JP4496696B2

JP4496696B2 - Secondary battery temperature rise control device

Info

Publication number: JP4496696B2
Application number: JP2001293193A
Authority: JP
Inventors: 孝昭安部
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2001-09-26
Filing date: 2001-09-26
Publication date: 2010-07-07
Anticipated expiration: 2021-09-26
Also published as: JP2003102133A

Description

【０００１】
【発明の属する技術分野】
本発明は、２次電池の昇温制御装置に関する。
【０００２】
【従来の技術】
化学反応を伴う２次電池は、電池の温度が低下すると内部抵抗が大きくなり、放電可能出力が低下してしまう。
【０００３】
図４は、２次電池とエンジンの両方が搭載されるパラレルハイブリット型車両における２次電池放電可能出力に対する車両の燃料消費率を示す図である。横軸に２次電池放電可能出力、縦軸に車両の燃料消費率を示す。図４において、線ａは２次電池を放電しながら走行する場合の燃料消費率を示し、線ｂは２次電池を充電しながら走行する場合の燃料消費率を示している。２次電池を充電しながら走行する場合は、エンジン駆動により発電機を作動させ２次電池を充電するので、２次電池を放電しながら走行する場合に比べ、２次電池を充電するエネルギー分燃料消費率が低下する。
【０００４】
２次電池放電可能出力が大きいほどモータを駆動源とした走行が長くできるため、車両発進時であるエンジン低回転時の低効率運転状態を回避できるので燃料消費率が良くなる。２次電池放電可能出力がゼロとなると、通常のエンジン搭載車両の燃費効率になる。本来のパラレルハイブリット車の燃費性能を発揮するためには、２次電池の放電可能出力が設計値の出力を出せるようにしなければならない。
【０００５】
常温時での２次電池の性能で車両設計を行うと、低温時での燃費性能が低下し、また低温時での２次電池の性能で車両設計を行うと、２次電池を多く搭載することになり、２次電池のコストアップや２次電池の重量増加による車両の燃費性能が低下してしまう。通常、低温時の２次電池性能を多少犠牲にして、車両の燃費性能の設計を行うことになる。そこで、低温時の２次電池を早く昇温させて２次電池の放電可能出力を向上させ、車両の燃費を向上させることが必要となる。
【０００６】
２次電池を最も早く昇温させる方法としては、２次電池が流せる最大電流値を車両駆動用モータ及び補機に流すことが考えられる。この事を利用した従来技術として、例えば特開平１１−０２６０３２号公報に記載されたものがある。
【０００７】
この技術をパラレルハイブリット型車両に適用すると、２次電池が流せる最大電流値を車両駆動用モータ及び補機に流し、２次電池の残容量が低下したら２次電池を発電機で充電し、２次電池の残容量がある所定値以上となると充電をやめ、再度、２次電池が流せる最大電流値を車両駆動用モータ及び補機に流すことになる。
【０００８】
【発明が解決しようとする課題】
しかしながら、車両の走行条件や補機の容量の制限によって２次電池の持つ性能の最大電流を充放電に使用する事ができないといった問題が生じる。そのため、定電力での充放電となる。
【０００９】
図５に定電力での充電と放電を行ったときの２次電池の発熱量を表わす実験結果を示す。
２次電池の残容量を２次電池の残容量ＳＯＣ、２次電池充電放電電力に対する２次電池発熱量が最大となる２次電池の残容量を２次電池の残容量ＳＯＣ＊とする。
横軸に２次電池の残容量ＳＯＣ、縦軸に２次電池の発熱量を示す。２次電池を定電力で放電しているときの発熱量は、図５中の線ｃとなり、ある２次電池の残容量ＳＯＣ＊の時に最大となる。２次電池の残容量ＳＯＣ＊を境に２次電池の残容量ＳＯＣが高いほど発熱量は低くなる。このようになるのは、２次電池の残容量ＳＯＣが高いほど２次電池の開放電圧が高く、電流値が小さくなるためである。２次電池の残容量ＳＯＣ＊を境に２次電池の残容量ＳＯＣが低くなると発熱量は低くなる。これは２次電池の放電可能出力が要求される放電電力以下となり電流値が小さくなるからである。
【００１０】
２次電池を定電力で充電しているときの発熱量は、図５中の線ｄとなり２次電池の残容量ＳＯＣが高いほど小さくなる。このようになるのは、２次電池の残容量ＳＯＣが高いほど２次電池の開放電圧が高く、電流値が小さくなるためである。
【００１１】
放電と充電を繰り返したときの発熱量は、図５中の線ｅとなり、ある２次電池の残容量ＳＯＣ＊の時に最大となる。放電と充電を繰り返した際、２次電池の残容量がΔＳＯＣの範囲で変化する。しかし、２次電池の残容量の振れ幅ΔＳＯＣは０．５％以下を考えているので、ここでは２次電池の残容量の振れ幅ΔＳＯＣが２次電池発熱量に与える影響は無視できる。
【００１２】
本発明は上記２次電池を定電力で充放電しているときに発熱量が最大となる２次電池の残容量ＳＯＣ＊について着目し、すばやく２次電池を昇温させることのできる２次電池の昇温制御装置を提供することを目的とする。
【００１３】
請求項１記載の発明は、２次電池と、前記２次電池を充電するための発電手段と、前記２次電池を放電させるための放電手段と、前記２次電池の動作時の発熱量が最大となる電池の残容量を演算する容量演算手段と、前記２次電池の実際の実残容量を検出する容量検出手段と、検出した２次電池の実残容量が前記容量演算手段で演算した残容量となるように、前記２次電池の充放電を行う制御手段とを有し、前記容量演算手段は、前記２次電池の状態に相関する発熱量のデータを予め保有し、前記データに基づき前記残容量を演算するものとした。
【００１４】
請求項２記載の発明は、さらに前記２次電池の温度を測定するための測定手段を有し、前記制御手段は、検出した温度が、前記２次電池の充放電可能入出力が所定値未満となる温度である場合には、前記２次電池の充電または放電を行って前記容量演算手段で演算した残容量となるように設定し、前記２次電池の残容量が前記設定した残容量から所定の範囲内となるように前記２次電池の充電と放電とを繰り返すように制御するものとした。
【００１５】
請求項３記載の発明は、前記容量演算手段は、前記２次電池の残容量と温度に相関する発熱量のデータを予め保有し、前記２次電池の温度に基づいて前記２次電池の動作時の発熱量が最大となる電池の残容量を演算するものとした。
【００１６】
請求項４記載の発明は、前記制御手段は、検出した温度が、前記２次電池の充放電可能入出力が前記発電手段及び前記放電手段の要求充放電入出力未満となる温度である場合には、前記２次電池の充電または放電を行って前記容量演算手段で演算した残容量となるように設定するものとした。
【００１７】
【発明の効果】
請求項１記載の発明によれば、２次電池の発熱量が最大となる２次電池の残容量ＳＯＣ＊になるように２次電池を充放電することにより、２次電池の温度が上昇し２次電池の放電可能出力と２次電池の充電可能入力が向上する。
【００１８】
請求項２記載の発明によれば、２次電池の残容量ＳＯＣが２次電池発熱量が最大となる２次電池の残容量ＳＯＣ＊の所定の範囲内で変化するように２次電池の充電量と放電量を制御することにより、２次電池の昇温速度が速くなる。２次電池の温度が上昇することにより２次電池の放電可能出力と２次電池の充電可能入力が向上する。
【００１９】
請求項３記載の発明によれば、２次電池の温度が変化すると、２次電池発熱量が最大となる２次電池残容量ＳＯＣ＊が変化するので、２次電池の残容量ＳＯＣが変化する２次電池発熱量が最大となる２次電池残容量ＳＯＣ＊の所定の範囲内で変化するように２次電池の充電量と放電量を制御することにより、２次電池の昇温速度が速くなる。２次電池の温度が上昇することにより２次電池の放電可能出力と２次電池の充電可能入力が向上する。
【００２０】
請求項４記載の発明によれば、２次電池の温度が上昇することにより２次電池の放電可能出力と充電可能出力が向上し、車両の燃費を向上させることができる。
【００２１】
２次電池の温度が変化すると、２次電池発熱量が最大となる２次電池残容量ＳＯＣ＊が変化することを図６で示す。
図６中、線ｆ、ｇ、ｈは２次電池温度が−３０℃、−２０℃、−１０℃の場合で、それぞれ一定の電力で放電と充電を繰り返した場合である。２次電池の温度が上昇すると２次電池の内部抵抗が小さくなるので、発熱量が低下する。また、内部抵抗が小さくなり２次電池の放電可能出力が大きくなることから、この条件の電力を放電できる２次電池の残容量が小さくなる。よって、２次電池の発熱量が最大となる２次電池の残容量ＳＯＣ＊は２次電池の温度によって変化する。
【００２２】
【発明の実施の形態】
次に発明の実施の形態を実施例により説明する。
図１は実施例として本発明を適用したパラレルハイブリット型車両の構成を示す図である。
図において、太い実線は機械力の伝達経路を示し、破線は電力線を示す。
この車両のパワートレインは、発電モータ１、エンジン２、クラッチ３、駆動モータ４、無段変速機５、ディファレンシャルギヤ６及び駆動輪７から構成される。発電モータ１の出力軸、エンジン２の出力軸およびクラッチ３の入力軸は互いに連結されており、また、クラッチ３の出力軸、駆動モータ４の出力軸及び無段変速機５の入力軸は互いに連結されている。
【００２３】
クラッチ３締結時はエンジン２と駆動モータ４が車両の推進源となり、クラッチ３解放時は駆動モータ４のみが車両の推進源となる。推進源の駆動力は、無段変速機５、およびディファレンシャルギヤ６を介して駆動輪７へ伝達される。
【００２４】
発電モータ１、駆動モータ４は三相同期電動機または三相誘導電動機などの交流機であり、発電モータ１は主としてエンジン２の始動と発電に用いられ、駆動モータ４は主として車両の推進と制動に用いられる。
クラッチ３はパウダークラッチであり、伝達トルクを調節することができる。
【００２５】
発電モータ１、駆動モータ４はそれぞれ、インバータ８、９により駆動される。インバータ８、９は共通のＤＣリンク１０を介して２次電池１１に接続されており、２次電池１１の直流電力を交流電力に変換して、駆動モータ４へ供給するとともに、発電モータ１の交流発電電力を直流電力に変換して２次電池１１を充電する。なお、インバータ８、９は互いにＤＣリンク１０を介して接続されているので、回生運転中のモータにより発電された電力を、２次電池１１を介さずに直接、力行運転中のモータへ供給することができる。
２次電池１１の電力はＤＣリンク１０を介してＤＣ／ＤＣコンバータ１２に接続され、車両の補機１３に電力を供給する。
【００２６】
コントローラ１４は、エンジン２の回転速度、出力およびトルク、クラッチ３の伝達トルク、発電モータ１の回転速度およびトルク、無段変速機５の変速比、２次電池１１の充放電などを制御する。
【００２７】
コントローラ１４は、２次電池１１の温度ＴＢを検出する温度センサ１５、２次電池１１の端子電圧ＶＢを検出する電圧センサ１６および２次電池１１の電流値ＩＢを検出する電流センサ１７からの信号が入力され、２次電池１１の残容量ＳＯＣを検出する機能を持っている。
【００２８】
また、コントローラ１４は２次電池１１の温度ＴＢと２次電池１１の残容量ＳＯＣに対する２次電池１１の放電可能出力と充電可能入力のマップデータを持っており、マップデータから２次電池１１の放電可能出力ＰＢＯＵＴと充電可能入力ＰＢＩＮを演算できるようようになっている。
【００２９】
また、コントローラ１４は２次電池１１の温度ＴＢ、２次電池１１の残容量ＳＯＣ、２次電池１１の放電電力と２次電池１１の充電電力に対する２次電池１１の発熱量のマップデータから発熱量を演算する機能を持っており、測定された２次電池１１の温度ＴＢと２次電池１１の残容量ＳＯＣから２次電池１１の発熱量を演算できるようになっている。
【００３０】
コントローラ１４は、車両の負荷変動が小さい状態である定速走行等において、エンジン２の動力により、車両を駆動させ、さらに発電モータ１を駆動させて発電を行うことができ２次電池１１を充電することができる。また、発電モータ１、駆動モータ４に電流を流し、２次電池１１を放電することができる。このように発電モータ１、駆動モータ４の両方を同時に発電用または駆動用に用いることにより、２次電池は車両の負荷変動が小さい状態である定速走行等においても、すばやく昇温することができる。
【００３１】
次に、図２のフローチャートにしたがって、コントローラ１４における２次電池１１を昇温させるための制御の流れを説明する。
この制御はイグニッションがオンされて開始する。
【００３２】
ステップ１００において、２次電池１１の放電可能出力ＰＢＯＵＴがハイブリット走行に必要な出力未満かどうか判断される。２次電池１１の放電可能出力がこの出力未満である場合はハイブリット車として燃費性能が十分に発揮できないと判断され、ステップ１０１へ進む。２次電池１１の放電可能出力がこの値以上である場合は、ハイブリット車として燃費性能が十分に発揮されると判断され、ステップ１０９へ進む。
【００３３】
ステップ１０１では２次電池１１の温度ＴＢが測定される。
ステップ１０２では２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊が演算される。
ステップ１０３では２次電池１１の残容量ＳＯＣが検出される。
【００３４】
ステップ１０４では２次電池１１の残容量ＳＯＣと２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊とが比較される。
【００３５】
２次電池１１の残容量ＳＯＣが２次電池１１の残容量ＳＯＣ＊より高い場合には、ステップ１０５へ進み、２次電池１１を２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊まで放電する。２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊まで放電後ステップ１０７へ進み、２次電池１１の昇温制御を行う。
【００３６】
２次電池１１の残容量ＳＯＣが２次電池１１の残容量ＳＯＣ＊より低い場合は、ステップ１０６へ進み、２次電池１１を２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊まで充電する。２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊まで充電後ステップ１０７へ進む。
【００３７】
２次電池１１の残容量ＳＯＣが２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊と等しい場合あるいは値が近い場合はステップ１０７へ進む。ステップ１０７での２次電池１１の昇温制御については後で説明する。
【００３８】
ステップ１０８では、昇温制御した結果２次電池１１の放電可能出力がハイブリット走行に必要な出力以上になったかどうか判断される。２次電池１１の放電可能出力がハイブリット走行に必要な出力未満である場合はステップ１０７へ戻り、２次電池１１の放電可能出力がこの値以上になるまで２次電池１１の昇温制御を続ける。２次電池１１の放電可能出力がこの値以上になるとステップ１０９へ進み、２次電池１１の昇温制御を停止して終了する。
【００３９】
図３はステップ１０７で行なわれる２次電池１１の昇温制御の説明を示すフローチャートである。
ステップ２００でコントローラ１４において、温度センサ１５からの信号より２次電池１１の温度ＴＢが測定される。
【００４０】
ステップ２０１でコントローラ１４において前記測定された２次電池１１の温度ＴＢより２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊が演算される。
ステップ２０２でコントローラ１４において２次電池１１の残容量ＳＯＣを検出する。
【００４１】
ステップ２０３で充電時間ｔ（ｃｈｇ）を演算する。
充電時間ｔ（ｃｈｇ）は放電時間ｔ（ｄｉｓ）に対し、２次電池１１の残容量ＳＯＣと２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊の差（％）に比例した分だけ増減するように次式で演算する。
ｔ（ｃｈｇ）＝ｔ（ｄｉｓ）−ｋ×（ＳＯＣ−ＳＯＣ＊）
ｋは２次電池１１の残容量ＳＯＣと２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊の差を充電時間に反映させるための定数である。
【００４２】
放電時間ｔ（ｄｉｓ）は２次電池１１の残容量ＳＯＣが２次電池１１の発熱量が最大となる２次電池１１の残容量ＳＯＣ＊から大きくずれない範囲で設定する。
例えば、１０００Ｗｈの２次電池で充放電の電力値が３０００Ｗの場合で、２次電池の残容量ＳＯＣの２次電池の発熱量が最大となる２次電池の残容量ＳＯＣ＊からのずれを１％許容できるとすると、放電時間ｔ（ｄｉｓ）は１２ｓｅｃとなる。放電時間ｔ（ｄｉｓ）を１２ｓｅｃとした場合、定数ｋを１２とすれば、充電時間ｔ（ｃｈｇ）は２４ｓｅｃとなり、２次電池１１の残容量ＳＯＣはＳＯＣ＊より１％低い点から充電によって１％高い点へ変化することになる。このようにＳＯＣ＊を挟んで充放電を繰り返すようにｋを設定する。
【００４３】
ステップ２０４において上記の放電時間ｔ（ｄｉｓ）、充電時間ｔ（ｃｈｇ）で放電、充電する。
ステップ２０５において、充放電の回数が設定回数（例えば４〜５回）になったかどうか判断される。設定回数未満である場合はステップ２００に戻る。充放電の回数が設定回数になった場合は、メインフローチャートのステップ１０８へ進む。２次電池１１を充放電する電力値は、発電モータ１、駆動モータ４の最大発電電力、最大駆動電力としている。２次電池１１を充放電する電力値が大きいほど、２次電池１１の昇温速度が速いためである。
ここでは説明しないが、車両の走行条件で２次電池１１を充放電する電力値を制御する必要がある場合は、電池を充放電する値を制御してもよい。
【００４４】
ステップ１０５、１０６で２次電池１１の残容量ＳＯＣがＳＯＣ＊に近い値になった後は、ステップ２００からステップ２０５において２次電池１１の残容量ＳＯＣ＊から所定の範囲内で２次電池の残容量ＳＯＣが変化するように２次電池１１の充電と放電を繰り返すことにより、効率的に２次電池の昇温を行うことができる。
【００４５】
２次電池１１からインバータ９を介して駆動モータ４、車両の補機１３を駆動する系統が放電手段を構成する。
ステップ１０１、２００は本発明における２次電池１１の温度を測定する測定手段を構成する。
ステップ１０２、２０１は本発明における２次電池１１の発熱量が最大となる２次電池１１の残容量を演算する容量演算手段を構成する。
【００４６】
ステップ１０４からステップ１０７、ステップ２０１からステップ２０５は本発明における制御手段を構成する。
ステップ１０３、２０２は本発明における２次電池１１の残容量を検出する容量検出手段を構成する。
【００４７】
本実施例は以上のように構成され、パラレルハイブリット型車両に搭載の２次電池１１がハイブリット走行必要出力に満たない場合、２次電池１１をコントローラ１４で演算された発熱量が最大となる２次電池１１の残容量ＳＯＣ＊から所定の範囲内で変化するように充放電することにしたので、すばやく２次電池１１の昇温を行う事ができる。
【００４８】
充放電を繰り返し２次電池１１の温度が上がることによって変化する発熱量が最大となる２次電池１１の残容量ＳＯＣ＊に対しても、２次電池１１の残容量ＳＯＣが変化する２次電池１１の残容量ＳＯＣ＊の所定の範囲内で変化するように充放電をすることにしたので、効率よく２次電池１１の昇温を行うことができる。
２次電池１１が昇温することにより、２次電池１１はハイブリット走行必要出力をすばやく出せるようになり、パラレルハイブリット車としての高い燃費性能を発揮することができる。
【００４９】
なお、発電モータ１、駆動モータ４には交流電動機に限らず直流電動機を用いることもできる。また、発電モータ１、駆動モータ４に直流電動機を用いた場合にはインバータ８、９はＤＣ／ＤＣコンバータを用いる。
クラッチ３締結時に、発電モータ１を車両の推進と制動に用いることもでき、駆動モータ４をエンジン２の始動や発電に用いることもできる。
【００５０】
クラッチ３はパウダークラッチの代りに乾式単板クラッチや湿式多板クラッチを用いることもできる。
さらに、発電機としての発電モータの代りに燃料電池を用いることもできる。
【００５１】
本実施例では温度センサ１５により測定された２次電池１１の温度ＴＢと２次電池１１の残容量ＳＯＣから２次電池１１の発熱量を演算したが、コントローラ１４は２次電池１１の内部抵抗および２次電池１１の開放電圧のマップデータから２次電池１１の発熱量を演算することもできる。
【図面の簡単な説明】
【図１】本発明の実施例を示す図である。
【図２】本発明の実施例における制御の流れを示すフローチャートである。
【図３】２次電池１１の昇温制御の詳細を示すフローチャートである。
【図４】パラレルハイブリット型車両の２次電池放電可能出力に対する車両の燃料消費率を示す図である。
【図５】定電力の放電と充電を行った時の２次電池の発熱量を示す図である。
【図６】２次電池の温度変化により、２次電池発熱量が最大となる２次電池残容量が変化することを示す図である。
【符号の説明】
１発電モータ（発電手段）
２エンジン
３クラッチ
４駆動モータ
５無段変速機
６デファレンシャルギヤ
７駆動輪
８インバータ
９インバータ
１０ＤＣリンク
１１２次電池
１２ＤＣ／ＤＣコンバータ
１３補機
１４コントローラ
１５温度センサ
１６電圧センサ
１７電流センサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a temperature increase control device for a secondary battery.
[0002]
[Prior art]
In a secondary battery with a chemical reaction, when the battery temperature decreases, the internal resistance increases and the dischargeable output decreases.
[0003]
FIG. 4 is a diagram showing the fuel consumption rate of the vehicle with respect to the secondary battery dischargeable output in the parallel hybrid type vehicle in which both the secondary battery and the engine are mounted. The horizontal axis shows the secondary battery dischargeable output, and the vertical axis shows the fuel consumption rate of the vehicle. In FIG. 4, line a indicates the fuel consumption rate when traveling while discharging the secondary battery, and line b indicates the fuel consumption rate when traveling while charging the secondary battery. When running while charging the secondary battery, the generator is operated by the engine to charge the secondary battery, so that the fuel for the energy that charges the secondary battery compared to running while discharging the secondary battery. The consumption rate decreases.
[0004]
The larger the secondary battery dischargeable output, the longer the travel using the motor as a drive source. Therefore, it is possible to avoid the low-efficiency operation state at the time of low engine speed when starting the vehicle, and the fuel consumption rate is improved. When the secondary battery dischargeable output becomes zero, the fuel efficiency of a normal engine-equipped vehicle is obtained. In order to exhibit the fuel efficiency performance of the original parallel hybrid vehicle, the dischargeable output of the secondary battery must be able to output the design value.
[0005]
If the vehicle design is performed with the performance of the secondary battery at normal temperature, the fuel efficiency performance is lowered at low temperatures, and if the vehicle design is performed with the performance of the secondary battery at low temperatures, many secondary batteries are installed. As a result, the fuel efficiency of the vehicle decreases due to the cost increase of the secondary battery and the weight increase of the secondary battery. Usually, the fuel efficiency performance of a vehicle is designed at the expense of a secondary battery performance at a low temperature. Therefore, it is necessary to quickly raise the temperature of the secondary battery at a low temperature to improve the dischargeable output of the secondary battery and improve the fuel efficiency of the vehicle.
[0006]
As a method for raising the temperature of the secondary battery earliest, it is conceivable to pass the maximum current value that can be passed through the secondary battery to the vehicle drive motor and the auxiliary machine. For example, Japanese Patent Laid-Open No. 11-026032 discloses a conventional technique using this fact.
[0007]
When this technology is applied to a parallel hybrid type vehicle, the maximum current value that can be supplied by the secondary battery is supplied to the vehicle drive motor and auxiliary equipment, and when the remaining capacity of the secondary battery decreases, the secondary battery is charged by the generator. When the remaining capacity of the secondary battery exceeds a predetermined value, charging is stopped, and the maximum current value that can be supplied by the secondary battery is passed again to the vehicle drive motor and the auxiliary machine.
[0008]
[Problems to be solved by the invention]
However, there arises a problem that the maximum current of the performance of the secondary battery cannot be used for charging and discharging due to the vehicle running conditions and the capacity of the auxiliary machine. Therefore, charging / discharging with constant power is performed.
[0009]
FIG. 5 shows the experimental results representing the amount of heat generated by the secondary battery when charging and discharging with constant power are performed.
The remaining capacity of the secondary battery is defined as the remaining capacity SOC of the secondary battery, and the remaining capacity of the secondary battery that maximizes the secondary battery heat generation amount with respect to the secondary battery charging / discharging power is defined as the remaining capacity SOC * of the secondary battery.
The horizontal axis shows the remaining capacity SOC of the secondary battery, and the vertical axis shows the calorific value of the secondary battery. The amount of heat generated when the secondary battery is discharged at a constant power is the line c in FIG. 5, and is maximum when the remaining capacity SOC * of a certain secondary battery. The higher the remaining capacity SOC of the secondary battery, the lower the remaining capacity SOC * of the secondary battery, the lower the heat generation amount. This is because the open circuit voltage of the secondary battery is higher and the current value is smaller as the remaining capacity SOC of the secondary battery is higher. When the remaining capacity SOC of the secondary battery becomes lower than the remaining capacity SOC * of the secondary battery, the calorific value becomes lower. This is because the dischargeable output of the secondary battery is less than the required discharge power and the current value becomes small.
[0010]
The amount of heat generated when the secondary battery is charged at a constant power becomes the line d in FIG. 5 and decreases as the remaining capacity SOC of the secondary battery increases. This is because the open circuit voltage of the secondary battery is higher and the current value is smaller as the remaining capacity SOC of the secondary battery is higher.
[0011]
The amount of heat generated when discharging and charging are repeated is the line e in FIG. 5, and becomes the maximum at the remaining capacity SOC * of a certain secondary battery. When discharging and charging are repeated, the remaining capacity of the secondary battery changes within a range of ΔSOC. However, since the amount of fluctuation ΔSOC of the remaining capacity of the secondary battery is considered to be 0.5% or less, the influence of the amount of fluctuation ΔSOC of the remaining capacity of the secondary battery on the secondary battery heat generation can be ignored.
[0012]
The present invention pays attention to the remaining capacity SOC * of the secondary battery that generates the maximum amount of heat when the secondary battery is charged and discharged with constant power, and can quickly raise the temperature of the secondary battery. An object of the present invention is to provide a temperature rise control device.
[0013]
The invention according to claim 1 is a secondary battery, a power generation means for charging the secondary battery, a discharge means for discharging the secondary battery, and a calorific value during operation of the secondary battery. a capacity calculation means for calculating the remaining capacity of the battery becomes maximum, and the capacitance detection means for detecting an actual actual remaining capacity of the secondary battery, the actual remaining capacity of the secondary battery detected is calculated by the volume calculating means as the remaining capacity, it has a control unit that performs charging and discharging of the secondary battery, the capacity calculation unit, the data of the heating value that is correlated to the state of the secondary battery in advance and held in the data Based on this, the remaining capacity was calculated .
[0014]
According to a second aspect of the invention, further comprising a measuring means for measuring the temperature of said secondary battery, said control means, the detected temperature, can be charged and discharged output is less than the predetermined value of said secondary battery and if the temperature is made by performing charging or discharging of the secondary battery is set so that the remaining capacity computed by the volume calculating means, from the remaining capacity the remaining capacity is the setting of the secondary battery The secondary battery is controlled to be repeatedly charged and discharged so as to be within a predetermined range.
[0015]
According to a third aspect of the present invention, the capacity calculation means holds in advance heat generation data correlated with the remaining capacity and temperature of the secondary battery, and the operation of the secondary battery based on the temperature of the secondary battery. The remaining battery capacity at which the amount of heat generated at the time was maximized was calculated.
[0016]
According to a fourth aspect of the present invention, the control means detects the temperature when the chargeable / dischargeable input / output of the secondary battery is less than the required charge / discharge input / output of the power generation means and the discharge means. Is set so as to be the remaining capacity calculated by the capacity calculating means by charging or discharging the secondary battery .
[0017]
【The invention's effect】
According to the first aspect of the present invention, the temperature of the secondary battery rises by charging and discharging the secondary battery so that the secondary battery has a maximum remaining heat SOC * that maximizes the amount of heat generated by the secondary battery. The dischargeable output of the secondary battery and the chargeable input of the secondary battery are improved.
[0018]
According to the second aspect of the present invention, the secondary battery is charged such that the remaining capacity SOC of the secondary battery changes within a predetermined range of the remaining capacity SOC * of the secondary battery that maximizes the secondary battery heat generation amount. By controlling the amount and the discharge amount, the temperature increase rate of the secondary battery is increased. As the temperature of the secondary battery rises, the dischargeable output of the secondary battery and the chargeable input of the secondary battery are improved.
[0019]
According to the third aspect of the present invention, when the temperature of the secondary battery changes, the secondary battery remaining capacity SOC * that maximizes the secondary battery heat generation changes, so the remaining capacity SOC of the secondary battery changes. By controlling the charge amount and discharge amount of the secondary battery so as to change within a predetermined range of the secondary battery remaining capacity SOC * at which the secondary battery heat generation amount becomes maximum, the temperature increase rate of the secondary battery is increased. Become. As the temperature of the secondary battery rises, the dischargeable output of the secondary battery and the chargeable input of the secondary battery are improved.
[0020]
According to the fourth aspect of the invention, when the temperature of the secondary battery rises, the dischargeable output and the chargeable output of the secondary battery are improved, and the fuel efficiency of the vehicle can be improved.
[0021]
FIG. 6 shows that when the temperature of the secondary battery changes, the secondary battery remaining capacity SOC * that maximizes the secondary battery heat generation amount changes.
In FIG. 6, lines f, g, and h are cases where the secondary battery temperatures are −30 ° C., −20 ° C., and −10 ° C., respectively, and discharging and charging are repeated with constant power. When the temperature of the secondary battery rises, the internal resistance of the secondary battery decreases, so the amount of heat generation decreases. Moreover, since the internal resistance is reduced and the dischargeable output of the secondary battery is increased, the remaining capacity of the secondary battery capable of discharging the power under this condition is reduced. Therefore, the remaining capacity SOC * of the secondary battery that maximizes the amount of heat generated by the secondary battery varies depending on the temperature of the secondary battery.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described by way of examples.
FIG. 1 is a diagram showing a configuration of a parallel hybrid vehicle to which the present invention is applied as an embodiment.
In the figure, a thick solid line indicates a transmission path of mechanical force, and a broken line indicates a power line.
The power train of the vehicle includes a generator motor 1, an engine 2, a clutch 3, a drive motor 4, a continuously variable transmission 5, a differential gear 6, and drive wheels 7. The output shaft of the generator motor 1, the output shaft of the engine 2, and the input shaft of the clutch 3 are connected to each other, and the output shaft of the clutch 3, the output shaft of the drive motor 4, and the input shaft of the continuously variable transmission 5 are mutually connected. It is connected.
[0023]
When the clutch 3 is engaged, the engine 2 and the drive motor 4 serve as a vehicle propulsion source, and when the clutch 3 is released, only the drive motor 4 serves as a vehicle propulsion source. The driving force of the propulsion source is transmitted to the driving wheel 7 via the continuously variable transmission 5 and the differential gear 6.
[0024]
The generator motor 1 and the drive motor 4 are AC machines such as a three-phase synchronous motor or a three-phase induction motor. The generator motor 1 is mainly used for starting and generating power of the engine 2, and the drive motor 4 is mainly used for propulsion and braking of the vehicle. Used.
The clutch 3 is a powder clutch and can adjust the transmission torque.
[0025]
The generator motor 1 and the drive motor 4 are driven by inverters 8 and 9, respectively. The inverters 8 and 9 are connected to the secondary battery 11 through a common DC link 10, convert the DC power of the secondary battery 11 into AC power, supply the AC power to the drive motor 4, and The secondary battery 11 is charged by converting AC generated power into DC power. Since the inverters 8 and 9 are connected to each other via the DC link 10, the electric power generated by the motor during the regenerative operation is directly supplied to the motor during the power running operation without going through the secondary battery 11. be able to.
The electric power of the secondary battery 11 is connected to the DC / DC converter 12 through the DC link 10 and supplies electric power to the auxiliary machine 13 of the vehicle.
[0026]
The controller 14 controls the rotational speed, output and torque of the engine 2, the transmission torque of the clutch 3, the rotational speed and torque of the generator motor 1, the gear ratio of the continuously variable transmission 5, the charge / discharge of the secondary battery 11, and the like.
[0027]
The controller 14 includes signals from a temperature sensor 15 that detects the temperature TB of the secondary battery 11, a voltage sensor 16 that detects the terminal voltage VB of the secondary battery 11, and a current sensor 17 that detects the current value IB of the secondary battery 11. Is input, and has a function of detecting the remaining capacity SOC of the secondary battery 11.
[0028]
Further, the controller 14 has map data of the dischargeable output and the chargeable input of the secondary battery 11 with respect to the temperature TB of the secondary battery 11 and the remaining capacity SOC of the secondary battery 11. The dischargeable output PBOUT and the chargeable input PBIN can be calculated.
[0029]
Further, the controller 14 generates heat from the map data of the heat generation amount of the secondary battery 11 with respect to the temperature TB of the secondary battery 11, the remaining capacity SOC of the secondary battery 11, the discharge power of the secondary battery 11 and the charge power of the secondary battery 11. It has a function of calculating the amount, and the calorific value of the secondary battery 11 can be calculated from the measured temperature TB of the secondary battery 11 and the remaining capacity SOC of the secondary battery 11.
[0030]
The controller 14 can drive the vehicle with the power of the engine 2 and drive the power generation motor 1 to generate power during charging at a constant speed where the load fluctuation of the vehicle is small. The secondary battery 11 is charged. can do. Further, the secondary battery 11 can be discharged by passing a current through the generator motor 1 and the drive motor 4. In this way, by using both the generator motor 1 and the drive motor 4 for power generation or driving simultaneously, the secondary battery can quickly rise in temperature even during constant speed driving where the load fluctuation of the vehicle is small. it can.
[0031]
Next, according to the flowchart of FIG. 2, the flow of control for raising the temperature of the secondary battery 11 in the controller 14 will be described.
This control is started when the ignition is turned on.
[0032]
In step 100, it is determined whether or not the dischargeable output PBOUT of the secondary battery 11 is less than the output required for the hybrid travel. If the dischargeable output of the secondary battery 11 is less than this output, it is determined that the fuel efficiency cannot be sufficiently exhibited as a hybrid vehicle, and the routine proceeds to step 101. If the dischargeable output of the secondary battery 11 is equal to or greater than this value, it is determined that the fuel efficiency is sufficiently exhibited as a hybrid vehicle, and the routine proceeds to step 109.
[0033]
In step 101, the temperature TB of the secondary battery 11 is measured.
In step 102, the remaining capacity SOC * of the secondary battery 11 at which the calorific value of the secondary battery 11 is maximized is calculated.
In step 103, the remaining capacity SOC of the secondary battery 11 is detected.
[0034]
In step 104, the remaining capacity SOC of the secondary battery 11 is compared with the remaining capacity SOC * of the secondary battery 11 that maximizes the amount of heat generated by the secondary battery 11.
[0035]
When the remaining capacity SOC of the secondary battery 11 is higher than the remaining capacity SOC * of the secondary battery 11, the process proceeds to step 105, and the secondary battery 11 has the maximum amount of heat generated by the secondary battery 11. Discharge to remaining capacity SOC *. After discharging to the remaining capacity SOC * of the secondary battery 11 at which the calorific value of the secondary battery 11 is maximized, the process proceeds to step 107 after discharging and the temperature rise control of the secondary battery 11 is performed.
[0036]
When the remaining capacity SOC of the secondary battery 11 is lower than the remaining capacity SOC * of the secondary battery 11, the process proceeds to step 106 and the remaining capacity of the secondary battery 11 in which the amount of heat generated by the secondary battery 11 is maximized. Charge to capacity SOC *. The process proceeds to step 107 after charging until the remaining capacity SOC * of the secondary battery 11 at which the calorific value of the secondary battery 11 is maximized.
[0037]
If the remaining capacity SOC of the secondary battery 11 is equal to or close to the remaining capacity SOC * of the secondary battery 11 at which the secondary battery 11 generates the largest amount of heat, the process proceeds to step 107. The temperature increase control of the secondary battery 11 in step 107 will be described later.
[0038]
In step 108, it is determined whether or not the dischargeable output of the secondary battery 11 has become equal to or higher than the output required for hybrid travel as a result of the temperature rise control. When the dischargeable output of the secondary battery 11 is less than the output required for the hybrid running, the process returns to step 107 and the temperature increase control of the secondary battery 11 is continued until the dischargeable output of the secondary battery 11 exceeds this value. . When the dischargeable output of the secondary battery 11 exceeds this value, the routine proceeds to step 109, where the temperature rise control of the secondary battery 11 is stopped and terminated.
[0039]
FIG. 3 is a flowchart illustrating the temperature rise control of the secondary battery 11 performed in step 107.
In step 200, the controller 14 measures the temperature TB of the secondary battery 11 from the signal from the temperature sensor 15.
[0040]
In step 201, the remaining capacity SOC * of the secondary battery 11 at which the amount of heat generated by the secondary battery 11 is maximized is calculated from the measured temperature TB of the secondary battery 11 in the controller 14.
In step 202, the controller 14 detects the remaining capacity SOC of the secondary battery 11.
[0041]
In step 203, the charging time t (chg) is calculated.
The charging time t (chg) is the difference (%) between the remaining capacity SOC of the secondary battery 11 and the remaining capacity SOC * of the secondary battery 11 at which the amount of heat generated by the secondary battery 11 is maximized with respect to the discharging time t (dis). It is calculated by the following formula so as to increase or decrease by an amount proportional to.
t (chg) = t (dis) −k × (SOC−SOC *)
k is a constant for reflecting the difference between the remaining capacity SOC of the secondary battery 11 and the remaining capacity SOC * of the secondary battery 11 at which the calorific value of the secondary battery 11 is maximized in the charging time.
[0042]
The discharge time t (dis) is set in a range in which the remaining capacity SOC of the secondary battery 11 does not greatly deviate from the remaining capacity SOC * of the secondary battery 11 at which the secondary battery 11 generates the largest amount of heat.
For example, when a 1000 Wh secondary battery has a charge / discharge power value of 3000 W, the deviation of the secondary battery remaining capacity SOC from the secondary battery remaining capacity SOC * that maximizes the secondary battery heat generation amount is 1 If it is acceptable, the discharge time t (dis) is 12 sec. If the discharge time t (dis) is 12 sec, and the constant k is 12, the charge time t (chg) is 24 sec. The remaining capacity SOC of the secondary battery 11 is 1 by charging from a point 1% lower than SOC *. % Will change to a higher point. In this way, k is set so that charging / discharging is repeated with the SOC * interposed therebetween.
[0043]
In step 204, the battery is discharged and charged at the discharge time t (dis) and the charge time t (chg).
In step 205, it is determined whether the number of times of charging / discharging has reached a set number (for example, 4 to 5 times). If the number is less than the set number, the process returns to step 200. When the number of times of charging / discharging has reached the set number, the process proceeds to step 108 in the main flowchart. The power values for charging and discharging the secondary battery 11 are the maximum generated power and the maximum drive power of the generator motor 1 and the drive motor 4. This is because the temperature increase rate of the secondary battery 11 is faster as the power value for charging and discharging the secondary battery 11 is larger.
Although not described here, when it is necessary to control the power value for charging / discharging the secondary battery 11 under the driving conditions of the vehicle, the value for charging / discharging the battery may be controlled.
[0044]
After the remaining capacity SOC of the secondary battery 11 becomes close to the SOC * in Steps 105 and 106, the secondary battery capacity of the secondary battery is within a predetermined range from the remaining capacity SOC * of the secondary battery 11 in Step 200 to Step 205. By repeating charging and discharging of the secondary battery 11 so that the remaining capacity SOC changes, the temperature of the secondary battery can be efficiently increased.
[0045]
A system that drives the drive motor 4 and the auxiliary machine 13 of the vehicle from the secondary battery 11 via the inverter 9 constitutes a discharging means.
Steps 101 and 200 constitute measuring means for measuring the temperature of the secondary battery 11 in the present invention.
Steps 102 and 201 constitute capacity calculating means for calculating the remaining capacity of the secondary battery 11 that maximizes the amount of heat generated by the secondary battery 11 in the present invention.
[0046]
Steps 104 to 107 and steps 201 to 205 constitute the control means in the present invention.
Steps 103 and 202 constitute capacity detecting means for detecting the remaining capacity of the secondary battery 11 in the present invention.
[0047]
The present embodiment is configured as described above, and when the secondary battery 11 mounted on the parallel hybrid vehicle is less than the required hybrid running output, the calorific value calculated by the controller 14 for the secondary battery 11 is maximized 2 Since charging / discharging is performed so that the remaining capacity SOC * of the secondary battery 11 changes within a predetermined range, the secondary battery 11 can be quickly heated.
[0048]
The secondary battery in which the remaining capacity SOC of the secondary battery 11 also changes with respect to the remaining capacity SOC * of the secondary battery 11 in which the amount of heat generation that changes as the temperature of the secondary battery 11 rises by repeatedly charging and discharging. Since the charging / discharging is performed so as to change within a predetermined range of the remaining capacity SOC * of 11, the secondary battery 11 can be efficiently heated.
As the secondary battery 11 rises in temperature, the secondary battery 11 can quickly output the required hybrid travel output and can exhibit high fuel efficiency as a parallel hybrid vehicle.
[0049]
The generator motor 1 and the drive motor 4 are not limited to AC motors, and DC motors can also be used. Further, when a DC motor is used for the generator motor 1 and the drive motor 4, the inverters 8 and 9 use DC / DC converters.
When the clutch 3 is engaged, the generator motor 1 can be used for propulsion and braking of the vehicle, and the drive motor 4 can also be used for starting the engine 2 and generating power.
[0050]
The clutch 3 may be a dry single plate clutch or a wet multi-plate clutch instead of the powder clutch.
Furthermore, a fuel cell can be used instead of the generator motor as a generator.
[0051]
In this embodiment, the calorific value of the secondary battery 11 is calculated from the temperature TB of the secondary battery 11 measured by the temperature sensor 15 and the remaining capacity SOC of the secondary battery 11, but the controller 14 uses the internal resistance of the secondary battery 11. And the calorific value of the secondary battery 11 can be calculated from the map data of the open circuit voltage of the secondary battery 11.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of the present invention.
FIG. 2 is a flowchart showing a control flow in an embodiment of the present invention.
FIG. 3 is a flowchart showing details of temperature increase control of the secondary battery 11;
FIG. 4 is a diagram showing a fuel consumption rate of a vehicle with respect to a secondary battery dischargeable output of a parallel hybrid type vehicle.
FIG. 5 is a diagram showing a calorific value of a secondary battery when discharging and charging a constant power.
FIG. 6 is a diagram showing that the remaining secondary battery capacity at which the secondary battery heat generation amount becomes maximum changes due to temperature change of the secondary battery.
[Explanation of symbols]
1 Electric motor (power generation means)
2 Engine 3 Clutch 4 Drive motor 5 Continuously variable transmission 6 Differential gear 7 Drive wheel 8 Inverter 9 Inverter 10 DC link 11 Secondary battery 12 DC / DC converter 13 Auxiliary machine 14 Controller 15 Temperature sensor 16 Voltage sensor 17 Current sensor

Claims

A secondary battery;
Power generation means for charging the secondary battery;
Discharging means for discharging the secondary battery;
Capacity calculating means for calculating the remaining capacity of the battery that maximizes the amount of heat generated during operation of the secondary battery; capacity detecting means for detecting the actual actual remaining capacity of the secondary battery;
As the actual remaining capacity of the detected secondary battery is remaining capacity calculated in the capacity calculation means, have a control unit that performs charging and discharging of the secondary battery,
The secondary battery temperature rise control device , wherein the capacity calculation means stores in advance heat generation data correlated with the state of the secondary battery and calculates the remaining capacity based on the data .

In claim 1,
Measuring means for measuring the temperature of the secondary battery;
The control means includes
When the detected temperature is a temperature at which the chargeable / dischargeable input / output of the secondary battery is less than a predetermined value, the secondary battery is charged or discharged and becomes the remaining capacity calculated by the capacity calculating means. Set as
The secondary battery temperature increase control device controls the secondary battery to be repeatedly charged and discharged so that the remaining capacity of the secondary battery falls within a predetermined range from the set remaining capacity. .

In claim 1 or claim 2,
The capacity calculating means includes
Preliminary data of calorific value correlated with remaining capacity and temperature of the secondary battery,
A secondary battery temperature increase control device that calculates a remaining battery capacity that maximizes the amount of heat generated during operation of the secondary battery based on the temperature of the secondary battery.

In claim 2,
The control means includes
When the detected temperature is such that the chargeable / dischargeable input / output of the secondary battery is less than the required charge / discharge input / output of the power generation means and the discharge means, the secondary battery is charged or discharged. A temperature increase control device for a secondary battery, which is set to have a remaining capacity calculated by the capacity calculating means .