JP4006877B2 - Battery pack voltage adjustment device and battery pack voltage adjustment method - Google Patents

Description

【００４３】
即ち、コンパレータ２７Ｈは、分圧電位Ｅr1が、端子Ｊc1の電位Ｅc1よりも高い場合にハイレベルとなり、コンパレータ２７Ｌは、分圧電位Ｅr1が、電位Ｅc1から微小電圧Ｖαを減じたものよりも低くなった場合にハイレベルとなる。従って、分圧電位Ｅr1が、Ｅc1−Ｖα≦Ｅr1≦Ｅc1，の範囲にあり電位Ｅc1にほぼ等しいとみなされる場合には、コンパレータ２７Ｈ，２７Ｌは何れもロウレベルとなる。また、コンパレータ２８Ｈ，２８Ｌについても、分圧電位Ｅr2，端子Ｊc2の電位Ｅc2に関して同様である。
【００４４】
そして、これら４つのコンパレータ２７Ｈ，２７Ｌ，２８Ｈ，２８Ｌの出力レベルを論理合成することにより、３つのスイッチ３５（１）乃至３５（３）を夫々オン状態“１”とする条件は、図２に示す真理値表のようになる。但し、“×”は任意のレベルを示す。
【００４５】
▲１▼Ｖ３＞Ｖ２＞Ｖ１
ここで、単位セル２１（１）〜２１（３）の各端子電圧が、Ｖ３＞Ｖ２＞Ｖ１となっている初期状態からの作用について図３も参照して説明する。
【００４６】
［期間Ａ］
この場合、

となることから、コンパレータ２７Ｈ，２８Ｈの出力信号は何れもハイレベル“Ｈ”となる。従って、図２に示す真理値表では、スイッチ３５（３）がオン状態“１”となる条件が成立するので、放電回路３３（３）により単位セル２１（３）が放電される。
【００４７】
単位セル２１（３）が放電されることにより端子電圧Ｖ３が低下すると、組電池２２の端子電圧Ｅc3（＝Ｅr3）が低下し、それに応じて分圧電位Ｅr2も低下する。そして、Ｖ３＜Ｖ２となり、Ｅr2＝Ｅc2となると、コンパレータ２８Ｈの出力信号はロウレベル“Ｌ”となる。
【００４８】
このとき、図３の時点Ｐに示すように、端子電圧Ｖ３は、組電池２２の平均セル電圧となっているが、単位セル２１（２）は放電されていないのでＶ２＞Ｖ１の関係は維持されており、（４）式におけるＥr1＞Ｅc1、は変わらない。従って、コンパレータ２７Ｈの出力信号は“Ｈ”のままである。すると、図２に示す真理値表では、スイッチ３５（２）がオン状態“１”となる条件が成立するので、放電回路３３（２）により単位セル２１（２）が放電されると同時に、放電回路３３（３）による単位セル２１（３）の放電は停止する。
【００４９】
ここで、コンパレータ２７Ｈ，２７Ｌについて、コンパレータ２７Ｈの出力信号が“Ｌ”であり、コンパレータ２７Ｌの出力信号レベルは問わないという条件は、少なくともＥr2がＥc2よりも高くないという条件であり、即ち、Ｅr2がＥc2にほぼ等しいかまたはＥr2がＥc2よりも低い、Ｅr2≦Ｅc2という条件を意味している。
【００５０】
［期間Ｂ］
単位セル２１（２）が放電されることにより端子電圧Ｖ２が低下すると、電圧Ｅc2及びＥr3が低下するので、それに伴って分圧電位Ｅr2も低下する。ここで、Ｅr2とＥc2とを比較すると、（１）式及び（２）式から、
Ｅc2＝ Ｖ１＋Ｖ２
Ｅr2＝２（Ｖ１＋Ｖ２＋Ｖ３）／３
であり、端子電圧Ｖ２の低下の影響はＥc2の方が明らかに大きい。従って、両者の大小関係は、Ｅr2＝Ｅc2から再びＥr2＞Ｅc2となり、コンパレータ２８Ｈの出力信号は再び“Ｈ”となる。すると、スイッチ３５（３）がオン状態“１”となる条件が成立して、放電回路３３（２）による放電は停止し、放電回路３３（３）により単位セル２１（３）が放電される。
【００５１】
即ち、この場合、単位セル２１（２）が放電されて端子電圧Ｖ２が低下することで、単位セル２１の平均電圧も低下することになる。すると、端子電圧Ｖ３もまた、その電位が時点Ｐから維持されたままでは平均電圧とのずれが生じることになるので、単位セル２１（３）が再び放電されて、端子電圧Ｖ３が平均電圧に略一致するように作用する。
【００５２】
単位セル２１（３）が放電されることにより端子電圧Ｖ３が低下して、再び平均電圧に略一致すると、前述のように分圧電位Ｅr3，Ｅr2が低下し、Ｅr2＝Ｅc2となってコンパレータ２８Ｈの出力信号は“Ｌ”となる。また、単位セル２１（２）は放電されないのでＶ２＞Ｖ１であり、Ｅr1＞Ｅc1であるから、コンパレータ２７Ｈの出力信号は“Ｈ”のままである。すると、スイッチ３５（２）がオン状態“１”となる条件が成立するので、単位セル２１（２）が放電されると同時に、単位セル２１（３）の放電は停止する。
【００５３】
即ち、期間Ｂにおいては、スイッチ３５（２），３５（３）が交互にオン状態となり、単位セル２１（２），２１（３）が交互に放電される。また、図３においては、端子電圧Ｖ２，Ｖ３は直線状に低下するように図示されているが、実際には、一方の電位が低下している場合に他方の電位は変化しないようになっており、その状態が短期間で交互に繰り返されるようになっている。
【００５４】
そして、最終的に、Ｅr1＝Ｅc1，Ｅr2＝Ｅc2，即ち、Ｖ１＝Ｖ２＝Ｖ３になると、コンパレータ２７Ｈ，２７Ｌ，２８Ｈ，２８Ｌの出力レベルは何れも“Ｌ”となり、単位セル２１（１）〜２１（３）の放電は停止する。以上で端子電圧Ｖ１，Ｖ２，Ｖ３のばらつき調整作用は終了する。
【００５５】
▲２▼Ｖ１＞Ｖ２＞Ｖ３
次に、初期状態としてＶ１＞Ｖ２＞Ｖ３である場合の作用について説明する。この場合、

となることから、コンパレータ２７Ｌ，２８Ｌの出力信号は何れも“Ｈ”となる。従って、図２に示す真理値表では、スイッチ３５（１）がオン状態“１”となる条件が成立するので、放電回路３３（１）により単位セル２１（１）が放電される。
【００５６】
単位セル２１（１）が放電されることにより端子電圧Ｖ１が低下すると、端子電圧Ｅc1が低下し、それに応じて電圧Ｅr3，Ｅr1も低下する。ここで、Ｅr1とＥc1とを比較すると、（１）式及び（２）式から、
Ｅc1＝ Ｖ１
Ｅr1＝（Ｖ１＋Ｖ２＋Ｖ３）／３
であり、端子電圧Ｖ１の低下の影響はＥc1の方が明らかに大きい。従って、Ｅc1はＥr1に近付いてやがてＥr1＝Ｅc1となり、コンパレータ２７Ｌの出力信号は“Ｌ”となる。すると、スイッチ３５（２）がオン状態“１”となる条件が成立して、放電回路３３（１）による放電は停止し、放電回路３３（２）により単位セル２１（２）が放電される。
【００５７】
単位セル２１（２）が放電されることにより端子電圧Ｖ２が低下すると、電圧Ｅr3，Ｅr1が低下する。また、単位セル２１（１）は放電されないので、Ｖ１＝Ｅc1は低下しない。その結果、再びＥr1＜Ｅc1となり、コンパレータ２７Ｌの出力信号は再び“Ｈ”となる。すると、放電回路３３（２）による放電は停止し、放電回路３３（１）により単位セル２１（１）が放電される。
【００５８】
単位セル２１（１）が放電されることにより端子電圧Ｖ１が低下すると、端子電圧Ｅc1が低下し、再びＥr1＝Ｅc1となり、放電回路３３（１）による放電は停止し、放電回路３３（２）により単位セル２１（２）が放電される。以降、スイッチ３５（１），３５（２）が交互にオン状態となり、単位セル２１（１），２１（２）が交互に放電される。そして、最終的にＥr1＝Ｅc1，Ｅr2＝Ｅc2，即ち、Ｖ１＝Ｖ２＝Ｖ３になると、単位セル２１（１）〜２１（３）の放電は停止して、端子電圧Ｖ１，Ｖ２，Ｖ３のばらつき調整作用は終了する。この電圧変化は、図３におけるＶ１とＶ３とを入れ替えたものとなる。
【００５９】
▲３▼Ｖ２＞Ｖ３＝Ｖ１
次に、初期状態がＶ２＞Ｖ３＝Ｖ１である場合の作用について図４をも参照して説明する。この場合、

となることから、コンパレータ２７Ｈ，２８Ｌの出力信号は何れも“Ｈ”となる。この時、コンパレータ２７Ｌ，２８Ｈの出力信号は何れも“Ｌ”であり、図２に示す真理値表では、スイッチ３５（２）がオン状態“１”となる条件が成立するので、放電回路３３（２）により単位セル２１（２）が放電される。
【００６０】
単位セル２１（２）が放電されることにより端子電圧Ｖ２が低下すると、電圧Ｅc2及びＥr3が低下するので、それに伴って分圧電位Ｅr2，Ｅr1も低下し、Ｅr1はＥc1に近付いて行く。また、前述のように、Ｅr2，Ｅc2間では、端子電圧Ｖ２の低下の影響はＥc2の方が明らかに大きいので、Ｅc2はＥr2に近付いて行く。そして、最終的に、Ｅr1＝Ｅc1，Ｅr2＝Ｅc2，Ｖ１＝Ｖ２＝Ｖ３になると、端子電圧Ｖ１，Ｖ２，Ｖ３のばらつき調整動作は終了する。
【００６１】
即ち、この場合過渡状態においては、単位セル２１の平均電圧に対して端子電圧Ｖ２のみが常に高く、端子電圧Ｖ１及びＶ３は常に低いことから、単位セル２１（２）のみが終始放電されることになる。
【００６２】
以上のように本実施例によれば、３個の単位セル２１（１）〜２１（３）を直列接続してなる組電池２２の端子電圧を、抵抗２３，２４，２５を直列に接続してなる分圧回路２６により分圧して、論理回路部３７は、コンパレータ２７Ｈ乃至２８Ｌの出力信号に基づいて、単位セル２１（１）〜２１（３）の内端子電圧が平均電圧よりも高いものを自動的に放電させて、最終的に全ての単位セル２１（１）〜２１（３）の端子電圧を略等しくしてばらつきを解消するようにした。
【００６３】
そして、例えば、単位セル２１（２）については、論理回路部３７は、正極側の連結点Ｊc2の電位Ｅc2が対応する分圧点Ｊr2の電位Ｅr2よりも高いか又は略等しく（Ｅc2≧Ｅr2）且つ負極側の連結点Ｊc1の電位Ｅc1よりも対応する分圧点Ｊr1の電位Ｅr1が高い場合（Ｅc1＜Ｅr1）、または、電位Ｅc2が電位Ｅr2よりも高く（Ｅc2＞Ｅr2）且つ電位Ｅc1よりも電位Ｅr1が高いか又は両者が略等しい場合（Ｅc1≦Ｅr1）に、端子電圧Ｖ２が平均電圧よりも高いと判断するようにした。
【００６４】
従って、単位セル２１の端子電圧と分圧回路２６より得られる平均電圧との高低を確実に判断して、各単位セル間の端子電圧、即ち、残存容量のばらつきを解消することができるので、過充電や過放電を防止すると共に組電池２２の使用効率を向上させることができる。
【００６５】
また、本実施例によれば、高いエネルギ密度を有するが、より厳密な過充電，過放電対策が必要とされるリチウム電池を単位セル２１とする組電池２２に適用することによって、充放電を安全に制御した上でリチウム電池の性能を十分に引出して活用することができる。
【００６６】
ところで、従来の電圧調整装置はＭＰＵを使用する構成であり、そのＭＰＵに対して安定したレベルの動作用電源を供給する必要があった。そのため、従来は、その動作用電源を駆動用電源のバッテリとは別個に設けられている制御用電源（１２Ｖバッテリ，所謂ガソリン自動車のバッテリに相当する）から供給するようにしていた。
【００６７】
これに対して、本実施例によれば、コンパレータ２７Ｈ〜４１Ｌ及び論理回路部３７の動作用電源を駆動用電源たる組電池２２から得るようにした。即ち、論理回路部３７は、従来とは異なり、ＭＰＵなどを用いることなしに論理ゲートの組合わせで構成することができるので、その消費電力は、従来に比して極めて僅かとなっている。そして、組電池２２は３直列構成であるから、その端子電圧は３．６×３＝１０．８（Ｖ）程度であり、３．３〜５Ｖ程度の動作用電源の作成にも適している。加えて、これらの回路はＭＰＵとは異なり、電源電圧が多少低下しても動作が可能であることから、これらの動作用電源を組電池２２から得ることができるようになっている。従って、前記動作用電源に対しては相対的に容量が小さい制御用電源の電力消費を抑制することができる。
【００６８】
（第２実施例）
図５及び図６は本発明の第２実施例を示すものであり、第１実施例と同一部分には同一符号を付して説明を省略し、以下異なる部分についてのみ説明する。第２実施例では、組電池２２に単位セル２１（４）を加えて、直列接続数を４とした組電池３８に適用した構成である。
【００６９】
また、分圧回路２６の抵抗２５は、抵抗２３及び２４と同様に、抵抗比４０００：１の抵抗２５ａ及び２５ｂで構成され、更に、単位セル２１（４）に対応する抵抗３９を直列に加えたものが分圧回路４０を構成している。そして、単位セル２１（３）及び２１（４）の連結点Ｊc3と抵抗２５ｂの両端とには、コンパレータ４１Ｈ及び４１Ｌ（電位比較手段）が、コンパレータ２８Ｈ及び２８Ｌなどと同様に接続されている。
【００７０】
一方、コンパレータ２８Ｌの出力端子は、ＮＯＴゲート４２を介してＡＮＤゲート４３の一方の入力端子に接続されており、そのＡＮＤゲート４３の他方の入力端子は、コンパレータ４１Ｌの出力端子に接続されている。また、コンパレータ２８Ｈの出力端子は、スイッチ３５（３）の制御端子に代えて、ＡＮＤゲート４４の一方の入力端子に接続されており、そのＡＮＤゲート４４の他方の入力端子は、ＮＯＴゲート４５を介してコンパレータ４１Ｈの出力端子に接続されている。
【００７１】
そして、ＡＮＤゲート４３及び４４の出力端子は、ＯＲゲート４６の入力端子に夫々接続されており、そのＯＲゲート４６の出力端子は、スイッチ３５（３）の制御端子に接続されている。また、単位セル２１（４）に対応して設けられた放電回路３３（４）を構成するスイッチ３５（４）の制御端子は、コンパレータ４１Ｈの出力端子に接続されている。
【００７２】
尚、論理回路部３７の構成要素に、ＮＯＴゲート４２及び４５，ＡＮＤゲート４３及び４４並びにＯＲゲート４６を加えたものが、論理回路部４７を構成している。また、放電回路３３に論理回路部４７を加えたものが、放電制御手段を構成している。加えて、第１実施例と同様に、コンパレータ２７Ｈ〜４１Ｌ並びに論理回路部４７の動作用電源は、組電池３８から作成されて供給されるようになっている。
【００７３】
次に、第２実施例の作用について図６をも参照して説明する。図６に示す論理回路部４７の真理値表は、下から２〜４段目は、第１実施例の図２と同様にコンパレータ２７Ｈ乃至２８Ｌの論理で決定される。また、何れのスイッチ３５もオフ状態となる最下段についても、コンパレータ４１Ｈ，４１Ｌが共にロウレベルである条件が加わっただけである。
【００７４】
そして、下から５，６段目のスイッチ３５（３）がオン状態“１”となる条件は、スイッチ３５（２）がオン状態となるコンパレータ２７Ｈ乃至２８Ｌの論理を、コンパレータ２８Ｈ乃至４１Ｌに対して同様に適用したものとなっている。また、最上段のスイッチ３５（４）がオン状態となる条件は、コンパレータ４１Ｈがハイレベルである条件となる。
【００７５】
即ち、組電池３８の内、最も負側となる単位セル２１（１）に対応するスイッチ３５（１）のオン条件は、正側の連結点Ｊc1の電位が分圧点Ｊr1（Ｊr1′）の電位よりも高い時にハイレベルの信号を出力するコンパレータ２７Ｌの出力論理のみで決定され、最も正側となる単位セル２１（４）に対応するスイッチ３５（４）のオン条件は、分圧点Ｊr3の電位が、負側の連結点Ｊc3の電位よりも高い時にハイレベルの信号を出力するコンパレータ４１Ｈの出力論理のみで決定される。
【００７６】
また、それらの中間に配置される例えば単位セル２１（２）に対応するスイッチ３５（２）のオン条件は、単位セル２１（２）の正側に配置されたコンパレータ２８Ｈ，２８Ｌと、負側に配置されたコンパレータ２７Ｈ，２７Ｌとの出力論理で決定される。
【００７７】
以上のように構成された第２実施例によれば、４直列構成の組電池３８に適用した場合でも、第１実施例と同様の効果を得ることができる。また、従来とは異なり、多直列の組電池３８に適用した場合でも、誤差が累積されることがなく、精密な電圧調整を行うことができる。
【００７８】
ここで、第１及び第２実施例を普遍化して、ｎ（ｎは自然数）直列構成の組電池に適用した場合を図７及び図８に示す。即ち、第ｉ番目（１＜ｉ＜ｎ）の単位セルＣi の正側，負側の連結点をＪci，Ｊci-1，対応する分圧抵抗Ｒi ，Ｒi-1 の連結点をＪri，Ｊri-1として、図示しない端子Ｊc0を基準とする連結点Ｊci，Ｊci-1の電位をＥci，Ｅci-1，連結点Ｊri，Ｊri-1の電位をＥri，Ｅri-1とする。
【００７９】
そして、単位セルＣi について、分圧点Ｊriの電位が連結点Ｊciの電位よりも高い時にハイレベルの信号を出力するコンパレータをＣＰi Ｈ，逆に、連結点Ｊciの電位が分圧点Ｊriの電位よりも高い時にハイレベルの信号を出力するコンパレータをＣＰi Ｌとする。また、分圧抵抗Ｒによって得られる単位セルＣの平均電圧をＶM ，単位セルＣi の端子電圧をＶi とすると、各値には（７）式の関係がある。
Ｖi ＝Ｅci−Ｅci-1
ＶM ＝Ｅri−Ｅri-1 …（７）
【００８０】
従って、Ｖi ＞ＶM と判定するための条件、即ち、単位セルＣi に対応する放電回路のスイッチＳＷi をオン状態にする条件は、
（Ｅci≧Ｅri）・（Ｅci-1＜Ｅri-1）
＋（Ｅci＞Ｅri）・（Ｅci-1≦Ｅri-1） …（８）
であり、上記（８）の条件を満たすコンパレータＣＰの出力条件は、図８に示すように、

となる。尚、（８）式において、シンボル“・”は論理ＡＮＤを、シンボル“＋”は論理ＯＲを示している。
【００８１】
例えば、（８），（９）の第１式の対応を見ると、少なくともコンパレータＣＰi-1 Ｈが“Ｈ”である、ということは、条件（Ｅci-1＜Ｅri-1）そのものであり、少なくともコンパレータＣＰi Ｈが“Ｌ”である、ということは、条件（Ｅci＜Ｅri）の否定であるから、条件（Ｅci≧Ｅri）を意味している。尚、コンパレータＣＰi Ｈ及びＣＰi Ｌが共に“Ｌ”である、ということは、条件（Ｅci＝Ｅri）を意味する。
【００８２】
以上のように、ｎが例えば数１０個であるような多直列構成の組電池であっても、第１番目，第ｎ番目の単位セルＣ1 ，Ｃn については、コンパレータＣＰ1 Ｌ，ＣＰn Ｈの出力レベルが夫々“Ｈ”の時に対応する放電回路のスイッチＳＷ1 ，ＳＷn をオン状態にするように、また、それらの中間にある負側から第ｉ番目の単位セルＣi については、コンパレータＣＰの出力条件が（８）式のように成立した時に、対応する放電回路のスイッチＳＷi をオン状態にするように論理回路部を構成すれば良い。
【００８３】
（第３実施例）
図９は本発明の第３実施例を示すものである。上述したように、本発明は、理論的には組電池の直列数が幾つのものであっても適用することが可能である。しかしながら、実際には、使用する素子の耐圧などの問題があるため、単位セルがセル電圧約３．６Ｖのリチウム電池の場合には、４〜５直列程度の組電池を１単位として構成するのが好ましいと考えられる。
【００８４】
そこで、第３実施例は、第２実施例のように４直列構成の組電池３８に、放電回路３３，分圧回路４０及び論理回路部４７からなる電圧調整機構を加えたものを１つの電池モジュール４８としている。そして、その電池モジュール４８を２０個直列に接続することにより、リチウム電池の単位セル２１のセル電圧３．６Ｖ×８０個で電圧約３００ＶとなるＨＥＶの駆動用バッテリ４９を構成した。
【００８５】
そして、その駆動用バッテリ４９に対して、図１２に示す従来構成の電圧調整装置を適用したものであり、図１２における単位セル２が、電池モジュール４８に置き換わっている。即ち、各電池モジュール４８においては、内蔵された論理回路部４７の作用により、４つの単位セル２１間における端子電圧のばらつきは自動的に補正される。従って、ＭＰＵ７は、電池モジュール４８を１個のセルのように扱うことが可能である。
【００８６】
以上のように構成された第３実施例によれば、ＭＰＵ７が２０個の電池モジュール４８の端子電圧を夫々電圧検出器４で周期的に測定し、マルチプレクサ５及びＡ／Ｄコンバータ６を介して読み込むことにより、１個のＭＰＵ７により実質８０個の単位セル２１を直列接続してなる駆動用バッテリ４９の電圧調整を行うことができる。従って、従来とは異なり、複数のＭＰＵを使用する必要がないので、装置のコストを大幅に削減することができる。
【００８７】
（第４実施例）
図１０は本発明の第４実施例を示すものであり、第２実施例と同一部分には同一符号を付して説明を省略し、以下異なる部分についてのみ説明する。第４実施例の分圧回路（分圧手段）４０′は、第２実施例の分圧回路４０から小分圧抵抗２３ｂ，２４ｂ及び２５ｂを削除した構成となっている。
【００８８】
そして、差動増幅器（電位差増幅手段，電位比較手段）５０（１）の反転及び非反転入力端子は、端子Ｊc1及びＪr1に夫々接続されており、出力端子は、（第２実施例の端子Ｊc1に代わって）コンパレータ２７Ｈ及び２７Ｌの非反転及び反転入力端子に接続されている。また、差動増幅器５０（１）の反転入力端子に挿入されている抵抗５７（１）と、当該反転入力端子と出力端子との間に接続されている抵抗５８（１）とは、差動増幅器５０（１）の増幅率を決定するために設けられている。
【００８９】
また、端子Ｊc2，Ｊc0間には、抵抗５１Ｈ，ダイオード５２Ｈ及び５２Ｌ，抵抗５１Ｌの直列回路が接続されており、ダイオード５２Ｈのカソード及び５２Ｌのアノード（共通接続点）は、端子Ｊc1に接続されている。そして、コンパレータ２７Ｈの反転入力端子はダイオード５２Ｈのアノードに接続され、コンパレータ２７Ｌの非反転入力端子はダイオード５２Ｈのカソードに接続されている。
【００９０】
同様にして、差動増幅器（電位差増幅手段，電位比較手段）５０（２）が、端子Ｊc2及びＪr2とコンパレータ２８Ｈ及び２８Ｌとの間に配置され、差動増幅器（電位差増幅手段，電位比較手段）５０（３）が、端子Ｊc3及びＪr3とコンパレータ４１Ｈ及び４１Ｌとの間に配置されている。そして、端子Ｊc3，Ｊc1間には、抵抗５３Ｈ，ダイオード５４Ｈ及び５４Ｌ，抵抗５３Ｌの直列回路が接続され、端子Ｊc4，Ｊc2間には、抵抗５５Ｈ，ダイオード５６Ｈ及び５６Ｌ，抵抗５５Ｌの直列回路が接続されている。その他の構成は第２実施例と同様である。
【００９１】
次に、第４実施例の作用について説明する。例えば、差動増幅器５０（１）は、端子Ｊr1における電位Ｅr1と端子Ｊc1における電位Ｅc1との電位差Ｖd1（＝Ｅri−Ｅci）を増幅して増幅信号α・Ｖd1をコンパレータ２７Ｈ及び２７Ｌに出力する。コンパレータ２７Ｈは、増幅信号α・Ｖd1のレベルが、ダイオード５２Ｈの順方向電圧ＶF よりも高い場合、即ち、
α・Ｖd1＞ＶF
の時に“Ｈ”を出力する。
【００９２】
また、コンパレータ２７Ｌは、増幅信号α・Ｖd1のレベルが負（即ち、Ｅri＜Ｅci）の場合において、その絶対値がダイオード５２Ｌの順方向電圧ＶF よりも高い場合、即ち、
｜α・Ｖd1｜＞ＶF （Ｖd1＜０）
の時に“Ｈ”を出力する。また、差動増幅器５０（２）、５０（３）も夫々対応する電位について同様に動作して、論理回路部４７（図１０では図示せず）は、コンパレータ２７Ｈ〜４１Ｌの出力信号を第２実施例と同様に論理合成する。
【００９３】
即ち、第２実施例のように小分圧抵抗２３ｂ，２４ｂ及び２５ｂを用いてコンパレータ２８Ｈ〜４１Ｌが電位比較を行うと、実際には、動作環境の温度変化などによって抵抗値が変化することなどから、比較動作が安定し難いという問題がある。
【００９４】
これに対して、第４実施例によれば、組電池３８側の電位と分圧回路４０′側の電位との差Ｖd を差動増幅器５０により増幅してコンパレータ２８Ｈ〜４１Ｌに与え、コンパレータ２８Ｈ〜４１Ｌは、増幅信号α・Ｖd のレベルを、安定性の良いダイオード５２，５４，５６の順方向電圧ＶF を利用して作成された基準電圧と比較するので、単位セル２１の端子電圧Ｅc と平均電圧ＶM との高低をより確実に判定することができ、動作の安定性を向上させることができる。
【００９５】
（第５実施例）
図１１乃至図１３は本発明の第５実施例を示すものであり、第４実施例と同一部分には同一符号を付して説明を省略し、以下異なる部分についてのみ説明する。第５実施例では、端子Ｊc1と抵抗５７（１）との間，端子Ｊc2と抵抗５７（２）との間，端子Ｊc3と抵抗５７（３）との間，端子Ｊc4と端子Ｊr4との間に、夫々ヒューズ（経路遮断手段）５９（１），５９（２），５９（３），５９（４）が挿入されている。
【００９６】
また、端子Ｊr4とヒューズ５９（３）及び抵抗５７（３）の共通接続点との間には、抵抗６０及びサーミスタ（温度検出手段）６１の直列回路並びに抵抗６３及び６４の直列回路が接続されている。そして、抵抗６０及びサーミスタ６１の共通接続点はコンパレータ（温度比較手段）６２の反転入力端子に接続されており、抵抗６３及び６４の共通接続点は、抵抗６５を介してコンパレータ６２の非反転入力端子に接続されている。コンパレータ６２の出力端子は、抵抗６６を介して自身の非反転入力端子に接続されていると共に、論理回路部４７に代わる論理回路部（放電制御手段）６７のIHBT端子に接続されている。
【００９７】
サーミスタ６１は、温度が低下すると抵抗値が増大するネガティブサーミスタであり、コンパレータ６２の反転入力端子に印加される電圧は、単位セル２１（４）の端子間電圧が一定であれば、抵抗６０及びサーミスタ６１の抵抗値の比で決定される。一例として、単位セル２１（４）の端子間電圧が４．０Ｖ，抵抗６０，６３及び６４の抵抗値が１５０ｋΩであれば、コンパレータ６２の非反転入力端子に印加される基準電圧は、２．０Ｖとなる。そして、サーミスタ６１は、温度が−３０℃（基準温度）以下になると抵抗値が１５０ｋΩ以上となる特性のものを選択する。尚、抵抗５１Ｈ，５１Ｌ，５３Ｈ，５３Ｌ，５５Ｈ，５５Ｌは図示を省略している。
【００９８】
ここで、図１２は、論理回路部６７の一構成例を示すものである。即ち、論理回路部６７は、論理回路部４７にＡＮＤゲート６８（１），６８（２），６８（３），６８（４）を加えた構成である。これらのＡＮＤゲート６８の一方の入力端子はIHBT端子に接続されており、ＡＮＤゲート６８（１），６８（２），６８（３），６８（４）の他方の端子は、コンパレータ２７Ｌの出力端子，ＯＲゲート３６の出力端子，ＯＲゲート４６の出力端子，コンパレータ４１Ｈの出力端子に夫々接続されている。そして、ＡＮＤゲート６８（１）〜６８（４）の出力端子は、スイッチ３５（１）〜３５（４）のオンオフ制御端子に夫々接続されている。
【００９９】
次に、第５実施例の作用について図１３をも参照して説明する。図１３は、論理回路部６７の真理値を示すものである。コンパレータ６２は、サーミスタ６１両端の電圧が、非反転入力端子に印加される基準電圧よりも低い場合には出力端子がハイレベル“Ｈ”となり、サーミスタ６１両端の電圧が、基準電圧よりも高い場合には出力端子がロウレベル“Ｌ”となる。
【０１００】
従って、サーミスタ６１によって検出される周囲温度が−３０℃を超えている場合には、論理回路部６７のIHBT端子は“Ｈ”となり、前記周囲温度が−３０℃以下である場合には、IHBT端子は“Ｌ”となる。即ち、図１３に示すように、周囲温度が−３０℃を超えておりIHBT端子が“Ｈ”であれば、スイッチ３５（１）〜３５（４）のオンオフ制御は、図６に示す第２実施例の場合と全く同様に行われる。そして、周囲温度が−３０℃以下でありIHBT端子が“Ｌ”の場合は、コンパレータ２７，２８，４１の出力状態の如何にかかわらず、スイッチ３５（１）〜３５（４）は全てオフされて、各単位セル２１（１）〜２１（４）の放電は禁止される。
【０１０１】
このように制御するのは、以下の理由による。即ち、ＨＥＶ等は、様々な環境下において走行することが想定されるが、寒冷地などの周囲温度が−３０℃以下となるような低温環境下においては、単位セル２１の内部抵抗が極めて大きくなる場合がある。このような状態で単位セル２１の放電を行うと、その放電により大きな電圧降下が生じるため、ある単位セル２１の電圧がその時点での最低電圧を下回ると、本来電圧調整しなくても良い単位セル２１の電圧を調整する場合がある。
【０１０２】
つまり、放電により電圧降下が生じると単位セル２１の端子間電圧は低下するが、電圧降下が大き過ぎると、本来最低電圧を示している単位セル２１の電圧をも下回ってしまい、放電中の単位セル２１が見かけ上の最低電圧セルとなってしまう。すると、他の単位セル２１は、その放電中の単位セル２１を目標に電圧調整が行われ放電されることになり、放電すべきでない本来の最低電圧セルまで放電されてしまう。その結果、最低電圧が更に下がり、他の単位セル２１がそれを目標に電圧調整されて放電され、調整動作が継続されて組電池３８全体の電圧を低下させることになる。従って、周囲温度が−３０℃以下になった場合には、単位セル２１の放電を禁止するようにしている。
【０１０３】
また、例えば、ＨＥＶが走行中であり、組電池３８に対して充電または放電動作が行われている途中で単位セル２１（３）の付近で何らかの理由により断線が生じた場合を想定する。すると、組電池３８に接続されている例えばインバータ回路等が有するインダクタンス成分などにより、断線箇所Ｊc2−Ｊc3間には、組電池３８の総電圧（各単位セル２１の電圧の総和）相当の起電力が発生する。
【０１０４】
そして、端子Ｊc2−Ｊc3間に起電力が発生したことにより、ヒューズ５９（２），５９（３）及び各放電経路を介して電圧調整装置に大電流が流れ込もうとするが、ヒューズ５９（２），５９（３）が溶断することによって当該経路は遮断される。
【０１０５】
以上のように第５実施例によれば、サーミスタ６１によって周囲温度を検出し、周囲温度が−３０℃以下になると、論理回路部６７は、コンパレータ６２の出力信号を受けて、単位セル２１（１）〜２１（４）の放電を禁止するので、低温環境下において単位セル２１の内部抵抗が極めて大きくなった場合には放電を抑制することで、本来電圧調整しなくても良い単位セル２１の電圧を調整する事態に陥ることを回避できる。
【０１０６】
また、第５実施例によれば、端子Ｊc1〜Ｊc4と、抵抗５７（１）〜５７（３）及び端子Ｊr4との間に、夫々ヒューズ５９（１）〜５９（４）を挿入したので、単位セル２１の内の何れか１つに断線が生じて、その断線箇所の両端に高電圧が発生した場合でも、ヒューズ５９が溶断して放電経路を遮断するので組電池３８に接続されている電圧調整装置を高電圧，大電流による破壊や焼損から保護することができる。また、例えば、異物の侵入や絶縁の低下などにより、逆に、電圧調整装置側において回路の短絡が発生した場合には、ヒューズ５９（１）〜５９（４）によって組電池３８側を保護することができる。
【０１０７】
（第６実施例）
図１４は本発明の第６実施例を示すものであり、第５実施例と同一部分には同一符号を付して説明を省略し、以下異なる部分についてのみ説明する。第６実施例では、コンパレータ６２に代わるコンパレータ（電圧比較手段）６２ａの反転入力端子には、第５実施例における抵抗６０及びサーミスタ６１の共通接続点に代わって、１．５Ｖの基準電圧Ｖref を与える定電圧源６９の正側端子が接続されており、その定電圧源６９の負側端子は、ヒューズ５９（３）と抵抗５７（３）との共通接続点に接続されている。
【０１０８】
この場合、抵抗６３及び６４は、単位セル２１（４）の端子間電圧を等分圧しているので、コンパレータ６２ａは、非反転入力端子に与えられる単位セル２１（４）の端子間電圧の１／２の電圧Ｖc と、反転入力端子に与えられる基準電圧Ｖref とを比較するようになっている。ここで、１．５Ｖの基準電圧Ｖref は、単位セル２１の使用可能な下限電圧を３．０Ｖに設定した場合に、その下限電圧に抵抗６３及び６４の分圧比１／２を乗じたものとして設定されている。
【０１０９】
そして、コンパレータ６２ａの出力端子は、電圧Ｖc が基準電圧Ｖref よりも高い場合はハイレベル“Ｈ”となり、電圧Ｖc が基準電圧Ｖref よりも低い場合はロウレベル“Ｌ”となる。その他の構成は第５実施例と同様である。
【０１１０】
次に、第６実施例の作用について説明する。本発明の電圧調整装置は、以上述べてきたように、各単位セル２１の端子間電圧の内で最低レベルのものに、その他の単位セル２１の端子電圧を合わせるように調整を行うものである。故に、組電池３８の中の何れかの単位セル２１が何らかの原因によって短絡し、その端子電圧が使用可能な下限電圧を大きく下回った場合を想定すると、その電圧に合わせてその他の健全な単位セル２１の端子電圧までもが、使用可能な下限電圧を下回るように調整されてしまうおそれがある。
【０１１１】
そこで、第６実施例では、そのような事態の発生を防止するため、コンパレータ６２ａは、非反転入力端子に与えられる単位セル２１（４）の端子間電圧Ｖc が使用可能な下限電圧３．０Ｖを下回ると、ロウレベルの信号を論理回路部６７のIHBT端子に与えることで、単位セル２１の放電を禁止するようにしている。
【０１１２】
以上のように第６実施例によれば、抵抗６３及び６４によって単位セル２１（４）の端子間電圧Ｖc を検出し、端子間電圧Ｖc が使用可能な下限電圧を下回ると、コンパレータ６２ａ及び論理回路部６７によって単位セル２１の放電を禁止するので、何れかの単位セル２１に短絡が発生した場合でも、他の単位セル２１の電圧を著しく低下させることを防止できる。
【０１１３】
本発明は上記し且つ図面に記載した実施例にのみ限定されるものではなく、次のような変形または拡張が可能である。
第２実施例において、２個のＮＯＴゲート３２及び４２を使用する代わりに、図１５に示すように、負論理入力のＡＮＤゲート７０を用いて、そのＡＮＤゲート７０の出力端子をＡＮＤゲート３１及び４３の入力端子に共通に接続しても良い。斯様に構成した場合、当該変形部分にかかる単位セル２１（２）の論理条件は、正極側の端子電圧Ｅc2が分圧電位Ｅr2にほぼ等しい（Ｅc2＝Ｅr2）という条件が成立し、且つ、負極側の端子電圧Ｅc1よりも分圧電位Ｅr1が高い場合（Ｅc1＜Ｅr1）に、端子電圧Ｖ２が平均電圧よりも高いと判断することになる。
また、単位セル２１（３）については、負極側の端子電圧Ｅc2が分圧電位Ｅr2にほぼ等しい（Ｅc2＝Ｅr2）という条件が成立し、且つ、正極側の端子電圧Ｅc3が分圧電位Ｅr3よりも高い場合（Ｅc3＞Ｅr3）に、端子電圧Ｖ３が平均電圧よりも高いと判断することになる。更に、図７に示すｎ直列構成の場合のコンパレータＣＰi ，ＣＰi-1 ，ＣＰi+1 などの出力信号の論理合成についても同様である。斯様に構成すれば、特に多直列構成で論理回路部にディスクリートの素子を使用する場合などには、共通化によってゲート数を削減することができる。
【０１１４】
単位セルは、リチウム電池に限らず、鉛電池やニッケル系電池であっても同様に適用が可能である。
必ずしも組電池を構成する全ての単位セルについて電圧調整を行う必要はなく、その内の特定の１個のみについて、或いは特定の複数個について電圧調整を行っても良い。
電気自動車やＨＥＶに限ることなく、複数の単位セルを直列に接続して構成されるバッテリを使用するものであれば適用が可能である。
第６実施例において、基準電圧Ｖref を調整動作の上限電圧（例えば、４．０Ｖ）に設定し、コンパレータ６２ａの反転入力端子と非反転入力端子とを入替えたり、或いは、コンパレータ６２ａの出力信号をＮＯＴゲートにより反転させても良い。斯様に構成した場合は、以下のような作用効果が得られる。
即ち、各単位セル２１の電圧がばらつく要因としては、上述した残存容量のばらつきの他に、満充電容量のばらつきがある。そして、リチウム電池の場合、電池の電圧は充電状態、即ち残存容量と満充電容量の比に対して一意の相関があるので、仮に残存容量が等しくても満充電容量が異なれば電圧はばらつき、そのばらつきの大きさは、残存容量が多いほど大きくなる。そのような場合、単位セル２１の電圧をそろえる必要がないにもかかわらず電圧調整動作が行われて放電した分はエネルギの無駄となってしまう。
そこで、電圧調整動作の上限を基準電圧Ｖref により定めることにより、満充電容量のばらつきに起因する不必要な電圧調整動作を抑制し、無駄なエネルギの消耗を抑制することができる。
【０１１５】
更に、２つの電圧コンパレータを用意して、その一方を上限電圧用，他方を下限電圧用とする。そして、それらの出力信号をＡＮＤ（負論理入出力のＯＲ）ゲートを介して論理回路部６７のIHBT端子に与えるようにすることで、電圧調整動作の上限，下限を定め、限られた電圧（残存容量）範囲においてのみ電圧調整動作を可能とすることもできる。これは、ＨＥＶの駆動用バッテリのように、中間的な残存容量を中心として充放電が行われるものにおいて、常に中心付近の残存容量で電圧をそろえることが可能となり、出力（放電）と回生（充電）とのバランスが取れた状態で単位セル２１を使用することができる。
第５実施例におけるコンパレータ６２を中心とする温度検出手段及び温度比較手段と、第６実施例におけるコンパレータ６２ａを中心とする電圧検出手段及び電圧比較手段とを、両方同時に配置しても良い。その場合、コンパレータ６２及び６２ａの各出力信号は、ＡＮＤゲートを介して論理回路部６７のIHBT端子に与えるようにすれば良い。
経路遮断手段は、ヒューズ５９に限ることなく、例えば、放電経路となる基板上の配線パターンの一部について幅寸法を狭くした箇所を設けて、過電流が流れた場合に当該箇所が焼き切れるようにしたものでも良い。
【図面の簡単な説明】
【図１】本発明を３直列構成の組電池に適用した場合の第１実施例を示す電気的構成図
【図２】論理回路部の真理値を示す図
【図３】単位セルの端子電圧のばらつき調整を行う場合の、各端子電圧の変化の一例を示す図（その１）
【図４】図３相当図（その２）
【図５】本発明を４直列構成の組電池に適用した場合の第２実施例を示す図１相当図
【図６】図２相当図
【図７】本発明をｎ直列構成の組電池に適用した場合の図１相当図
【図８】図２相当図
【図９】本発明をハイブリッド電気自動車の駆動用バッテリに適用した場合の第３実施例を示す図
【図１０】本発明の第４実施例を示す図５相当図
【図１１】本発明の第５実施例を示す図５相当図
【図１２】論理回路部の詳細な構成の一例を示す図
【図１３】図２相当図
【図１４】本発明の第６実施例を示す図５相当図
【図１５】変形例を示す図５相当図
【図１６】従来技術を示す図９相当図
【図１７】複数個の単位セルをモジュール化した場合の図１６相当図
【図１８】他の従来技術を示す図１相当図
【符号の説明】
２１は単位セル（リチウム電池）、２２は組電池、２３，２４，２５は抵抗、２６は分圧回路（分圧手段）、２７Ｈ，２７Ｌ，２８Ｈ及び２８Ｌはコンパレータ（電位比較手段）、３３は放電回路（放電制御手段）、３７は論理回路部（放電制御手段）、３８は組電池、３９は抵抗、４０及び４０′は分圧回路（分圧手段）、４１Ｈ及び４１Ｌはコンパレータ（電位比較手段）、４７は論理回路部（放電制御手段）、４９は駆動用バッテリ、５０は差動増幅器（電位差増幅手段，電位比較手段）、５９はヒューズ（経路遮断手段）、６１はサーミスタ（温度検出手段）、６２はコンパレータ（温度比較手段）、６２ａはコンパレータ（電圧比較手段）、６３及び６４は抵抗（電圧検出手段）、６７は論理回路部（放電制御手段）、Ｊc1，Ｊc2，Ｊc3，Ｊci-1，Ｊciは連結点、Ｊr1，Ｊr2，Ｊr3，Ｊri-1，Ｊriは分圧点を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an assembled battery voltage adjusting device and an assembled battery voltage adjusting method for adjusting variations in terminal voltage between unit cells for an assembled battery formed by connecting a plurality of unit cells in series.
[0002]
[Prior art]
In recent years, hybrid electric vehicles (hereinafter referred to as HEVs) that combine a mechanism of an electric vehicle and a gasoline engine have been developed for the purpose of achieving both low pollution and high driving performance. HEV is equipped with a gasoline engine, so it is possible to secure the same driving performance as a gasoline car without using a battery with a capacity as high as that of an electric vehicle, but the engine efficiency is low and emissions of carbon dioxide and nitrogen oxides are low. Since the motor is driven by a battery during low rotation when the speed increases, low pollution can be achieved.
[0003]
Even in such HEVs, high power is required for the battery because electric power supplied from the battery is used at the time of starting or full acceleration. In addition, HEVs must be equipped with many components such as engines, motors / generators, and batteries, and the weight of the entire vehicle increases. It is required to be.
[0004]
Under such circumstances, lithium batteries have attracted attention as an alternative to lead, nickel cadmium, nickel metal hydride batteries, and the like. Lithium batteries have a weight energy density that is about 3 to 4 times higher than lead and nickel cadmium batteries of the same capacity, and are expected to be suitable for HEVs that require small and light weight. Yes.
[0005]
However, lithium batteries are vulnerable to overcharge and overdischarge, and if they are not used within a predetermined voltage range, the material may decompose and the capacity may be significantly reduced, or the battery may be abnormally heated and become unusable. Therefore, when using a lithium battery, the upper limit voltage and the lower limit voltage are clearly specified, and charge / discharge control is performed so that the terminal voltage is within the range, or a set with a protection circuit that limits the voltage range. It is common to use.
[0006]
By the way, since the battery used for an electric vehicle or HEV requires a high voltage in order to drive a motor, it is normally configured by connecting a plurality of unit cells in series. For example, in order to obtain a battery voltage of 300V, about 150 cells are connected in series for a lead battery of 2V per unit cell, and about 80 cells are connected in series for a lithium battery of 3.6V per unit cell. Become.
[0007]
When charging an assembled battery formed by connecting a large number of unit cells in this way, conventionally, charging is controlled by monitoring the voltage between the positive and negative terminals of the assembled battery. For example, in the case of 150 lead batteries having a voltage range of 1.8 to 2.4 V per unit cell and being in series, charge / discharge control is performed so that the voltage range of the assembled battery is in the range of 270 to 360 V.
[0008]
A problem in this case is the variation in terminal voltage between the unit cells based on the remaining capacity (state of charge, hereinafter referred to as SOC) of each unit cell. In the state of being connected in series, the value of current flowing through each unit cell is the same, but the remaining capacity of each unit cell always varies, and as a result, the terminal voltage of each unit cell also differs. This variation in remaining capacity is mainly caused by differences in self-discharge and charge / discharge efficiency for each cell, and accumulates and expands with time.
[0009]
In other words, even if charging control is performed by monitoring the inter-terminal voltage of the assembled battery, which is the total of these, each unit cell as the constituent element has the terminal voltage of (the inter-terminal voltage of the assembled battery) / (number of unit cells). Some are higher or lower than the average voltage obtained. For this reason, there are unit cells that are overcharged when charged to the upper limit voltage and overdischarged when discharged to the lower limit voltage.
[0010]
However, the NiCad or NiMH battery has little performance degradation even if it is overdischarged or overcharged, and the lead battery has no particular safety problem even if the performance deteriorates. Therefore, it is sufficient to control the battery by referring only to the voltage across the assembled battery. However, when using a lithium battery as a multi-series assembled battery, each unit cell should not be overcharged or overdischarged. It is essential to take measures.
[0011]
[Problems to be solved by the invention]
In consideration of such countermeasures, for example, in Japanese Utility Model Laid-Open No. 2-136445, during charging, the maximum value of the terminal voltages of each unit cell is detected, and control is performed based on the maximum voltage. In some cases, a technique is disclosed in which the lowest value is detected and control is performed based on the lowest voltage. In this prior art, it is possible to control charging / discharging of all unit cells within a predetermined voltage range, but when the SOC of each unit cell is shifted, charging is performed with the unit cell having the highest and lowest SOC. Discharge is limited, and there is a problem that the capacity is reduced by the amount of SOC shift.
[0012]
As a solution to such a problem, for example, in Japanese Patent Laid-Open No. 6-253463, a discharge circuit (bypass circuit) composed of a resistor and a switch is connected in parallel to each unit cell, and the voltage of the unit cell varies. When this occurs, the discharge circuit switch corresponding to the unit cell whose voltage is high is closed and discharged, or the voltage difference between the unit cells is reduced by so-called balanced charge / discharge that shunts the charging current during charging. Technology is disclosed.
[0013]
Japanese Patent Application Laid-Open No. 8-213055 discloses that all unit cells are fully charged by monitoring the charge state of each unit cell, and by dividing the charge current to the bypass circuit for the unit cell that has reached the full charge state. A technology for aligning the state of charge and eliminating variations is disclosed.
[0014]
A specific configuration example of these prior arts is shown in FIG. The assembled battery 1 is configured by connecting a plurality (n) of unit cells 2 (1), 2 (2),..., 2 (n) in series. A discharge circuit 3 and a voltage detector 4 configured by connecting a discharge resistor 3a and a switch 3b made of a transistor, FET, or the like in series are connected to each other. The output signal of the voltage detector 4 is given to the MPU 7 via the multiplexer 5 and the A / D converter 6.
[0015]
The MPU 7 refers to the terminal voltage of each unit cell 2 and stores it in the memory 8 at regular intervals, and discharges the unit cell 2 having a higher terminal voltage, or bypasses the charging current. For this purpose, a control signal is output to the decoder 9. When the control signal is decoded by the decoder 9, the control signal is output to the switch 3 b of the discharge circuit 3 of the corresponding unit cell 2 via the photocoupler (or isolation amplifier) 10. Then, the switch 3b of the discharge circuit 3 is closed, and the unit cell 2 is discharged or the charge current is bypassed via the resistor 3a.
[0016]
In such a configuration, the discharge circuit 3, the voltage detector 4, the photocoupler 10 and the like are required for the number of unit cells 2, and there is a problem that the total number of parts increases. In addition, the number of unit cells 2 that can actually be controlled by one MPU 7 is limited to about 10 to 20 due to limitations on insulation (voltage resistance) and controllability.
[0017]
Therefore, in order to apply to HEVs and electric vehicles, as shown in FIG. 17, the entire assembled battery 1 is divided into groups of about 10 to 20 unit cells 2, and the control of each group is performed with the configuration of FIG. It is necessary to configure the modules 11 to be assigned to the corresponding MPUs 7 and to arrange the upper MPUs 7H that control the MPUs 7 of the modules 11 in an integrated manner. For example, when 80 lithium batteries are used for the unit cell 2, the configuration is 10 × 8 groups or 20 × 4 groups. As a result, 5 or 9 MPUs, which are expensive parts, are required, and an increase in cost is inevitable.
[0018]
In view of this, Japanese Patent Application Laid-Open No. 8-55643 discloses a technique that enables charging control without using an MPU. As shown in FIG. 18, a series circuit of two resistors 14 a and 14 b having the same resistance value is connected in parallel to the assembled battery 13 composed of two unit cells 12 connected in series. The potentials of the common connection point VCM of the two unit cells 12 and the common connection point VRM of the two resistors 14a and 14b are compared.
[0019]
The output terminal of the comparator 15 is connected to the base of an npn transistor 17a via a base resistor 16a and to the base of a pnp transistor 17b via a base resistor 16b. The collectors of the transistors 17a and 17b are respectively connected to the positive electrode and the negative electrode of the assembled battery 13 via discharging resistors 18a and 18b, and the emitters of both are commonly connected to a common connection point VCM. The above constitutes the adjustment module 19.
[0020]
When the terminal voltages of the unit cells 12 (1) and 12 (2) are VC1 and VC2, respectively, when VC1> VC2 and potential VCM <potential VRM, the output terminal of the comparator 15 becomes high level and the transistor 17a is turned on. Therefore, the unit cell 12 (1) is discharged through the resistor 18a. When VC1 <VC2 and potential VCM> V potential RM, the output terminal of the comparator 15 goes low and the transistor 17b is turned on, so that the unit cell 12 (2) is discharged through the resistor 18b. Yes.
[0021]
However, each of these adjustment modules 19 is configured to adjust terminal voltage variation for two unit cells connected to each other. Therefore, assuming that this adjustment module 19 is applied to several tens or more, for example, N (N is a natural number) series assembled battery, (N-1) adjustment modules 19 must be used correspondingly. Then, adjustment errors between the adjustment modules 19 may be accumulated, and there is no guarantee that high-precision control can be achieved as a whole.
[0022]
The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent overdischarge and overcharge of each unit cell and to charge an assembled battery configured by connecting these unit cells in series. An object of the present invention is to provide an assembled battery voltage regulator capable of preventing the capacity from being limited as much as possible by the variation in capacity of each unit cell.
[0023]
[Means for Solving the Problems]
According to the voltage adjustment device for the assembled battery according to claim 1 or the voltage adjustment method for the assembled battery according to claim 5, the voltage dividing means divides the terminal voltage of the assembled battery according to the number of unit cells, and compares the potential. The means compares a potential at a specific connection point among a plurality of connection points between the unit cells with a potential at a voltage dividing point corresponding to the connection point. The discharge control means determines that the potential of the positive electrode side connection point is higher than or equal to the potential of the voltage dividing point based on the comparison result of the potential comparison means corresponding to the positive electrode side and negative electrode side connection points of the unit cell. When the potential is equal and the potential at the corresponding voltage dividing point is higher than the potential at the negative electrode side connecting point, or the potential at the positive electrode side connecting point is higher than the potential at the corresponding voltage dividing point and the negative electrode side connecting point when dividing point potential is higher or both potentials corresponding than the potential equal to, when the terminal voltage before Kitan position cell is determined to be higher than the average voltage is controlled so as to discharge the unit cell .
[0024]
Accordingly, the terminal voltage of the unit cell corresponding to a specific connection point can be adjusted to be equal to the average voltage to adjust the terminal voltage variation, that is, the remaining capacity variation, thereby preventing overdischarge and overcharge. However, the use efficiency of the assembled battery can be improved.
[0025]
Further, the discharge control means prohibits the discharge of the unit cell when it is determined that the ambient temperature is equal to or lower than a preset reference temperature. That is, in a low temperature environment, the internal resistance of the unit cell may become extremely large. If the voltage of a unit cell falls below the minimum voltage at that time due to the voltage drop caused by discharging, it is necessary to adjust it originally. There is a risk of adjusting the voltage of the unit cell without any. Therefore, when the ambient temperature becomes lower than the reference temperature, it is possible to avoid such a situation by prohibiting the discharge.
[0026]
According to the voltage adjustment device for the assembled battery according to claim 2 or the voltage adjustment method for the assembled battery according to claim 6, the discharge control means is provided on the positive electrode side and the negative electrode side of the unit cell as in the case of claim 1 or 5 . Based on the comparison result of the potential comparison means corresponding to the connection point, the potential at the positive side connection point is higher than the potential at the corresponding voltage dividing point, or both potentials are equal and correspond to the potential at the negative side connection point. When the potential at the pressure point is high, or the potential at the positive connection point is higher than the corresponding potential at the partial pressure point and the potential at the partial pressure point is higher than the potential at the negative connection point. when the potential is equal, since the terminal voltage before Kitan position cell is controlled so as to discharge the unit cell when it is determined to be higher than the average voltage, it is possible to adjust the variation of the residual capacity, over-discharge or over- Use battery packs efficiently while preventing charging It is possible to above.
[0027]
Further, when the discharge control means determines that the terminal voltage of at least one unit cell of the plurality of unit cells is equal to or lower than a preset reference voltage, the discharge control unit prohibits discharge of the unit cell. That is, when a short circuit or the like occurs in any one of the plurality of unit cells and the cell voltage decreases, there is a possibility that adjustment is performed so as to decrease the voltages of other unit cells accordingly. Therefore, when the inter-terminal voltage of at least one unit cell becomes equal to or lower than the reference voltage, it is possible to prevent the voltage of other unit cells from being inadvertently lowered by prohibiting discharge.
[0028]
According to the assembled battery voltage adjusting device according to claim 3 and the assembled battery voltage adjusting method according to claim 7, as in the case of claim 1, 2, 5, 6, the discharge control means is provided on the positive side of the unit cell. From the comparison result of the potential comparison means corresponding to the connection point on the negative electrode side, the potential at the connection point on the positive electrode side is higher than the potential at the corresponding voltage dividing point or equal to the potential at the partial pressure point and more than the potential at the connection point on the negative electrode side. If the potential at the corresponding voltage dividing point is high, or the potential at the voltage dividing point is higher than the potential at the corresponding voltage dividing point and the potential at the voltage dividing point is higher than the potential at the voltage connecting point on the negative electrode side. If equal high or both potentials, since the terminal voltage before Kitan position cell is controlled so as to discharge the unit cell when it is determined to be higher than the average voltage, it is possible to adjust the variation of the remaining capacity, Use of assembled batteries while preventing overdischarge and overcharge It is possible to improve the.
[0029]
In addition, when the discharge control means determines that the voltage between the terminals of at least one unit cell among the plurality of unit cells is equal to or higher than a preset reference voltage, the discharge control unit prohibits discharge of the unit cell. That is, by setting the upper limit of the voltage adjustment operation, it is possible to limit the voltage or remaining capacity range for performing the adjustment operation. Therefore, due to the variation in the full charge capacity between the unit cells, which is different from the variation in the remaining capacity, especially in the range where the remaining capacity is large (close to full charge), the unit cells have different terminal capacities even though the remaining capacity is equal. Since the voltage varies, an unnecessary voltage adjustment operation is performed, and unnecessary discharge can be suppressed.
[0030]
Voltage regulator for a battery pack according to claim 4, wherein, according to the voltage adjusting method for a battery pack according to claim 8, similarly to claims 1 to 5, 6, 7, the discharge control means, the unit Based on the comparison result of the potential comparison means corresponding to the positive and negative connection points of the cell, the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative connection When the potential at the corresponding voltage dividing point is higher than the potential at the point, or when the potential at the positive-side connection point is higher than the potential at the corresponding voltage-dividing point and corresponding to the potential at the negative-side connection point. when the potential of the point are equal high or both potentials, since the terminal voltage before Kitan position cell is controlled so as to discharge the unit cell when it is determined to be higher than the average voltage, to adjust the variation in the remaining capacity Can be assembled battery while preventing overdischarge and overcharge Thereby improving the use efficiency.
[0031]
Moreover, the path | route interruption | blocking means arrange | positioned in the discharge path | route of each unit cell and the vicinity side of each unit cell interrupts | blocks the said path | route, when an overcurrent flows into the discharge path | route. That is, for example, if a disconnection occurs for any reason in any one of the plurality of unit cells while the assembled battery is being charged or discharged, the assembled battery is connected to both ends of the disconnection point. There is a possibility that high voltage may be generated due to inductance of a circuit connected to the battery. In such a case, an overcurrent flows through the discharge path connected to both ends of the disconnection point, and thus the voltage regulator is protected from destruction by blocking the discharge path by the path blocking means. Can do.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, a first embodiment when the present invention is applied to an assembled battery formed by connecting three unit cells in series will be described with reference to FIGS. In FIG. 1 showing the electrical configuration, three unit cells 21 (1), 21 (2), and 21 (3) composed of lithium secondary batteries are connected in series to form an assembled battery 22. Yes. A voltage dividing circuit (voltage dividing means) 26 formed by connecting resistors 23, 24, and 25 in series is connected to the assembled battery 22 in parallel.
[0033]
Among these, the resistors 23 and 24 are each constituted by a series circuit of resistors 23a and 23b, 24a and 24b, and the resistance ratio is set to about 4000: 1, for example. The resistance values of the resistors 23a, 24a and 25 are set to be equal to each other, and the resistance values of the resistors 23b and 24b are negligibly small compared to these resistance values. Therefore, the terminal voltage of the assembled battery 22 is substantially divided into three equal parts by the three resistors 23a, 24a and 25.
[0034]
Here, the negative terminal of the battery pack 22 is Jc0, the positive terminal is Jc3, the connecting point of the unit cells 21 (1) and 21 (2) between them is Jc1, and the unit cells 21 (2) and 21 (3 ) Is Jc2. Also, the negative side terminal of the voltage dividing circuit 26 is Jr0, the positive side terminal is Jr3, and the common connection points of the resistors 23a and 23b, 24a and 24b between them are Jr1 and Jr2, respectively. The common connection point of the resistors 23b and 24a is Jr1 ', and the common connection point of the resistors 24b and 25 is Jr2'. Below, each said connection point is called a terminal.
[0035]
The inverting input terminal of the comparator 27H and the non-inverting input terminal of the comparator 27L are commonly connected to the terminal Jc1. The non-inverting input terminal of the comparator 27H is connected to the terminal Jr1, and the inverting input terminal of the comparator 27L is connected to the terminal Jr1 ′. Further, the two comparators 28H and 28L are similarly connected to the unit cell 21 (2) and the resistor 24. The four comparators 27H, 27L, 28H, and 28L constitute a potential comparison unit.
[0036]
The output terminal of the comparator 27L is connected to one input terminal of the AND gate 30 via the INV (inverter) gate 29, and the output terminal of the comparator 27H is connected to one input terminal of the AND gate 31. ing. The output terminal of the comparator 28L is connected to the other input terminal of the AND gate 30, and the output terminal of the comparator 28H is connected to the other input terminal of the AND gate 31 via the INV gate 32.
[0037]
The discharge circuit 33 is formed by connecting a discharge resistor 34 and a normally open switch 35 in series. The three discharge circuits 33 (1) to 33 (3) are connected in series so as to correspond to the unit cells 21 (1) to 21 (3), and are connected in parallel to both ends of the assembled battery 22. Yes. The common connection point of the discharge circuits 33 (1) and 33 (2) is connected to the terminal Jc1, and the common connection point of the discharge circuits 33 (2) and 33 (3) is connected to the terminal Jc2. Yes.
[0038]
The switches 35 (1) to 35 (3) are composed of, for example, transistors or FETs, and close the contacts (conduct) when a high-level control signal is given to the control signal terminal. The control signal terminals of the switches 35 (1) and 35 (3) are connected to the output terminals of the comparators 27L and 28H, respectively. The control signal terminal of the switch 35 (2) is connected to the output terminal of the OR gate 36, and the two input terminals of the OR gate 36 are connected to the output terminals of the AND gates 30 and 31, respectively. .
[0039]
The NOT gates 29 and 32, the AND gates 30 and 31, and the OR gate 36 constitute a logic circuit unit 37. The discharge circuit 33 and the logic circuit unit 37 constitute a discharge control means. By the way, although not specifically shown, the operation power supplies of the comparators 27H, 27L, 28H and 28L and the logic circuit unit 37 are generated from the assembled battery 22 and supplied.
[0040]
Next, the operation of the present invention will be described with reference to FIGS. Here, the terminal voltages of the unit cells 21 (1), 21 (2), and 21 (3) are V1, V2, and V3, respectively. The potentials of the terminals Jc1, Jc2, and Jc3 with respect to the terminal Jc0 are set as Ec1, Ec2, and Ec3, respectively, and the potentials of the terminals Jr1, Jr2, and Jr3 with respect to the terminal Jr0 are set as Er1, Er2, and Er3, respectively. . Then, the potentials Ec1, Ec2, and Ec3 are expressed as shown in Equation (1), respectively.
Ec1 = V1
Ec2 = V1 + V2 (1)
Ec3 = V1 + V2 + V3 = Er3
[0041]
Further, the resistance values of the resistors 23a, 24a, and 25 are equal, and when the resistors 23b and 24b are ignored, there are unit cells 21 (1), 21 (2), and 21 (3) at both ends of the resistors 23a, 24a, and 25, respectively. The average values of the terminal voltages are respectively applied. Therefore, the potentials Er1, Er2, and Er3 are expressed as shown in Equation (2), respectively.
Er1 = Ec3 / 3 = (V1 + V2 + V3) / 3
Er2 = 2 · Ec3 / 3 = 2 (V1 + V2 + V3) / 3 (2)
Er3 = 3 ・ Ec3 / 3 = V1 + V2 + V3
[0042]
Here, when the output levels of the four comparators 27H, 27L, 28H, and 28L are considered to be high “H” under each input condition, it is as follows. The terminal voltage of the resistors 23b and 24b is Vα.

[0043]
That is, the comparator 27H is at a high level when the divided potential Er1 is higher than the potential Ec1 of the terminal Jc1, and the comparator 27L is lower than the divided potential Er1 that is obtained by subtracting the minute voltage Vα from the potential Ec1. High level when Accordingly, when the divided potential Er1 is in the range of Ec1−Vα ≦ Er1 ≦ Ec1 and is considered to be substantially equal to the potential Ec1, both the comparators 27H and 27L are at the low level. The same applies to the comparators 28H and 28L with respect to the divided potential Er2 and the potential Ec2 of the terminal Jc2.
[0044]
The conditions for turning on the three switches 35 (1) to 35 (3) by logically synthesizing the output levels of these four comparators 27H, 27L, 28H, and 28L are shown in FIG. It becomes like the truth table shown. However, “x” indicates an arbitrary level.
[0045]
(1) V3>V2> V1
Here, the operation from the initial state where the terminal voltages of the unit cells 21 (1) to 21 (3) satisfy V3>V2> V1 will be described with reference to FIG.
[0046]
[Period A]
in this case,

Therefore, the output signals of the comparators 27H and 28H are both at the high level “H”. Accordingly, in the truth table shown in FIG. 2, since the condition that the switch 35 (3) is in the ON state “1” is satisfied, the unit cell 21 (3) is discharged by the discharge circuit 33 (3).
[0047]
When the terminal voltage V3 decreases due to the discharge of the unit cell 21 (3), the terminal voltage Ec3 (= Er3) of the assembled battery 22 decreases, and the divided potential Er2 also decreases accordingly. When V3 <V2 and Er2 = Ec2, the output signal of the comparator 28H becomes low level “L”.
[0048]
At this time, as shown at time P in FIG. 3, the terminal voltage V3 is the average cell voltage of the assembled battery 22, but the unit cell 21 (2) is not discharged, so the relationship of V2> V1 is maintained. Therefore, Er1> Ec1 in the equation (4) does not change. Therefore, the output signal of the comparator 27H remains “H”. Then, in the truth table shown in FIG. 2, since the condition that the switch 35 (2) is turned on is “1”, the unit cell 21 (2) is discharged by the discharge circuit 33 (2). The discharge of the unit cell 21 (3) by the discharge circuit 33 (3) is stopped.
[0049]
Here, for the comparators 27H and 27L, the condition that the output signal of the comparator 27H is “L” and the output signal level of the comparator 27L is not limited is that at least Er2 is not higher than Ec2. Is substantially equal to Ec2 or Er2 is lower than Ec2, meaning Er2 ≦ Ec2.
[0050]
[Period B]
When the terminal voltage V2 is decreased by discharging the unit cell 21 (2), the voltages Ec2 and Er3 are decreased, and accordingly, the divided potential Er2 is also decreased. Here, when Er2 and Ec2 are compared, from the equations (1) and (2),
Ec2 = V1 + V2
Er2 = 2 (V1 + V2 + V3) / 3
Therefore, Ec2 is clearly more affected by the decrease in terminal voltage V2. Therefore, the magnitude relationship between the two becomes Er2> Ec2 again from Er2 = Ec2, and the output signal of the comparator 28H becomes “H” again. Then, the condition that the switch 35 (3) is in the ON state “1” is satisfied, the discharge by the discharge circuit 33 (2) is stopped, and the unit cell 21 (3) is discharged by the discharge circuit 33 (3). .
[0051]
That is, in this case, the unit cell 21 (2) is discharged and the terminal voltage V2 is lowered, so that the average voltage of the unit cell 21 is also lowered. Then, since the terminal voltage V3 also deviates from the average voltage if the potential is maintained from the time point P, the unit cell 21 (3) is discharged again, and the terminal voltage V3 becomes the average voltage. It acts to be approximately the same.
[0052]
When the unit cell 21 (3) is discharged and the terminal voltage V3 decreases and substantially coincides with the average voltage again, the divided potentials Er3 and Er2 decrease as described above, and Er2 = Ec2 and the comparator 28H The output signal becomes “L”. Further, since the unit cell 21 (2) is not discharged, V2> V1 and Er1> Ec1, so that the output signal of the comparator 27H remains “H”. Then, since the condition that the switch 35 (2) is in the ON state “1” is satisfied, the discharge of the unit cell 21 (3) is stopped simultaneously with the discharge of the unit cell 21 (2).
[0053]
That is, in the period B, the switches 35 (2) and 35 (3) are alternately turned on, and the unit cells 21 (2) and 21 (3) are alternately discharged. Further, in FIG. 3, the terminal voltages V2 and V3 are illustrated so as to decrease linearly, but actually, when one potential is decreased, the other potential is not changed. The state is repeated alternately in a short period.
[0054]
Finally, when Er1 = Ec1, Er2 = Ec2, that is, V1 = V2 = V3, the output levels of the comparators 27H, 27L, 28H, 28L are all “L”, and the unit cells 21 (1) ˜21 The discharge of 21 (3) stops. This completes the function of adjusting the variations in the terminal voltages V1, V2, and V3.
[0055]
(2) V1>V2> V3
Next, the operation when V1>V2> V3 as an initial state will be described. in this case,

Therefore, the output signals of the comparators 27L and 28L are both “H”. Accordingly, in the truth table shown in FIG. 2, since the condition that the switch 35 (1) is in the ON state “1” is satisfied, the unit cell 21 (1) is discharged by the discharge circuit 33 (1).
[0056]
When the terminal voltage V1 decreases due to the discharge of the unit cell 21 (1), the terminal voltage Ec1 decreases, and the voltages Er3 and Er1 also decrease accordingly. Here, when Er1 and Ec1 are compared, from the equations (1) and (2),
Ec1 = V1
Er1 = (V1 + V2 + V3) / 3
Thus, the effect of the decrease in the terminal voltage V1 is clearly larger in Ec1. Therefore, Ec1 approaches Er1 and eventually becomes Er1 = Ec1, and the output signal of the comparator 27L becomes “L”. Then, the condition that the switch 35 (2) is in the ON state “1” is satisfied, the discharge by the discharge circuit 33 (1) is stopped, and the unit cell 21 (2) is discharged by the discharge circuit 33 (2). .
[0057]
When the terminal voltage V2 is decreased by discharging the unit cell 21 (2), the voltages Er3 and Er1 are decreased. Further, since the unit cell 21 (1) is not discharged, V1 = Ec1 does not decrease. As a result, Er1 <Ec1 again, and the output signal of the comparator 27L becomes “H” again. Then, the discharge by the discharge circuit 33 (2) is stopped, and the unit cell 21 (1) is discharged by the discharge circuit 33 (1).
[0058]
When the terminal voltage V1 decreases due to the discharge of the unit cell 21 (1), the terminal voltage Ec1 decreases, Er1 = Ec1 again, the discharge by the discharge circuit 33 (1) stops, and the discharge circuit 33 (2) As a result, the unit cell 21 (2) is discharged. Thereafter, the switches 35 (1) and 35 (2) are alternately turned on, and the unit cells 21 (1) and 21 (2) are alternately discharged. Finally, when Er1 = Ec1, Er2 = Ec2, that is, V1 = V2 = V3, the discharge of the unit cells 21 (1) to 21 (3) is stopped, and the terminal voltages V1, V2, and V3 vary. The adjusting action ends. This voltage change is obtained by switching V1 and V3 in FIG.
[0059]
(3) V2> V3 = V1
Next, the operation when the initial state is V2> V3 = V1 will be described with reference to FIG. in this case,

Therefore, the output signals of the comparators 27H and 28L are both “H”. At this time, the output signals of the comparators 27L and 28H are both “L”, and in the truth table shown in FIG. 2, the condition that the switch 35 (2) is in the ON state “1” is satisfied. The unit cell 21 (2) is discharged by (2).
[0060]
When the terminal voltage V2 is decreased by discharging the unit cell 21 (2), the voltages Ec2 and Er3 are decreased. Accordingly, the divided potentials Er2 and Er1 are also decreased, and Er1 approaches Ec1. As described above, between Er2 and Ec2, the effect of the decrease in the terminal voltage V2 is clearly larger in Ec2, so that Ec2 approaches Er2. Finally, when Er1 = Ec1, Er2 = Ec2, and V1 = V2 = V3, the variation adjustment operation of the terminal voltages V1, V2, and V3 ends.
[0061]
That is, in this case, since only the terminal voltage V2 is always high and the terminal voltages V1 and V3 are always low with respect to the average voltage of the unit cell 21 in the transient state, only the unit cell 21 (2) is discharged all the time. become.
[0062]
As described above, according to this embodiment, the terminal voltage of the assembled battery 22 formed by connecting the three unit cells 21 (1) to 21 (3) in series is connected to the resistors 23, 24, and 25 in series. The voltage dividing circuit 26 divides the voltage, and the logic circuit unit 37 has the internal terminal voltages of the unit cells 21 (1) to 21 (3) higher than the average voltage based on the output signals of the comparators 27H to 28L. Was discharged automatically, and finally the terminal voltages of all the unit cells 21 (1) to 21 (3) were made substantially equal to eliminate the variation.
[0063]
For example, for the unit cell 21 (2), the logic circuit unit 37 determines that the potential Ec2 of the positive connection point Jc2 is higher than or substantially equal to the potential Er2 of the corresponding voltage dividing point Jr2. (Ec2 ≧ Er2) In addition, when the potential Er1 at the corresponding voltage dividing point Jr1 is higher than the potential Ec1 at the connecting point Jc1 on the negative electrode side (Ec1 <Er1), or the potential Ec2 is higher than the potential Er2 (Ec2> Er2) and higher than the potential Ec1. When the potential Er1 is high or both are substantially equal (Ec1 ≦ Er1), it is determined that the terminal voltage V2 is higher than the average voltage.
[0064]
Therefore, it is possible to reliably determine the level of the terminal voltage of the unit cell 21 and the average voltage obtained from the voltage dividing circuit 26, and to eliminate the terminal voltage between the unit cells, that is, the variation in the remaining capacity. It is possible to prevent overcharge and overdischarge and improve the use efficiency of the assembled battery 22.
[0065]
Further, according to the present embodiment, charging / discharging is performed by applying the lithium battery, which has a high energy density but requires more strict measures against overcharge and overdischarge, to the assembled battery 22 having the unit cell 21. It is possible to draw out and utilize the performance of the lithium battery sufficiently while being controlled safely.
[0066]
By the way, the conventional voltage regulator is configured to use an MPU, and it is necessary to supply a stable level of operation power to the MPU. For this reason, conventionally, the operation power supply is supplied from a control power supply (12V battery, which corresponds to a so-called gasoline vehicle battery) provided separately from the drive power supply battery.
[0067]
On the other hand, according to the present embodiment, the operation power supply for the comparators 27H to 41L and the logic circuit unit 37 is obtained from the assembled battery 22 as the drive power supply. That is, unlike the conventional circuit, the logic circuit unit 37 can be configured with a combination of logic gates without using an MPU or the like, so that its power consumption is extremely small compared to the conventional circuit. Since the assembled battery 22 has a three-series configuration, the terminal voltage is about 3.6 × 3 = 10.8 (V), which is suitable for the production of an operating power supply of about 3.3 to 5 V. . In addition, unlike the MPU, these circuits can operate even when the power supply voltage is somewhat reduced, so that these operating power supplies can be obtained from the assembled battery 22. Therefore, it is possible to suppress the power consumption of the control power supply having a relatively small capacity with respect to the operation power supply.
[0068]
(Second embodiment)
5 and 6 show a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. Only different parts will be described below. In the second embodiment, the unit cell 21 (4) is added to the assembled battery 22 to apply to the assembled battery 38 in which the number of series connections is four.
[0069]
Similarly to the resistors 23 and 24, the resistor 25 of the voltage dividing circuit 26 is composed of resistors 25a and 25b having a resistance ratio of 4000: 1, and a resistor 39 corresponding to the unit cell 21 (4) is added in series. Constitutes the voltage dividing circuit 40. The comparators 41H and 41L (potential comparison means) are connected to the connection point Jc3 of the unit cells 21 (3) and 21 (4) and both ends of the resistor 25b in the same manner as the comparators 28H and 28L.
[0070]
On the other hand, the output terminal of the comparator 28L is connected to one input terminal of the AND gate 43 via the NOT gate 42, and the other input terminal of the AND gate 43 is connected to the output terminal of the comparator 41L. . The output terminal of the comparator 28H is connected to one input terminal of the AND gate 44 instead of the control terminal of the switch 35 (3), and the other input terminal of the AND gate 44 is connected to the NOT gate 45. To the output terminal of the comparator 41H.
[0071]
The output terminals of the AND gates 43 and 44 are connected to the input terminal of the OR gate 46, respectively, and the output terminal of the OR gate 46 is connected to the control terminal of the switch 35 (3). The control terminal of the switch 35 (4) constituting the discharge circuit 33 (4) provided corresponding to the unit cell 21 (4) is connected to the output terminal of the comparator 41H.
[0072]
Note that a logic circuit unit 47 is configured by adding NOT gates 42 and 45, AND gates 43 and 44, and an OR gate 46 to the components of the logic circuit unit 37. The discharge circuit 33 plus the logic circuit unit 47 constitutes a discharge control means. In addition, as in the first embodiment, the operation power supplies of the comparators 27H to 41L and the logic circuit unit 47 are generated from the assembled battery 38 and supplied.
[0073]
Next, the operation of the second embodiment will be described with reference to FIG. In the truth table of the logic circuit unit 47 shown in FIG. 6, the second to fourth stages from the bottom are determined by the logic of the comparators 27H to 28L, as in FIG. 2 of the first embodiment. In addition, only the condition that both the comparators 41H and 41L are at the low level is added to the lowest stage in which any of the switches 35 is turned off.
[0074]
Then, the condition that the switch 35 (3) in the fifth and sixth stages from the bottom is in the on state “1” is that the logic of the comparators 27H to 28L in which the switch 35 (2) is in the on state is set to the comparators 28H to 41L. The same applies. The condition that the uppermost switch 35 (4) is turned on is a condition that the comparator 41H is at a high level.
[0075]
That is, the switch 35 (1) corresponding to the unit cell 21 (1) on the most negative side of the assembled battery 38 is turned on under the condition that the potential at the positive connection point Jc1 is the voltage dividing point Jr1 (Jr1 ′). The ON condition of the switch 35 (4) corresponding to the unit cell 21 (4) that is the most positive side is determined only by the output logic of the comparator 27L that outputs a high level signal when the potential is higher than the potential. Is determined only by the output logic of the comparator 41H that outputs a high level signal when the potential is higher than the potential at the negative connection point Jc3.
[0076]
Further, for example, the ON condition of the switch 35 (2) corresponding to the unit cell 21 (2) arranged in the middle of them is the comparators 28H and 28L arranged on the positive side of the unit cell 21 (2) and the negative side. It is determined by the output logic with the comparators 27H and 27L arranged at.
[0077]
According to the second embodiment configured as described above, the same effects as those of the first embodiment can be obtained even when applied to the assembled battery 38 having a four-series configuration. Further, unlike the conventional case, even when applied to a multi-series assembled battery 38, errors are not accumulated and precise voltage adjustment can be performed.
[0078]
Here, the case where the first and second embodiments are generalized and applied to an assembled battery having an n (n is a natural number) series configuration is shown in FIGS. That is, the positive and negative connection points of the i-th (1 <i <n) unit cell Ci are Jci and Jci-1, and the corresponding connection points of the voltage dividing resistors Ri and Ri-1 are Jri and Jri-. 1, the potentials of the connection points Jci and Jci-1 with reference to the terminal Jc0 (not shown) are Eci and Eci-1, and the potentials of the connection points Jri and Jri-1 are Eri and Eri-1.
[0079]
For the unit cell Ci, when the potential at the voltage dividing point Jri is higher than the potential at the connection point Jci, the comparator that outputs a high level signal is CPi H, and conversely, the potential at the connection point Jci is the potential at the voltage dividing point Jri. A comparator that outputs a high-level signal when the voltage is higher than that is CPiL. Further, when the average voltage of the unit cell C obtained by the voltage dividing resistor R is VM and the terminal voltage of the unit cell Ci is Vi, each value has the relationship of the equation (7).
Vi = Eci-Eci-1
VM = Eri-Eri-1 (7)
[0080]
Therefore, the condition for determining that Vi> VM, that is, the condition for turning on the switch SWi of the discharge circuit corresponding to the unit cell Ci is as follows:
(Eci ≧ Eri) ・ (Eci-1 <Eri-1)
+ (Eci> Eri) (Eci-1 ≦ Eri-1) (8)
The output condition of the comparator CP that satisfies the condition (8) is as shown in FIG.

It becomes. In the equation (8), the symbol “·” indicates a logical AND, and the symbol “+” indicates a logical OR.
[0081]
For example, looking at the correspondence of the first expression of (8) and (9), that at least the comparator CPi-1 H is “H” is the condition (Eci-1 <Eri-1) itself, The fact that at least the comparator CPi H is “L” means the condition (Eci ≧ Eri) because it is a negative of the condition (Eci <Eri). The fact that the comparators CPi H and CPi L are both “L” means a condition (Eci = Eri).
[0082]
As described above, even if the assembled battery has a multi-series configuration in which n is, for example, several tens, the outputs of the comparators CP1 L and CPn H are used for the first and nth unit cells C1 and Cn. The output condition of the comparator CP is set so that the switches SW1 and SWn of the corresponding discharge circuit are turned on when the level is "H", and the i-th unit cell Ci from the negative side in the middle thereof. When the above is established as shown in the equation (8), the logic circuit unit may be configured to turn on the switch SWi of the corresponding discharge circuit.
[0083]
(Third embodiment)
FIG. 9 shows a third embodiment of the present invention. As described above, the present invention is theoretically applicable to any number of battery packs in series. However, in reality, there is a problem such as the withstand voltage of the element to be used. Therefore, when the unit cell is a lithium battery having a cell voltage of about 3.6 V, an assembled battery of about 4 to 5 series is configured as one unit. Is considered preferable.
[0084]
Therefore, in the third embodiment, one battery is obtained by adding a voltage adjusting mechanism including the discharge circuit 33, the voltage dividing circuit 40, and the logic circuit section 47 to the assembled battery 38 having a 4-series configuration as in the second embodiment. The module 48 is used. Then, by connecting 20 battery modules 48 in series, an HEV driving battery 49 having a voltage of about 300 V with a cell voltage of 3.6 V × 80 unit cells 21 of the lithium battery was configured.
[0085]
Then, the voltage regulator of the conventional configuration shown in FIG. 12 is applied to the driving battery 49, and the unit cell 2 in FIG. 12 is replaced with a battery module 48. That is, in each battery module 48, the terminal voltage variation among the four unit cells 21 is automatically corrected by the action of the built-in logic circuit unit 47. Therefore, the MPU 7 can handle the battery module 48 like one cell.
[0086]
According to the third embodiment configured as described above, the MPU 7 periodically measures the terminal voltages of the 20 battery modules 48 by the voltage detector 4 and passes through the multiplexer 5 and the A / D converter 6. By reading, it is possible to adjust the voltage of the driving battery 49 formed by connecting substantially 80 unit cells 21 in series by one MPU 7. Therefore, unlike the prior art, it is not necessary to use a plurality of MPUs, and the cost of the apparatus can be greatly reduced.
[0087]
(Fourth embodiment)
FIG. 10 shows a fourth embodiment of the present invention. The same parts as those of the second embodiment are denoted by the same reference numerals and the description thereof is omitted. Only different parts will be described below. The voltage dividing circuit (voltage dividing means) 40 'of the fourth embodiment has a configuration in which the small voltage dividing resistors 23b, 24b and 25b are deleted from the voltage dividing circuit 40 of the second embodiment.
[0088]
The inverting and non-inverting input terminals of the differential amplifier (potential difference amplifying means, potential comparing means) 50 (1) are connected to terminals Jc1 and Jr1, respectively, and the output terminals are (terminal Jc1 of the second embodiment). (Instead of) are connected to the non-inverting and inverting input terminals of the comparators 27H and 27L. In addition, the resistor 57 (1) inserted in the inverting input terminal of the differential amplifier 50 (1) and the resistor 58 (1) connected between the inverting input terminal and the output terminal are differential. It is provided to determine the amplification factor of the amplifier 50 (1).
[0089]
A series circuit of a resistor 51H, diodes 52H and 52L, and a resistor 51L is connected between the terminals Jc2 and Jc0, and a cathode of the diode 52H and an anode (common connection point) of the 52L are connected to the terminal Jc1. Yes. The inverting input terminal of the comparator 27H is connected to the anode of the diode 52H, and the non-inverting input terminal of the comparator 27L is connected to the cathode of the diode 52H.
[0090]
Similarly, a differential amplifier (potential difference amplifying means, potential comparing means) 50 (2) is disposed between the terminals Jc2 and Jr2 and the comparators 28H and 28L, and the differential amplifier (potential difference amplifying means, potential comparing means). 50 (3) is disposed between the terminals Jc3 and Jr3 and the comparators 41H and 41L. A series circuit of a resistor 53H, diodes 54H and 54L, and a resistor 53L is connected between the terminals Jc3 and Jc1, and a series circuit of a resistor 55H, diodes 56H and 56L, and a resistor 55L is connected between the terminals Jc4 and Jc2. Has been. Other configurations are the same as those of the second embodiment.
[0091]
Next, the operation of the fourth embodiment will be described. For example, the differential amplifier 50 (1) amplifies the potential difference Vd1 (= Eri−Eci) between the potential Er1 at the terminal Jr1 and the potential Ec1 at the terminal Jc1, and outputs the amplified signal α · Vd1 to the comparators 27H and 27L. When the level of the amplified signal α · Vd1 is higher than the forward voltage VF of the diode 52H,
α ・ Vd1 ＞ VF
"H" is output at the time.
[0092]
Further, the comparator 27L, when the level of the amplified signal α · Vd1 is negative (that is, Eri <Eci), the absolute value thereof is higher than the forward voltage VF of the diode 52L, that is,
| Α ・ Vd1 | ＞ VF (Vd1 <0)
"H" is output at the time. Further, the differential amplifiers 50 (2) and 50 (3) operate in the same manner for the corresponding potentials, and the logic circuit unit 47 (not shown in FIG. 10) outputs the output signals of the comparators 27H to 41L to the second. Logic synthesis is performed in the same manner as in the embodiment.
[0093]
That is, when the comparators 28H to 41L perform potential comparison using the small voltage dividing resistors 23b, 24b, and 25b as in the second embodiment, the resistance value actually changes due to the temperature change of the operating environment. Therefore, there is a problem that the comparison operation is difficult to stabilize.
[0094]
On the other hand, according to the fourth embodiment, the difference Vd between the potential on the assembled battery 38 side and the potential on the voltage dividing circuit 40 'side is amplified by the differential amplifier 50 and applied to the comparators 28H to 41L. ˜41L compares the level of the amplified signal α · Vd with the reference voltage created by using the forward voltage VF of the diodes 52, 54 and 56 having good stability, so that the terminal voltage Ec of the unit cell 21 and The level of the average voltage VM can be determined more reliably, and the operation stability can be improved.
[0095]
(5th Example)
11 to 13 show a fifth embodiment of the present invention. The same parts as those of the fourth embodiment are denoted by the same reference numerals and the description thereof will be omitted. Only different parts will be described below. In the fifth embodiment, between the terminal Jc1 and the resistor 57 (1), between the terminal Jc2 and the resistor 57 (2), between the terminal Jc3 and the resistor 57 (3), and between the terminal Jc4 and the terminal Jr4. In addition, fuses (path blocking means) 59 (1), 59 (2), 59 (3), 59 (4) are inserted, respectively.
[0096]
A series circuit of the resistor 60 and the thermistor (temperature detecting means) 61 and a series circuit of the resistors 63 and 64 are connected between the terminal Jr4 and the common connection point of the fuse 59 (3) and the resistor 57 (3). ing. The common connection point of the resistor 60 and the thermistor 61 is connected to the inverting input terminal of the comparator (temperature comparison means) 62, and the common connection point of the resistors 63 and 64 is connected to the non-inverting input of the comparator 62 via the resistor 65. Connected to the terminal. The output terminal of the comparator 62 is connected to its own non-inverting input terminal via a resistor 66, and is connected to the IHBT terminal of a logic circuit unit (discharge control means) 67 instead of the logic circuit unit 47.
[0097]
The thermistor 61 is a negative thermistor whose resistance value increases as the temperature decreases. The voltage applied to the inverting input terminal of the comparator 62 is the resistance 60 and the voltage of the unit cell 21 (4) if the voltage across the terminals is constant. It is determined by the ratio of resistance values of the thermistor 61. As an example, if the inter-terminal voltage of the unit cell 21 (4) is 4.0V and the resistance values of the resistors 60, 63, and 64 are 150 kΩ, the reference voltage applied to the non-inverting input terminal of the comparator 62 is 2. 0V. The thermistor 61 is selected so as to have a resistance value of 150 kΩ or higher when the temperature is −30 ° C. (reference temperature) or lower. The resistors 51H, 51L, 53H, 53L, 55H, and 55L are not shown.
[0098]
Here, FIG. 12 shows an example of the configuration of the logic circuit section 67. That is, the logic circuit unit 67 is configured by adding AND gates 68 (1), 68 (2), 68 (3), and 68 (4) to the logic circuit unit 47. One input terminal of these AND gates 68 is connected to the IHBT terminal, and the other terminals of the AND gates 68 (1), 68 (2), 68 (3), 68 (4) are output from the comparator 27L. The output terminal of the OR gate 36, the output terminal of the OR gate 46, and the output terminal of the comparator 41H. The output terminals of the AND gates 68 (1) to 68 (4) are connected to the on / off control terminals of the switches 35 (1) to 35 (4), respectively.
[0099]
Next, the operation of the fifth embodiment will be described with reference to FIG. FIG. 13 shows the truth value of the logic circuit unit 67. When the voltage across the thermistor 61 is lower than the reference voltage applied to the non-inverting input terminal, the comparator 62 outputs a high level “H”, and the voltage across the thermistor 61 is higher than the reference voltage. The output terminal is at the low level “L”.
[0100]
Accordingly, when the ambient temperature detected by the thermistor 61 exceeds −30 ° C., the IHBT terminal of the logic circuit section 67 becomes “H”, and when the ambient temperature is −30 ° C. or less, IHBT The terminal becomes “L”. That is, as shown in FIG. 13, when the ambient temperature exceeds −30 ° C. and the IHBT terminal is “H”, the on / off control of the switches 35 (1) to 35 (4) is performed as shown in FIG. This is done in exactly the same way as in the embodiment. When the ambient temperature is −30 ° C. or lower and the IHBT terminal is “L”, the switches 35 (1) to 35 (4) are all turned off regardless of the output states of the comparators 27, 28, and 41. Thus, the discharge of the unit cells 21 (1) to 21 (4) is prohibited.
[0101]
The reason for this control is as follows. That is, the HEV or the like is assumed to travel under various environments, but the internal resistance of the unit cell 21 is extremely large in a low temperature environment where the ambient temperature is -30 ° C. or lower such as in a cold district. There is a case. When the unit cell 21 is discharged in such a state, a large voltage drop occurs due to the discharge. Therefore, if the voltage of a certain unit cell 21 is lower than the lowest voltage at that time, the unit that does not need to be adjusted in voltage is originally necessary. The voltage of the cell 21 may be adjusted.
[0102]
That is, when a voltage drop occurs due to the discharge, the voltage between the terminals of the unit cell 21 decreases. However, if the voltage drop is too large, the voltage of the unit cell 21 that originally shows the lowest voltage also falls below the unit being discharged. The cell 21 becomes the apparent minimum voltage cell. Then, the other unit cells 21 are discharged by adjusting the voltage with the target unit cell 21 being discharged as a target, and are discharged to the original lowest voltage cell that should not be discharged. As a result, the minimum voltage is further lowered, the voltage of the other unit cells 21 is adjusted and discharged for that purpose, and the adjustment operation is continued to reduce the voltage of the assembled battery 38 as a whole. Therefore, the discharge of the unit cell 21 is prohibited when the ambient temperature becomes −30 ° C. or lower.
[0103]
Further, for example, a case is assumed in which the HEV is running and a disconnection occurs for some reason in the vicinity of the unit cell 21 (3) while the assembled battery 38 is being charged or discharged. Then, an electromotive force corresponding to the total voltage of the assembled battery 38 (the sum of the voltages of the unit cells 21) is present between the disconnection points Jc2 and Jc3 due to, for example, an inductance component of the inverter circuit or the like connected to the assembled battery 38. Will occur.
[0104]
When an electromotive force is generated between the terminals Jc2 and Jc3, a large current tends to flow into the voltage regulator via the fuses 59 (2) and 59 (3) and the respective discharge paths. 2), 59 (3) is blown, and the path is blocked.
[0105]
As described above, according to the fifth embodiment, when the ambient temperature is detected by the thermistor 61 and the ambient temperature falls below −30 ° C., the logic circuit unit 67 receives the output signal from the comparator 62 and receives the unit cell 21 ( Since the discharges 1) to 21 (4) are prohibited, when the internal resistance of the unit cell 21 becomes extremely large under a low temperature environment, the unit cell 21 that does not need to be originally adjusted in voltage is suppressed by suppressing the discharge. It is possible to avoid falling into the situation of adjusting the voltage of.
[0106]
According to the fifth embodiment, since the fuses 59 (1) to 59 (4) are inserted between the terminals Jc1 to Jc4 and the resistors 57 (1) to 57 (3) and the terminal Jr4, respectively. Even when one of the unit cells 21 is disconnected and a high voltage is generated at both ends of the disconnected portion, the fuse 59 is melted and the discharge path is cut off, so that it is connected to the assembled battery 38. The voltage regulator can be protected from destruction and burning due to high voltage and large current. On the other hand, for example, when a short circuit occurs on the voltage regulator side due to the entry of foreign matter or a decrease in insulation, the assembled battery 38 side is protected by the fuses 59 (1) to 59 (4). be able to.
[0107]
(Sixth embodiment)
FIG. 14 shows a sixth embodiment of the present invention. The same parts as those of the fifth embodiment are denoted by the same reference numerals and the description thereof will be omitted. Only different parts will be described below. In the sixth embodiment, a reference voltage Vref of 1.5 V is applied to the inverting input terminal of a comparator (voltage comparison means) 62a instead of the comparator 62, instead of the common connection point of the resistor 60 and the thermistor 61 in the fifth embodiment. The positive side terminal of the constant voltage source 69 to be applied is connected, and the negative side terminal of the constant voltage source 69 is connected to a common connection point between the fuse 59 (3) and the resistor 57 (3).
[0108]
In this case, since the resistors 63 and 64 equally divide the voltage between the terminals of the unit cell 21 (4), the comparator 62a has 1 of the voltage between the terminals of the unit cell 21 (4) given to the non-inverting input terminal. The voltage Vc of / 2 is compared with the reference voltage Vref applied to the inverting input terminal. Here, the reference voltage Vref of 1.5V is obtained by multiplying the lower limit voltage by the voltage dividing ratio 1/2 of the resistors 63 and 64 when the usable lower limit voltage of the unit cell 21 is set to 3.0V. Is set.
[0109]
The output terminal of the comparator 62a is at the high level “H” when the voltage Vc is higher than the reference voltage Vref, and is at the low level “L” when the voltage Vc is lower than the reference voltage Vref. Other configurations are the same as those of the fifth embodiment.
[0110]
Next, the operation of the sixth embodiment will be described. As described above, the voltage regulator of the present invention performs adjustment so that the terminal voltage of the other unit cell 21 is matched with the lowest voltage among the terminal voltages of each unit cell 21. . Therefore, assuming that any unit cell 21 in the assembled battery 38 is short-circuited for some reason and its terminal voltage is significantly below the lower limit voltage that can be used, other healthy unit cells according to the voltage Even the terminal voltage of 21 may be adjusted to be lower than the usable lower limit voltage.
[0111]
Therefore, in the sixth embodiment, in order to prevent the occurrence of such a situation, the comparator 62a has a lower limit voltage 3.0V at which the inter-terminal voltage Vc of the unit cell 21 (4) given to the non-inverting input terminal can be used. If the value is lower than, discharge of the unit cell 21 is prohibited by supplying a low level signal to the IHBT terminal of the logic circuit section 67.
[0112]
As described above, according to the sixth embodiment, when the inter-terminal voltage Vc of the unit cell 21 (4) is detected by the resistors 63 and 64 and the inter-terminal voltage Vc falls below the usable lower limit voltage, the comparator 62a and the logic Since the discharge of the unit cell 21 is prohibited by the circuit unit 67, it is possible to prevent the voltage of the other unit cell 21 from being significantly reduced even when a short circuit occurs in any of the unit cells 21.
[0113]
The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following modifications or expansions are possible.
In the second embodiment, instead of using two NOT gates 32 and 42, an AND gate 70 having a negative logic input is used as shown in FIG. You may connect in common to 43 input terminals. When configured in this manner, the logical condition of the unit cell 21 (2) relating to the modified portion satisfies the condition that the positive terminal voltage Ec2 is substantially equal to the divided potential Er2 (Ec2 = Er2), and When the divided potential Er1 is higher than the negative terminal voltage Ec1 (Ec1 <Er1), it is determined that the terminal voltage V2 is higher than the average voltage.
For the unit cell 21 (3), the condition that the negative terminal voltage Ec2 is substantially equal to the divided potential Er2 (Ec2 = Er2) is satisfied, and the positive terminal voltage Ec3 is greater than the divided potential Er3. Is higher (Ec3> Er3), it is determined that the terminal voltage V3 is higher than the average voltage. Further, the same applies to the logical synthesis of output signals from the comparators CPi, CPi-1, CPi + 1, etc. in the case of the n-series configuration shown in FIG. If configured in this way, the number of gates can be reduced by sharing, especially when discrete elements are used in the logic circuit section in a multi-series configuration.
[0114]
The unit cell is not limited to a lithium battery, but can be similarly applied to a lead battery or a nickel battery.
It is not always necessary to perform voltage adjustment for all unit cells constituting the assembled battery, and voltage adjustment may be performed for only a specific one or a specific plurality of unit cells.
The present invention is not limited to an electric vehicle or HEV, and can be applied to any battery that uses a battery configured by connecting a plurality of unit cells in series.
In the sixth embodiment, the reference voltage Vref is set to the upper limit voltage (for example, 4.0 V) of the adjustment operation, the inverting input terminal and the non-inverting input terminal of the comparator 62a are switched, or the output signal of the comparator 62a is changed. It may be inverted by a NOT gate. In such a configuration, the following operational effects can be obtained.
That is, as a factor that the voltage of each unit cell 21 varies, there is a variation in the full charge capacity in addition to the variation in the remaining capacity described above. And in the case of a lithium battery, the voltage of the battery has a unique correlation with the state of charge, i.e., the ratio between the remaining capacity and the full charge capacity, so even if the remaining capacity is equal, the voltage varies if the full charge capacity is different, The magnitude of the variation increases as the remaining capacity increases. In such a case, although the voltage of the unit cell 21 does not need to be equalized, the amount of discharge caused by the voltage adjustment operation is wasted.
Therefore, by setting the upper limit of the voltage adjustment operation with the reference voltage Vref, unnecessary voltage adjustment operation due to the variation in the full charge capacity can be suppressed, and wasteful energy consumption can be suppressed.
[0115]
Further, two voltage comparators are prepared, one of which is for the upper limit voltage and the other is for the lower limit voltage. Then, by providing these output signals to the IHBT terminal of the logic circuit section 67 via an AND (negative logic input / output OR) gate, an upper limit and a lower limit of the voltage adjustment operation are determined, and a limited voltage ( It is also possible to make the voltage adjustment operation only in the (remaining capacity) range. This is because charging and discharging are performed with an intermediate remaining capacity as the center, such as a HEV drive battery, and it is possible to always equalize the voltage with the remaining capacity near the center, and output (discharge) and regenerative ( The unit cell 21 can be used in a state of being balanced with (charging).
Both the temperature detection means and the temperature comparison means centered on the comparator 62 in the fifth embodiment and the voltage detection means and the voltage comparison means centered on the comparator 62a in the sixth embodiment may be arranged simultaneously. In that case, the output signals of the comparators 62 and 62a may be supplied to the IHBT terminal of the logic circuit section 67 via an AND gate.
The path cut-off means is not limited to the fuse 59, and for example, a part having a narrow width dimension is provided for a part of the wiring pattern on the substrate serving as a discharge path, and the part is burned out when an overcurrent flows. It may be the one made.
[Brief description of the drawings]
FIG. 1 is an electrical configuration diagram showing a first embodiment when the present invention is applied to an assembled battery having a three-series configuration. FIG. 2 is a diagram showing a truth value of a logic circuit portion. (1) which shows an example of the change of each terminal voltage when performing the dispersion | variation adjustment of 1
4 is a view corresponding to FIG. 3 (part 2).
FIG. 5 is a view corresponding to FIG. 1 showing a second embodiment when the present invention is applied to a 4-series assembled battery. FIG. 6 is a view corresponding to FIG. 2. FIG. 7 is an n-series assembled battery. FIG. 8 is a diagram corresponding to FIG. 1 when applied. FIG. 9 is a diagram showing a third embodiment when the present invention is applied to a drive battery for a hybrid electric vehicle. FIG. 11 is a diagram corresponding to FIG. 5 illustrating the fourth embodiment. FIG. 11 is a diagram corresponding to FIG. 5 illustrating the fifth embodiment of the present invention. 14 is a diagram corresponding to FIG. 5 showing a sixth embodiment of the present invention. FIG. 15 is a diagram corresponding to FIG. 5 showing a modified example. FIG. 16 is a diagram corresponding to FIG. Fig. 16 equivalent diagram when modularized as a module [Fig. 18] Fig. 1 equivalent diagram showing another prior art [Explanation of symbols]
21 is a unit cell (lithium battery), 22 is an assembled battery, 23, 24 and 25 are resistors, 26 is a voltage dividing circuit (voltage dividing means), 27H, 27L, 28H and 28L are comparators (potential comparison means), and 33 is Discharge circuit (discharge control means), 37 is a logic circuit section (discharge control means), 38 is an assembled battery, 39 is a resistor, 40 and 40 'are voltage dividing circuits (voltage dividing means), 41H and 41L are comparators (potential comparison) Means), 47 is a logic circuit section (discharge control means), 49 is a drive battery, 50 is a differential amplifier (potential difference amplifying means, potential comparison means), 59 is a fuse (path cut-off means), and 61 is a thermistor (temperature detection). Means), 62 is a comparator (temperature comparison means), 62a is a comparator (voltage comparison means), 63 and 64 are resistors (voltage detection means), 67 is a logic circuit section (discharge control means), Jc1, Jc2, Jc3, Jci-1, and Jci represent connection points, and Jr1, Jr2, Jr3, Jri-1, and Jri represent partial pressure points.

Claims (8)

An assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series;
Voltage dividing means for dividing the terminal voltage of the assembled battery in accordance with the number of the unit cells;
A potential comparison means for comparing a potential at a specific connection point among the connection points between the plurality of unit cells and a potential at a voltage dividing point divided by the voltage dividing means corresponding to the connection point;
Temperature detecting means for detecting the ambient temperature;
A temperature comparison means for comparing the ambient temperature detected by the temperature detection means with a preset reference temperature;
Based on the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potentials equal, with the terminal voltage before Kitan position cell determines that higher than the average voltage is controlled so as to discharge the unit cell, the temperature comparing means And a discharge control means for prohibiting discharge of the unit cell when it is determined that the ambient temperature is equal to or lower than the reference temperature based on the comparison result of the battery pack. An assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series;
Voltage dividing means for dividing the terminal voltage of the assembled battery in accordance with the number of the unit cells;
A potential comparison means for comparing a potential at a specific connection point among the connection points between the plurality of unit cells and a potential at a voltage dividing point divided by the voltage dividing means corresponding to the connection point;
An inter-terminal voltage detection means for detecting an inter-terminal voltage of at least one unit cell among the plurality of unit cells;
Voltage comparison means for comparing the voltage between the terminals detected by the voltage detection means between the terminal and a preset reference voltage;
According to the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potentials equal, the terminal voltage before Kitan position cell is determined to be higher than the average voltage, controls so as to discharge the unit cell, the voltage comparing means Based on the result of the comparison, when it is determined that the voltage between the terminals is equal to or lower than the reference voltage, discharging of the unit cell is prohibited. An assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series;
A voltage dividing means for dividing the terminal voltage of the assembled battery according to the number of the unit cells, a potential of a specific connection point among the connection points between the plurality of unit cells, and the corresponding to the connection point A potential comparison means for comparing the potential at the voltage dividing point divided by the voltage dividing means;
An inter-terminal voltage detection means for detecting an inter-terminal voltage of at least one unit cell among the plurality of unit cells;
Voltage comparison means for comparing the voltage between the terminals detected by the voltage detection means between the terminal and a preset reference voltage;
According to the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potentials equal, the terminal voltage before Kitan position cell is determined to be higher than the average voltage, controls so as to discharge the unit cell, the voltage comparing means Based on the result of the comparison, when it is determined that the inter-terminal voltage is equal to or higher than the reference voltage, discharging of the unit cell is prohibited. An assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series;
A voltage dividing means for dividing the terminal voltage of the assembled battery according to the number of the unit cells, a potential of a specific connection point among the connection points between the plurality of unit cells, and the corresponding to the connection point A potential comparison means for comparing the potential at the voltage dividing point divided by the voltage dividing means;
Based on the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potentials equal, provided the terminal voltage before Kitan position cell is determined to be higher than the average voltage, and a discharge control means for controlling so as to discharge the unit cell With
A voltage adjustment device for a battery pack, characterized in that path blocking means for blocking the discharge path when an overcurrent flows in the discharge path of the unit cell is disposed on each side of the discharge path near the unit cell. The terminal voltage of the assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series is divided according to the number of the unit cells by the voltage dividing means,
Of the connection points between the plurality of unit cells, the potential of a specific connection point and the potential of the voltage dividing point divided by the voltage dividing unit corresponding to the connection point are compared by the potential comparison unit,
Based on the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potential equal to the terminal voltage of the pre Kitan position cell to discharge the corresponding unit cell when determined to be higher than the average voltage,
The ambient temperature detected by the temperature detecting means is compared with a preset reference temperature by the temperature comparing means,
A voltage adjustment method for a battery pack, wherein discharge of a unit cell is prohibited when it is determined that the ambient temperature is equal to or lower than the reference temperature based on a comparison result by the temperature comparison means. The terminal voltage of the assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series is divided according to the number of the unit cells by the voltage dividing means,
Of the connection points between the plurality of unit cells, the potential of a specific connection point and the potential of the voltage dividing point divided by the voltage dividing unit corresponding to the connection point are compared by the potential comparison unit,
Based on the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potential equal to the terminal voltage of the pre Kitan position cell to discharge the corresponding unit cell when determined to be higher than the average voltage,
The voltage between the terminals of at least one unit cell of the plurality of unit cells and a preset reference voltage are compared by a voltage comparison unit,
A voltage adjustment method for a battery pack, wherein discharge of a unit cell is prohibited when it is determined that the inter-terminal voltage is equal to or lower than the reference voltage based on a comparison result by the voltage comparison means. The terminal voltage of the assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series is divided according to the number of the unit cells by the voltage dividing means,
Of the connection points between the plurality of unit cells, the potential of a specific connection point and the potential of the voltage dividing point divided by the voltage dividing unit corresponding to the connection point are compared by the potential comparison unit,
Comparison result from the previous SL higher or both potentials are equal and the than the potential of the voltage dividing point of the potential of the positive electrode side connection point corresponds to a potential comparison unit corresponding to the connection point of the positive electrode side and negative electrode side of the unit cell When the potential of the corresponding voltage dividing point is higher than the potential of the negative electrode side connection point, or the electric potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point when the potential dividing point equals higher or both potential causes the terminal voltage before Kitan position cell discharges the unit cell when it is determined to be higher than the average voltage,
The voltage between the terminals of at least one unit cell of the plurality of unit cells and a preset reference voltage are compared by a voltage comparison unit,
A voltage adjustment method for a battery pack, wherein discharge of a unit cell is prohibited when it is determined that the inter-terminal voltage is equal to or higher than the reference voltage based on a comparison result by the voltage comparison means. The terminal voltage of the assembled battery configured by connecting a plurality of unit cells made of secondary batteries in series is divided according to the number of the unit cells by the voltage dividing means,
Of the connection points between the plurality of unit cells, the potential of a specific connection point and the potential of the voltage dividing point divided by the voltage dividing unit corresponding to the connection point are compared by the potential comparison unit,
Based on the comparison result of the potential comparison means corresponding to the positive and negative connection points of the unit cell, the potential of the positive connection point is higher than the corresponding voltage dividing point or both potentials are equal and the negative electrode When the potential of the corresponding voltage dividing point is higher than the potential of the side connection point, or the potential of the positive electrode side connection point is higher than the potential of the corresponding voltage dividing point and corresponds to the potential of the negative electrode side connection point. when the potential dividing point is higher or both potential equal to the terminal voltage of the pre Kitan position cell to discharge the corresponding unit cell when determined to be higher than the average voltage,
When an overcurrent flows through a discharge path of a unit cell, the discharge path is cut off by a path cut-off means arranged in the vicinity of each unit cell.

Images