JP2013088183A

JP2013088183A - Abnormality detection system of electric power supply, abnormality detection device and abnormality detection method

Info

Publication number: JP2013088183A
Application number: JP2011227002A
Authority: JP
Inventors: Yuji Nishi; 勇二西; Yukinari Tanabe; 千済田邉; Hiroyuki Umitani; 裕之海谷; Hiromasa Tanaka; 宏昌田中
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2011-10-14
Filing date: 2011-10-14
Publication date: 2013-05-13

Abstract

PROBLEM TO BE SOLVED: To provide an abnormality detection system of an electric power supply, in which the increase of the number of components is suppressed.SOLUTION: The abnormality detection system of the electric power supply is mounted on a vehicle, and a plurality of power storage elements are connected in series therein. The abnormality detection system includes a voltage sensor for detecting a voltage of the power storage element and a controller for calculating respective voltage fluctuation amounts of at least two power storage elements during a prescribed period to detect the abnormality of the power storage elements by comparing the voltage fluctuation amounts between the power storage elements. The abnormality of the electric power supply can be detected by only the detection values by the voltage sensor, and a reduction of the number of components can be facilitated and also the erroneous detection is reducible.

Description

本発明は、車両に搭載される電源装置の異常検出技術に関する。 The present invention relates to an abnormality detection technique for a power supply device mounted on a vehicle.

特許文献１に記載の二次電池の異常検出は、二次電池を流れる電流を検出する電流センサの検出値と、二次電池の電圧を検出する電圧センサの検出値とを用いている。例えば、充電中の二次電池の電圧が減少している場合に、二次電池の異常を検出している。 The abnormality detection of the secondary battery described in Patent Document 1 uses the detection value of the current sensor that detects the current flowing through the secondary battery and the detection value of the voltage sensor that detects the voltage of the secondary battery. For example, the abnormality of the secondary battery is detected when the voltage of the secondary battery being charged is decreasing.

特許文献２では、二次電池を構成する電池セル間の電圧差が所定値以上である場合に電池セルの異常を検出するとともに、二次電池のＳＯＣが低残存領域の際には、異常検出を中止して誤検出を防止している。 In Patent Document 2, an abnormality of a battery cell is detected when the voltage difference between the battery cells constituting the secondary battery is a predetermined value or more, and an abnormality is detected when the SOC of the secondary battery is in a low remaining region. Is stopped to prevent false detection.

特開２００８−２２０１６８号公報JP 2008-220168 A 特開２００９−２５４１６５号公報JP 2009-254165 A 特開２００９−０３７９６２号公報JP 2009-037962 A

特許文献１では、異常検出のために二次電池の電圧検出値及び電流検出値が必要となり、少なくとも電流センサ、電圧センサの各センサを備える必要がある。 In Patent Document 1, a voltage detection value and a current detection value of a secondary battery are required for abnormality detection, and it is necessary to include at least each of a current sensor and a voltage sensor.

また、特許文献２のように単に電池セル間で電圧差を比較するだけでは、電圧検出時の状況や電池セルの状態によって異常検出の精度が低減してしまう。 Moreover, if the voltage difference is simply compared between battery cells as in Patent Document 2, the accuracy of abnormality detection is reduced depending on the situation at the time of voltage detection and the state of the battery cells.

本願第１の発明である車両に搭載される電源装置の異常検出システムは、直列に接続された複数の蓄電素子のうち少なくとも２つの蓄電素子の電圧値を電圧センサで測定し、所定期間における蓄電素子それぞれの電圧変動量を算出する。蓄電素子間の電圧変動量を比較することで、蓄電素子の異常を検出する。 An abnormality detection system for a power supply device mounted on a vehicle according to a first invention of the present application measures a voltage value of at least two power storage elements among a plurality of power storage elements connected in series with a voltage sensor, and stores power in a predetermined period. The voltage fluctuation amount of each element is calculated. By comparing the voltage fluctuation amount between the storage elements, an abnormality of the storage element is detected.

本願第１の発明によれば、電圧センサの検出値のみで蓄電素子の異常を検出できるので、電圧センサ以外の電流センサ等の機器類が不要となり、部品点数の増加を抑制できるとともに、所定期間における各電圧変動量を蓄電素子間で比較して蓄電素子の異常を検出しているので、電圧センサの電圧検出値を比較した異常検出に比べて誤検出を抑制でき、精度よく蓄電素子の異常を検出することができる。 According to the first invention of the present application, since the abnormality of the storage element can be detected only by the detection value of the voltage sensor, devices such as a current sensor other than the voltage sensor become unnecessary, and an increase in the number of parts can be suppressed, and a predetermined period Since each storage element is compared with each other to detect the voltage fluctuation amount, the detection error can be suppressed compared with the abnormality detection that compares the voltage detection value of the voltage sensor, and the storage element abnormality Can be detected.

蓄電素子間での電圧変動量の比率を算出し、比率が所定の閾値を超える場合に蓄電素子の異常を検出することで、電流センサによる計測によらずに各蓄電素子に実際に流れた電流に対する蓄電素子間の抵抗倍率が所定の閾値を超えているか否かによって、蓄電素子の異常を検出することができる。 By calculating the ratio of the amount of voltage fluctuation between the storage elements and detecting the abnormality of the storage element when the ratio exceeds a predetermined threshold, the current that actually flows to each storage element without being measured by the current sensor An abnormality of the power storage element can be detected based on whether or not the resistance magnification between the power storage elements exceeds a predetermined threshold value.

各蓄電素子の電圧変動量として、一定の電圧挙動検出時間内に検出された最大電圧と最小電圧との電圧差、又は所定の時間間隔で検出された各電圧値の変化量を用いることができる。 As the voltage fluctuation amount of each storage element, the voltage difference between the maximum voltage and the minimum voltage detected within a certain voltage behavior detection time, or the change amount of each voltage value detected at a predetermined time interval can be used. .

電源装置の温度及びＳＯＣの少なくとも一方に応じて所定の閾値を変化させることができ、電源装置の温度を検出する温度センサをさらに含むように構成して、電源装置の温度とＳＯＣに応じて予め設定された閾値の中から温度センサによって検出された温度及び電源装置のＳＯＣ情報に応じた閾値を選択し、比率が選択された閾値を超える場合に蓄電素子の異常を検出することができる。 A predetermined threshold value can be changed according to at least one of the temperature of the power supply device and the SOC, and a temperature sensor for detecting the temperature of the power supply device is further included, and the power supply device is configured in advance according to the temperature and the SOC of the power supply device. A threshold value corresponding to the temperature detected by the temperature sensor and the SOC information of the power supply device is selected from the set threshold values. When the ratio exceeds the selected threshold value, the abnormality of the storage element can be detected.

温度とＳＯＣによって異なる蓄電素子の電圧（蓄電素子の抵抗）に対し、電源装置の温度とＳＯＣに応じて異常検出を判定する基準値を変化させることで、異常検出精度を向上させることができる。 The abnormality detection accuracy can be improved by changing the reference value for determining abnormality detection according to the temperature and SOC of the power supply device with respect to the voltage of the energy storage element (resistance of the energy storage element) that varies depending on the temperature and the SOC.

直列に接続された１つの蓄電素子と他の２つの蓄電素子それぞれとを比較して、少なくとも一方の蓄電素子間での比較で異常が検出された場合に、蓄電素子の異常を検出するように構成できる。 Comparing one storage element connected in series with each of the other two storage elements, and detecting an abnormality in the storage element when an abnormality is detected by comparison between at least one of the storage elements Can be configured.

本願第２の発明である車両に搭載される電源装置の異常検出装置は、電圧センサによって検出される検出値を用いて直列に接続された複数の蓄電素子のうち少なくとも２つの蓄電素子の所定期間における蓄電素子それぞれの電圧変動量を算出する。蓄電素子間での電圧変動量を比較することで、蓄電素子の異常を検出する。 An abnormality detection device for a power supply device mounted on a vehicle according to a second invention of the present application is a predetermined period of at least two power storage elements among a plurality of power storage elements connected in series using a detection value detected by a voltage sensor. The amount of voltage fluctuation of each storage element is calculated. An abnormality of the power storage element is detected by comparing the amount of voltage fluctuation between the power storage elements.

本願第３の発明である車両に搭載される電源装置の異常検出方法は、電圧センサによって検出される検出値を用いて直列に接続された複数の蓄電素子のうち少なくとも２つの蓄電素子の所定期間におけるそれぞれの電圧変動量を算出するステップと、蓄電素子間の電圧変動量を比較して蓄電素子の異常を検出ステップと、を含む。 According to a third aspect of the present invention, there is provided an abnormality detection method for a power supply device mounted on a vehicle, wherein a predetermined period of at least two power storage elements among a plurality of power storage elements connected in series using a detection value detected by a voltage sensor. And calculating a voltage fluctuation amount of each of the power storage elements, and comparing a voltage fluctuation quantity between the power storage elements to detect an abnormality of the power storage element.

電圧変動量を算出するステップは、一定の電圧挙動検出時間内に検出された最大電圧と最小電圧との電圧差、又は所定の時間間隔で検出された各電圧値の変化量を電圧変動量として算出することができる。 The step of calculating the voltage fluctuation amount is a difference between the maximum voltage and the minimum voltage detected within a certain voltage behavior detection time, or the change amount of each voltage value detected at a predetermined time interval as the voltage fluctuation amount. Can be calculated.

異常を検出するステップは、蓄電素子間での電圧変動量の比率を算出して、比率が所定の閾値を超える場合に蓄電素子の異常を検出することができ、上記異常検出方法は、電源装置の温度及びＳＯＣの少なくとも一方に応じて所定の閾値を変化させるステップをさらに含むことができる。所定の閾値を変化させるステップは、電源装置の温度を検出する温度センサによって検出される検出値と電源装置のＳＯＣ情報に基づいて、電源装置の温度とＳＯＣに対して予め設定された閾値の中から該当する閾値を選択するように構成することができる。 The step of detecting the abnormality can calculate a ratio of the amount of voltage fluctuation between the power storage elements, and can detect the abnormality of the power storage element when the ratio exceeds a predetermined threshold value. The method may further include changing the predetermined threshold according to at least one of the temperature and the SOC. The step of changing the predetermined threshold is based on the detection value detected by the temperature sensor that detects the temperature of the power supply device and the SOC information of the power supply device. The corresponding threshold value can be selected from the following.

組電池の異常検出システムの構成を示す図である。It is a figure which shows the structure of the abnormality detection system of an assembled battery. 正常な単電池の電圧挙動，抵抗異常の単電池の電圧挙動の一例を示す図である。It is a figure which shows an example of the voltage behavior of a normal cell, and the voltage behavior of the cell of resistance abnormality. 正常な単電池の電圧挙動，抵抗異常の単電池の電圧挙動の一例を示す図である。It is a figure which shows an example of the voltage behavior of a normal cell, and the voltage behavior of the cell of resistance abnormality. 組電池の温度及びＳＯＣに応じた閾値マップの一例を示す図である。It is a figure which shows an example of the threshold value map according to the temperature and SOC of an assembled battery. 組電池の異常検出動作を示すフローチャートである。It is a flowchart which shows the abnormality detection operation | movement of an assembled battery.

以下、本発明の実施例について説明する。 Examples of the present invention will be described below.

（実施例１）
本発明の実施例１である組電池（電源装置に相当する）の異常検出システムについて説明する。図１は、本実施例の組電池の異常検出システムの構成を示す図である。 Example 1
An abnormality detection system for an assembled battery (corresponding to a power supply device) that is Embodiment 1 of the present invention will be described. FIG. 1 is a diagram illustrating a configuration of an assembled battery abnormality detection system according to the present embodiment.

組電池１０は、直列に接続された複数の単電池（蓄電素子に相当する）１１を有する。単電池１１としては、ニッケル水素電池やリチウムイオン電池といった二次電池を用いることができる。また、二次電池の代わりに、電気二重層キャパシタ（コンデンサ）を用いることができる。組電池１０を構成する単電池１１の数は、要求出力などに基づいて、適宜設定することができる。また、組電池１０は、並列に接続された複数の単電池１１を含んでいてもよい。 The assembled battery 10 includes a plurality of single cells (corresponding to power storage elements) 11 connected in series. As the cell 11, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor (capacitor) can be used instead of the secondary battery. The number of the single cells 11 constituting the assembled battery 10 can be set as appropriate based on the required output. The assembled battery 10 may include a plurality of unit cells 11 connected in parallel.

本実施例の組電池１０は、車両に搭載することができる。車両としては、ハイブリッド自動車や電気自動車がある。ハイブリッド自動車は、車両を走行させるための動力源として、組電池１０に加えて、エンジン又は燃料電池を備えている。電気自動車は、車両の動力源として、組電池１０のみを備えている。 The assembled battery 10 of the present embodiment can be mounted on a vehicle. Vehicles include hybrid cars and electric cars. The hybrid vehicle includes an engine or a fuel cell in addition to the assembled battery 10 as a power source for running the vehicle. The electric vehicle includes only the assembled battery 10 as a power source of the vehicle.

組電池１０の正極端子及び負極端子は、昇圧コンバータ２３と接続されている。システムメインリレーＳＭＲ−Ｂ，ＳＭＲ−Ｇがコントローラ３０からの制御信号を受けて、オン（接続状態）およびオフ（遮断状態）の間で切り替わることで、組電池１０と昇圧コンバータ２３との接続が制御される。 The positive terminal and the negative terminal of the assembled battery 10 are connected to the boost converter 23. The system main relays SMR-B and SMR-G receive a control signal from the controller 30 and are switched between on (connected state) and off (cut-off state), whereby the assembled battery 10 and the boost converter 23 are connected. Be controlled.

昇圧コンバータ２３は、組電池１０の出力電圧を昇圧して、昇圧後の電力をインバータ２３に出力する。また、昇圧コンバータ２３は、インバータ２４の出力電圧を降圧して、降圧後の電力を組電池１０に出力する。昇圧コンバータ２３は、例えば、チョッパ回路で構成することができる。昇圧コンバータ２３は、コントローラ３０からの制御信号を受けて動作する。 Boost converter 23 boosts the output voltage of battery pack 10 and outputs the boosted power to inverter 23. Further, the boost converter 23 steps down the output voltage of the inverter 24 and outputs the lowered power to the assembled battery 10. The step-up converter 23 can be composed of, for example, a chopper circuit. Boost converter 23 operates in response to a control signal from controller 30.

インバータ２４は、昇圧コンバータ２３から出力された直流電力を交流電力に変換して、交流電力をモータ・ジェネレータ（ＭＧ）２５に出力する。モータ・ジェネレータ２５としては、例えば、三相交流モータを用いることができる。また、インバータ２４は、モータ・ジェネレータ２５から出力された交流電力を直流電力に変換して、直流電力を昇圧コンバータ２３に出力する。 The inverter 24 converts the DC power output from the boost converter 23 into AC power, and outputs the AC power to the motor generator (MG) 25. For example, a three-phase AC motor can be used as the motor / generator 25. The inverter 24 converts AC power output from the motor / generator 25 into DC power and outputs the DC power to the boost converter 23.

モータ・ジェネレータ２５は、インバータ２４からの交流電力を受けて、車両を走行させるための運動エネルギを生成する。モータ・ジェネレータ２５は、車輪と接続されており、モータ・ジェネレータ２５によって生成された運動エネルギは、車輪に伝達される。車両を減速させたり、停止させたりするとき、モータ・ジェネレータ２５は、車両の制動時に発生する運動エネルギを電気エネルギ（交流電力）に変換する。モータ・ジェネレータ２５によって生成された交流電力は、インバータ２４に出力される。これにより、回生電力を組電池１０に蓄えることができる。 The motor / generator 25 receives AC power from the inverter 24 and generates kinetic energy for running the vehicle. The motor / generator 25 is connected to wheels, and the kinetic energy generated by the motor / generator 25 is transmitted to the wheels. When the vehicle is decelerated or stopped, the motor / generator 25 converts kinetic energy generated during braking of the vehicle into electric energy (AC power). The AC power generated by the motor / generator 25 is output to the inverter 24. Thereby, regenerative electric power can be stored in the assembled battery 10.

電圧監視ＩＣ２０は、電圧センサ２１を含んで構成される。電圧センサ２１は、組電池１０を構成する直列に接続された各単電池１１に設けられ、単電池１１それぞれの電圧を検出する。電圧監視ＩＣ２０は、コントローラ３０に接続され、電圧センサ２１によって検出された各検出値をコントローラ３０に出力する。 The voltage monitoring IC 20 includes a voltage sensor 21. The voltage sensor 21 is provided in each of the unit cells 11 connected in series constituting the assembled battery 10 and detects the voltage of each unit cell 11. The voltage monitoring IC 20 is connected to the controller 30 and outputs each detection value detected by the voltage sensor 21 to the controller 30.

温度センサ２２は、組電池１０の温度を検出する。温度センサ２２は、コントローラ３０に接続され、検出結果をコントローラ３０に出力する。なお、温度センサ２２は、電圧監視ＩＣ２０に含まれるように構成することができ、例えば、組電池１０の電圧及び温度を検出する監視ＩＣとして構成できる。 The temperature sensor 22 detects the temperature of the assembled battery 10. The temperature sensor 22 is connected to the controller 30 and outputs a detection result to the controller 30. The temperature sensor 22 can be configured to be included in the voltage monitoring IC 20, and can be configured as a monitoring IC that detects the voltage and temperature of the assembled battery 10, for example.

コントローラ３０は、組電池１０の充放電制御を行う制御装置である。コントローラ３０は、車両出力要求に基づいて負荷に組電池１０の電力を出力する放電制御、車両が減速したり、停止したりする際の車両制動時における回生電力を組電池１０に充電する充電制御を行う。 The controller 30 is a control device that performs charge / discharge control of the assembled battery 10. The controller 30 is a discharge control that outputs the power of the assembled battery 10 to a load based on a vehicle output request, and a charging control that charges the assembled battery 10 with regenerative power during vehicle braking when the vehicle decelerates or stops. I do.

ＳＯＣ（State of Charge）は、組電池１０の満充電容量に対する現在充電容量の割合を示すものであり、コントローラ３０は、組電池１０のＳＯＣを管理するために、電圧センサ２１による検出結果を用いて組電池１０のＳＯＣを算出したり特定する処理を行い、記憶部３２に組電池１０の充放電履歴やＳＯＣ情報を記憶して管理することができる。 The SOC (State of Charge) indicates the ratio of the current charge capacity to the full charge capacity of the battery pack 10, and the controller 30 uses the detection result of the voltage sensor 21 in order to manage the SOC of the battery pack 10. Thus, the SOC of the assembled battery 10 can be calculated or specified, and the storage unit 32 can store and manage the charge / discharge history and SOC information of the assembled battery 10.

組電池１０のＳＯＣは、組電池１０のＯＣＶ（Open Circuit Voltage）から特定することができる。ＳＯＣ及びＯＣＶは対応関係にあるため、この対応関係を予め求めておけば、ＯＣＶからＳＯＣを特定することができる。組電池１０のＯＣＶは、電圧センサ２１によって検出された組電池１０の電圧（ＣＣＶ：Closed Circuit Voltage）から算出することができる。組電池１０のＳＯＣと共に、組電池１０を構成する直列に接続された単電池１１それぞれのＳＯＣを算出することもでき、本実施例のコントローラ３０は、組電池１０全体のＳＯＣと各単電池１１それぞれのＳＯＣを管理することができる。 The SOC of the assembled battery 10 can be specified from the OCV (Open Circuit Voltage) of the assembled battery 10. Since SOC and OCV are in a correspondence relationship, if this correspondence relationship is obtained in advance, the SOC can be specified from the OCV. The OCV of the assembled battery 10 can be calculated from the voltage (CCV: Closed Circuit Voltage) of the assembled battery 10 detected by the voltage sensor 21. The SOC of each of the battery cells 11 connected in series that constitute the battery pack 10 can be calculated together with the SOC of the battery pack 10, and the controller 30 of this embodiment can determine the SOC of the battery pack 10 as a whole and each battery cell 11. Each SOC can be managed.

コントローラ３０は、電圧センサ２１によって検出された検出値を用いて組電池１０の異常検出を行う異常検出部３１と記憶部３２を含んで構成される。本実施例の異常検出部３１を含むコントローラ３０は、組電池１０の異常検出を行う制御装置として機能する。なお、異常検出部３１は、コントローラ３０とは別途の制御装置として構成することもでき、コントローラ３０に対して外的に又は内的に設けることができる。 The controller 30 includes an abnormality detection unit 31 and a storage unit 32 that detect an abnormality of the assembled battery 10 using the detection value detected by the voltage sensor 21. The controller 30 including the abnormality detection unit 31 of the present embodiment functions as a control device that detects abnormality of the assembled battery 10. The abnormality detection unit 31 can also be configured as a control device separate from the controller 30 and can be provided externally or internally with respect to the controller 30.

次に、本実施例の組電池１０の異常検出について説明する。異常検出は、異常検出部３１によって遂行される。異常検出部３１は、組電池１０の電圧を検出する電圧センサ２１によって検出される電圧検出値を用いて当該組電池１０の異常を検出する異常検出装置として機能する。また、異常検出部３１及び組電池１０の電圧を検出する電圧センサ２１は、組電池１０の異常検出システムを構成する。 Next, abnormality detection of the assembled battery 10 of the present embodiment will be described. The abnormality detection is performed by the abnormality detection unit 31. The abnormality detection unit 31 functions as an abnormality detection device that detects an abnormality of the assembled battery 10 using a voltage detection value detected by the voltage sensor 21 that detects the voltage of the assembled battery 10. The abnormality detection unit 31 and the voltage sensor 21 that detects the voltage of the assembled battery 10 constitute an abnormality detection system for the assembled battery 10.

異常検出部３１は、車両のイグニッションスイッチがオフからオンに切り替わり、システムメインリレーＳＭＲ−Ｂ，ＳＭＲ−Ｇがオンされてコントローラ３０によって充放電制御が開始された後に、組電池１０の異常検出処理を行う。異常検出部３１は、組電池１０を構成する直列に接続された複数の単電池１１のうち、少なくとも２つの単電池１１について電圧センサ２１で検出された電圧挙動から所定期間における電圧変動値を算出し、算出された各電圧変動値を単電池１１間で比較して、電圧変動値の比率が基準値（閾値）を超える場合、単電池１１の異常（組電池１０の異常）を検出する。 The abnormality detection unit 31 performs an abnormality detection process for the assembled battery 10 after the ignition switch of the vehicle is switched from OFF to ON, the system main relays SMR-B and SMR-G are turned ON, and charge / discharge control is started by the controller 30. I do. The abnormality detection unit 31 calculates a voltage fluctuation value in a predetermined period from the voltage behavior detected by the voltage sensor 21 for at least two unit cells 11 among a plurality of unit cells 11 connected in series constituting the assembled battery 10. Then, the calculated voltage fluctuation values are compared between the single cells 11, and when the ratio of the voltage fluctuation values exceeds the reference value (threshold value), an abnormality of the single battery 11 (abnormality of the assembled battery 10) is detected.

図２に示すように、単電池１１に異常が発生した場合、正常時の電圧挙動（太線で示した電圧挙動）と異なる電圧挙動（点線で示した電圧挙動）が検出される。本実施例では、電圧センサ２１によって検出された単電池１１間の各電圧値を比較するのではなく、直列に接続された単電池１１それぞれの所定期間における電圧変動値を比較して、単電池１１の異常を検出する。 As shown in FIG. 2, when an abnormality occurs in the unit cell 11, a voltage behavior (voltage behavior shown by a dotted line) different from the normal voltage behavior (voltage behavior shown by a thick line) is detected. In this embodiment, the voltage values between the single cells 11 detected by the voltage sensor 21 are not compared, but the voltage fluctuation values of each of the single cells 11 connected in series are compared with each other in a predetermined period. 11 abnormalities are detected.

ある計測点、例えば、時間ｔにおける単電池１１それぞれで検出された電圧値を比較すると、一方の単電池１１に異常が発生している場合でも同じ電圧値が検出されたり、電圧値の差分が小さく検出される場合があるため、単電池１１の異常を精度よく検出できないことがある。具体的には、図２の例において点線と太線とが重なる個所に相当する時点の電圧検出値は、正常な単電池１１及び異常な単電池１１それぞれで同じ電圧が検出されてしまい、単電池１１の異常を的確に検出できない。 Comparing the voltage values detected by each unit cell 11 at a certain measurement point, for example, time t, even if an abnormality occurs in one unit cell 11, the same voltage value is detected or the difference between the voltage values is Since it may be detected small, an abnormality of the unit cell 11 may not be detected accurately. Specifically, in the example of FIG. 2, the voltage detection value at the time corresponding to the place where the dotted line and the thick line overlap is detected as the same voltage in each of the normal cell 11 and the abnormal cell 11. 11 abnormalities cannot be accurately detected.

一方で、電圧センサ２１で検出される電圧検出値は、単電池１１のＳＯＣによって異なる。このため、各単電池１１でＳＯＣにバラツキがあると、ＳＯＣの低い単電池１１とＳＯＣが高い単電池１１それぞれの電圧検出値の間にＳＯＣ差に応じた差分値が含まれるので、誤検出などの検出精度の低下を招く要因となる。これに対しは、電流センサによって測定された電流値を用いて単電池１１間のＳＯＣのバラツキによる誤差を補正することが考えられるが、別途電流センサが必要となり、部品点数の増加を抑制することができない。 On the other hand, the voltage detection value detected by the voltage sensor 21 varies depending on the SOC of the unit cell 11. For this reason, if the SOC of each unit cell 11 varies, a difference value corresponding to the SOC difference is included between the voltage detection values of the unit cell 11 having a low SOC and the unit cell 11 having a high SOC. This causes a decrease in detection accuracy. For this, it is conceivable to correct the error due to the variation in the SOC between the single cells 11 using the current value measured by the current sensor, but a separate current sensor is required to suppress an increase in the number of parts. I can't.

本実施例では、電圧センサ２１によって検出された検出結果から所定期間の電圧変動量を算出することで、単電池１１間にＳＯＣのバラツキがあっても電流センサによる計測によらずに各単電池１１に実際に流れた電流に対してＳＯＣの影響を低減した電圧、すなわち、各単電池１１に実際に流れた電流に対してＳＯＣの影響が抑制された単電池１１の抵抗を単電池１１間で比較し、単電池１１間のＳＯＣのバラツキによる検出精度の低下を抑制している。 In this embodiment, by calculating the voltage fluctuation amount for a predetermined period from the detection result detected by the voltage sensor 21, even if there is a variation in SOC between the single cells 11, each single cell is not measured by the current sensor. 11 is a voltage obtained by reducing the influence of the SOC with respect to the current actually flowing in the battery 11, that is, the resistance of the battery 11 in which the influence of the SOC is suppressed with respect to the current actually flowing in each battery 11. Therefore, a decrease in detection accuracy due to variations in SOC between the single cells 11 is suppressed.

本実施例では、図２及び図３に示す２通りの方法で電圧変動量を算出することができる。図２は、単電池１１の正常時及び異常時の電圧挙動の一例を示す図であり、縦軸が電圧（Ｖ）、横軸が時間ｔである。 In this embodiment, the voltage fluctuation amount can be calculated by the two methods shown in FIGS. FIG. 2 is a diagram illustrating an example of the voltage behavior of the cell 11 when it is normal and abnormal. The vertical axis represents voltage (V) and the horizontal axis represents time t.

異常検出部３１は、電圧センサ２１の検出結果から組電池１０を構成する単電池１１の一定時間の電圧検出期間Ｔ（電圧挙動検出期間）内の最大電圧及び最小電圧を取得する。 The abnormality detection unit 31 acquires the maximum voltage and the minimum voltage within the voltage detection period T (voltage behavior detection period) of the unit cell 11 constituting the assembled battery 10 from the detection result of the voltage sensor 21 for a certain time.

異常検出部３１は、時間ｔ１からｔ２までの電圧検出期間Ｔにおける最大電圧と最小電圧を取得し、最大電圧と最小電圧との電圧差を電圧変動値として算出する。異常検出部３１は、少なくとも２つの単電池１１それぞれの同じ電圧検出期間Ｔにおける最大電圧と最小電圧との電圧差に基づく電圧変動値を算出する。 The abnormality detection unit 31 acquires the maximum voltage and the minimum voltage in the voltage detection period T from time t1 to t2, and calculates the voltage difference between the maximum voltage and the minimum voltage as a voltage fluctuation value. The abnormality detection unit 31 calculates a voltage fluctuation value based on the voltage difference between the maximum voltage and the minimum voltage in the same voltage detection period T of each of at least two unit cells 11.

図２の例では、一定時間内の電圧挙動における最大電圧及び最小電圧の電圧差を算出するので、電圧検出期間Ｔは、後述する図３の例の所定期間よりも長い時間（例えば、数十秒、数分）とすることができる。 In the example of FIG. 2, since the voltage difference between the maximum voltage and the minimum voltage in the voltage behavior within a certain time is calculated, the voltage detection period T is longer than a predetermined period of the example of FIG. Seconds, minutes).

単電池１１の電圧変動値ΔＩＲは、電圧検出期間Ｔの最大電圧（ＭａｘＣＣＶ）から最小電圧（ＭｉｎＣＣＶ）を減算して算出することができる。
（式１）ΔＩＲ＝ＭａｘＣＣＶ−ＭｉｎＣＣＶ The voltage fluctuation value ΔIR of the unit cell 11 can be calculated by subtracting the minimum voltage (MinCCV) from the maximum voltage (MaxCCV) in the voltage detection period T.
(Formula 1) ΔIR = MaxCCV−MinCCV

ＣＣＶは、電圧センサ２１によって検出された電圧検出値である。電圧センサ２１によって検出された単電池１１のＣＣＶとＯＣＶは、下記に示す式２の関係を有するので、式１は下記に示す式３に変形できる。
（式２）ＣＣＶ＝ＯＣＶ＋ＩＲ
（式３）ΔＩＲ＝ＯＣＶ＋ＭａｘＩＲ−（ＯＣＶ＋ＭｉｎＩＲ）
ここで、Ｒは単電池１１の抵抗、ΔＩは電流センサ等の機器で検出した値ではなく、電圧センサ２１によって検出された電圧値に基づく実際に単電池１１に流れた電流値である。 CCV is a voltage detection value detected by the voltage sensor 21. Since CCV and OCV of the cell 11 detected by the voltage sensor 21 have the relationship of the following formula 2, the formula 1 can be transformed into the formula 3 shown below.
(Formula 2) CCV = OCV + IR
(Expression 3) ΔIR = OCV + MaxIR− (OCV + MinIR)
Here, R is the resistance of the unit cell 11, and ΔI is not a value detected by a device such as a current sensor, but a current value actually flowing through the unit cell 11 based on the voltage value detected by the voltage sensor 21.

単電池１１のＯＣＶは、電圧検出期間Ｔが短時間である場合、その間の単電池１１のＯＣＶの変動は、極めて小さく、最大電圧及び最小電圧それぞれの各ＯＣＶを同じ値とみなすことができる。このため、上記式３において最大電圧と最小電圧それぞれに含まれるＯＣＶは互いに相殺され、電圧検出期間Ｔにおける単電池１１の電圧変動量ΔＩＲは、以下の式４で表すことができる。
（式４）ΔＩＲ＝ＭａｘＩＲ−ＭｉｎＩＲ When the voltage detection period T is a short time, the OCV of the unit cell 11 has a very small variation in the OCV of the unit cell 11 during that time, and each OCV of the maximum voltage and the minimum voltage can be regarded as the same value. For this reason, the OCV included in each of the maximum voltage and the minimum voltage in the above expression 3 cancels each other, and the voltage fluctuation amount ΔIR of the unit cell 11 in the voltage detection period T can be expressed by the following expression 4.
(Formula 4) ΔIR = MaxIR−MinIR

このように異常検出部３１は、電圧センサ２１によって検出される検出値のみを用いて、単電池１１それぞれの電圧検出期間Ｔにおける電圧変動値ΔＩＲを算出することができる。 As described above, the abnormality detection unit 31 can calculate the voltage fluctuation value ΔIR in the voltage detection period T of each unit cell 11 using only the detection value detected by the voltage sensor 21.

図３は、単電池１１の正常時及び異常時の電圧挙動の一例を示す図であり、縦軸が電圧（Ｖ）、横軸が時間ｔである。また、正常時の電圧挙動を太線で、異常時の電圧挙動を点線で示している。 FIG. 3 is a diagram illustrating an example of the voltage behavior of the cell 11 when it is normal and abnormal, where the vertical axis represents voltage (V) and the horizontal axis represents time t. In addition, the voltage behavior at normal time is indicated by a thick line, and the voltage behavior at abnormal time is indicated by a dotted line.

異常検出部３１は、電圧センサ２１の検出結果から組電池１０を構成する単電池１１の所定の時間間隔（電圧検出周期ｔｓ）で検出された各電圧値を取得する。すなわち、電圧センサ２１は、例えば、秒間隔で各単電池１１の電圧を検出する。 The abnormality detection unit 31 acquires each voltage value detected at a predetermined time interval (voltage detection cycle ts) of the cells 11 constituting the assembled battery 10 from the detection result of the voltage sensor 21. That is, the voltage sensor 21 detects the voltage of each cell 11 at intervals of seconds, for example.

異常検出部３１は、電圧検出周期ｔｓで今回検出された時間ｔｂの電圧検出値と前回検出された電圧検出値とを取得し、少なくとも２つの単電池１１それぞれの時間ｔａから時間ｔｂ間の電圧変化量を電圧変動量として算出する。 The abnormality detection unit 31 acquires the voltage detection value at the time tb detected this time and the voltage detection value detected last time in the voltage detection cycle ts, and the voltage between the time ta and the time tb of each of the at least two unit cells 11. The amount of change is calculated as the amount of voltage fluctuation.

図３の例における単電池１１の電圧変動値ΔＩＲは、電圧検出周期ｔｓで今回検出された時間ｔｂの電圧検出値（ＣＣＶ（ｔ））から前回検出された時間ｔａの電圧検出値（ＣＣＶ（ｔ−１））を減算することで、算出することができる。ｔは、電圧検出周期ｔｓで検出された時系列順を示している。
（式５）ΔＩ（ｔ）Ｒ＝ＣＣＶ（ｔ）−ＣＣＶ（ｔ−１） The voltage fluctuation value ΔIR of the cell 11 in the example of FIG. 3 is the voltage detection value (CCV (CCV (t)) detected at the previous time from the voltage detection value (CCV (t)) at the time tb detected this time in the voltage detection cycle ts. It can be calculated by subtracting t-1)). t indicates the time-series order detected in the voltage detection period ts.
(Formula 5) ΔI (t) R = CCV (t) −CCV (t−1)

ＣＣＶは、電圧センサ２１によって検出された電圧検出値であり、上述のように電圧センサ２１によって検出された単電池１１のＣＣＶとＯＣＶは、上記式２の関係を有するので、式５は下記に示す式６に変形できる。
（式６）ΔＩ（ｔ）Ｒ＝{ＯＣＶ＋Ｉ（ｔ）Ｒ−（ＯＣＶ＋Ｉ（ｔ−１）Ｒ）}
Ｒは単電池１１の抵抗、ΔＩ（ｔ）は図２の例と同様に、電圧センサ２１によって検出された電圧値に基づいて電圧検出周期ｔｓにおいて実際に単電池１１に流れた電流値である。 CCV is a voltage detection value detected by the voltage sensor 21. As described above, the CCV and OCV of the unit cell 11 detected by the voltage sensor 21 have the relationship of the above equation 2, so that the equation 5 is It can deform | transform into the formula 6 shown.
(Expression 6) ΔI (t) R = {OCV + I (t) R− (OCV + I (t−1) R)}
R is the resistance of the cell 11 and ΔI (t) is the current value that actually flows through the cell 11 in the voltage detection period ts based on the voltage value detected by the voltage sensor 21 as in the example of FIG. .

図２に例と同様に、図３の例においても単電池１１のＯＣＶは、電圧検出周期ｔｓが短時間である場合、その間の単電池１１のＯＣＶの変動は、極めて小さく、時間ｔ及び時間ｔ−１それぞれの各ＯＣＶを同じ値とみなすことができるので、時間ｔａから時間ｔｂの電圧検出周期ｔｓにおける単電池１１の電圧変動量ΔＩ（ｔ）Ｒは、以下の式６で表すことができる。
（式６）ΔＩ（ｔ）Ｒ＝Ｉ（ｔ）Ｒ−Ｉ（ｔ−１）Ｒ 2, in the example of FIG. 3, the OCV of the unit cell 11 also has a very small fluctuation of the OCV of the unit cell 11 when the voltage detection period ts is short, and the time t and time Since each OCV of t−1 can be regarded as the same value, the voltage fluctuation amount ΔI (t) R of the cell 11 in the voltage detection period ts from time ta to time tb can be expressed by the following formula 6. it can.
(Expression 6) ΔI (t) R = I (t) R−I (t−1) R

このように異常検出部３１は、電圧センサ２１によって検出される検出値のみを用いて、単電池１１それぞれの電圧検出周期ｔｓにおける所定の時間間隔での電圧変化量を電圧変動値ΔＩ（ｔ）Ｒとして算出することができる。 As described above, the abnormality detection unit 31 uses only the detection value detected by the voltage sensor 21 to calculate the voltage change amount ΔI (t) at a predetermined time interval in the voltage detection cycle ts of each unit cell 11. R can be calculated.

異常検出部３１は、図２及び図３に示した一方の算出方法で、少なくとも２つの単電池１１（１）の電圧変動値ΔＩＲ_１、単電池１１（２）の電圧変動値ΔＩＲ₂を求めて、さらに２つの単電池１１の一方の単電池１１に対する他方の単電池１１の電圧変動値の比率を求める。
（式７）ΔＩ（ｔ）Ｒ_１／ΔＩ（ｔ）Ｒ₂（＝Ｒ_１／Ｒ₂） Abnormality detecting unit 31, while the calculation method shown in FIGS. 2 and 3, the voltage variation value .DELTA.iR ₁ of at least two cells 11 (1), the voltage fluctuation value .DELTA.iR ₂ of the cell 11 (2) determined Then, the ratio of the voltage fluctuation value of the other unit cell 11 to the one unit cell 11 of the two unit cells 11 is obtained.
(Expression 7) ΔI (t) R ₁ / ΔI (t) R ₂ (= R ₁ / R ₂ )

式７に示すように、単電池１１それぞれは直列に接続されているので、各単電池１１に流れる電流値は一定であり、単電池１１間の電圧変動値の比率は、各単電池１１間の抵抗倍率（抵抗比率）を表している。 As shown in Equation 7, since each of the single cells 11 is connected in series, the current value flowing through each single cell 11 is constant, and the ratio of the voltage fluctuation value between the single cells 11 is the same between the single cells 11. Represents the resistance magnification (resistance ratio).

本実施例では、所定期間における各電圧変動量を単電池１１間で比較して単電池１１の抵抗異常を検出することで、組電池１０の異常を検出する。具体的には、上記式７のように少なくとも２つの単電池１１間での抵抗倍率を算出し、抵抗倍率が所定の閾値を超える場合に単電池１１の異常を検出することができる。 In the present embodiment, the abnormality of the battery pack 10 is detected by comparing each voltage fluctuation amount in the predetermined period between the battery cells 11 and detecting the resistance abnormality of the battery cells 11. Specifically, the resistance magnification between at least two unit cells 11 is calculated as in the above formula 7, and the abnormality of the unit cell 11 can be detected when the resistance factor exceeds a predetermined threshold.

単電池１１が正常である場合、直列に接続された単電池１１それぞれは、同じ電圧挙動を示すので、単電池１１間の抵抗倍率は、１又は１に近い値となる。一方、他方の単電池１１に抵抗異常がある場合、電圧挙動が正常時に比べてより大きく（又はより小さく）なり、抵抗異常が発生していない単電池１１と抵抗異常が発生した単電池１１との間の抵抗倍率は、数倍又は数分の１となる。本実施例では、所定期間における各電圧変動量を単電池１１間で比較して抵抗倍率が所定の閾値を超えるか否か、又は所定の閾値よりも小さいか否かを判別し、単電池１１の抵抗異常を検出することで、単電池１１の異常を検出する。 When the unit cells 11 are normal, the unit cells 11 connected in series exhibit the same voltage behavior, and thus the resistance magnification between the unit cells 11 is a value close to 1 or 1. On the other hand, when the other unit cell 11 has a resistance abnormality, the voltage behavior becomes larger (or smaller) than that in the normal state, and the unit cell 11 in which the resistance abnormality has occurred and the unit cell 11 in which the resistance abnormality has occurred The resistance magnification between is several times or a fraction. In the present embodiment, each voltage fluctuation amount in a predetermined period is compared between the single cells 11 to determine whether or not the resistance magnification exceeds a predetermined threshold value or smaller than the predetermined threshold value. The abnormality of the unit cell 11 is detected by detecting the resistance abnormality.

なお、少なくとも２つの単電池１１は、直列に接続された隣り合う２つの単電池１１や任意の接続位置における２つの単電池１１（例えば、単電池１１（１）と単電池１１（３）や単電池１１（１）と単電池１１（ｎ））とすることができる。 The at least two unit cells 11 include two adjacent unit cells 11 connected in series, or two unit cells 11 (for example, the unit cell 11 (1) and the unit cell 11 (3) A single cell 11 (1) and a single cell 11 (n)) can be used.

また、図３の例における電圧変動値（電圧検出周期ｔｓにおける所定の時間間隔での電圧変化量）を用いた抵抗倍率の算出では、過去に算出された抵抗倍率を今回算出された抵抗倍率に反映させる重み付け処理を適用することができる。 Further, in the calculation of the resistance magnification using the voltage fluctuation value (voltage change amount at a predetermined time interval in the voltage detection cycle ts) in the example of FIG. 3, the resistance magnification calculated in the past is changed to the resistance magnification calculated this time. A weighting process to be reflected can be applied.

例えば、式６において今回時間ｔの電圧変動量ΔＩ（ｔ）Ｒ＝Ｉ（ｔ）Ｒ−Ｉ（ｔ−１）Ｒに、前回時間ｔ−１の電圧変動量ΔＩ（ｔ−１）Ｒ＝Ｉ（ｔ−１）Ｒ−Ｉ（ｔ−２）Ｒを重み値として反映させることができる。 For example, in Equation 6, the voltage fluctuation amount ΔI (t) R = I (t) R−I (t−1) R at the current time t is changed to the voltage fluctuation amount ΔI (t−1) R = at the previous time t−1. I (t-1) R-I (t-2) R can be reflected as a weight value.

今回時間ｔの電圧変動量ΔＩ（ｔ）Ｒを、今回時間ｔの電圧変動量ΔＩ（ｔ）Ｒと前回（電圧検出周期で１つ前の）時間ｔ−１の電圧変動量ΔＩ（ｔ−１）Ｒを所定の割合で加算して算出したり、前回時間ｔ−１，前々回時間ｔ−２、・・・・の複数の過去の電圧変動量を平均した値と今回時間ｔの電圧変動量ΔＩ（ｔ）Ｒとを所定の割合で加算した値を、今回時間ｔの電圧変動量ΔＩ（ｔ）Ｒとして算出することができる。また、今回時間ｔから順に前の時間ｔ−１、時間ｔ−２、時間ｔ−３・・・・それぞれを所定の割合で今回時間ｔの電圧変動量ΔＩ（ｔ）Ｒに反映させたり、今回時間ｔから前の任意の時間ｔ−ｎ（ｔ＞ｎ）の電圧変動量を１つ又は複数選択して反映させることができる。 The voltage fluctuation amount ΔI (t) R at the current time t is divided into the voltage fluctuation amount ΔI (t) R at the current time t and the voltage fluctuation amount ΔI (t−t) at the previous time (one previous in the voltage detection cycle) t−1. 1) Calculate by adding R at a predetermined ratio, or average a plurality of past voltage fluctuation amounts at the previous time t-1, the previous time t-2,... And the voltage fluctuation at the current time t. A value obtained by adding the amount ΔI (t) R at a predetermined ratio can be calculated as the voltage fluctuation amount ΔI (t) R at the current time t. In addition, the previous time t-1, time t-2, time t-3,... Are sequentially reflected in the voltage fluctuation amount ΔI (t) R at the current time t at a predetermined rate from the current time t, One or a plurality of voltage fluctuation amounts at an arbitrary time t−n (t> n) before the current time t can be selected and reflected.

図３の例における電圧検出周期ｔｓで検出された電圧検出値を用いて算出される抵抗倍率を、それ以前に算出された過去の抵抗倍率で評価するように重み付け処理を行うことで、電圧検出時のノイズの影響を小さくすることができ、異常検出精度をさらに向上させることができる。 Voltage detection is performed by performing a weighting process so that the resistance magnification calculated using the voltage detection value detected in the voltage detection period ts in the example of FIG. 3 is evaluated with the past resistance magnification calculated before that. The influence of noise at the time can be reduced, and the abnormality detection accuracy can be further improved.

次に、本実施例の抵抗倍率を用いた抵抗異常を判別するための基準値である閾値について説明する。本実施例の閾値は、組電池１０の温度及びＳＯＣの少なくとも一方に応じて変化する。 Next, a threshold value that is a reference value for determining resistance abnormality using the resistance magnification of the present embodiment will be described. The threshold value of the present embodiment changes according to at least one of the temperature of the battery pack 10 and the SOC.

組電池１０の温度が低いと、単電池１１の抵抗が大きくなり、また、単電池１１のＳＯＣが低いと単電池１１の抵抗が大きくなる。正常な単電池１１であっても単電池１１の状態及び環境に応じて内部抵抗が相違するので、電圧変動量に基づく抵抗倍率も温度とＳＯＣの一方又は両方の影響を受けて相違する。本実施例では、閾値と抵抗倍率との関係を組電池１０の温度とＳＯＣに応じて変化させることで、異常検出の精度をさらに向上させている。 When the temperature of the assembled battery 10 is low, the resistance of the single battery 11 increases, and when the SOC of the single battery 11 is low, the resistance of the single battery 11 increases. Even in the normal cell 11, the internal resistance differs depending on the state and environment of the cell 11, so the resistance magnification based on the amount of voltage variation also varies depending on one or both of temperature and SOC. In the present embodiment, the relationship between the threshold value and the resistance magnification is changed according to the temperature and SOC of the assembled battery 10, thereby further improving the accuracy of abnormality detection.

図４は、組電池１０の温度及びＳＯＣに応じて予め作成された閾値マップの一例であり、異常検出部３１は、組電池１０の温度又はＳＯＣのいずれか一方、又は温度及びＳＯＣに基づいて、図４に示した閾値マップから該当の閾値を選択し、選択された閾値と抵抗倍率とを比較して抵抗倍率が閾値を超えている場合、又は閾値よりも小さい場合に、単電池１１の異常を検出する。図４の閾値マップは、記憶部３２に格納することができる。 FIG. 4 is an example of a threshold map prepared in advance according to the temperature and SOC of the assembled battery 10, and the abnormality detection unit 31 is based on either the temperature or SOC of the assembled battery 10, or the temperature and SOC. 4, when a corresponding threshold value is selected from the threshold map shown in FIG. 4 and the selected threshold value is compared with the resistance magnification, and the resistance magnification exceeds the threshold, or is smaller than the threshold, Detect anomalies. The threshold map in FIG. 4 can be stored in the storage unit 32.

図４の縦軸は温度（℃）、横軸はＳＯＣ（％）であり、異常検出部３１は、温度センサ２２によって検出された組電池１０の温度に該当する閾値を選択したり、組電池１０のＳＯＣに該当する閾値を選択することができる。また、温度及びＳＯＣに該当する閾値を選択することができる。図４の閾値マップでは、組電池１０の温度が低く、かつＳＯＣが低い場合に閾値が大きくなり、組電池１０の温度及びＳＯＣが高い場合に閾値が低くなるように閾値が設定されている。 The vertical axis in FIG. 4 is temperature (° C.) and the horizontal axis is SOC (%), and the abnormality detection unit 31 selects a threshold corresponding to the temperature of the assembled battery 10 detected by the temperature sensor 22, or the assembled battery A threshold value corresponding to 10 SOCs can be selected. In addition, threshold values corresponding to temperature and SOC can be selected. In the threshold map of FIG. 4, the threshold is set so that the threshold increases when the temperature of the assembled battery 10 is low and the SOC is low, and the threshold decreases when the temperature and SOC of the assembled battery 10 are high.

また、本実施例では、２つの閾値それぞれと抵抗倍率とを比較し、単電池１１間の抵抗異常を判別することができる。例えば、閾値Ａは、抵抗倍率が１以上の場合の閾値、閾値Ｂは抵抗倍率が１未満の閾値として用いることができる。すなわち、本実施例の組電池１０の異常検出では、単電池１１間での電圧変動量の比率が閾値Ａと閾値Ｂとの間（閾値の上限値と下限値との間）であれば単電池１１は正常であると判別し、単電池１１間での電圧変動量の比率が閾値Ａを超えている場合、又は閾値Ｂを下回る場合には、単電池１１は異常であると判別する。 In this embodiment, each of the two threshold values is compared with the resistance magnification, and a resistance abnormality between the single cells 11 can be determined. For example, the threshold A can be used as a threshold when the resistance magnification is 1 or more, and the threshold B can be used as a threshold when the resistance magnification is less than 1. That is, in the abnormality detection of the assembled battery 10 of this embodiment, if the ratio of the voltage fluctuation amount between the single cells 11 is between the threshold value A and the threshold value B (between the upper limit value and the lower limit value of the threshold value), The battery 11 is determined to be normal, and when the ratio of the voltage fluctuation amount between the single cells 11 exceeds the threshold A or is lower than the threshold B, the single cell 11 is determined to be abnormal.

図５は、本実施例の電流センサの異常検出の動作を示すフローチャートである。図５に示す処理は、コントローラ３０の異常検出部３１によって実行される。異常検出部３１は、例えば、車両のイグニッションスイッチがオフからオンに切り替わり、システムメインリレーＳＭＲ−Ｂ，ＳＭＲ−Ｇがオンされて充放電制御が開始されることに伴って、組電池１０の異常検出処理を開始することができる（Ｓ１０１）。 FIG. 5 is a flowchart showing an abnormality detection operation of the current sensor of this embodiment. The process shown in FIG. 5 is executed by the abnormality detection unit 31 of the controller 30. For example, the abnormality detection unit 31 detects the abnormality of the assembled battery 10 when the ignition switch of the vehicle is switched from OFF to ON, and the system main relays SMR-B and SMR-G are turned ON to start charge / discharge control. The detection process can be started (S101).

ステップＳ１０２において、異常検出部３１は、組電池１０の直列に接続された各単電池１１それぞれの電圧検出値を、電圧監視ＩＣ２０を介して取得する。 In step S 102, the abnormality detection unit 31 acquires the voltage detection value of each unit cell 11 connected in series with the assembled battery 10 via the voltage monitoring IC 20.

ステップＳ１０３において、異常検出部３１は、電圧センサ２１によって検出された所定期間の電圧値を用いて、図２及び図３に示した一方の算出手法で電圧変動量ΔＩＲ（ΔＶ）を算出する。電圧電動量ΔＩＲの算出については上述した通りであり、予め一方の算出プログラムが記憶部３２に記憶され、異常検出部３１は、記憶部３２に記憶された算出プログラムに従って、図２又は図３に示した一方の算出方法を用いて所定期間における各単電池１１それぞれの電圧変動量ΔＩＲを算出する。 In step S 103, the abnormality detection unit 31 calculates the voltage fluctuation amount ΔIR (ΔV) using one of the calculation methods shown in FIGS. 2 and 3 using the voltage value of the predetermined period detected by the voltage sensor 21. The calculation of the voltage electric quantity ΔIR is as described above, and one calculation program is stored in the storage unit 32 in advance, and the abnormality detection unit 31 is shown in FIG. 2 or FIG. 3 according to the calculation program stored in the storage unit 32. The voltage fluctuation amount ΔIR of each unit cell 11 in a predetermined period is calculated using one of the calculation methods shown.

ステップＳ１０４において、異常検出部３１は、ステップＳ１０３で算出した所定期間における各電圧変動量を単電池１１間で比較した抵抗倍率を算出する。抵抗倍率は、上記式７のように求めることができる。 In step S 104, the abnormality detection unit 31 calculates a resistance magnification by comparing the voltage fluctuation amounts in the predetermined period calculated in step S 103 between the single cells 11. The resistance magnification can be obtained as shown in Equation 7 above.

ステップＳ１０５において、異常検出部３１は、組電池１０の温度とＳＯＣに応じて閾値を変化させる閾値選択処理を行う。異常検出部３１は、温度センサ２２によって検出された組電池１０の温度及びコントローラ３０で管理されている組電池１０のＳＯＣ情報を取得し、取得した組電池１０の温度及びＳＯＣ情報に応じた閾値を図４に示した閾値マップから選択する。 In step S 105, the abnormality detection unit 31 performs a threshold selection process for changing the threshold according to the temperature and SOC of the assembled battery 10. The abnormality detection unit 31 acquires the temperature of the assembled battery 10 detected by the temperature sensor 22 and the SOC information of the assembled battery 10 managed by the controller 30, and a threshold value corresponding to the acquired temperature and SOC information of the assembled battery 10 Is selected from the threshold map shown in FIG.

ステップＳ１０６、Ｓ１０７において、異常検出部３１は、ステップＳ１０４で算出された抵抗倍率とステップＳ１０５で選択された閾値を用いて、比較対象の単電池１１に抵抗異常があるか否かを判別する。 In steps S106 and S107, the abnormality detection unit 31 determines whether there is a resistance abnormality in the comparison target cell 11 using the resistance magnification calculated in step S104 and the threshold selected in step S105.

本実施例では、直列に接続された隣り合う単電池１１間の抵抗異常を判別したり、任意の単電池１１間の抵抗異常を判別することで、単電池１１の異常が検出するが、さらに検出精度を向上させるために、１つの単電池１１を他の異なる２つの単電池１１それぞれと比較することで、単電池１１の異常を検出するように構成できる。 In this embodiment, the abnormality of the unit cell 11 is detected by determining the resistance abnormality between the adjacent unit cells 11 connected in series or by determining the resistance abnormality between the arbitrary unit cells 11. In order to improve the detection accuracy, it can be configured to detect an abnormality of the unit cell 11 by comparing one unit cell 11 with each of two other different unit cells 11.

なお、抵抗倍率を求める各単電池１１の選択は、任意であり、異常検出部３１は、例えば、異常検出処理を開始する際に比較対象の単電池１１を決定し、決定された単電池１１のみの電圧変動量ΔＩＲを求めるようにしたり、複数の各単電池１１それぞれの電圧変動量ΔＩＲを求めてから、比較対象の単電池１１それぞれをランダムに又は所定のルールに従って決定するようにしてもよい。また、図５の例では、１つの単電池１１を他の異なる２つの単電池１１それぞれと比較することで、単電池１１の異常を検出しているが、上述のように、後述するステップＳ１０６及びステップＳ１０７の少なくとも一方を含む異常検出によって組電池１０の異常を検出するようにしてもよい。 The selection of each unit cell 11 for obtaining the resistance magnification is arbitrary, and the abnormality detection unit 31 determines, for example, the unit cell 11 to be compared when starting the abnormality detection process, and the determined unit cell 11 is determined. Only the voltage fluctuation amount ΔIR is obtained, or the voltage fluctuation amount ΔIR of each of the plurality of single cells 11 is obtained, and then each single cell 11 to be compared is determined randomly or according to a predetermined rule. Good. Further, in the example of FIG. 5, the abnormality of the unit cell 11 is detected by comparing one unit cell 11 with each of two other different unit cells 11, but as described above, step S 106 described later is performed. In addition, the abnormality of the assembled battery 10 may be detected by abnormality detection including at least one of step S107.

まず、ステップ１０６において、異常検出部３１は、第１単電池１１及び第２単電池１１間の電圧変動量に基づく抵抗倍率を閾値と比較して抵抗異常を判別する。抵抗異常があると判別された場合には、ステップＳ１１０に進み、組電池１０に異常があると判別して異常処理を遂行する。 First, in step 106, the abnormality detection unit 31 determines a resistance abnormality by comparing a resistance magnification based on a voltage fluctuation amount between the first unit cell 11 and the second unit cell 11 with a threshold value. If it is determined that there is a resistance abnormality, the process proceeds to step S110, where it is determined that there is an abnormality in the assembled battery 10, and abnormality processing is performed.

一方、ステップＳ１０６において、第１単電池１１及び第２単電池１１間の電圧変動量に基づく抵抗倍率が抵抗異常ではないと判別された場合、異常検出部３１は、ステップＳ１０７に進む。 On the other hand, in step S106, when it is determined that the resistance magnification based on the voltage fluctuation amount between the first unit cell 11 and the second unit cell 11 is not a resistance abnormality, the abnormality detection unit 31 proceeds to step S107.

ステップＳ１０７において、異常検出部３１は、ステップＳ１０６で比較対象の第２単電池１１と第１単電池１１を除く他の第３単電池１１との間の電圧変動量に基づく抵抗倍率を閾値と比較して抵抗異常を判別する。抵抗異常があると判別された場合には、ステップＳ１１０に進み、組電池１０に異常があると判別して異常処理を遂行する。 In step S107, the abnormality detection unit 31 sets the resistance magnification based on the amount of voltage fluctuation between the second unit cell 11 to be compared in step S106 and the third unit cell 11 other than the first unit cell 11 as a threshold value. The resistance abnormality is determined by comparison. If it is determined that there is a resistance abnormality, the process proceeds to step S110, where it is determined that there is an abnormality in the assembled battery 10, and abnormality processing is performed.

一方、ステップＳ１０７において、第２単電池１１及び第３単電池１１間の電圧変動量に基づく抵抗倍率が抵抗異常ではないと判別された場合、異常検出部３１は、ステップＳ１０８に進み、組電池１０が正常であると判別してステップＳ１０９に進む。 On the other hand, if it is determined in step S107 that the resistance magnification based on the voltage fluctuation amount between the second unit cell 11 and the third unit cell 11 is not a resistance abnormality, the abnormality detection unit 31 proceeds to step S108, and the assembled battery 10 is determined to be normal, and the process proceeds to step S109.

ステップＳ１０９において、異常検出部３１は、組電池１０が正常であると判別されている間は、イグニッションスイッチがオフされるまで、ステップＳ１０２からステップＳ１０９を繰り返し行い、組電池１０の異常検出を行う。 In step S109, while it is determined that the assembled battery 10 is normal, the abnormality detection unit 31 repeats steps S102 to S109 until the ignition switch is turned off to detect abnormality of the assembled battery 10. .

このように、１つの単電池１１を他の異なる２つの単電池１１それぞれと比較することで、少なくとも一方の単電池１１間での抵抗比率に異常が検出された場合に、単電池１１の異常を判別する、言い換えれば、１つの単電池１１と他の異なる２つの単電池１１それぞれとの間で各抵抗比率に異常が検出されない場合に、組電池１０が正常であると判別することで、２つの単電池１１間での抵抗比率の異常検出に比べてさらに精度よく異常検出を行うことができる。 As described above, when an abnormality is detected in the resistance ratio between at least one unit cell 11 by comparing one unit cell 11 with each other two different unit cells 11, the abnormality of the unit cell 11 is detected. In other words, when no abnormality is detected in each resistance ratio between one unit cell 11 and each of two other different unit cells 11, it is determined that the assembled battery 10 is normal. Anomaly detection can be performed with higher accuracy than the anomaly detection of the resistance ratio between the two single cells 11.

ステップＳ１１０の異常処理としては、例えば、ユーザなどに対して異常が発生していることを通知することができる。この通知は、ユーザの視覚又は聴覚で認識できるものであればよく、例えば、異常検出ランプを点灯させたり、スピーカを用いて異常が発生していることを示す情報を出力したり、異常が発生していることを示す情報をディスプレイに表示させることができる。 As the abnormality process in step S110, for example, it can be notified to the user that an abnormality has occurred. This notification may be anything that can be recognized by the user's visual or auditory sense. For example, an abnormality detection lamp is turned on, information indicating that an abnormality has occurred using a speaker, or an abnormality has occurred. It is possible to display information indicating that the display is in progress on the display.

また、組電池１０の異常を検出した場合に、本実施例の組電池１０を搭載するハイブリッド車両では、エンジンのみを駆動源とする走行モードに設定したり、電気自動車では、走行を中止する通知を行うなど、組電池１０からの電力を用いた走行や機器の駆動を行わないようにすることもできる。ステップＳ１０９を遂行した後、異常検出部３１は、異常検出処理を終了する。 In addition, when an abnormality is detected in the assembled battery 10, in a hybrid vehicle equipped with the assembled battery 10 according to the present embodiment, a driving mode in which only the engine is used as a driving source is set, or in an electric vehicle, the driving is stopped. For example, it is possible not to run the vehicle using the electric power from the assembled battery 10 or drive the device. After performing Step S109, the abnormality detection unit 31 ends the abnormality detection process.

本実施では、電圧センサ２１の検出値のみで単電池１１の異常を検出できるので、電圧センサ２１以外の電流センサ等の機器類が不要となり、部品点数の増加を抑制できる。さらに、所定期間における各電圧変動量を単電池１１間で比較して単電池１１の異常、すなわち、組電池１０の異常を検出するので、電圧センサ２１の電圧検出値を単に比較した異常検出に比べて精度よく単電池１１の異常を検出することができる。 In this embodiment, since the abnormality of the unit cell 11 can be detected only by the detection value of the voltage sensor 21, devices such as a current sensor other than the voltage sensor 21 are not required, and an increase in the number of parts can be suppressed. Furthermore, each voltage fluctuation amount in a predetermined period is compared between the cells 11 to detect the abnormality of the cells 11, that is, the abnormality of the assembled battery 10, so that the abnormality detection is simply performed by comparing the voltage detection value of the voltage sensor 21. The abnormality of the unit cell 11 can be detected with higher accuracy than that.

また、電圧センサ２１によって検出された検出結果から所定期間の電圧変動量を算出することで、単電池１１間にＳＯＣのバラツキがあっても電流センサによる計測によらずに各単電池１１に実際に流れた電流に対してＳＯＣの影響を低減した電圧、すなわち、各単電池１１に実際に流れた電流に対してＳＯＣの影響が抑制された単電池１１の抵抗を単電池１１間で比較して異常を検出するので、検出精度が向上する。 Further, by calculating the voltage fluctuation amount for a predetermined period from the detection result detected by the voltage sensor 21, even if there is a variation in SOC between the single cells 11, each single cell 11 is actually measured regardless of the measurement by the current sensor. The voltage in which the influence of the SOC is reduced with respect to the current that flows in the battery, that is, the resistance of the single battery 11 in which the influence of the SOC is suppressed with respect to the current that actually flows in each of the single batteries 11 is compared between the single batteries 11 Therefore, the detection accuracy is improved.

１０組電池（電源装置）
１１単電池（蓄電素子）
２０電圧監視ＩＣ
２１電圧センサ
２２温度センサ
２３昇圧コンバータ
２４インバータ
２５モータ・ジェネレータ
３０コントローラ 10 battery pack (power supply)
11 Single cell (storage element)
20 Voltage monitoring IC
21 Voltage sensor 22 Temperature sensor 23 Boost converter 24 Inverter 25 Motor generator 30 Controller

Claims

An abnormality detection system for a power supply device mounted on a vehicle and having a plurality of power storage elements connected in series,
A voltage sensor for detecting a voltage of the storage element;
A control device for calculating a voltage fluctuation amount of each of the at least two power storage elements in a predetermined period, comparing each voltage fluctuation amount between the power storage elements, and detecting an abnormality of the power storage element;
An anomaly detection system comprising:

The said control apparatus calculates the ratio of the said voltage fluctuation amount between the said electrical storage elements, and when the said ratio exceeds a predetermined threshold value, it detects the abnormality of the said electrical storage element. Anomaly detection system.

The abnormality detection system according to claim 1, wherein the control device calculates a voltage difference between a maximum voltage and a minimum voltage detected within a certain voltage behavior detection time as the voltage fluctuation amount.

The abnormality detection system according to claim 1, wherein the control device calculates a change amount of each voltage value detected at a predetermined time interval as the voltage fluctuation amount.

The abnormality detection system according to claim 2, wherein the control device changes the predetermined threshold according to at least one of a temperature of the power supply device and an SOC.

A temperature sensor for detecting a temperature of the power supply device;
The control device selects a temperature detected by the temperature sensor and a threshold value corresponding to the SOC information of the power supply device from threshold values preset according to the temperature and SOC of the power supply device, and the ratio is the ratio The abnormality detection device according to claim 5, wherein an abnormality of the power storage element is detected when the selected threshold value is exceeded.

The control device compares the voltage fluctuation amount between the first power storage element and the second power storage element, and further compares the voltage fluctuation amount between the second power storage element and the third power storage element. The abnormality detection system according to claim 1, wherein an abnormality of the electric storage element is detected when an abnormality is detected by comparison between the electric storage elements.

A plurality of power storage elements are connected in series, an abnormality detection device for a power supply device mounted on a vehicle,
Using the detection value detected by the voltage sensor that detects the voltage of the storage element, calculate a voltage fluctuation amount of each of the at least two storage elements in a predetermined period, and compare each voltage fluctuation amount between the storage elements. The abnormality detection apparatus characterized by including the control part which detects abnormality of the said electrical storage element.

A power storage device abnormality detection method in which a plurality of power storage elements are connected in series and mounted on a vehicle,
Calculating a voltage fluctuation amount of each of at least two power storage elements in a predetermined period using a detection value detected by a voltage sensor that detects a voltage of the power storage element;
Comparing each voltage fluctuation amount between the storage elements to detect an abnormality of the storage element;
An abnormality detection method comprising:

The step of calculating the voltage fluctuation amount includes calculating a voltage difference between a maximum voltage and a minimum voltage detected within a certain voltage behavior detection time or a change amount of each voltage value detected at a predetermined time interval. The abnormality detection method according to claim 9, wherein the abnormality detection method is calculated as a quantity.

The step of detecting the abnormality calculates a ratio of the voltage fluctuation amount between the storage elements, and detects an abnormality of the storage element when the ratio exceeds a predetermined threshold.
Changing the predetermined threshold according to at least one of temperature and SOC of the power supply device;
The step of changing the predetermined threshold includes:
Based on the detection value detected by the temperature sensor for detecting the temperature of the power supply device and the SOC information of the power supply device, a corresponding threshold value is selected from the preset threshold values for the temperature and SOC of the power supply device The abnormality detection method according to claim 9 or 10, wherein: