59 calculates, for example, the value of |ΔSOC1(+)|-|ΔSOC2(+)| and |ΔSOC2( -) | - | ΔSOC1 (-) | are calculated respectively, and both are compared and the smaller value or the average value of both values is determined as the "negative" (discharge direction) SOC correction value K (soc). shall be.

尚、電流取得部30が取得した電流値Iにオフセット誤差がある場合、電流積算値ΔAhの誤差が時間経過とともに蓄積していく。このため、算出したSOC補正値K(soc)が適正値よりも過大となる可能性がある。よって、SOC補正部59は算出されたSOC補正値K(soc)をそのまま推定充電率算出部60に出力しても良いが、算出されたSOC補正値K(soc)を低減して推定充電率算出部60に出力することが好ましい。このSOC補正値K(soc)の低減は、例えば予め設定した1未満の任意の低減係数A’(固定値)を乗算することで行っても良いが、電流積算値ΔAh(+)、ΔAh(-)に基づいて下記(B)式および(B’)式にて低減係数A’(+)、低減係数A’(-)を算出し、これらの双方を比較して小さい方の値、もしくは双方の値の平均値を上記のSOC補正値K(soc)に乗算して行うことが好ましい。
A’(+)=電流積算値ΔAh(+)/(区間電流積算絶対値(+))・・・(B)
A’(-)=電流積算値ΔAh(-)/(区間電流積算絶対値(-))・・・(B’)
ここで、区間電流積算絶対値(+)とは充電点の電流積算値ΔAh(+)を測定する際の測定開始点から測定完了点までのすべての充電区間と放電区間の各電流積算値の絶対値の合計である。また、区間電流積算絶対値(-)とは放電点の電流積算値ΔAh(-)を測定する際の測定開始点から測定完了点までのすべての充電区間と放電区間の各電流積算値の絶対値の合計である。
Note that if there is an offset error in the current value I acquired by the current acquisition unit 30, the error in the current integrated value ΔAh accumulates over time. Therefore, the calculated SOC correction value K (soc) may be larger than the appropriate value. Therefore, the SOC correction unit 59 may output the calculated SOC correction value K (soc) as it is to the estimated charging rate calculation unit 60, but the calculated SOC correction value K (soc) may be reduced to obtain the estimated charging rate. It is preferable to output it to the calculation unit 60. This SOC correction value K (soc) may be reduced by, for example, multiplying by a preset arbitrary reduction coefficient A' (fixed value) less than 1, but the current integrated values ΔAh (+), ΔAh ( -), calculate the reduction coefficient A' (+) and reduction coefficient A' (-) using the following formulas (B) and (B'), compare both of these, and select the smaller value or It is preferable to multiply the above SOC correction value K (soc) by the average value of both values.
A'(+) = Current integrated value ΔAh(+)/(section current integrated absolute value (+))...(B)
A' (-) = Current integrated value ΔAh (-) / (section current integrated absolute value (-)) ... (B')
Here, the section current integrated absolute value (+) is the current integrated value of all the current integrated values in all charging sections and discharging sections from the measurement start point to the measurement completion point when measuring the current integrated value ΔAh (+) at the charging point. It is the sum of absolute values. Also, the section current integrated absolute value (-) is the absolute value of each current integrated value in all charging sections and discharging sections from the measurement start point to the measurement completion point when measuring the current integrated value ΔAh (-) at the discharge point. It is the sum of the values.

また、低減係数A’(+)、低減係数A’(-)はSOC補正値K(soc)の算出の前に乗算しても良い。即ち、低減係数A’(+)を、|ΔSOC2(+)|-|ΔSOC1(+)|の値、または、|ΔSOC1(+)|-|ΔSOC2(+)|の値に乗算した後、SOC補正値K(soc)を算出しても良い。また、低減係数A’(-)を、|ΔSOC1(-)|-|ΔSOC2(-)|の値、または、|ΔSOC2(-)|-|ΔSOC1(-)|の値に乗算した後、SOC補正値K(soc)を算出しても良い。 Further, the reduction coefficient A'(+) and the reduction coefficient A'(-) may be multiplied before calculating the SOC correction value K(soc). That is, after multiplying the reduction coefficient A'(+) by the value of |ΔSOC2(+)|-|ΔSOC1(+)| or the value of |ΔSOC1(+)|-|ΔSOC2(+)|, the SOC A correction value K (soc) may also be calculated. In addition, after multiplying the reduction coefficient A'(-) by the value of |ΔSOC1(-)|-|ΔSOC2(-)| or the value of |ΔSOC2(-)|-|ΔSOC1(-)|, A correction value K (soc) may also be calculated.

そして、SOC補正部59は低減係数A’(+)、低減係数A’(-)を適用して算出されたSOC補正値K(soc)を最終的なSOC補正値K(soc)とする。そして、算出されたSOC補正値K(soc)を推定充電率算出部60に出力する。以上がSOC補正値設定ステップS320に相当する。 Then, the SOC correction unit 59 sets the SOC correction value K (soc) calculated by applying the reduction coefficient A' (+) and the reduction coefficient A' (-) as the final SOC correction value K (soc). Then, the calculated SOC correction value K (soc) is output to the estimated charging rate calculation section 60. The above corresponds to SOC correction value setting step S320.

尚、充電側補正値K(+)と放電側補正値K(-)とが双方とも1の場合には(ステップS306:No、ステップS308:No、ステップS309:No:判定ステップ)、二次電池10に容量低下が生じていないか、現在適用されている容量補正値K(n-1)が適正であるとして、新たな容量補正値K(n)の算出は行わず、電流取得ステップS200に帰還する。 Note that if the charging side correction value K(+) and the discharging side correction value K(-) are both 1 (step S306: No, step S308: No, step S309: No: determination step), the secondary Assuming that the capacity of the battery 10 has not decreased or that the currently applied capacity correction value K(n-1) is appropriate, a new capacity correction value K(n) is not calculated and the current acquisition step S200 is performed. to return to.

また、容量補正部58は上記の補正係数設定ステップで設定された新たな容量補正値K(n)が入力すると、この新たな容量補正値K(n)を用いて下記(5)式に基づいて補正後の総容量Ah(n)を算出する(容量値補正ステップS312)。
Ah(n)=Ah(0)×K(n)・・・(5)
そして、この補正後の総容量Ah(n)を推定充電率算出部60に出力する。
Further, when the new capacity correction value K(n) set in the correction coefficient setting step described above is input, the capacity correction unit 58 uses this new capacity correction value K(n) to calculate the capacity correction value based on the following equation (5). The total capacitance Ah(n) after correction is calculated (capacitance value correction step S312).
Ah(n)=Ah(0)×K(n)...(5)
Then, this corrected total capacity Ah(n) is output to the estimated charging rate calculation section 60.

また、推定充電率算出部60は、容量補正部58が算出した補正後の総容量Ah(n)と、電流積算値算出部32が出力する現在の電流積算値ΔAhと、基準点の充電率SOC(0)と、SOC補正部59が算出したSOC補正値K(soc)とから下記(6)式に基づいて推定充電率SOC’を算出する(推定充電率算出ステップS330)。
SOC’=ΔAh/Ah(n)+SOC(0)+K(soc)・・・(6)
尚、SOC補正値K(soc)が存在しない場合にはK(soc)=0となる。また、新たなSOC補正値K(soc)が算出されなかった場合、SOC補正値K(soc)は過去の値が維持される。尚、記録部55にSOC補正値K(soc)を記録させておき、システムの再起動時にはこの過去のSOC補正値K(soc)を読み出して使用しても良い。この構成によれば、起動時に二次電池10に電流が流れ開回路電圧OCV(0)が取得できず、システムオフ時点の推定充電率SOC’を基準点の充電率SOC(0)とする場合に、SOC補正値K(soc)を読み出して適用できるため、起動時の推定充電率SOC’をより正確に算出することができる。
The estimated charging rate calculation unit 60 also calculates the corrected total capacity Ah(n) calculated by the capacity correction unit 58, the current integrated current value ΔAh output by the current integrated value calculation unit 32, and the charging rate at the reference point. The estimated charging rate SOC' is calculated from the SOC (0) and the SOC correction value K (soc) calculated by the SOC correction unit 59 based on the following equation (6) (estimated charging rate calculation step S330).
SOC'=ΔAh/Ah(n)+SOC(0)+K(soc)...(6)
Note that if the SOC correction value K(soc) does not exist, K(soc)=0. Further, if a new SOC correction value K (soc) is not calculated, the past value of the SOC correction value K (soc) is maintained. Note that the SOC correction value K (soc) may be recorded in the recording unit 55, and this past SOC correction value K (soc) may be read out and used when the system is restarted. According to this configuration, when a current flows through the secondary battery 10 at startup and the open circuit voltage OCV(0) cannot be obtained, the estimated charging rate SOC' at the time the system is turned off is set as the charging rate SOC(0) at the reference point. Since the SOC correction value K (soc) can be read out and applied to the battery, the estimated charging rate SOC' at the time of startup can be calculated more accurately.

そして、上記の(6)式で算出された推定充電率SOC’はシステム内の各部に出力され、二次電池10の状態判定や電力変換器3の制御等に用いられる。尚、推定充電率算出部60から出力する推定充電率SOC’にはローパスフィルタ等によるなまし処理を行い、推定充電率SOC’の急変を防止することが好ましい(なましステップS332)。 The estimated charging rate SOC' calculated by the above equation (6) is output to each part in the system and used for determining the state of the secondary battery 10, controlling the power converter 3, etc. Note that it is preferable to perform smoothing processing on the estimated charging rate SOC' output from the estimated charging rate calculation unit 60 using a low-pass filter or the like to prevent sudden changes in the estimated charging rate SOC' (smoothing step S332).

尚、二次電池10の容量低下と電流取得手段30aのオフセット誤差とが混在している場合や、電流取得手段30aのゲイン誤差と電流取得手段30aのオフセット誤差とが混在している場合、さらには二次電池10の容量低下と電流取得手段30aのゲイン誤差及びオフセット誤差が混在している場合でも、上記の補正処理を複数回行うことで、それぞれに対応した補正が行われ、最終的に適切な推定充電率SOC’の算出が可能となる。 In addition, when the capacity reduction of the secondary battery 10 and the offset error of the current acquisition means 30a coexist, or when the gain error of the current acquisition means 30a and the offset error of the current acquisition means 30a coexist, Even if the capacity reduction of the secondary battery 10 and the gain error and offset error of the current acquisition means 30a coexist, by performing the above correction process multiple times, corrections corresponding to each are performed, and finally It becomes possible to calculate an appropriate estimated charging rate SOC'.

そして、推定充電率SOC’が算出されると、放電点及び充電点はリセットされ、電流取得ステップS200に帰還する。このとき、基準点もリセットして分極緩和時間経過後の点を新たな基準点として設定しても良いし、最後に取得した放電点または充電点を新たな基準点としても良い。さらに、システム起動時の基準点をシステムオフ時まで維持しても良い。 Then, when the estimated charging rate SOC' is calculated, the discharging point and the charging point are reset, and the process returns to the current acquisition step S200. At this time, the reference point may also be reset and the point after the polarization relaxation time has elapsed may be set as the new reference point, or the last acquired discharge point or charging point may be used as the new reference point. Furthermore, the reference point at the time of system startup may be maintained until the system is turned off.

尚、頻繁に補正値K’(n)が算出可能なシステムでは、1度のシステムの稼働期間(1回のシステム起動から電源オフまでの期間)における容量補正値K(n)の算出回数に上限を設けても良い。また、予め設定された時間間隔内における容量補正値K(n)の算出回数に上限を設けても良い。これらの構成では頻繁な補正動作の実施を抑制し、処理能力の負荷を軽減することができる。 In addition, in a system where the correction value K'(n) can be calculated frequently, the number of calculations of the capacity correction value K(n) during one system operation period (period from one system startup to power off) An upper limit may be set. Further, an upper limit may be set on the number of times the capacitance correction value K(n) is calculated within a preset time interval. With these configurations, frequent correction operations can be suppressed and the load on processing capacity can be reduced.

次に、システムのオフが指示されると(ステップS400:Yes)、電池状態推定装置80が記録部55を有する場合には、記録部55がシステムオフ時点に適用されていた容量補正値K(n-1)と、その容量補正値K(n-1)の算出時の基準点の充電率SOC(0)’と、システムオフ時点の電流積算値ΔAh’と、SOC補正値K(soc)とを記録する(記録ステップS402)。そして、電池状態推定装置80の終了処理が完了したことをシステム制御部5等に伝達する。そして、システムがオフする(ステップS404)。 Next, when the system is instructed to turn off (step S400: Yes), if the battery state estimating device 80 has the recording section 55, the recording section 55 records the capacity correction value K ( n-1), the charging rate SOC(0)' at the reference point when calculating the capacity correction value K(n-1), the current integrated value ΔAh' at the time of system off, and the SOC correction value K(soc) is recorded (recording step S402). Then, the completion of the termination process of the battery state estimating device 80 is transmitted to the system control unit 5 and the like. Then, the system is turned off (step S404).

次に、初期補正値算出ステップS120の好ましい一例に関して説明を行う。先ず、記録部55にシステムオフ時点のデータが記録された状態で再度システムを起動し、且つ起動直後に二次電池10に電流が流れない場合、ステップS012を行ってシステムオフ時点に適用されていた一つ前の容量補正値K(n-1)を記録部55から読み出す。また、充電率取得部40が前述のようにステップS102、基準点設定(ステップS103)、開回路電圧取得ステップ(ステップS112)、充電率取得ステップ(ステップS114)、基準点における電流積算値ΔAh(0)の取得(ステップS116)を行って、基準点の充電率SOC(0)と、電流積算値ΔAh(0)とを取得する。そして、記録部55から読み出された容量補正値K(n-1)は補正係数設定部57にて容量補正値K(n)とされ、容量補正部58はこの容量補正値K(n)と基準総容量Ah(0)とに基づいて下記(5’)式により、初回の補正後総容量Ah(n)を算出し、推定充電率算出部60に出力する。
Ah(n)=Ah(0)×K(n)・・・(5’)
また、推定充電率算出部60は、この補正後総容量Ah(n)と、上記のステップS114、ステップS116で取得された起動時の充電率SOC(0)とそのときの電流積算値ΔAh(0)(=ΔAh)とに基づいて上記(6)式により推定充電率SOC’を算出する。以上が初期補正値算出ステップS120に相当する。
Next, a preferred example of the initial correction value calculation step S120 will be described. First, if the system is restarted with the data at the time of system off recorded in the recording unit 55, and no current flows to the secondary battery 10 immediately after startup, step S012 is performed to determine the data applied at the time of system off. The previous capacitance correction value K(n-1) is read from the recording unit 55. Further, the charging rate acquisition unit 40 performs step S102, reference point setting (step S103), open circuit voltage acquisition step (step S112), charging rate acquisition step (step S114), current integrated value ΔAh at the reference point, as described above. 0) (step S116) to obtain the charging rate SOC(0) at the reference point and the current integrated value ΔAh(0). Then, the capacitance correction value K(n-1) read from the recording section 55 is set as the capacitance correction value K(n) by the correction coefficient setting section 57, and the capacitance correction section 58 sets this capacitance correction value K(n). Based on the reference total capacity Ah(0), the first corrected total capacity Ah(n) is calculated by the following equation (5') and output to the estimated charging rate calculation section 60.
Ah(n)=Ah(0)×K(n)...(5')
In addition, the estimated charging rate calculation unit 60 calculates the corrected total capacity Ah(n), the charging rate SOC(0) at startup obtained in steps S114 and S116 above, and the current integrated value ΔAh( 0) (=ΔAh), the estimated charging rate SOC' is calculated using the above equation (6). The above corresponds to the initial correction value calculation step S120.

また、本発明に係る電池状態推定方法では初期補正値算出ステップS120に加えて、以下のような構成を備えていても良い。先ず、記録部55は、システムのオフ時点で適用されていた容量補正値K(n-1)とそのときの基準点の充電率SOC(0)’と電流積算値ΔAh(total)とを記録する。尚、電流積算値ΔAh(total)とは、直近のシステム起動時点からシステムオフ時点までの全ての期間の電流値Iの積算値である。そして、システムの再起動時には、OCV-SOC取得部42が起動時の電池電圧Vを基準点の開回路電圧OCV(0)とし、この開回路電圧OCV(0)と対応した基準点の充電率SOC(0)を取得する。また、記録部55に記録されている容量補正値K(n-1)、充電率SOC(0)’、電流積算値ΔAh(total)を読み出して、先ず、電流積算値ΔAh(total)が前回の基準点に対して充電側にあるか放電側にあるかを確認する。尚、電流積算値ΔAh(total)はシステムオフ時点の前回の基準点からの電流積算値であり起動時の充電率SOC(0)と対応しているから、記録部55から読み出した充電率SOC(0)’と充電率SOC(0)との位置関係を比較し、充電率SOC(0)がシステムのオフ時点の基準点の充電率SOC(0)’よりも充電側にあれば電流積算値ΔAh(total)も充電側に位置し、放電側にあれば電流積算値ΔAh(total)も放電側に位置する。そして、電流積算値ΔAh(total)が充電側にあった場合、SOC算出部52は電流積算値ΔAh(total)を充電点の電流積算値ΔAh(+)とし、記録部55から読み出した容量補正値K(n-1)と上記(1)式に基づいてΔSOC1(+)を算出する。また、放電側にあれば電流積算値ΔAh(total)を放電点の電流積算値ΔAh(-)とし、容量補正値K(n-1)と上記(1’)式に基づいてΔSOC1(-)を算出する。そして、補正係数算出部54に出力する。 Further, the battery state estimation method according to the present invention may include the following configuration in addition to the initial correction value calculation step S120. First, the recording unit 55 records the capacity correction value K(n-1) applied when the system was turned off, the charging rate SOC(0)' at the reference point at that time, and the integrated current value ΔAh(total). do. Note that the current integrated value ΔAh (total) is the integrated value of the current value I over the entire period from the most recent system startup time to the system off time. When the system is restarted, the OCV-SOC acquisition unit 42 sets the battery voltage V at the time of startup to the reference point open circuit voltage OCV(0), and sets the charging rate at the reference point corresponding to this open circuit voltage OCV(0). Get SOC(0). In addition, the capacity correction value K (n-1), charging rate SOC (0)', and current integrated value ΔAh (total) recorded in the recording section 55 are read out, and first, the current integrated value ΔAh (total) is the previous value. Check whether it is on the charging side or discharging side with respect to the reference point. Note that since the current integrated value ΔAh (total) is the current integrated value from the previous reference point at the time of system off and corresponds to the charging rate SOC (0) at startup, the charging rate SOC read from the recording unit 55 (0)' and the charging rate SOC(0), and if the charging rate SOC(0) is on the charging side than the charging rate SOC(0)' at the reference point when the system is turned off, the current is integrated. The value ΔAh (total) is also located on the charging side, and if it is on the discharging side, the current integrated value ΔAh (total) is also located on the discharging side. Then, when the current integrated value ΔAh (total) is on the charging side, the SOC calculation unit 52 sets the current integrated value ΔAh (total) as the current integrated value ΔAh (+) at the charging point, and the capacity correction read from the recording unit 55 ΔSOC1(+) is calculated based on the value K(n-1) and the above equation (1). If it is on the discharge side, the current integrated value ΔAh (total) is set as the current integrated value ΔAh (-) at the discharge point, and based on the capacity correction value K (n-1) and the above equation (1'), ΔSOC1 (-) Calculate. Then, it is output to the correction coefficient calculating section 54.

また、充電率SOC(0)が充電率SOC(0)’に対して充電側にあるか放電側にあるかを確認し、充電側にあればΔSOC算出部52が充電率SOC(0)を充電点の充電率SOC(+)とみなして、上記(2)式に基づいてΔSOC2(+)を算出する。また、放電側にあれば充電率SOC(0)を放電点の充電率SOC(-)とみなして上記(2’)式に基づいてΔSOC2(-)を算出する。 Also, it is checked whether the charging rate SOC(0) is on the charging side or the discharging side with respect to the charging rate SOC(0)', and if it is on the charging side, the ΔSOC calculation unit 52 calculates the charging rate SOC(0). The charging rate at the charging point is regarded as SOC(+), and ΔSOC2(+) is calculated based on the above equation (2). Further, if it is on the discharging side, the charging rate SOC(0) is regarded as the charging rate SOC(-) at the discharging point, and ΔSOC2(-) is calculated based on the above equation (2').

次に、補正係数算出部54はΔSOC1(+)、ΔSOC2(+)が取得された場合には、上記(3)式に基づいて充電側補正値K(+)を算出する。また、ΔSOC1(-)、ΔSOC2(-)が取得された場合には、上記(3’)式に基づいて放電側補正値K(-)を算出する。 Next, when ΔSOC1(+) and ΔSOC2(+) are acquired, the correction coefficient calculation unit 54 calculates the charging side correction value K(+) based on the above equation (3). Further, when ΔSOC1(-) and ΔSOC2(-) are obtained, the discharge side correction value K(-) is calculated based on the above equation (3').

そして、一方の充電側補正値K(+)もしくは放電側補正値K(-)が算出された状態で、ステップS200~ステップS240が行われ、もう一方の放電側補正値K(-)もしくは充電側補正値K(+)が取得される。そして、これらの充電側補正値K(+)及び放電側補正値K(-)は初回のみ補正係数設定部57に出力される。補正係数設定部57は入力した充電側補正値K(+)及び放電側補正値K(-)に基づいて、例えば両者の平均値をとるなどして容量補正値K(n)を設定する。そして、容量補正部58はこの容量補正値K(n)を用いた上記(5’)式により、初回の補正後総容量Ah(n)を算出する。そして、推定充電率算出部60はこの補正後総容量Ah(n)を用いて上記(6)式により推定充電率SOC’を算出する。 Then, with one charging side correction value K(+) or discharging side correction value K(-) calculated, steps S200 to S240 are performed, and the other discharging side correction value K(-) or charging side correction value K(-) is calculated. A side correction value K(+) is obtained. These charging side correction value K(+) and discharging side correction value K(-) are output to the correction coefficient setting section 57 only the first time. The correction coefficient setting unit 57 sets a capacity correction value K(n) based on the input charging side correction value K(+) and discharging side correction value K(-), for example, by taking the average value of both. Then, the capacity correction unit 58 calculates the initial corrected total capacity Ah(n) using the above equation (5') using this capacity correction value K(n). Then, the estimated charging rate calculation unit 60 uses this corrected total capacity Ah(n) to calculate the estimated charging rate SOC' according to the above equation (6).

また、初期補正値算出ステップS120は以下のようにしても良い。先ず、ステップS012を行ってシステムオフ時点に適用されていた一つ前の容量補正値K(n-1)と、そのときの基準点の充電率SOC(0)’と、システムオフ時点の電流積算値ΔAh’とを記録部55から読み出す。また、充電率取得部40がステップS102~ステップS116を行って、基準点の充電率SOC(0)と、電流積算値ΔAh(0)とを取得する。 Further, the initial correction value calculation step S120 may be performed as follows. First, step S012 is performed to calculate the previous capacity correction value K(n-1) that was applied at the time the system was turned off, the charging rate SOC(0)' at the reference point at that time, and the current at the time the system was turned off. The integrated value ΔAh' is read out from the recording section 55. Further, the charging rate acquisition unit 40 performs steps S102 to S116 to acquire the charging rate SOC(0) at the reference point and the current integrated value ΔAh(0).

また、補正係数設定部57は、充電率SOC(0)’と充電率SOC(0)との差が十分に大きく、且つ、電流積算値ΔAh’が所定の値よりも大きい場合、下記(7)、(8)式に基づいて、初回のみΔSOC1’、ΔSOC2’を算出する。
ΔSOC1’=ΔAh’/(Ah(0)×K(n-1))・・・(7)
ΔSOC2’=|SOC(0)-SOC(0)’|・・・(8)
そして、下記(9)式に基づいて、容量補正値K(n)を算出する。
K(n)=ΔSOC1’/ΔSOC2’・・・(9)
そして、補正係数設定部57はこの容量補正値K(n)を容量補正部58に出力する。また、容量補正部58はこの容量補正値K(n)に基づいて上記(5’)式により、初回の補正後総容量Ah(n)を算出し、推定充電率算出部60に出力する。そして、推定充電率算出部60はこの補正後総容量Ah(n)を用いて上記(6)式により推定充電率SOC’を算出する。
In addition, when the difference between the charging rate SOC(0)' and the charging rate SOC(0) is sufficiently large and the current integrated value ΔAh' is larger than a predetermined value, the correction coefficient setting unit 57 sets the following (7). ) and (8), ΔSOC1' and ΔSOC2' are calculated only for the first time.
ΔSOC1'=ΔAh'/(Ah(0)×K(n-1))...(7)
ΔSOC2'=|SOC(0)-SOC(0)'|...(8)
Then, the capacitance correction value K(n) is calculated based on the following equation (9).
K(n)=ΔSOC1'/ΔSOC2'...(9)
Then, the correction coefficient setting section 57 outputs this capacitance correction value K(n) to the capacitance correction section 58. Further, the capacity correction section 58 calculates the initial corrected total capacity Ah(n) based on the capacity correction value K(n) using the above equation (5'), and outputs it to the estimated charging rate calculation section 60. Then, the estimated charging rate calculation unit 60 uses this corrected total capacity Ah(n) to calculate the estimated charging rate SOC' according to the above equation (6).

尚、上記の(7)、(8)、(9)式を用いる構成では、充電率SOC(0)’と充電率SOC(0)との差が小さい場合、または電流積算値ΔAh’の値が所定の値より小さい場合に(9)式で算出される容量補正値K(n)が著しく大きな値もしくは小さな値をとる可能性がある。よって、このような場合、補正係数設定部57は上記の(7)(8)(9)式による演算を行わず、記録部55に記録されている容量補正値K(n-1)を容量補正値K(n)として、上記(5’)式により初回の補正後総容量Ah(n)を算出し推定充電率SOC’を取得するようにしても良い。 In addition, in the configuration using the above equations (7), (8), and (9), if the difference between the charging rate SOC(0)' and the charging rate SOC(0) is small, or the value of the current integrated value ΔAh' is smaller than a predetermined value, the capacitance correction value K(n) calculated by equation (9) may take a significantly large or small value. Therefore, in such a case, the correction coefficient setting section 57 does not perform the calculations according to the above equations (7), (8), and (9), but uses the capacity correction value K(n-1) recorded in the recording section 55 as the capacity. As the correction value K(n), the estimated charging rate SOC' may be obtained by calculating the initial corrected total capacity Ah(n) using the above equation (5').

これらの初期補正値算出ステップS120を備えた構成では、前回のシステムオフ時点の補正後総容量Ah(n-1)の値を引き継いで、二次電池10の総容量(基準総容量Ah(0))を補正するため、起動時から適切な推定充電率SOC’を算出することができる。 In the configuration including these initial correction value calculation steps S120, the value of the corrected total capacity Ah (n-1) at the time of the previous system off is inherited, and the total capacity of the secondary battery 10 (reference total capacity Ah (0 )), it is possible to calculate an appropriate estimated charging rate SOC' from the time of startup.

さらに、本発明に係る電池状態推定装置80及び電池状態推定方法では、以下に示す推定内部抵抗値による電池容量の低下の検出手法を併用しても良い。先ず、この構成の電池状態推定装置80では、二次電池10の劣化による内部抵抗の増加量と電池容量の低下量との関係を予め測定等で取得してデータマッピングして記録しておく。そして、前述の補正値設定部50の動作において、補正係数算出部54の算出した充電側補正値K(+)及び放電側補正値K(-)の双方がともに1未満の場合、判定部56はこの判定結果の出力を一旦保留する。 Furthermore, in the battery state estimating device 80 and the battery state estimating method according to the present invention, a method for detecting a decrease in battery capacity using an estimated internal resistance value described below may be used in combination. First, in the battery state estimating device 80 having this configuration, the relationship between the amount of increase in internal resistance due to deterioration of the secondary battery 10 and the amount of decrease in battery capacity is obtained in advance by measurement, etc., and data is mapped and recorded. In the operation of the correction value setting section 50 described above, if both the charging side correction value K(+) and the discharging side correction value K(-) calculated by the correction coefficient calculation section 54 are less than 1, the determination section 56 temporarily suspends the output of this determination result.

そして、図示しない内部抵抗取得部が電圧取得部34の取得した電池電圧Vと電流取得部30が取得した電流値Iとの変化の比率から二次電池10の推定内部抵抗値Rを算出する(内部抵抗算出ステップ)。次に、算出された推定内部抵抗値Rから上記のデータマップを参照し、算出された推定内部抵抗値Rと対応した電池容量を取得する(電池容量取得ステップ)。次に、この電池容量が二次電池10の容量低下を示すか否かを判定する(容量低下判定ステップ)。そして、この内部抵抗値に基づく判定結果が二次電池10の容量低下を示した場合、判定部56は保留していた「充電側補正値K(+)及び放電側補正値K(-)の双方がともに1未満」という判定結果を補正係数設定部57に出力し前述のステップに則って容量補正値K(n)と推定充電率SOC’との算出を行う。また、推定内部抵抗値Rに基づく判定結果では二次電池10の容量低下が認められない場合、判定部56は保留していた判定結果をクリアし電流取得ステップS200に帰還する。この構成では二次電池10の容量低下の判定に、推定内部抵抗値Rに基づく判定を加えた二段で行う。このため、測定誤差による誤った補正の発生をより一層防止することができる。 Then, an internal resistance acquisition unit (not shown) calculates an estimated internal resistance value R of the secondary battery 10 from the ratio of change between the battery voltage V acquired by the voltage acquisition unit 34 and the current value I acquired by the current acquisition unit 30 ( internal resistance calculation step). Next, the battery capacity corresponding to the calculated estimated internal resistance value R is obtained by referring to the data map from the calculated estimated internal resistance value R (battery capacity obtaining step). Next, it is determined whether this battery capacity indicates a decrease in the capacity of the secondary battery 10 (capacity decrease determination step). Then, when the determination result based on this internal resistance value indicates a decrease in the capacity of the secondary battery 10, the determination unit 56 determines that the charging side correction value K(+) and discharging side correction value K(-) The determination result that "both are less than 1" is output to the correction coefficient setting section 57, and the capacity correction value K(n) and estimated charging rate SOC' are calculated according to the steps described above. Further, if a decrease in the capacity of the secondary battery 10 is not recognized in the determination result based on the estimated internal resistance value R, the determination unit 56 clears the pending determination result and returns to the current acquisition step S200. In this configuration, determination of capacity reduction of the secondary battery 10 is performed in two stages, including determination based on the estimated internal resistance value R. Therefore, the occurrence of erroneous correction due to measurement errors can be further prevented.

以上のように、本発明に係る電池状態推定装置80及び電池状態推定方法は、基準点、充電点、放電点の少なくとも3点以上の充電率SOC(0)、SOC(+)、SOC(-)と、これらに対応した少なくとも2区間以上の電流積算値ΔAh(+)、ΔAh(-)とから充電側補正値K(+)、放電側補正値K(-)を算出する。そして、充電側補正値K(+)、放電側補正値K(-)の双方がともに1未満の場合、ともに1よりも大きい場合、一方のみが1未満の場合、のそれぞれに対応した方法で補正を行う。これにより、電流取得手段30aのオフセット誤差に対する補正と、二次電池10の電池容量の低下、電流取得手段30aのゲイン誤差、及び両者が混在する状態に対する補正とを区別して行うことができる。これにより、これら双方の要因に対応した補正を適切に行うことが可能となり、より正確な推定充電率SOC’を算出することができる。 As described above, the battery state estimating device 80 and the battery state estimating method according to the present invention have the charging rates SOC(0), SOC(+), and SOC(-) at at least three points: the reference point, the charging point, and the discharging point. ) and the corresponding current integrated values ΔAh(+) and ΔAh(-) for at least two sections, the charging side correction value K(+) and the discharging side correction value K(-) are calculated. Then, in the case where both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, when both are greater than 1, and when only one is less than 1, Make corrections. Thereby, it is possible to distinguish between correction for the offset error of the current acquisition means 30a, correction for a decrease in the battery capacity of the secondary battery 10, a gain error of the current acquisition means 30a, and a state where both are mixed. Thereby, it becomes possible to appropriately perform correction corresponding to both of these factors, and it is possible to calculate a more accurate estimated charging rate SOC'.

尚、本例で示した電池状態推定装置80及び電池状態推定方法の各部の構成、動作、機構、計算式等は一例であるから、特に本例に限定される訳ではなく、例えば、電池状態推定装置80を適用するシステム側、即ち、負荷1、電力変換器3、システム制御部5、外部電力源7側の構成はこれに限定しない。また、外部電力源7は、太陽光パネルの他、商用電源等が挙げられる。さらに、負荷1がモータの場合、減速時に発電される電力は、商用電源に戻す、もしくは、二次電池10に充電する、もしくは図示しない負荷抵抗にて熱として散逸されることで消費される。さらに、本発明は本発明の要旨を逸脱しない範囲で変更して実施することが可能である。 Note that the configuration, operation, mechanism, calculation formula, etc. of each part of the battery state estimation device 80 and the battery state estimation method shown in this example are merely examples, and are not particularly limited to this example. The configuration of the system to which the estimation device 80 is applied, that is, the load 1, power converter 3, system control unit 5, and external power source 7 is not limited to this. Further, the external power source 7 includes a solar panel, a commercial power source, and the like. Further, when the load 1 is a motor, the electric power generated during deceleration is consumed by being returned to the commercial power source, charging the secondary battery 10, or being dissipated as heat by a load resistor (not shown). Furthermore, the present invention can be modified and implemented without departing from the gist of the present invention.

10 二次電池
30 電流取得部
32 電流積算値算出部
34 電圧取得部
42 OCV-SOC取得部
46 緩和状態判定部
52 ΔSOC算出部
54 補正係数算出部
55 記録部
56 判定部
57 補正係数設定部
58 容量補正部
59 SOC補正部
60 推定充電率算出部
80 電池状態推定装置
10 Secondary battery
30 Current acquisition section
32 Current integrated value calculation unit
34 Voltage acquisition section
42 OCV-SOC acquisition part
46 Relaxation state determination unit
52 ΔSOC calculation unit
54 Correction coefficient calculation unit
55 Recording Department
56 Judgment section
57 Correction coefficient setting section
58 Capacity correction section
59 SOC correction section
60 Estimated charging rate calculation unit
80 Battery condition estimation device

Claims (38)

システムに電力供給を行う充電可能な二次電池の推定充電率SOC’を算出する電池状態推定装置であって、
前記二次電池の電流値を取得する電流取得部と、
前記電流取得部が取得した電流値に基づいて前記二次電池の電流積算値ΔAhを算出する電流積算値算出部と、
前記二次電池の電圧値を取得する電圧取得部と、
前記電圧取得部が取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得し、さらに少なくとも1つの前記基準点の開回路電圧、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)と対応した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得するOCV-SOC取得部と、
前記電流積算値算出部から入力した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得するとともに、取得した充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、取得した放電点の電流積算値ΔAh(-)に基づいて第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、また、前記OCV-SOC取得部から取得した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)に基づいて、第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、第2の放電側の充電率の変化量としてのΔSOC2(-)を算出するΔSOC算出部と、
前記ΔSOC算出部が算出した前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出部と、
前記補正係数算出部が算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定部と、
前記判定部で、充電側補正値K(+)と放電側補正値K(-)の双方が1未満もしくは、充電側補正値K(+)と放電側補正値K(-)の双方が1より大きいと判定された場合、前記充電側補正値K(+)と前記放電側補正値K(-)とに基いて補正値K’(n)を算出するとともに、前記補正値K’(n)に基づいて容量補正値K(n)を設定する補正係数設定部と、
前記補正係数設定部が設定した容量補正値K(n)に基づいて二次電池の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量補正部と、
前記容量補正部が算出した総容量Ah(n)に基づいて前記推定充電率SOC’を算出する推定充電率算出部と、を有することを特徴とする電池状態推定装置。
A battery state estimation device that calculates an estimated charging rate SOC' of a rechargeable secondary battery that supplies power to a system,
a current acquisition unit that acquires a current value of the secondary battery;
a current integrated value calculation unit that calculates a current integrated value ΔAh of the secondary battery based on the current value acquired by the current acquisition unit;
a voltage acquisition unit that acquires a voltage value of the secondary battery;
an open circuit voltage of at least one or more reference points based on the voltage value acquired by the voltage acquisition unit; and an open circuit voltage OCV (+) of a charging point located in the charging direction from at least one of the reference points; Obtain the open circuit voltage OCV (-) of a discharge point located in the discharge direction from at least one reference point, and further obtain the open circuit voltage OCV (+) of at least one reference point and the open circuit voltage OCV (+) of a charging point. , an OCV-SOC acquisition unit that acquires the charging rate of at least one reference point corresponding to the open circuit voltage OCV (-) of the discharge point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharge point. and,
Based on the current integrated value ΔAh inputted from the current integrated value calculation unit, calculate the current integrated value ΔAh(+) of the charging point based on the current integrated value of at least one of the reference points, and the current integrated value ΔAh(+) of the at least one of the reference points. Obtain the integrated current value ΔAh(-) at the discharge point based on the integrated current value, and calculate the amount of change in the charging rate on the first charging side based on the integrated current value ΔAh(+) at the charging point. ΔSOC1(+) is calculated as the OCV. - The amount of change in the charging rate on the second charging side based on the charging rate of at least one reference point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharging point acquired from the SOC acquisition unit. a ΔSOC calculation unit that calculates ΔSOC2(+) as the amount of change in the charging rate on the second discharging side;
A charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) calculated by the ΔSOC calculation unit, and based on the ratio of the ΔSOC1(-) and ΔSOC2(-). a correction coefficient calculation unit that calculates a discharge side correction value K(-);
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated by the correction coefficient calculating section are each larger or smaller than 1, and the estimated charging rate SOC' is calculated according to the judgment result. a determination unit that selects a calculation method;
In the determination section, both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, or both the charging side correction value K(+) and the discharging side correction value K(-) are 1. If it is determined that the correction value K'(n) is larger than the charging side correction value K(+) and the discharging side correction value K(-), the correction value K'(n) is ); a correction coefficient setting unit that sets a capacitance correction value K(n) based on
a capacity correction unit that calculates the total capacity Ah (n) by correcting the total capacity Ah (n-1) of the secondary battery based on the capacity correction value K (n) set by the correction coefficient setting unit;
A battery state estimating device comprising: an estimated charging rate calculation unit that calculates the estimated charging rate SOC′ based on the total capacity Ah(n) calculated by the capacity correction unit.
ΔSOC算出部が、二次電池の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
また、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出部が、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする請求項1記載の電池状態推定装置。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
The ΔSOC calculation unit calculates the amount of change in the charging rate on the first charging side using the following formula (1) based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (+) at the charging point. ΔSOC1 (+) of the secondary battery is calculated, and the first discharge side is calculated using the following formula (1') based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (-) at the discharge point. Calculate ΔSOC1 (-) as the amount of change in charging rate,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
In addition, based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point, ΔSOC2(+ ), or calculate the following formula (2'') based on the charging rate SOC (0') of another reference point different from the charging rate SOC (0) and the charging rate SOC (+) of the charging point. Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
A correction coefficient calculating section calculates a charging side correction value K (+) based on the above-mentioned ΔSOC1 (+) and ΔSOC2 (+) using the following formula (3), and calculates a charging side correction value K (+) based on the above-mentioned ΔSOC1 (-) and ΔSOC2 (-) 2. The battery state estimating device according to claim 1, wherein the discharge side correction value K(-) is calculated based on the following equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
システムに電力供給を行う充電可能な二次電池の推定充電率SOC’を算出する電池状態推定装置であって、
前記二次電池の電流値を取得する電流取得部と、
前記電流取得部が取得した電流値に基づいて前記二次電池の電流積算値ΔAhを算出する電流積算値算出部と、
前記二次電池の電圧値を取得する電圧取得部と、
前記電圧取得部が取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得し、さらに少なくとも1つの前記基準点の開回路電圧、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)と対応した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得するOCV-SOC取得部と、
前記電流積算値算出部から入力した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得するとともに、取得した充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、取得した放電点の電流積算値ΔAh(-)に基づいて第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、また、前記OCV-SOC取得部から取得した少なくとも1つの基準点の充電率、充電点の充電率SOC(+)、放電点の充電率SOC(-)に基づいて、第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、第2の放電側の充電率の変化量としてのΔSOC2(-)を算出するΔSOC算出部と、
前記ΔSOC算出部が算出した前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出部と、
前記補正係数算出部が算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定部と、
前記判定部で、充電側補正値K(+)と放電側補正値K(-)の一方が1より小さく、他方が1より大きいと判定された場合、過去の容量補正値K(n-1)を容量補正値K(n)に設定する補正係数設定部と、
前記補正係数設定部が設定した容量補正値K(n)に基づいて二次電池の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量補正部と、
前記ΔSOC1(+)、SOC1(-)、ΔSOC2(+)、ΔSOC2(-)の値に基づいてSOC補正値K(soc)を設定するSOC補正部と、
前記総容量Ah(n)と前記SOC補正値K(soc)に基づいて前記推定充電率SOC’を算出する推定充電率算出部と、を有することを特徴とする電池状態推定装置。
A battery state estimation device that calculates an estimated charging rate SOC' of a rechargeable secondary battery that supplies power to a system,
a current acquisition unit that acquires a current value of the secondary battery;
a current integrated value calculation unit that calculates a current integrated value ΔAh of the secondary battery based on the current value acquired by the current acquisition unit;
a voltage acquisition unit that acquires a voltage value of the secondary battery;
an open circuit voltage of at least one or more reference points based on the voltage value acquired by the voltage acquisition unit; and an open circuit voltage OCV (+) of a charging point located in the charging direction from at least one of the reference points; Obtain the open circuit voltage OCV (-) of a discharge point located in the discharge direction from at least one reference point, and further obtain the open circuit voltage OCV (+) of at least one reference point and the open circuit voltage OCV (+) of a charging point. , an OCV-SOC acquisition unit that acquires the charging rate of at least one reference point corresponding to the open circuit voltage OCV (-) of the discharge point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharge point. and,
Based on the current integrated value ΔAh inputted from the current integrated value calculation unit, calculate the current integrated value ΔAh(+) of the charging point based on the current integrated value of at least one of the reference points, and the current integrated value ΔAh(+) of the at least one of the reference points. Obtain the integrated current value ΔAh(-) at the discharge point based on the integrated current value, and calculate the amount of change in the charging rate on the first charging side based on the integrated current value ΔAh(+) at the charging point. ΔSOC1(+) is calculated as the OCV. - The amount of change in the charging rate on the second charging side based on the charging rate of at least one reference point, the charging rate SOC (+) of the charging point, and the charging rate SOC (-) of the discharging point acquired from the SOC acquisition unit. a ΔSOC calculation unit that calculates ΔSOC2(+) as the amount of change in the charging rate on the second discharging side;
A charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) calculated by the ΔSOC calculation unit, and based on the ratio of the ΔSOC1(-) and ΔSOC2(-). a correction coefficient calculation unit that calculates a discharge side correction value K(-);
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated by the correction coefficient calculating section are each larger or smaller than 1, and the estimated charging rate SOC' is calculated according to the judgment result. a determination unit that selects a calculation method;
If the determination unit determines that one of the charging side correction value K(+) and the discharging side correction value K(-) is smaller than 1 and the other is larger than 1, the past capacity correction value K(n-1 ) as a capacity correction value K(n);
a capacity correction section that calculates the total capacity Ah (n) by correcting the total capacity Ah (n-1) of the secondary battery based on the capacity correction value K (n) set by the correction coefficient setting section;
an SOC correction unit that sets an SOC correction value K (soc) based on the values of ΔSOC1 (+), SOC1 (-), ΔSOC2 (+), and ΔSOC2 (-);
A battery state estimating device comprising: an estimated charging rate calculating section that calculates the estimated charging rate SOC' based on the total capacity Ah(n) and the SOC correction value K(soc).
ΔSOC算出部が、二次電池の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
また、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出部が、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする請求項3記載の電池状態推定装置。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
The ΔSOC calculation unit calculates the amount of change in the charging rate on the first charging side using the following formula (1) based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (+) at the charging point. ΔSOC1 (+) of the secondary battery is calculated, and the first discharge side is calculated using the following formula (1') based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (-) at the discharge point. Calculate ΔSOC1 (-) as the amount of change in charging rate,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
In addition, based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point, ΔSOC2(+ ), or calculate the following formula (2'') based on the charging rate SOC (0') of another reference point different from the charging rate SOC (0) and the charging rate SOC (+) of the charging point. Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
A correction coefficient calculating section calculates a charging side correction value K (+) based on the above-mentioned ΔSOC1 (+) and ΔSOC2 (+) using the following formula (3), and calculates a charging side correction value K (+) based on the above-mentioned ΔSOC1 (-) and ΔSOC2 (-) 4. The battery state estimating device according to claim 3, wherein the discharge side correction value K(-) is calculated based on the following equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
補正係数設定部が、1よりも小さい補正下限値K(min)を有し、補正値K’(n)が補正下限値K(min)よりも小さい場合には、補正下限値K(min)を容量補正値K(n)として設定することを特徴とする請求項1または請求項2に記載の電池状態推定装置。 When the correction coefficient setting section has a correction lower limit value K (min) smaller than 1 and the correction value K' (n) is smaller than the correction lower limit value K (min), the correction lower limit value K (min) 3. The battery state estimating device according to claim 1, wherein K(n) is set as the capacity correction value K(n). 補正係数設定部が軽減係数Aを有し、前記軽減係数Aと1つ前の容量補正値K(n-1)とから下記(4’)式に基づいて容量補正値K(n)を算出することを特徴とする請求項1または請求項2に記載の電池状態推定装置。
K(n)=(1-A×(1-K’(n)))×K(n-1)・・・(4’)
The correction coefficient setting section has a reduction coefficient A, and calculates a capacity correction value K(n) from the reduction coefficient A and the previous capacity correction value K(n-1) based on the following formula (4'). The battery state estimating device according to claim 1 or 2, characterized in that:
K(n)=(1-A×(1-K'(n)))×K(n-1)...(4')
SOC補正部が、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値に基づいてSOC補正値K(soc)を設定することを特徴とする請求項3または請求項4記載の電池状態推定装置。 The SOC correction unit is characterized in that the SOC correction value K (soc) is set based on the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| The battery state estimation device according to claim 3 or 4. SOC補正部が、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値の平均値をSOC補正値K(soc)とすることを特徴とする請求項7記載の電池状態推定装置。 The SOC correction unit is characterized in that the average value of the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| is set as the SOC correction value K(soc). The battery state estimation device according to claim 7. 基準点の開回路電圧OCV(0)、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)のうち少なくとも1つに、システム起動時の二次電池の開回路電圧を用いることを特徴とする請求項1乃至請求項8のいずれかに記載の電池状態推定装置。 The open circuit voltage of the secondary battery at the time of system startup is set to at least one of the open circuit voltage OCV (0) at the reference point, the open circuit voltage OCV (+) at the charging point, and the open circuit voltage OCV (-) at the discharge point. The battery state estimating device according to any one of claims 1 to 8, characterized in that the device uses: 判定部が充電側補正値K(+)と放電側補正値K(-)の双方が1よりも大きいと判定した場合、補正係数設定部が下記(4’’)式に基づいて、前記充電側補正値K(+)と前記放電側補正値K(-)との平均値に1つ前の容量補正値K(n-1)を乗じた値を容量補正値K(n)として設定することを特徴とする請求項1乃至請求項9のいずれかに記載の電池状態推定装置。
K(n)=((K(+)+K(-))/2)×K(n-1)・・・(4’’)
When the determination unit determines that both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1, the correction coefficient setting unit determines the charging side correction value K(-) based on the following equation (4''). A value obtained by multiplying the average value of the side correction value K(+) and the discharge side correction value K(-) by the previous capacity correction value K(n-1) is set as the capacity correction value K(n). The battery state estimating device according to any one of claims 1 to 9.
K(n)=((K(+)+K(-))/2)×K(n-1)...(4'')
容量補正部が、下記(5)式に基づいて総容量Ah(n-1)を補正し総容量Ah(n)を算出することを特徴とする請求項1乃至請求項10のいずれかに記載の電池状態推定装置。
Ah(n)=Ah(n-1)×K(n)・・・(5)
According to any one of claims 1 to 10, wherein the capacity correction section corrects the total capacity Ah (n-1) based on the following equation (5) to calculate the total capacity Ah (n). battery condition estimation device.
Ah(n)=Ah(n-1)×K(n)...(5)
複数の充電点もしくは複数の放電点を取得した場合に、
OCV-SOC取得部はそれぞれの充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得するとともに、
ΔSOC算出部は、それぞれの充電点もしくは放電点に対して個別にΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)を算出し、
補正係数算出部は、前記(3)式、(3’)式に基づいて、それぞれの充電点もしくは放電点の暫定充電側補正値、暫定放電側補正値を個別に算出した上で、これら暫定充電側補正値、暫定放電側補正値の充電点もしくは放電点ごとの平均値を充電側補正値K(+)、放電側補正値K(-)とすることを特徴とする請求項1乃至請求項11のいずれかに記載の電池状態推定装置。
When multiple charging points or multiple discharging points are acquired,
The OCV-SOC acquisition unit acquires the charging rate SOC (+) of each charging point and the charging rate SOC (-) of the discharging point,
The ΔSOC calculation unit calculates ΔSOC1(+), ΔSOC1(-), ΔSOC2(+), ΔSOC2(-) individually for each charging point or discharging point,
The correction coefficient calculation unit individually calculates a provisional charging side correction value and a provisional discharge side correction value for each charging point or discharge point based on equations (3) and (3'), and then calculates these provisional correction values. Claims 1 to 3, characterized in that the average value of the charging side correction value and the temporary discharging side correction value for each charging point or discharging point is used as the charging side correction value K(+) and the discharging side correction value K(-). The battery state estimation device according to any one of Item 11.
OCV-SOC取得部が取得した充電点もしくは放電点が、基準点の上下に設定された所定の閾値の範囲を超えた場合に、この点を充電点もしくは放電点として設定することを特徴とする請求項1乃至請求項12のいずれかに記載の電池状態推定装置。 If the charging point or discharging point acquired by the OCV-SOC acquisition unit exceeds a range of predetermined threshold values set above and below the reference point, this point is set as the charging point or discharging point. The battery state estimation device according to any one of claims 1 to 12. 電流取得部からの電流値が予め設定された所定の時間、ゼロ近傍の予め設定された所定の電流ゼロ状態を継続した場合に、OCV-SOC取得部に対し開回路電圧の取得を許可する緩和状態判定部をさらに有することを特徴とする請求項1乃至請求項13のいずれかに記載の電池状態推定装置。 Relaxation that allows the OCV-SOC acquisition unit to acquire open circuit voltage when the current value from the current acquisition unit continues in a preset zero current state near zero for a preset time. The battery state estimating device according to any one of claims 1 to 13, further comprising a state determining section. 補正後の総容量Ah(n)を適用した後、再度、容量補正値K(n+1)を算出することを特徴とする請求項1乃至請求項14のいずれかに記載の電池状態推定装置。 15. The battery state estimating device according to claim 1, wherein the capacity correction value K(n+1) is calculated again after applying the corrected total capacity Ah(n). 1回のシステムの稼働期間における容量補正値K(n)の算出動作の回数に上限を設けることを特徴とする請求項15記載の電池状態推定装置。 16. The battery state estimating device according to claim 15, wherein an upper limit is set on the number of times the capacity correction value K(n) is calculated during one system operation period. システムオフ時点に適用されていた容量補正値K(n-1)を少なくとも記録する記録部をさらに有し、
システムの起動時には、前記記録部に記録されている前記容量補正値K(n-1)を読み出して、前記容量補正値K(n-1)を容量補正値K(n)とし、下記(5’)式に基づいて初回の総容量Ah(n)を算出することを特徴とする請求項1乃至請求項16のいずれかに記載の電池状態推定装置。
Ah(n)=Ah(0)×K(n)・・・(5’)
further comprising a recording unit that records at least the capacitance correction value K(n-1) applied at the time the system was turned off;
When the system is started, the capacitance correction value K(n-1) recorded in the recording section is read out, the capacitance correction value K(n-1) is set as the capacitance correction value K(n), and the following (5) 17. The battery state estimating device according to claim 1, wherein the initial total capacity Ah(n) is calculated based on the equation ').
Ah(n)=Ah(0)×K(n)...(5')
システムオフ時点に適用されていた容量補正値K(n-1)とそのときの基準点の充電率SOC(0)’と前回のシステム起動からシステムオフ時点までの全ての期間の電流積算値ΔAh(total)とを少なくとも記録する記録部をさらに有し、
システムの起動時には、起動時の開回路電圧OCV(0)から充電率SOC(0)を取得するとともに、前記記録部に記録されている基準点の充電率SOC(0)’と前記電流積算値ΔAh(total)とを読み出して、
前記電流積算値ΔAh(total)がシステムオフ時点の基準点に対して充電側に位置するか放電側に位置するかを判別した上で前記ΔAh(total)に基づいてΔSOC1(+)もしくはΔSOC1(-)を算出し、
前記充電率SOC(0)’と充電率SOC(0)とに基づいてΔSOC2(+)もしくはΔSOC2(-)を算出し、充電側補正値K(+)もしくは放電側補正値K(-)のいずれか一方を算出することを特徴とする請求項1乃至請求項16のいずれかに記載の電池状態推定装置。
Capacity correction value K(n-1) applied at the time the system was turned off, charging rate SOC(0)' at the reference point at that time, and integrated current value ΔAh for all periods from the previous system startup to the time the system was turned off. (total);
At the time of system startup, the charging rate SOC(0) is obtained from the open circuit voltage OCV(0) at startup, and the charging rate SOC(0)' at the reference point recorded in the recording unit and the current integrated value are obtained. Read out ΔAh (total),
After determining whether the current integrated value ΔAh (total) is located on the charging side or discharging side with respect to the reference point at the time of system off, ΔSOC1 (+) or ΔSOC1 ( -) is calculated,
ΔSOC2(+) or ΔSOC2(-) is calculated based on the charging rate SOC(0)' and the charging rate SOC(0), and the charging side correction value K(+) or the discharging side correction value K(-) is calculated. The battery state estimating device according to any one of claims 1 to 16, characterized in that one of the two is calculated.
二次電池の内部抵抗と電池容量の関係を記録したデータマッピングをさらに有し、
電圧取得部の取得した電圧値と電流取得部が取得した電流値とから二次電池の推定内部抵抗値を算出し、前記推定内部抵抗値と対応する電池容量を前記データマッピングから取得して、前記電池容量が容量低下を示し且つ、判定部が充電側補正値K(+)と放電側補正値K(-)の双方が1未満と判定した場合に総容量Ah(n)を算出することを特徴とする請求項1乃至請求項18のいずれかに記載の電池状態推定装置。
It also has data mapping that records the relationship between the internal resistance of the secondary battery and the battery capacity.
Calculating an estimated internal resistance value of the secondary battery from the voltage value acquired by the voltage acquisition unit and the current value acquired by the current acquisition unit, and acquiring the battery capacity corresponding to the estimated internal resistance value from the data mapping, Calculating the total capacity Ah(n) when the battery capacity shows a capacity decrease and the determination unit determines that both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1. The battery state estimating device according to any one of claims 1 to 18, characterized by:
システムに電力供給を行う充電可能な二次電池の推定充電率SOC’を算出する電池状態推定方法であって、
前記二次電池の電流値を取得する電流取得ステップと、
前記電流取得ステップで取得した電流値に基づいて前記二次電池の電流積算値ΔAhを算出する電流積算値算出ステップと、
前記二次電池の電圧値を取得する電圧取得ステップと、
前記電圧取得ステップで取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得する開回路電圧取得ステップと、
前記開回路電圧取得ステップで取得した少なくとも1つの基準点の開回路電圧と、充電点の開回路電圧OCV(+)と、放電点の開回路電圧OCV(-)とにそれぞれ対応した少なくとも1つの基準点の充電率と、充電点の充電率SOC(+)と、放電点の充電率SOC(-)とを取得する充電率取得ステップと、
前記電流積算値算出ステップで取得した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得する充放電電流積算値取得ステップと、
前記充放電電流積算値取得ステップで得られた充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、放電点の電流積算値ΔAh(-)に基づいて、第1の放電側の充電率の変化量としてのΔSOC1(-)を算出する第1の充電率変化量算出ステップと、
前記充電率取得ステップで得られた少なくとも1つの基準点の充電率と充電点の充電率SOC(+)とに基づいて第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて第2の放電側の充電率の変化量としてのΔSOC2(-)を算出する第2の充電率変化量算出ステップと、
前記第1の充電率変化量算出ステップと前記第2の充電率変化量算出ステップにより得られた前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出ステップと、
前記補正係数算出ステップで算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定ステップと、
前記判定ステップで充電側補正値K(+)と放電側補正値K(-)の双方が1未満もしくは、充電側補正値K(+)と放電側補正値K(-)の双方が1より大きいと判定された場合、前記充電側補正値K(+)と前記放電側補正値K(-)とに基いて補正値K’(n)を算出するとともに、前記補正値K’(n)に基づいて容量補正値K(n)を設定する補正係数設定ステップと、
前記補正係数設定ステップで設定された容量補正値K(n)に基づいて二次電池の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量値補正ステップと、
前記容量値補正ステップで算出された総容量Ah(n)に基づいて前記推定充電率SOC’を算出する推定充電率算出ステップと、を有することを特徴とする電池状態推定方法。
A battery state estimation method for calculating an estimated charging rate SOC' of a rechargeable secondary battery that supplies power to a system, the method comprising:
a current acquisition step of acquiring a current value of the secondary battery;
a current integrated value calculation step of calculating a current integrated value ΔAh of the secondary battery based on the current value obtained in the current obtaining step;
a voltage acquisition step of acquiring a voltage value of the secondary battery;
an open circuit voltage of at least one or more reference points based on the voltage value acquired in the voltage acquisition step; and an open circuit voltage OCV (+) of a charging point located in the charging direction than the at least one reference point; an open circuit voltage obtaining step of obtaining an open circuit voltage OCV(-) of a discharge point located in the discharge direction with respect to at least one reference point;
At least one open circuit voltage corresponding to the at least one reference point open circuit voltage obtained in the open circuit voltage obtaining step, the charging point open circuit voltage OCV (+), and the discharging point open circuit voltage OCV (−), respectively. a charging rate acquisition step of acquiring a charging rate at a reference point, a charging rate SOC (+) at a charging point, and a charging rate SOC (-) at a discharging point;
Based on the current integrated value ΔAh obtained in the current integrated value calculation step, calculate the current integrated value ΔAh (+) of the charging point based on the current integrated value of at least one of the reference points, and the current integrated value ΔAh (+) of the at least one of the reference points. a charging/discharging current integrated value acquisition step of respectively obtaining a current integrated value ΔAh(-) at a discharge point based on the current integrated value;
Based on the integrated current value ΔAh(+) at the charging point obtained in the charging/discharging current integrated value acquisition step, ΔSOC1(+) as the amount of change in the charging rate on the first charging side is calculated, and the current at the discharging point is calculated. a first charge rate change amount calculation step of calculating ΔSOC1(-) as a change amount in the charge rate on the first discharging side based on the integrated value ΔAh(-);
Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side based on the charging rate of at least one reference point obtained in the charging rate acquisition step and the charging rate SOC(+) of the charging point. and a second charging rate that calculates ΔSOC2(-) as the amount of change in the charging rate on the second discharge side based on the charging rate SOC(0) at the reference point and the charging rate SOC(-) at the discharge point. a step of calculating the amount of change;
A charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) obtained by the first charging rate change amount calculating step and the second charging rate change amount calculating step. a correction coefficient calculation step of calculating a discharge side correction value K(-) based on the ratio of the ΔSOC1(-) and ΔSOC2(-);
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated in the correction coefficient calculation step are each larger or smaller than 1, and the estimated charging rate SOC' is calculated according to the judgment result. a determination step of selecting a calculation method;
In the determination step, both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1, or both the charging side correction value K(+) and the discharging side correction value K(-) are greater than 1. If it is determined that the correction value K'(n) is large, a correction value K'(n) is calculated based on the charging side correction value K(+) and the discharging side correction value K(-), and the correction value K'(n) a correction coefficient setting step of setting a capacity correction value K(n) based on;
a capacity value correction step of calculating the total capacity Ah(n) by correcting the total capacity Ah(n-1) of the secondary battery based on the capacity correction value K(n) set in the correction coefficient setting step;
A battery state estimation method comprising: an estimated charging rate calculation step of calculating the estimated charging rate SOC' based on the total capacity Ah(n) calculated in the capacity value correction step.
第1の充電率変化量算出ステップが、二次電池の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
第2の充電率変化量算出ステップが、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出ステップが、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする請求項20記載の電池状態推定方法。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
The first charging rate change calculation step calculates the amount of change on the first charging side using the following formula (1) based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (+) at the charging point. Calculate ΔSOC1 (+) as the amount of change in the charging rate, and use the following formula (1') based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (-) at the discharge point. Calculate ΔSOC1 (-) as the amount of change in the charging rate on the first discharge side,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
The second charging rate change calculation step calculates the charging rate on the second charging side using the following formula (2) based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point. Calculate ΔSOC2 (+) as the amount of change in the charging rate, or calculate the charging rate SOC (0') at another reference point different from the charging rate SOC (0) and the charging rate SOC (+) at the charging point. Based on the following formula (2''), calculate ΔSOC2 (+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
The correction coefficient calculating step calculates a charging side correction value K(+) based on the above-mentioned ΔSOC1(+) and ΔSOC2(+) using the following equation (3), and calculates the charging-side correction value K(+) based on the above-mentioned ΔSOC1(-) and ΔSOC2(-). 21. The battery state estimation method according to claim 20, wherein the discharge side correction value K(-) is calculated based on the following equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
システムに電力供給を行う充電可能な二次電池の推定充電率SOC’を算出する電池状態推定方法であって、
前記二次電池の電流値を取得する電流取得ステップと、
前記電流取得ステップで取得した電流値に基づいて前記二次電池の電流積算値ΔAhを算出する電流積算値算出ステップと、
前記二次電池の電圧値を取得する電圧取得ステップと、
前記電圧取得ステップで取得した電圧値に基づいて少なくとも1つ以上の基準点の開回路電圧と、少なくとも1つの前記基準点よりも充電方向に位置する充電点の開回路電圧OCV(+)と、少なくとも1つの前記基準点よりも放電方向に位置する放電点の開回路電圧OCV(-)とを取得する開回路電圧取得ステップと、
前記開回路電圧取得ステップで取得した少なくとも1つの基準点の開回路電圧と、充電点の開回路電圧OCV(+)と、放電点の開回路電圧OCV(-)とにそれぞれ対応した少なくとも1つの基準点の充電率と、充電点の充電率SOC(+)と、放電点の充電率SOC(-)とを取得する充電率取得ステップと、
前記電流積算値算出ステップで取得した電流積算値ΔAhに基づいて、少なくとも1つの前記基準点の電流積算値を基準とした充電点の電流積算値ΔAh(+)と、少なくとも1つの前記基準点の電流積算値を基準とした放電点の電流積算値ΔAh(-)とをそれぞれ取得する充放電電流積算値取得ステップと、
前記充放電電流積算値取得ステップで得られた充電点の電流積算値ΔAh(+)に基づいて第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、放電点の電流積算値ΔAh(-)に基づいて、第1の放電側の充電率の変化量としてのΔSOC1(-)を算出する第1の充電率変化量算出ステップと、
前記充電率取得ステップで得られた少なくとも1つの基準点の充電率と充電点の充電率SOC(+)とに基づいて第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて第2の放電側の充電率の変化量としてのΔSOC2(-)を算出する第2の充電率変化量算出ステップと、
前記第1の充電率変化量算出ステップと前記第2の充電率変化量算出ステップにより得られた前記ΔSOC1(+)とΔSOC2(+)との比率に基づいて充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)との比率に基づいて放電側補正値K(-)を算出する補正係数算出ステップと、
前記補正係数算出ステップで算出した充電側補正値K(+)と放電側補正値K(-)とがそれぞれ1より大きいか小さいかを判定し、その判定結果に応じて推定充電率SOC’の算出方法を選択する判定ステップと、
前記判定ステップで、充電側補正値K(+)と放電側補正値K(-)の一方が1より小さく、他方が1より大きいと判定された場合、
過去の容量補正値K(n-1)に基づいて容量補正値K(n)を設定する補正係数設定ステップと、
前記補正係数設定ステップで設定された容量補正値K(n)に基づいて二次電池の総容量Ah(n-1)を補正して総容量Ah(n)を算出する容量値補正ステップと、
前記ΔSOC1(+)、SOC1(-)、ΔSOC2(+)、ΔSOC2(-)の値に基づいてSOC補正値K(soc)を設定するSOC補正値設定ステップと、
前記容量値補正ステップで算出された総容量Ah(n)と前記SOC補正値設定ステップで設定されたSOC補正値K(soc)に基づいて前記推定充電率SOC’を算出する推定充電率算出ステップと、を有することを特徴とする電池状態推定方法。
A battery state estimation method for calculating an estimated charging rate SOC' of a rechargeable secondary battery that supplies power to a system, the method comprising:
a current acquisition step of acquiring a current value of the secondary battery;
a current integrated value calculation step of calculating a current integrated value ΔAh of the secondary battery based on the current value obtained in the current obtaining step;
a voltage acquisition step of acquiring a voltage value of the secondary battery;
an open circuit voltage of at least one or more reference points based on the voltage value acquired in the voltage acquisition step; and an open circuit voltage OCV (+) of a charging point located in the charging direction than the at least one reference point; an open circuit voltage obtaining step of obtaining an open circuit voltage OCV(-) of a discharge point located in the discharge direction with respect to at least one reference point;
At least one open circuit voltage corresponding to the at least one reference point open circuit voltage obtained in the open circuit voltage obtaining step, the charging point open circuit voltage OCV (+), and the discharging point open circuit voltage OCV (−), respectively. a charging rate acquisition step of acquiring a charging rate at a reference point, a charging rate SOC (+) at a charging point, and a charging rate SOC (-) at a discharging point;
Based on the current integrated value ΔAh obtained in the current integrated value calculation step, calculate the current integrated value ΔAh (+) of the charging point based on the current integrated value of at least one of the reference points, and the current integrated value ΔAh (+) of the at least one of the reference points. a charging/discharging current integrated value acquisition step of respectively obtaining a current integrated value ΔAh(-) at a discharge point based on the current integrated value;
Based on the integrated current value ΔAh(+) at the charging point obtained in the charging/discharging current integrated value acquisition step, ΔSOC1(+) as the amount of change in the charging rate on the first charging side is calculated, and the current at the discharging point is calculated. a first charge rate change amount calculation step of calculating ΔSOC1(-) as a change amount in the charge rate on the first discharging side based on the integrated value ΔAh(-);
Calculate ΔSOC2(+) as the amount of change in the charging rate on the second charging side based on the charging rate of at least one reference point obtained in the charging rate acquisition step and the charging rate SOC(+) of the charging point. and a second charging rate that calculates ΔSOC2(-) as the amount of change in the charging rate on the second discharge side based on the charging rate SOC(0) at the reference point and the charging rate SOC(-) at the discharge point. a step of calculating the amount of change;
A charging side correction value K(+) is calculated based on the ratio of the ΔSOC1(+) and ΔSOC2(+) obtained by the first charging rate change amount calculating step and the second charging rate change amount calculating step. a correction coefficient calculation step of calculating a discharge side correction value K(-) based on the ratio of the ΔSOC1(-) and ΔSOC2(-);
It is determined whether the charging side correction value K(+) and the discharging side correction value K(-) calculated in the correction coefficient calculation step are each larger or smaller than 1, and the estimated charging rate SOC' is calculated according to the judgment result. a determination step of selecting a calculation method;
If it is determined in the determination step that one of the charging side correction value K(+) and the discharging side correction value K(-) is smaller than 1 and the other is larger than 1,
a correction coefficient setting step of setting a capacity correction value K(n) based on a past capacity correction value K(n-1);
a capacity value correction step of calculating the total capacity Ah(n) by correcting the total capacity Ah(n-1) of the secondary battery based on the capacity correction value K(n) set in the correction coefficient setting step;
an SOC correction value setting step of setting an SOC correction value K (soc) based on the values of ΔSOC1(+), SOC1(-), ΔSOC2(+), ΔSOC2(-);
An estimated charging rate calculation step of calculating the estimated charging rate SOC' based on the total capacity Ah (n) calculated in the capacity value correction step and the SOC correction value K (soc) set in the SOC correction value setting step. A battery state estimation method comprising:
第1の充電率変化量算出ステップが、二次電池の総容量Ah(n-1)と充電点の電流積算値ΔAh(+)とに基づいて下記(1)式により第1の充電側の充電率の変化量としてのΔSOC1(+)を算出し、前記二次電池の総容量Ah(n-1)と放電点の電流積算値ΔAh(-)とに基づいて下記(1’)式により第1の放電側の充電率の変化量としてのΔSOC1(-)を算出し、
ΔSOC1(+)=ΔAh(+)/Ah(n-1)・・・(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)・・・(1’)
第2の充電率変化量算出ステップが、少なくとも1つの基準点の充電率SOC(0)と充電点の充電率SOC(+)とに基づいて下記(2)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と充電点の充電率SOC(+)とに基づいて下記(2’’)式により第2の充電側の充電率の変化量としてのΔSOC2(+)を算出し、
少なくとも1つの基準点の充電率SOC(0)と放電点の充電率SOC(-)とに基づいて下記(2’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、もしくは、前記充電率SOC(0)とは異なる別の基準点の充電率SOC(0’)と放電点の充電率SOC(-)とに基づいて下記(2’’’)式により第2の放電側の充電率の変化量としてのΔSOC2(-)を算出し、
ΔSOC2(+)=|SOC(+)-SOC(0)|・・・(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|・・・(2’)
ΔSOC2(+)=|SOC(+)-SOC(0’)|・・・(2’’)
ΔSOC2(-)=|SOC(-)-SOC(0’)|・・・(2’’’)
補正係数算出ステップが、前記ΔSOC1(+)とΔSOC2(+)とに基づいて下記(3)式により充電側補正値K(+)を算出し、前記ΔSOC1(-)とΔSOC2(-)とに基づいて下記(3’)式により放電側補正値K(-)を算出することを特徴とする請求項22記載の電池状態推定方法。
K(+)=ΔSOC1(+)/ΔSOC2(+)・・・(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)・・・(3’)
The first charging rate change calculation step calculates the amount of change on the first charging side using the following formula (1) based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (+) at the charging point. Calculate ΔSOC1 (+) as the amount of change in the charging rate, and use the following formula (1') based on the total capacity Ah (n-1) of the secondary battery and the integrated current value ΔAh (-) at the discharge point. Calculate ΔSOC1 (-) as the amount of change in the charging rate on the first discharge side,
ΔSOC1(+)=ΔAh(+)/Ah(n-1)...(1)
ΔSOC1(-)=ΔAh(-)/Ah(n-1)...(1')
The second charging rate change calculation step calculates the charging rate on the second charging side using the following formula (2) based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(+) of the charging point. Calculate ΔSOC2 (+) as the amount of change in the charging rate, or calculate the charging rate SOC (0') at another reference point different from the charging rate SOC (0) and the charging rate SOC (+) at the charging point. Based on the following formula (2''), calculate ΔSOC2 (+) as the amount of change in the charging rate on the second charging side,
Based on the charging rate SOC(0) of at least one reference point and the charging rate SOC(-) of the discharging point, ΔSOC2(-) is calculated as the amount of change in the charging rate on the second discharging side using equation (2') below. or calculate the following formula (2''') based on the charging rate SOC(0') at another reference point different from the charging rate SOC(0) and the charging rate SOC(-) at the discharge point. Calculate ΔSOC2(-) as the amount of change in the charging rate on the second discharge side,
ΔSOC2(+)=|SOC(+)−SOC(0)|...(2)
ΔSOC2(-)=|SOC(-)-SOC(0)|...(2')
ΔSOC2(+)=|SOC(+)−SOC(0')|...(2'')
ΔSOC2(-)=|SOC(-)-SOC(0')|...(2''')
The correction coefficient calculating step calculates a charging side correction value K(+) based on the above-mentioned ΔSOC1(+) and ΔSOC2(+) using the following equation (3), and calculates the charging-side correction value K(+) based on the above-mentioned ΔSOC1(-) and ΔSOC2(-). 23. The battery state estimation method according to claim 22, wherein the discharge side correction value K(-) is calculated based on the following equation (3').
K(+)=ΔSOC1(+)/ΔSOC2(+)...(3)
K(-)=ΔSOC1(-)/ΔSOC2(-)...(3')
補正係数設定ステップが、1よりも小さい補正下限値K(min)よりも補正値K’(n)が小さい場合には、補正下限値K(min)を容量補正値K(n)として設定することを特徴とする請求項20または請求項21に記載の電池状態推定方法。 In the correction coefficient setting step, if the correction value K'(n) is smaller than the correction lower limit value K(min) which is smaller than 1, the correction lower limit value K(min) is set as the capacity correction value K(n). The battery state estimation method according to claim 20 or claim 21. 補正係数設定ステップが、1よりも小さい軽減係数Aと1つ前の容量補正値K(n-1)とから下記(4’)式に基づいて容量補正値K(n)を算出することを特徴とする請求項20または請求項21に記載の電池状態推定方法。
K(n)=(1-A×(1-K’(n)))×K(n-1)・・・(4’)
The correction coefficient setting step calculates the capacity correction value K(n) based on the following equation (4') from the reduction coefficient A smaller than 1 and the previous capacity correction value K(n-1). The battery state estimation method according to claim 20 or claim 21.
K(n)=(1-A×(1-K'(n)))×K(n-1)...(4')
SOC補正値設定ステップが、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値に基づいてSOC補正値K(soc)を設定することを特徴とする請求項22または請求項23に記載の電池状態推定方法。 The SOC correction value setting step sets the SOC correction value K (soc) based on the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| The battery state estimation method according to claim 22 or claim 23. SOC補正値設定ステップが、|ΔSOC2(+)-ΔSOC1(+)|の値及び|ΔSOC2(-)-ΔSOC1(-)|の値の平均値をSOC補正値K(soc)とすることを特徴とする請求項26に記載の電池状態推定方法。 The SOC correction value setting step is characterized in that the average value of the value of |ΔSOC2(+)−ΔSOC1(+)| and the value of |ΔSOC2(−)−ΔSOC1(−)| is set as the SOC correction value K(soc). The battery state estimation method according to claim 26. 開回路電圧取得ステップが、基準点の開回路電圧OCV(0)、充電点の開回路電圧OCV(+)、放電点の開回路電圧OCV(-)のうち少なくとも1つに、システム起動時の二次電池の開回路電圧を用いることを特徴とする請求項20乃至請求項27のいずれかに記載の電池状態推定方法。 In the open circuit voltage acquisition step, at least one of the open circuit voltage OCV (0) at the reference point, the open circuit voltage OCV (+) at the charging point, and the open circuit voltage OCV (-) at the discharge point is set at the time of system startup. The battery state estimation method according to any one of claims 20 to 27, characterized in that an open circuit voltage of a secondary battery is used. 判定ステップで、充電側補正値K(+)と放電側補正値K(-)の双方が1よりも大きいと判定された場合、補正係数設定ステップが下記(4’’)式に基づいて、前記充電側補正値K(+)と前記放電側補正値K(-)との平均値に1つ前の容量補正値K(n-1)を乗じた値を容量補正値K(n)として設定することを特徴とする請求項20乃至請求項28のいずれかに記載の電池状態推定方法。
K(n)=((K(+)+K(-))/2)×K(n-1)・・・(4’’)
If it is determined in the determination step that both the charging side correction value K(+) and the discharging side correction value K(-) are larger than 1, the correction coefficient setting step is performed based on the following equation (4''). A value obtained by multiplying the average value of the charging side correction value K(+) and the discharging side correction value K(-) by the previous capacity correction value K(n-1) is set as the capacity correction value K(n). The battery state estimation method according to any one of claims 20 to 28, characterized in that the battery state estimation method is set.
K(n)=((K(+)+K(-))/2)×K(n-1)...(4'')
容量値補正ステップが、下記(5)式に基づいて総容量Ah(n-1)を補正し総容量Ah(n)を算出することを特徴とする請求項20乃至請求項29のいずれかに記載の電池状態推定方法。
Ah(n)=Ah(n-1)×K(n)・・・(5)
Any one of claims 20 to 29, characterized in that the capacitance value correction step corrects the total capacity Ah (n-1) based on the following equation (5) to calculate the total capacity Ah (n). The described battery condition estimation method.
Ah(n)=Ah(n-1)×K(n)...(5)
開回路電圧取得ステップが、複数の充電点もしくは複数の放電点を取得した場合に、
充電率取得ステップはそれぞれの充電点の充電率SOC(+)、放電点の充電率SOC(-)を取得し、
充電率変化量算出ステップは、それぞれの充電点もしくは放電点に対して個別にΔSOC1(+)、ΔSOC1(-)、ΔSOC2(+)、ΔSOC2(-)を算出し、
補正係数算出ステップは、前記(3)式、(3’)式に基づいて、それぞれの充電点もしくは放電点の暫定充電側補正値、暫定放電側補正値を個別に算出した上で、これら暫定充電側補正値、暫定放電側補正値の充電点もしくは放電点ごとの平均値を充電側補正値K(+)、放電側補正値K(-)とすることを特徴とする請求項20乃至請求項30のいずれかに記載の電池状態推定方法。
When the open circuit voltage acquisition step acquires multiple charging points or multiple discharging points,
The charging rate acquisition step acquires the charging rate SOC (+) of each charging point and the charging rate SOC (-) of the discharging point,
The charging rate change calculation step calculates ΔSOC1(+), ΔSOC1(-), ΔSOC2(+), ΔSOC2(-) for each charging point or discharging point individually,
In the correction coefficient calculation step, the provisional charging side correction value and the provisional discharging side correction value for each charging point or discharging point are individually calculated based on equations (3) and (3'), and then these provisional correction values are calculated. Claims 20 and 20 are characterized in that the average value of the charging side correction value and the provisional discharging side correction value for each charging point or each discharging point is used as the charging side correction value K(+) and the discharging side correction value K(-). 31. The battery condition estimation method according to any one of Item 30.
開回路電圧取得ステップが、取得した充電点もしくは放電点が基準点の上下に設定された所定の閾値の範囲を超えた場合に、この点を充電点もしくは放電点として設定することを特徴とする請求項20乃至請求項31のいずれかに記載の電池状態推定方法。 The open circuit voltage acquisition step is characterized in that when the acquired charging point or discharging point exceeds a range of predetermined threshold values set above and below a reference point, this point is set as the charging point or discharging point. The battery state estimation method according to any one of claims 20 to 31. 開回路電圧取得ステップが、電流取得部からの電流値が予め設定された所定の時間、ゼロ近傍の予め設定された所定の電流ゼロ状態を継続した場合に、開回路電圧を取得する緩和状態待機ステップをさらに有することを特徴とする請求項20乃至請求項32のいずれかに記載の電池状態推定方法。 The open circuit voltage acquisition step is a relaxed state standby in which the open circuit voltage is acquired when the current value from the current acquisition unit continues to be in a preset zero current state near zero for a preset time. The battery state estimation method according to any one of claims 20 to 32, further comprising a step. 補正後の総容量Ah(n)を適用した後、再度、容量補正値K(n+1)を算出することを特徴とする請求項20乃至請求項33のいずれかに記載の電池状態推定方法。 34. The battery state estimation method according to claim 20, further comprising calculating the capacity correction value K(n+1) again after applying the corrected total capacity Ah(n). 1回のシステムの稼働期間における容量補正値K(n)の算出動作の回数に上限を設けることを特徴とする請求項34記載の電池状態推定方法。 35. The battery state estimation method according to claim 34, further comprising setting an upper limit on the number of times the capacity correction value K(n) is calculated during one system operation period. システムオフ時点で適用中の容量補正値K(n-1)を少なくとも記録する記録ステップと、
システムの起動時に実行される初期補正値算出ステップと、をさらに有し、
前記初期補正値算出ステップは、前記記録ステップで記録された前記容量補正値K(n-1)を読み出して、前記容量補正値K(n-1)を容量補正値K(n)とし、下記(5’)式に基づいて初回の総容量Ah(n)を算出することを特徴とする請求項20乃至請求項35のいずれかに記載の電池状態推定方法。
Ah(n)=Ah(0)×K(n)・・・(5’)
a recording step of recording at least the capacitance correction value K(n-1) being applied at the time the system is turned off;
further comprising an initial correction value calculation step executed at system startup;
The initial correction value calculation step reads the capacitance correction value K(n-1) recorded in the recording step, sets the capacitance correction value K(n-1) to the capacitance correction value K(n), and performs the following process. 36. The battery state estimation method according to claim 20, wherein the initial total capacity Ah(n) is calculated based on equation (5').
Ah(n)=Ah(0)×K(n)...(5')
システムオフ時点に適用されていた容量補正値K(n-1)とそのときの基準点の充電率SOC(0)’と前回のシステム起動からシステムオフ時点までの全ての期間の電流積算値ΔAh(total)とを少なくとも記録する記録ステップをさらに有し、
システムの起動時には、起動時の開回路電圧OCV(0)から充電率SOC(0)を取得するとともに、前記記録部に記録されている基準点の充電率SOC(0)’と前記電流積算値ΔAh(total)とを読み出して、
前記電流積算値ΔAh(total)がシステムオフ時点の基準点に対して充電側に位置するか放電側に位置するかを判別した上で前記ΔAh(total)に基づいてΔSOC1(+)もしくはΔSOC1(-)を算出し、
前記充電率SOC(0)’と充電率SOC(0)とに基づいてΔSOC2(+)もしくはΔSOC2(-)を算出し、充電側補正値K(+)もしくは放電側補正値K(-)のいずれか一方を算出することを特徴とする請求項20乃至請求項35のいずれかに記載の電池状態推定方法。
Capacity correction value K(n-1) applied at the time the system was turned off, charging rate SOC(0)' at the reference point at that time, and integrated current value ΔAh for all periods from the previous system startup to the time the system was turned off. further comprising a recording step of recording at least (total);
At the time of system startup, the charging rate SOC(0) is obtained from the open circuit voltage OCV(0) at startup, and the charging rate SOC(0)' at the reference point recorded in the recording unit and the current integrated value are obtained. Read out ΔAh (total),
After determining whether the current integrated value ΔAh (total) is located on the charging side or discharging side with respect to the reference point at the time of system off, ΔSOC1 (+) or ΔSOC1 ( -) is calculated,
ΔSOC2(+) or ΔSOC2(-) is calculated based on the charging rate SOC(0)' and the charging rate SOC(0), and the charging side correction value K(+) or the discharging side correction value K(-) is calculated. The battery state estimation method according to any one of claims 20 to 35, characterized in that either one is calculated.
二次電池の内部抵抗と電池容量の関係を記録したデータマッピングを備えるとともに、
電圧取得ステップで取得した電圧値と電流取得ステップで取得した電流値とから二次電池の推定内部抵抗値を算出する内部抵抗算出ステップと、
前記内部抵抗算出ステップで算出した推定内部抵抗値と対応する電池容量を前記データマッピングから取得する電池容量取得ステップと、
前記電池容量取得ステップが取得した電池容量が容量低下を示すか否かを判定する容量低下判定ステップと、をさらに有し、
前記容量低下判定ステップにて前記電池容量取得ステップで取得した電池容量が容量低下を示し、且つ判定ステップにて充電側補正値K(+)と放電側補正値K(-)の双方が1未満と判定した場合に総容量Ah(n)を算出することを特徴とする請求項20乃至請求項37のいずれかに記載の電池状態推定方法。
In addition to being equipped with data mapping that records the relationship between the internal resistance of the secondary battery and the battery capacity,
an internal resistance calculation step of calculating an estimated internal resistance value of the secondary battery from the voltage value acquired in the voltage acquisition step and the current value acquired in the current acquisition step;
a battery capacity acquisition step of acquiring a battery capacity corresponding to the estimated internal resistance value calculated in the internal resistance calculation step from the data mapping;
further comprising a capacity reduction determination step of determining whether the battery capacity acquired in the battery capacity acquisition step indicates a decrease in capacity;
In the capacity decrease determination step, the battery capacity acquired in the battery capacity acquisition step indicates a decrease in capacity, and in the determination step, both the charging side correction value K(+) and the discharging side correction value K(-) are less than 1. 38. The battery state estimation method according to claim 20, wherein the total capacity Ah(n) is calculated when it is determined that.
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