JP4575555B2 - Power output device - Google Patents

Description

表１から解るように、ｕ相の指令値Ｖｕ＊が三角搬送波ＣＡＲ１より大きいときには、トランジスタＴＵ１，ＴＵ２をオンとすると共にトランジスタＴＵ３，ＴＵ４をオフとして図２に例示する状態とし、三相コイルのｕ相に正極母線２６の電圧（１／２ＶＢ）を作用させる。指令値Ｖｕ＊が三角搬送波ＣＡＲ１とＣＡＲ２との間のときには、トランジスタＴＵ１，ＴＵ４をオフとすると共にトランジスタＴＵ２，ＴＵ３をオンとして図４に例示する状態とし、三相コイルのｕ相にモータ２２の中性点の電圧（ゼロ）を作用させる。指令値Ｖｕ＊が三角搬送波ＣＡＲ２より小さいときには、トランジスタＴＵ１，ＴＵ２をオフとすると共にトランジスタＴＵ３，ＴＵ４をオンとして図３に例示する状態とし、三相コイルのｕ相に負極母線２８の電圧（−１／２ＶＢ）を作用させる。
【００３７】
こうした階層的な三角搬送波ＣＡＲ１，ＣＡＲ２と各相指令とに基づいて各トランジスタＴＵ１〜ＴＵ４，ＴＶ１〜ＴＶ４，ＴＷ１〜ＴＷ４をスイッチングすると、図５の中段の各相（Ｖｕ，Ｖｖ，Ｖｗ）のＰＷＭ波形となる。こうした各相のＰＷＭの波形から各相の電圧が同一となるゼロ電圧ベクトルの出力は、図５の最下段に示されるようになる。図６に、正極母線の電圧（１／２ＶＢ）と負極母線の電圧（−１／２ＶＢ）の２段階の電圧レベルによりＰＷＭ制御する従来例の動力出力装置における各相指令と三角搬送波，各相（Ｖｕ，Ｖｖ，Ｖｗ）のＰＷＭ波形，ゼロ電圧ベクトルの出力を示す。図５と図６とを比較すると解るように、実施例の動力出力装置２０は、３段階の電圧レベルによってＰＷＭ制御することにより、２段階の電圧レベルによってＰＷＭ制御する従来例の動力出力装置に比して、ゼロ電圧ベクトルの出力頻度を著しく少なくすることができる。したがって、ゼロ電圧ベクトルの出力とモータ２２の中性点の電位の固定に基づいて生じるモータ２２の中性点における電流脈動を低減することができる。
【００３８】
以上説明した実施例の動力出力装置２０によれば、３段階の電圧レベルによってＰＷＭ制御することにより、ゼロ電圧ベクトルの出力頻度を著しく少なくすることができる。この結果、ゼロ電圧ベクトルの出力に伴ってモータ２２の中性点に生じ得る電流脈動を低減することができると共にモータ２２の損失を抑制することができる。
【００３９】
実施例の動力出力装置２０では、インバータ回路２４の負極母線２８とモータ２２の中性点とを接続するよう第２直流電源３２を取り付けたが、インバータ回路２４の正極母線２６とモータ２２の中性点とを接続するよう第２直流電源３２を取り付けるものとしてもよい。また、実施例の動力出力装置２０では、第２直流電源３２の電圧Ｖ２の２倍の電圧Ｖ１の第１直流電源３０をインバータ回路２４の正極母線２６と負極母線２８とを接続するように取り付けたが、図７の変形例の動力出力装置２０Ｂに示すように、第２直流電源３２の電圧Ｖ２と同一の電圧の第１直流電源３０Ｂをインバータ回路２４の正極母線２６とモータ２２の中性点とを接続するよう取り付けるものとしてもよい。変形例の動力出力装置２０Ｂは、電気的に実施例の動力出力装置２０と等価だからである。
【００４０】
実施例の動力出力装置２０では、インバータ回路２４の正極母線２６と負極母線２８とを接続する第１直流電源３０を備えるものとしたが、図８の変形例の動力出力装置２０Ｃに示すように、第１直流電源３０に代えてコンデンサ３０Ｃを備えるものとしてもよい。なお、図８に例示する変形例の動力出力装置２０Ｃは、コンデンサ３０Ｃの端子間電圧Ｖｃを検出する電圧センサ６２を備えており、この電圧センサ６２からの検出信号は入力ポートを介して電子制御ユニット４０に入力されている。図９は、モータ２２の三相コイルの漏れインダクタンスに着目した変形例の動力出力装置２０Ｃの回路図である。いま、インバータ回路２４のｕ相のトランジスタＴＵ３，ＴＵ４をオンとした状態を考えると、この状態では、図中破線矢印で示す短絡回路が形成され、モータ２２の三相コイルのｕ相はリアクトルとして機能する。この状態からトランジスタＴＵ３，ＴＵ４のいずれかをオフすると、リアクトルとして機能している三相コイルのｕ相に蓄えられたエネルギは、図中実線矢印で示す充電回路によりコンデンサ３０Ｃに蓄えられる。その際の電圧は、第２直流電源３２の供給電圧より高くすることができる。一方、この回路でコンデンサ３０Ｃの電位を用いて第２直流電源３２を充電することもできる。したがって、この回路は、第２直流電源３２のエネルギをコンデンサ３０Ｃに昇圧して蓄えると共にコンデンサ３０Ｃの電位を用いて第２直流電源３２を充電可能な昇降圧チョッパ回路とみなすことができる。モータ２２の三相コイルのｖｗ相も、ｕ相と同様に昇降圧チョッパ回路とみなすことができるから、トランジスタＴＵ３，ＴＵ４，ＴＶ３，ＴＶ４，ＴＷ３，ＴＷ４をオンオフすることによりコンデンサ３０Ｃを充電したり、コンデンサ３０Ｃの電位を用いて第２直流電源３２を充電することができる。
【００４１】
こうした充電によりコンデンサ３０Ｃの端子間には電位差が生じるが、その電位差はコンデンサ３０Ｃに蓄えられる電荷の量、即ちリアクトルに流す電流を調節することにより制御することができる。したがって、コンデンサ３０Ｃの端子間電圧Ｖｃを第２直流電源３２の電圧Ｖ２の２倍にすることもできる。このように、コンデンサ３０Ｃの端子間電圧Ｖｃを第２直流電源３２の電圧Ｖ２の２倍にすれば、図８に例示する変形例の動力出力装置２０Ｃでは、正極母線２６と負極母線２８にコンデンサ３０Ｃによる端子間電圧Ｖｃが作用する状態、即ち実施例の動力出力装置２０の第１直流電源３０に相当する直流電源が接続された状態となり、実施例の動力出力装置２０と同様にモータ２２を駆動することができる。
【００４２】
ここで、モータ２２の駆動には、インバータ回路２４を構成するトランジスタＴＵ１〜ＴＵ４，ＴＶ１〜ＴＶ４，ＴＷ１〜ＴＷ４の前述のスイッチング制御による擬似的な三相交流を供給すればよく、コンデンサ３０Ｃの電圧は直流成分により行なうことができるから、擬似的な三相交流の電位をプラス側またはマイナス側にオフセットすることによって、直流成分を加えた三相交流をモータ２２に供給することができる。この結果、交流成分でモータ２２は回転駆動し、直流成分で図９を用いて説明したようにコンデンサ３０Ｃを充電することができる。
【００４３】
したがって、変形例の動力出力装置２０Ｃでは、図５における各相指令をプラス側またはマイナス側にオフセットすることにより、実施例の動力出力装置２０の各相のＰＷＭ制御と同様の制御を行なうことができると共にコンデンサ３０Ｃの端子間電圧Ｖｃを制御することができる。この結果、変形例の動力出力装置２０Ｃでも実施例の動力出力装置２０と同様の効果を得ることができる。
【００４４】
実施例の動力出力装置２０では、インバータ回路２４の正極母線２６と負極母線２８とを接続する第１直流電源３０を備えるものとしたが、図１０の変形例の動力出力装置２０Ｄに示すように、第１直流電源３０に代えてインバータ回路２４の正極母線２６とモータ２２の中性点とを接続するコンデンサ３０Ｄを備えるものとしてもよい。なお、図１０に例示する変形例の動力出力装置２０Ｄも、変形例の動力出力装置２０Ｃと同様に、コンデンサ３０Ｄの端子間電圧Ｖｃを検出する電圧センサ６２を備えており、この電圧センサ６２からの検出信号は入力ポートを介して電子制御ユニット４０に入力されている。図１１は、モータ２２の三相コイルの漏れインダクタンスに着目した変形例の動力出力装置２０Ｄの回路図である。いま、インバータ回路２４のｕ相のトランジスタＴＵ３，ＴＵ４をオンとした状態を考えると、この状態では、図中破線矢印で示す短絡回路が形成され、モータ２２の三相コイルのｕ相はリアクトルとして機能する。この状態からトランジスタＴＵ３，ＴＵ４のいずれかをオフすると、リアクトルとして機能している三相コイルのｕ相に蓄えられたエネルギは、図中実線矢印で示す充電回路によりコンデンサ３０Ｄに蓄えられる。したがって、この回路は、第２直流電源３２のエネルギをコンデンサ３０Ｄに昇圧して蓄えると共にコンデンサ３０Ｄの電位を用いて第２直流電源３２を充電可能なチョッパ回路とみなすことができる。モータ２２の三相コイルのｖｗ相も、ｕ相と同様に昇降圧チョッパ回路とみなすことができるから、トランジスタＴＵ１〜ＴＵ４，ＴＶ１〜ＴＶ４，ＴＷ１〜ＴＷ４をオンオフすることによりコンデンサ３０Ｄを充電したり、コンデンサ３０Ｄの電位を用いて第２直流電源３２を充電することができる。
【００４５】
こうした充電によりコンデンサ３０Ｄの端子間には電位差が生じるが、その電位差はコンデンサ３０Ｃに蓄えられる電荷の量、即ちリアクトルに流す電流を調節することにより制御することができる。したがって、コンデンサ３０Ｄの端子間電圧Ｖｃを第２直流電源３２の電圧Ｖ２と同一にすることもできる。このように、コンデンサ３０Ｄの端子間電圧Ｖｃを第２直流電源３２の電圧Ｖ２と同一にすれば、図１１に例示する変形例の動力出力装置２０Ｄでは、正極母線２６と負極母線２８にコンデンサ３０Ｄと第２直流電源３２とからなる電圧Ｖ２の２倍の電圧の直流電源が接続された状態、即ち実施例の動力出力装置２０の第１直流電源３０に相当する直流電源が接続された状態となり、実施例の動力出力装置２０と同様にモータ２２を駆動することができる。
【００４６】
ここで、モータ２２の駆動には、インバータ回路２４を構成するトランジスタＴＵ１〜ＴＵ４，ＴＶ１〜ＴＶ４，ＴＷ１〜ＴＷ４の前述のスイッチング制御による擬似的な三相交流を供給すればよく、コンデンサ３０Ｄの電圧は直流成分により行なうことができるから、擬似的な三相交流の電位をプラス側またはマイナス側にオフセットすることによって、直流成分を加えた三相交流をモータ２２に供給することができる。この結果、交流成分でモータ２２は回転駆動し、直流成分で図１１を用いて説明したようにコンデンサ３０Ｄを充電することができる。
【００４７】
したがって、変形例の動力出力装置２０Ｄでも、変形例の動力出力装置２０Ｃと同様に、図５における各相指令をプラス側またはマイナス側にオフセットすることにより、実施例の動力出力装置２０の各相のＰＷＭ制御と同様の制御を行なうことができると共にコンデンサ３０Ｄの端子間電圧Ｖｃを制御することができる。この結果、変形例の動力出力装置２０Ｄでも実施例の動力出力装置２０と同様の効果を得ることができる。
【００４８】
実施例の動力出力装置２０やその変形例では、各相のダイオードＤＵ５，ＤＵ６、ＤＶ５，ＤＶ６，ＤＷ５，ＤＷ６の中間接続点をコンデンサＣ１，Ｃ２の中間接続点と接続すると共に接続線３４によりモータ２２の中性点に接続したが、コンデンサＣ１，Ｃ２を備えずに各相のダイオードＤＵ５，ＤＵ６、ＤＶ５，ＤＶ６，ＤＷ５，ＤＷ６の中間接続点を単に接続線３４によりモータ２２の中性点に接続するものとしたり、各相のダイオードＤＵ５，ＤＵ６、ＤＶ５，ＤＶ６，ＤＷ５，ＤＷ６の中間接続点を接続線３４によりモータ２２の中性点に接続せずに単にコンデンサＣ１，Ｃ２の中間接続点に接続するものとしても差し支えない。
【００４９】
実施例の動力出力装置２０やその変形例では、３段階の電圧レベルによるＰＷＭ制御を行なうことによりゼロ電圧ベクトルの出現頻度を少なくしたが、４段階以上の電圧レベルによるＰＷＭ制御を行なってゼロ電圧ベクトルの出現頻度を少なくするものとしてもよい。また、実施例の動力出力装置２０やその変形例では、三相交流によるモータ２２を用いたが、ｎ相交流によるモータを用いるものとしてもよい。この場合でも、３段階あるいは４段階以上の電圧レベルによるＰＷＭ制御を行なうことによりゼロ電圧ベクトルの出現頻度を少なくすることができる。
【００５０】
次に、本発明の第２実施例としての動力出力装置１２０について説明する。図１２は、第２実施例の動力出力装置１２０の構成の概略を示す構成図である。第２実施例の動力出力装置１２０は、図示するように、三相交流により回転駆動するモータ１２２と、直流電力を三相交流電力に変換してモータ１２２に供給可能なインバータ回路１２４と、インバータ回路１２４の正極母線１２６と負極母線１２８とに接続された第１直流電源１３０と、インバータ回路１２４の負極母線１２８とモータ１２２の中性点とに接続された第２直流電源１３２と、装置全体をコントロールする電子制御ユニット１４０とを備える。
【００５１】
モータ１２２は、第１実施例の動力出力装置２０のモータ２２と同様に、外表面に永久磁石が貼り付けられたロータと三相コイルが巻回されたステータとから構成される発電可能な同期発電電動機として構成されている。
【００５２】
インバータ回路１２４は、６個のトランジスタＴ１〜Ｔ６と６個のダイオードＤ１〜Ｄ６とにより構成されている。６個のトランジスタＴ１〜Ｔ６は、それぞれ正極母線１２６と負極母線１２８とに対してソース側とシンク側となるよう２個ずつペアで配置され、その接続点にモータ１２２の三相コイル（ｕｖｗ）の各々が接続されている。したがって、正極母線１２６と負極母線１２８とに電圧が作用している状態で対をなすトランジスタＴ１〜Ｔ６のオン時間の割合を制御すれば、正極母線１２６の電圧と負極母線１２８の電圧の２段階の電圧レベルによるＰＷＭ制御により、モータ１２２の三相コイルにより回転磁界を形成し、モータ１２２を回転駆動することができる。
【００５３】
第１直流電源１３０と第２直流電源１３２も、第１実施例の動力出力装置２０の第１直流電源３０や第２直流電源３２と同様に、例えばニッケル水素系やリチウムイオン系の二次電池として構成されており、第１直流電源１３０の端子間電圧Ｖ１が第２直流電源１３２の端子間電圧Ｖ２の約２倍となるように調整されている。したがって、モータ１２２の中性点を基準とすれば、第１実施例の動力出力装置２０の場合と同様に、正極母線１２６の電位はＶ１−Ｖ２であり、負極母線１２８の電位は−Ｖ２となる。以下、正極母線１２６の電圧を１／２ＶＢとし、負極母線１２８の電圧を−１／２ＶＢとして考えるものとする。
【００５４】
電子制御ユニット１４０も、第１実施例の動力出力装置２０の電子制御ユニット４０と同様に、ＣＰＵ１４２を中心とするマイクロプロセッサとして構成されており、処理プログラムを記憶したＲＯＭ１４４と、一時的にデータを記憶するＲＡＭ１４６と、入出力ポート（図示せず）とを備える。この電子制御ユニット１４０には、モータ１２２の三相コイルのｕｖｗの各相に取り付けられた電流センサ１５２〜１５６からの各相の電流やモータ１２２の中性点に取り付けられた電流センサ１５８からの中性点電流，モータ１２２の回転軸に取り付けられた回転角センサ１６０からのモータ１２２の回転子の回転角，モータ１２２の動作に関する指令値などが入力ポートを介して入力されている。また、電子制御ユニット１４０からは、インバータ回路１２４のトランジスタＴ１〜Ｔ６のスイッチング制御を行なうための制御信号などが出力ポートを介して出力されている。
【００５５】
次に、こうして構成された第２実施例の動力出力装置１２０の動作、特にインバータ回路１２４によりモータ１２２に印加される擬似的な三相交流の形成について説明する。図１３は、第２実施例の動力出力装置１２０の電子制御ユニット１４０によるＰＷＭ制御の際に用いる各相変調波と各相搬送波とを例示する説明図である。図示するように、ｕ相搬送波とｖ相搬送波とｗ相搬送波は、いずれも三角波であり、１２０度ずつ位相が異なるものとなっている。ｕ相変調波とｖ相変調波とｗ相変調波は、いずれも各相指令に基づいて形成される。各相は、位相が異なるものの同様であるから、ｕ相について説明する。ｕ相変調波がｕ相搬送波より大きいときには、トランジスタＴ１をオンとすると共にトランジスタＴ２をオフとしてモータ１２２の三相コイルのｕ相に正極母線１２６の電圧（１／２ＶＢ）を作用させる。一方、ｕ相変調波がｕ相搬送波より小さいときには、トランジスタＴ１をオフとすると共にトランジスタＴ２をオンとしてモータ１２２の三相コイルのｕ相に負極母線１２８の電圧（−１／２ＶＢ）を作用させる。こうしたスイッチング制御を行なうことにより、図６に示すように、従来例の動力出力装置と同様に２段階の電圧レベルによるＰＷＭ制御を行なうことができる。ｖ相，ｗ相についても同様に各相変調波と各相搬送波とによるＰＷＭ制御の波形が得られるが、各相搬送波を１２０度ずつ位相を異なるものにすることにより、図６の各相（Ｖｕ，Ｖｖ，Ｖｗ）の波形とはならず、ゼロ電圧ベクトルの出現頻度が少ないものとなる。
【００５６】
図１４は、図１３の各相変調波と各相搬送波とに基づいてスイッチングした際に各相とモータ１２２の中性点に流れる電流を示す説明図である。図示するように、各相電流は１２０度の位相をもった擬似的な三相交流電流となっており、モータ１２２の中性点の電流は、小さな振幅でゼロ近傍に落ち着いている。
【００５７】
以上説明した第２実施例の動力出力装置１２０によれば、１２０度ずつ位相の異なる各相搬送波と各相指令に基づく各相変調波とに基づいてインバータ回路２４の各相のトランジスタをスイッチングすることによりゼロ電圧ベクトルの出現頻度を低減することができる。この結果、ゼロ電圧ベクトルの出力に伴ってモータ１２２の中性点に生じ得る電流脈動を低減することができると共にモータ１２２の損失を抑制することができる。
【００５８】
第２実施例の動力出力装置１２０では、インバータ回路１２４の負極母線１２８とモータ１２２の中性点とを接続するよう第２直流電源１３２を取り付けたが、インバータ回路１２４の正極母線１２６とモータ１２２の中性点とを接続するよう第２直流電源１３２を取り付けるものとしてもよい。また、第２実施例の動力出力装置１２０では、第２直流電源１３２の電圧Ｖ２の２倍の電圧Ｖ１の第１直流電源１３０をインバータ回路１２４の正極母線１２６と負極母線１２８とを接続するように取り付けたが、図１５の変形例の動力出力装置１２０Ｂに示すように、第２直流電源１３２の電圧Ｖ２と同一の電圧の第１直流電源１３０Ｂをインバータ回路１２４の正極母線１２６とモータ１２２の中性点とを接続するよう取り付けるものとしてもよい。変形例の動力出力装置１２０Ｂは、電気的に実施例の動力出力装置１２０と等価だからである。
【００５９】
第２実施例の動力出力装置１２０では、インバータ回路１２４の正極母線１２６と負極母線１２８とを接続する第１直流電源１３０を備えるものとしたが、図１６の変形例の動力出力装置１２０Ｃに示すように、第１直流電源１３０に代えてコンデンサ１３０Ｃを備えるものとしてもよい。なお、図１６に例示する変形例の動力出力装置１２０Ｃは、コンデンサ１３０Ｃの端子間電圧Ｖｃを検出する電圧センサ１６２を備えており、この電圧センサ１６２からの検出信号は入力ポートを介して電子制御ユニット１４０に入力されている。図１７は、モータ１２２の三相コイルの漏れインダクタンスに着目した変形例の動力出力装置１２０Ｃの回路図である。この回路図は、図９に例示した回路図においてトランジスタＴＵ１，ＴＵ２を一つのトランジスタＴ１に置き換えると共にトランジスタＴＵ３，ＴＵ４を一つのトランジスタＴ２に置き換えた構成となっている。したがって、図１７に示す回路は、図９に例示した回路と同様に、第２直流電源１３２のエネルギをコンデンサ１３０Ｃに昇圧して蓄えると共にコンデンサ１３０Ｃの電位を用いて第２直流電源１３２を充電可能な昇降圧チョッパ回路とみなすことができる。モータ１２２の三相コイルのｖｗ相も、ｕ相と同様に昇降圧チョッパ回路とみなすことができるから、トランジスタＴ２，Ｔ４，Ｔ６をオンオフすることによりコンデンサ１３０Ｃを充電したり、コンデンサ１３０Ｃの電位を用いて第２直流電源１３２を充電することができる。そして、コンデンサ１３０Ｃの端子間電圧Ｖｃの制御とモータ１２２の駆動制御は、変形例の動力出力装置２０Ｃの際に説明したように、擬似的な三相交流の電位をプラス側またはマイナス側にオフセットすることによって同時に行なうことができる。
【００６０】
したがって、変形例の動力出力装置１２０Ｃでは、図１３における各相変調波をプラス側またはマイナス側にオフセットすることにより、第２実施例の動力出力装置１２０の各相のＰＷＭ制御と同様の制御を行なうことができると共にコンデンサ１３０Ｃの端子間電圧Ｖｃを制御することができる。この結果、変形例の動力出力装置１２０Ｃでも第２実施例の動力出力装置１２０と同様の効果を得ることができる。
【００６１】
第２実施例の動力出力装置１２０では、インバータ回路１２４の正極母線１２６と負極母線１２８とを接続する第１直流電源１３０を備えるものとしたが、図１８の変形例の動力出力装置１２０Ｄに示すように、第１直流電源１３０に代えてインバータ回路１２４の正極母線１２６とモータ１２２の中性点とを接続するコンデンサ１３０Ｄを備えるものとしてもよい。なお、図１８に例示する変形例の動力出力装置１２０Ｄは、コンデンサ１３０Ｄの端子間電圧Ｖｃを検出する電圧センサ１６２を備えており、この電圧センサ１６２からの検出信号は入力ポートを介して電子制御ユニット１４０に入力されている。図１９は、モータ１２２の三相コイルの漏れインダクタンスに着目した変形例の動力出力装置１２０Ｄの回路図である。この回路図は、図１１に例示した回路図においてトランジスタＴＵ１，ＴＵ２を一つのトランジスタＴ１に置き換えると共にトランジスタＴＵ３，ＴＵ４を一つのトランジスタＴ２に置き換えた構成となっている。したがって、図１９に示す回路は、図１１に例示した回路と同様に、第２直流電源１３２のエネルギをコンデンサ１３０Ｄに蓄えると共にコンデンサ１３０Ｄの電位を用いて第２直流電源１３２を充電可能なチョッパ回路とみなすことができる。モータ１２２の三相コイルのｖｗ相も、ｕ相と同様に昇降圧チョッパ回路とみなすことができるから、トランジスタＴ１〜Ｔ６をオンオフすることによりコンデンサ１３０Ｄを充電したり、コンデンサ１３０Ｄの電位を用いて第２直流電源１３２を充電することができる。そして、コンデンサ１３０Ｄの端子間電圧Ｖｃの制御とモータ１２２の駆動制御は、変形例の動力出力装置２０Ｄの際に説明したように、擬似的な三相交流の電位をプラス側またはマイナス側にオフセットすることによって同時に行なうことができる。
【００６２】
したがって、変形例の動力出力装置１２０Ｄでは、図１３における各相変調波をプラス側またはマイナス側にオフセットすることにより、第２実施例の動力出力装置１２０の各相のＰＷＭ制御と同様の制御を行なうことができると共にコンデンサ１３０Ｄの端子間電圧Ｖｃを制御することができる。この結果、変形例の動力出力装置１２０Ｄでも第２実施例の動力出力装置１２０と同様の効果を得ることができる。
【００６３】
第２実施例の動力出力装置１２０やその変形例では、各相搬送波の位相を１２０度ずつ異なるものとしたが、ｎ相のモータを用いる場合には、３６０／ｎ度ずつ異なるものとすればよい。また、各相搬送波の位相は、電流脈動の許容範囲内であればよいから、１２０度あるいは３６０／ｎ度を含む許容範囲内の角度であればよい。更に、ゼロ電圧ベクトルの出現頻度が少なくすることができるものであれば、各相搬送波の位相は何度であってもよい。
【００６４】
第１実施例の動力出力装置２０や第２実施例の動力出力装置１２０およびその変形例では、モータ２２，１２２として三相交流の矩形波電圧駆動する同期発電電動機を用いたが、多相交流の矩形波電圧駆動する如何なるタイプの電動機を用いるものとしてもよい。
【００６５】
以上、本発明の実施の形態について実施例を用いて説明したが、本発明はこうした実施例に何等限定されるものではなく、本発明の要旨を逸脱しない範囲内において、種々なる形態で実施し得ることは勿論である。
【図面の簡単な説明】
【図１】本発明の一実施例である動力出力装置２０の構成の概略を示す構成図である。
【図２】トランジスタＴＵ１，ＴＵ２をオンとすると共にトランジスタＴＵ３，ＴＵ４をオフとした状態のｕ相に着目した実施例の動力出力装置２０の回路図である。
【図３】トランジスタＴＵ１，ＴＵ２をオフとすると共にトランジスタＴＵ３，ＴＵ４をオンとした状態のｕ相に着目した実施例の動力出力装置２０の回路図である。
【図４】トランジスタＴＵ１，ＴＵ４をオフとすると共にトランジスタＴＵ２，ＴＵ３をオンとした状態のｕ相に着目した実施例の動力出力装置２０の回路図である。
【図５】インバータ回路２４のトランジスタＴＵ１〜ＴＵ４，ＴＶ１〜ＴＶ４，ＴＷ１〜ＴＷ４のスイッチングにより擬似的な三相交流を得る様子を説明する説明図である。
【図６】従来例の動力出力装置における各相指令と三角搬送波，各相（Ｖｕ，Ｖｖ，Ｖｗ）のＰＷＭ波形，ゼロ電圧ベクトルの出力を示す説明図である。
【図７】変形例の動力出力装置２０Ｂの構成の概略を示す構成図である。
【図８】変形例の動力出力装置２０Ｃの構成の概略を示す構成図である。
【図９】モータ２２の三相コイルの漏れインダクタンスに着目した実施例の動力出力装置２０Ｃの回路図である。
【図１０】変形例の動力出力装置２０Ｄの構成の概略を示す構成図である。
【図１１】モータ２２の三相コイルの漏れインダクタンスに着目した実施例の動力出力装置２０Ｄの回路図である。
【図１２】第２実施例の動力出力装置１２０の構成の概略を示す構成図である。
【図１３】第２実施例の動力出力装置１２０の電子制御ユニット１４０によるＰＷＭ制御の際に用いる各相変調波と各相搬送波とを例示する説明図である。
【図１４】図１３の各相変調波と各相搬送波とに基づいてスイッチングした際に各相とモータ１２２の中性点に流れる電流を示す説明図である。
【図１５】変形例の動力出力装置１２０Ｂの構成の概略を示す構成図である。
【図１６】変形例の動力出力装置１２０Ｃの構成の概略を示す構成図である。
【図１７】モータ１２２の三相コイルの漏れインダクタンスに着目した実施例の動力出力装置１２０Ｃの回路図である。
【図１８】変形例の動力出力装置１２０Ｄの構成の概略を示す構成図である。
【図１９】モータ１２２の三相コイルの漏れインダクタンスに着目した実施例の動力出力装置１２０Ｄの回路図である。
【符号の説明】
２０，２０Ｂ，２０Ｃ，２０Ｄ，１２０，１２０Ｂ，１２０Ｃ，１２０Ｄ 動力出力装置、２２，１２２ モータ、２４，１２４ インバータ回路、２６，１２６ 正極母線、２８，１２８ 負極母線、３０，３０Ｂ，１３０，１３０Ｂ 第１直流電源、３０Ｃ，３０Ｄ，１３０Ｃ，１３０Ｄ コンデンサ、３２，１３２ 第２直流電源、３４ 接続線、４０，１４０ 電子制御ユニット、４２，１４２ ＣＰＵ、４４，１４４ ＲＯＭ、４６，１４６ ＲＡＭ、５２〜５８，１５２〜１５８ 電流センサ、６０，１６０ 回転角センサ、６２，１６２ 電圧センサ、Ｔ１〜Ｔ６，ＴＵ１〜ＴＵ４，ＴＶ１〜ＴＶ４，ＴＷ１〜ＴＷ４ トランジスタ、Ｄ１〜Ｄ６、ＤＵ１〜ＤＵ６，ＤＶ１〜ＤＶ６，ＤＷ１〜ＤＷ６ ダイオード、Ｃ１，Ｃ２ コンデンサ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power output device and an inverter device.
[0002]
[Prior art]
Conventionally, this type of power output device includes a capacitor connected to the positive and negative buses of an inverter circuit that applies three-phase alternating current to the motor, a positive or negative bus of the inverter circuit, and a neutral point of the motor. A device including a connected DC power source has been proposed (for example, Japanese Patent Laid-Open Nos. 10-337047 and 11-178114). In this device, a circuit composed of a coil of each phase of the motor and a switching element of each phase of the inverter is regarded as a boost chopper circuit that boosts the voltage of the DC power supply and stores electric charge in the capacitor, and uses the stored capacitor as the DC power supply. It is assumed that the motor is driven. The drive control of the motor and the storage control of the capacitor are simultaneously performed by the switching operation of the switching element of the inverter circuit when applying a pseudo three-phase alternating current to the motor. The pseudo three-phase alternating current applied to the electric motor is formed by PWM control using two voltage levels, a positive voltage and a negative voltage.
[0003]
[Problems to be solved by the invention]
However, in such a power output device, a large current pulsation occurs in the current flowing out from the neutral point of the motor, and the loss of the motor may increase. A pseudo three-phase alternating current formed by PWM control using two voltage levels of a positive voltage and a negative voltage causes a state in which a so-called zero voltage vector in which the voltages of the respective phases are the same is output. When this zero voltage vector is output, since the potential of the neutral point of the motor is fixed by the DC power supply, a large current flows through the neutral point connection line of the motor. The zero voltage vector has two states, a state in which each phase is a positive voltage and a state in which each is a negative voltage. Therefore, the direction of the current flowing through the neutral point connection line of the motor It depends on whether it is based on the state of. As a result, a large current pulsation occurs in the neutral point connection line of the electric motor.
[0004]
The power output apparatus of the present invention has an object to reduce current pulsation that may occur at the neutral point of an electric motor. Another object of the power output device of the present invention is to increase the efficiency of the device. The inverter apparatus of this invention aims at reducing the output of a zero voltage vector.
[0005]
[Means for solving the problems and their functions and effects]
The power output apparatus and the inverter apparatus of the present invention employ the following means in order to achieve at least a part of the above object.
[0006]
  The first power output device of the present invention comprises:
  An electric motor that is rotationally driven by polyphase alternating current;
  An inverter circuit capable of supplying pseudo multi-phase AC power to the electric motor by three or more voltage levels by switching operations of a plurality of switching elements;
  A first power source connected to the positive and negative buses of the inverter circuit;
  A second power source connected to one of the positive bus and the negative bus of the inverter circuit and a neutral point of the motor;
  Switching control means for controlling switching of a plurality of switching elements of the inverter circuit;
  With,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled.
  This is the gist.
[0007]
In the first power output apparatus of the present invention, pseudo-phase alternating current is generated by voltage levels of three or more levels of positive voltage, negative voltage, and intermediate voltage thereof, so that the voltage of each phase is all second. It is possible to reduce the appearance of a zero voltage vector having the same voltage with a large difference from the voltage of the power source, and to reduce the current pulsation that can occur at the neutral point of the motor. As a result, the loss of the electric motor can be reduced.
[0008]
In the first power output apparatus of the present invention, the first power source may be a chargeable / dischargeable power storage unit that is charged using the power from the second power source.
[0009]
  The second power output device of the present invention is:
  An electric motor that is rotationally driven by polyphase alternating current;
  An inverter circuit capable of supplying pseudo multi-phase AC power to the electric motor by three or more voltage levels by switching operations of a plurality of switching elements;
  A first power source connected to the positive bus of the inverter circuit and a neutral point of the motor;
  A second power source connected to the negative bus of the inverter circuit and a neutral point of the motor;
  Switching control means for controlling switching of a plurality of switching elements of the inverter circuit;
  With,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled.
  This is the gist.
[0010]
In the second power output apparatus of the present invention, by using pseudo multiphase alternating current with voltage levels of three or more stages, the voltages of each phase are all the same voltage having a large difference from the voltage of the second power supply. The occurrence of the zero voltage vector that becomes the current can be reduced, and the current pulsation that can occur at the neutral point of the motor can be reduced. As a result, the loss of the electric motor can be reduced.
[0011]
In such a second power output apparatus of the present invention, the first power source is chargeable / dischargeable power storage means that is charged using the power from the second power source, or the second power source is It can also be a chargeable / dischargeable power storage means that is charged using electric power from the first power source.
[0012]
In the first or second power output apparatus of the present invention, the inverter circuit may be a circuit that supplies pseudo multiphase AC power at three voltage levels. In the first or second power output device of the present invention of this aspect, each phase of the inverter circuit includes four switching elements that connect a positive electrode bus and a negative electrode bus in series, and the four switching elements. Two diodes connected in series across the two switching elements in the middle, with the negative electrode bus to the positive electrode bus in the forward direction, and the intermediate voltage of the three voltage levels at the intermediate node of the two diodes An intermediate voltage supply means for supplying a level may be provided.
Furthermore, in the first or second power output apparatus of the present invention according to this aspect, the intermediate voltage supply means includes two capacitors for connecting the positive electrode bus and the negative electrode bus in series, and an intermediate contact between the two capacitors. Can be a means for connecting to the intermediate contact of the two diodes, or a means for connecting the neutral point of the motor to the intermediate contact of the two diodes.
[0013]
Also, in the first or second power output apparatus of the present invention, the switching control means includes a plurality of carrier waves provided hierarchically between the voltage levels of the three or more stages and the voltages of the phases. It may be a means for controlling switching of a plurality of switching elements of the inverter circuit based on the command.
In the first or second power output apparatus of the present invention according to this aspect, the switching control means includes the inverter circuit based on whether the voltage command of each phase belongs to a hierarchy formed by the plurality of carrier waves. The voltage level of each phase of the inverter circuit may be set, and the switching of a plurality of switching elements of the inverter circuit may be controlled so that the voltage level of each phase of the inverter circuit becomes the set voltage level. it can.
[0014]
  The third power output device of the present invention is:
  An electric motor that is rotationally driven by polyphase alternating current;
  An inverter circuit capable of supplying pseudo multiphase AC power to the electric motor by switching operations of a plurality of switching elements;
  A first power source connected to the positive and negative buses of the inverter circuit;
  A second power source connected to one of the positive bus and the negative bus of the inverter circuit and a neutral point of the motor;
  Switching of a plurality of switching elements of the inverter circuit based on each phase modulated wave based on the voltage command of each phase of the polyphase AC and each phase carrier wave corresponding to each phase of the polyphase AC and having a predetermined phase difference Switching control means for controlling
  With,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled.
  This is the gist.
[0015]
In the third power output device of the present invention, based on each phase modulated wave based on the voltage command of each phase of the polyphase AC and each phase carrier wave having a predetermined phase difference corresponding to each phase of the polyphase AC. By controlling the switching of a plurality of switching elements of the inverter circuit, the occurrence of a zero voltage vector in which the voltages of each phase are all the same voltage with a large difference from the voltage of the second power supply is reduced, and the neutrality of the motor The current pulsation that can occur at the point can be reduced. As a result, the loss of the electric motor can be reduced.
[0016]
In the third power output apparatus of the present invention, the first power source may be a chargeable / dischargeable power storage unit that is charged using the power from the second power source.
[0017]
  The fourth power output device of the present invention is:
  An electric motor that is rotationally driven by polyphase alternating current;
  An inverter circuit capable of supplying pseudo multiphase AC power to the electric motor by switching operations of a plurality of switching elements;
  A first power source connected to the positive bus of the inverter circuit and a neutral point of the motor;
  A second power source connected to the negative bus of the inverter circuit and a neutral point of the motor;
  Switching of a plurality of switching elements of the inverter circuit based on each phase modulated wave based on the voltage command of each phase of the polyphase AC and each phase carrier wave corresponding to each phase of the polyphase AC and having a predetermined phase difference Switching control means for controlling
  With,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled.
  This is the gist.
[0018]
In the fourth power output apparatus of the present invention, based on each phase modulated wave based on the voltage command of each phase of the polyphase AC and each phase carrier wave corresponding to each phase of the polyphase AC and having a predetermined phase difference. By controlling the switching of the plurality of switching elements of the inverter circuit, it is possible to reduce the appearance of a zero voltage vector in which the voltages of the respective phases are the same, and to reduce the current pulsation that can occur at the neutral point of the motor. As a result, the loss of the electric motor can be reduced.
[0019]
In such a fourth power output apparatus of the present invention, the first power source is chargeable / dischargeable power storage means that is charged using the power from the second power source, or the second power source is It can also be a chargeable / dischargeable power storage means that is charged using electric power from the first power source.
[0020]
In the third or fourth power output apparatus of the present invention, the predetermined phase difference is a phase difference that cancels a current ripple at the neutral point of the motor, or 360 degrees is the number of phases of the motor. The angle may be a predetermined range including the divided angle, or may be an angle obtained by dividing 360 degrees by the number of phases of the electric motor.
[0021]
In any one of the first to fourth power output apparatuses of the present invention including various aspects, the electric motor is a generator motor capable of generating electricity by inputting power, and the first power source and / or the second power source is A plurality of the switching circuits of the inverter circuit that are chargeable / dischargeable power sources and drive the electric motor as a generator and charge the electric power generated by the electric motor to the first power source and / or the second power source. Charge control means for controlling the switching of the element can also be provided.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described using examples. FIG. 1 is a configuration diagram showing an outline of the configuration of a power output apparatus 20 according to an embodiment of the present invention. As shown in the figure, the power output device 20 of the embodiment includes a motor 22 that is rotationally driven by three-phase AC, an inverter circuit 24 that can convert DC power to three-phase AC power and supply the motor 22, and an inverter circuit 24. The first DC power supply 30 connected to the positive electrode bus 26 and the negative electrode bus 28, the second DC power supply 32 connected to the negative electrode bus 28 of the inverter circuit 24 and the neutral point of the motor 22, and the entire apparatus are controlled. Electronic control unit 40.
[0029]
The motor 22 is configured as a synchronous generator motor capable of generating electric power, for example, including a rotor having a permanent magnet attached to an outer surface and a stator wound with a three-phase coil. The rotating shaft of the motor 22 is the output shaft of the power output device 20 of the embodiment, and power is output from this rotating shaft. Since the motor 22 of the embodiment is configured as a generator motor, the motor 22 can generate power when power is input to the rotating shaft of the motor 22.
[0030]
The inverter circuit 24 includes 12 transistors TU1 to TU4, TV1 to TV4, TW1 to TW4, and 18 diodes DU1 to DU6, DV1 to DV6, DW1 to DW6. In the u phase of the inverter circuit 24, a positive bus 26 and a negative bus 28 are connected in series by four transistors TU1 to TU4. A connection point between the transistor TU2 and the transistor TU3 is connected to a three-phase coil of the motor 22. Are connected. A connection point between the transistor TU1 and the transistor TU2 and a connection point between the transistor TU3 and the transistor TU4 are connected in series by two diodes DU5 and DU6 having a forward direction from the negative electrode bus 28 to the positive electrode bus 26 side. A connection point between the DU 5 and the diode DU 6 is connected to a neutral point of the motor 22. Each transistor TU1 to TU4 is provided with a reflux diode DU1 to DU4. The v phase and the w phase of the inverter circuit 24 are configured similarly to the u phase.
[0031]
The positive bus 26 and the negative bus 28 of the inverter circuit 24 are connected in series by two capacitors C1 and C2, and the connection point of the capacitor C1 and the capacitor C2 is connected to the neutral point of the motor 22 by the connection line 34. Has been.
[0032]
The first DC power supply 30 and the second DC power supply 32 are configured as, for example, nickel hydrogen or lithium ion secondary batteries, and the voltage V1 between the terminals of the first DC power supply 30 is between the terminals of the second DC power supply 32. It is adjusted to be twice the voltage V2. Therefore, if the neutral point of the motor 22 is used as a reference, the potential of the positive electrode bus 26 is V1-V2, and the potential of the negative electrode bus 28 is -V2. Hereinafter, it is assumed that the voltage of the positive electrode bus 26 is ½ VB and the voltage of the negative electrode bus 28 is −½ VB.
[0033]
The electronic control unit 40 is configured as a microprocessor centered on a CPU 42, and includes a ROM 44 that stores a processing program, a RAM 46 that temporarily stores data, and an input / output port (not shown). The electronic control unit 40 includes a current of each phase from the current sensors 52 to 56 attached to each phase of the uvw of the three-phase coil of the motor 22 and a current sensor 58 attached to the neutral point of the motor 22. The neutral point current, the rotation angle of the rotor of the motor 22 from the rotation angle sensor 60 attached to the rotation shaft of the motor 22 are input via the input port. In the embodiment, the current sensors 52 to 58 are provided in order to obtain each phase current and neutral point current, but any one of these current sensors 52 to 58 can be omitted. May be used exclusively for abnormality detection. From the electronic control unit 40, control signals for performing switching control of the transistors TU1 to TU4, TV1 to TV4, and TW1 to TW4 of the inverter circuit 24 are output via an output port.
[0034]
Next, the operation of the power output apparatus 20 of the embodiment thus configured, particularly the formation of pseudo three-phase alternating current applied to the motor 22 by the inverter circuit 24 will be described. The inverter circuit 24 included in the power output apparatus 20 of the embodiment can apply three levels of voltage levels to each phase of the motor 22 as follows. FIG. 2 is a circuit diagram of the power output apparatus 20 of the embodiment focusing on the u phase in a state where the transistors TU1 and TU2 are turned on and the transistors TU3 and TU4 are turned off. In this state, the voltage (1/2 VB) of the positive electrode bus 26 acts on the u phase of the motor 22. FIG. 3 is a circuit diagram of the power output apparatus 20 of the embodiment focusing on the u phase in a state where the transistors TU1 and TU2 are turned off and the transistors TU3 and TU4 are turned on.
In this state, the voltage (−1/2 VB) of the negative electrode bus 28 acts on the u phase of the motor 22. FIG. 4 is a circuit diagram of the power output apparatus 20 of the embodiment focusing on the u phase in a state where the transistors TU1 and TU4 are turned off and the transistors TU2 and TU3 are turned on. In this state, the voltage at the neutral point of the motor 22 (zero reference voltage) acts. Therefore, three voltage levels can be applied to the u phase of the motor 22 by using the three switching patterns shown in FIGS. Since the v phase and w phase of the inverter circuit 24 are configured in the same manner as the u phase, three voltage levels can be applied to the v phase and w phase of the motor 22 in the same manner for the v phase and w phase. .
[0035]
FIG. 5 is an explanatory diagram for explaining how a pseudo three-phase alternating current is obtained by switching the transistors TU1 to TU4, TV1 to TV4, and TW1 to TW4 of the inverter circuit 24. As shown in the figure, each phase command of uvw having a phase difference of 120 degrees is compared in magnitude with two stages of hierarchical triangular carriers CAR1 and CAR2, and each transistor TU1 to TU4, TV1 to TV4, TW1 to TW4 is compared. Determine the on / off state of. Table 1 below shows the state of the u-phase command value Vu * and the on / off states of the transistors TU1 to TU4.
[0036]
[Table 1]

As can be seen from Table 1, when the u-phase command value Vu * is greater than the triangular carrier CAR1, the transistors TU1 and TU2 are turned on and the transistors TU3 and TU4 are turned off to the state illustrated in FIG. The voltage (1/2 VB) of the positive electrode bus 26 is applied to the u phase. When the command value Vu * is between the triangular carriers CAR1 and CAR2, the transistors TU1 and TU4 are turned off and the transistors TU2 and TU3 are turned on and the state illustrated in FIG. Apply neutral point voltage (zero). When the command value Vu * is smaller than the triangular carrier CAR2, the transistors TU1 and TU2 are turned off and the transistors TU3 and TU4 are turned on, and the state illustrated in FIG. 3 is established, and the voltage (− 1/2 VB) is applied.
[0037]
When the transistors TU1 to TU4, TV1 to TV4, and TW1 to TW4 are switched based on the hierarchical triangular carriers CAR1 and CAR2 and the phase commands, the PWM of each phase (Vu, Vv, Vw) in the middle stage of FIG. It becomes a waveform. The output of the zero voltage vector in which the voltage of each phase is the same from the PWM waveform of each phase is as shown in the lowermost stage of FIG. FIG. 6 shows each phase command, triangular carrier wave, and each phase in the conventional power output apparatus that performs PWM control by two voltage levels of the positive bus voltage (1/2 VB) and the negative bus voltage (−1/2 VB). The PWM waveform of (Vu, Vv, Vw) and the output of the zero voltage vector are shown. As can be seen by comparing FIG. 5 and FIG. 6, the power output apparatus 20 of the embodiment is a power output apparatus of a conventional example that performs PWM control with two voltage levels by performing PWM control with three voltage levels. In comparison, the output frequency of the zero voltage vector can be significantly reduced. Therefore, the current pulsation at the neutral point of the motor 22 caused by the output of the zero voltage vector and the fixation of the potential at the neutral point of the motor 22 can be reduced.
[0038]
According to the power output apparatus 20 of the embodiment described above, the output frequency of the zero voltage vector can be remarkably reduced by performing the PWM control with the three voltage levels. As a result, current pulsation that can occur at the neutral point of the motor 22 with the output of the zero voltage vector can be reduced, and loss of the motor 22 can be suppressed.
[0039]
In the power output device 20 of the embodiment, the second DC power supply 32 is attached so as to connect the negative bus 28 of the inverter circuit 24 and the neutral point of the motor 22. It is good also as what attaches the 2nd DC power supply 32 so that a sex point may be connected. In the power output apparatus 20 of the embodiment, the first DC power supply 30 having a voltage V1 that is twice the voltage V2 of the second DC power supply 32 is attached so as to connect the positive bus 26 and the negative bus 28 of the inverter circuit 24. However, as shown in the power output device 20B of the modified example of FIG. It is good also as what attaches so that a point may be connected. This is because the power output device 20B according to the modified example is electrically equivalent to the power output device 20 according to the embodiment.
[0040]
The power output apparatus 20 of the embodiment includes the first DC power supply 30 that connects the positive bus 26 and the negative bus 28 of the inverter circuit 24. As shown in the power output apparatus 20C of the modification of FIG. Instead of the first DC power supply 30, a capacitor 30C may be provided. Note that the power output apparatus 20C of the modified example illustrated in FIG. 8 includes a voltage sensor 62 that detects a voltage Vc between terminals of the capacitor 30C, and a detection signal from the voltage sensor 62 is electronically controlled via an input port. Input to the unit 40. FIG. 9 is a circuit diagram of a modified power output apparatus 20 </ b> C focusing on the leakage inductance of the three-phase coil of the motor 22. Considering a state where the u-phase transistors TU3 and TU4 of the inverter circuit 24 are turned on, in this state, a short circuit indicated by a broken line arrow is formed, and the u-phase of the three-phase coil of the motor 22 is used as a reactor. Function. When one of the transistors TU3 and TU4 is turned off from this state, the energy stored in the u phase of the three-phase coil functioning as the reactor is stored in the capacitor 30C by the charging circuit indicated by the solid line arrow in the figure. The voltage at that time can be higher than the supply voltage of the second DC power supply 32. On the other hand, in this circuit, the second DC power supply 32 can be charged using the potential of the capacitor 30C. Therefore, this circuit can be regarded as a step-up / step-down chopper circuit capable of boosting and storing the energy of the second DC power source 32 in the capacitor 30C and charging the second DC power source 32 using the potential of the capacitor 30C. Similarly to the u phase, the vw phase of the three-phase coil of the motor 22 can be regarded as a step-up / step-down chopper circuit, so that the capacitor 30C is charged by turning on and off the transistors TU3, TU4, TV3, TV4, TW3, and TW4. The second DC power supply 32 can be charged using the potential of the capacitor 30C.
[0041]
Such charging causes a potential difference between the terminals of the capacitor 30C. The potential difference can be controlled by adjusting the amount of charge stored in the capacitor 30C, that is, the current flowing through the reactor. Therefore, the inter-terminal voltage Vc of the capacitor 30C can be set to twice the voltage V2 of the second DC power supply 32. In this way, if the inter-terminal voltage Vc of the capacitor 30C is made twice the voltage V2 of the second DC power supply 32, the power output device 20C of the modified example illustrated in FIG. A state in which the inter-terminal voltage Vc by 30C is applied, that is, a DC power source corresponding to the first DC power source 30 of the power output device 20 of the embodiment is connected, and the motor 22 is turned on in the same manner as the power output device 20 of the embodiment. Can be driven.
[0042]
Here, the motor 22 may be driven by supplying pseudo three-phase alternating current by the above-described switching control of the transistors TU1 to TU4, TV1 to TV4, TW1 to TW4 constituting the inverter circuit 24, and the voltage of the capacitor 30C. Therefore, the three-phase alternating current to which the direct current component is added can be supplied to the motor 22 by offsetting the pseudo three-phase alternating potential to the plus side or the minus side. As a result, the motor 22 is rotationally driven with the AC component, and the capacitor 30C can be charged with the DC component as described with reference to FIG.
[0043]
Therefore, in the power output apparatus 20C of the modified example, the same control as the PWM control of each phase of the power output apparatus 20 of the embodiment can be performed by offsetting each phase command in FIG. 5 to the plus side or the minus side. In addition, the inter-terminal voltage Vc of the capacitor 30C can be controlled. As a result, the power output device 20C according to the modified example can obtain the same effects as those of the power output device 20 according to the embodiment.
[0044]
In the power output apparatus 20 of the embodiment, the first DC power supply 30 that connects the positive bus 26 and the negative bus 28 of the inverter circuit 24 is provided. However, as shown in a power output apparatus 20D of a modification of FIG. Instead of the first DC power supply 30, a capacitor 30 </ b> D that connects the positive bus 26 of the inverter circuit 24 and the neutral point of the motor 22 may be provided. The power output device 20D of the modification illustrated in FIG. 10 includes a voltage sensor 62 that detects the voltage Vc between the terminals of the capacitor 30D, similarly to the power output device 20C of the modification. The detection signal is input to the electronic control unit 40 via the input port. FIG. 11 is a circuit diagram of a modified power output apparatus 20D focusing on the leakage inductance of the three-phase coil of the motor 22. Considering a state where the u-phase transistors TU3 and TU4 of the inverter circuit 24 are turned on, in this state, a short circuit indicated by a broken line arrow is formed, and the u-phase of the three-phase coil of the motor 22 is used as a reactor. Function. When any one of the transistors TU3 and TU4 is turned off from this state, the energy stored in the u-phase of the three-phase coil functioning as the reactor is stored in the capacitor 30D by the charging circuit indicated by the solid line arrow in the figure. Therefore, this circuit can be regarded as a chopper circuit capable of boosting and storing the energy of the second DC power supply 32 in the capacitor 30D and charging the second DC power supply 32 using the potential of the capacitor 30D. Similarly to the u phase, the vw phase of the three-phase coil of the motor 22 can be regarded as a step-up / step-down chopper circuit, so that the capacitor 30D can be charged by turning on and off the transistors TU1 to TU4, TV1 to TV4, TW1 to TW4. The second DC power source 32 can be charged using the potential of the capacitor 30D.
[0045]
Such charging causes a potential difference between the terminals of the capacitor 30D. The potential difference can be controlled by adjusting the amount of charge stored in the capacitor 30C, that is, the current flowing through the reactor. Therefore, the inter-terminal voltage Vc of the capacitor 30D can be made the same as the voltage V2 of the second DC power supply 32. As described above, if the inter-terminal voltage Vc of the capacitor 30D is made the same as the voltage V2 of the second DC power supply 32, in the power output device 20D of the modified example illustrated in FIG. 11, the capacitor 30D is connected to the positive bus 26 and the negative bus 28. And the second DC power source 32 are connected to a DC power source having a voltage twice the voltage V2, that is, a DC power source corresponding to the first DC power source 30 of the power output device 20 of the embodiment is connected. The motor 22 can be driven in the same manner as the power output apparatus 20 of the embodiment.
[0046]
Here, the motor 22 may be driven by supplying pseudo three-phase alternating current by the switching control of the transistors TU1 to TU4, TV1 to TV4, TW1 to TW4 constituting the inverter circuit 24, and the voltage of the capacitor 30D. Therefore, the three-phase alternating current to which the direct current component is added can be supplied to the motor 22 by offsetting the pseudo three-phase alternating potential to the plus side or the minus side. As a result, the motor 22 is rotationally driven by the AC component, and the capacitor 30D can be charged by the DC component as described with reference to FIG.
[0047]
Therefore, also in the power output device 20D of the modified example, each phase of the power output device 20 of the embodiment is offset by offsetting each phase command in FIG. 5 to the plus side or the minus side, similarly to the power output device 20C of the modified example. The same control as that of PWM control can be performed, and the voltage Vc between terminals of the capacitor 30D can be controlled. As a result, the power output device 20D of the modification can obtain the same effects as those of the power output device 20 of the embodiment.
[0048]
In the power output apparatus 20 of the embodiment and its modifications, the intermediate connection point of the diodes DU5, DU6, DV5, DV6, DW5, DW6 of each phase is connected to the intermediate connection point of the capacitors C1, C2, and the motor is connected by the connection line 34. 22 is connected to the neutral point of the motor 22, but the intermediate connection point of the diodes DU5, DU6, DV5, DV6, DW5, and DW6 of each phase without the capacitors C1 and C2 is simply connected to the neutral point of the motor 22 by the connection line 34. Do not connect the intermediate connection point of the diodes DU5, DU6, DV5, DV6, DW5, DW6 of each phase to the neutral point of the motor 22 by the connection line 34, but simply connect the intermediate connection points of the capacitors C1, C2. It can be connected to
[0049]
In the power output apparatus 20 of the embodiment and its modification, the frequency of appearance of the zero voltage vector is reduced by performing the PWM control with three stages of voltage levels, but the zero voltage is performed by performing the PWM control with four or more stages of voltage levels. It is good also as what reduces the appearance frequency of a vector. Further, in the power output apparatus 20 of the embodiment and its modification example, the motor 22 based on three-phase alternating current is used, but a motor based on n-phase alternating current may be used. Even in this case, the appearance frequency of the zero voltage vector can be reduced by performing the PWM control with the voltage levels of three or four or more levels.
[0050]
Next, a power output apparatus 120 as a second embodiment of the present invention will be described. FIG. 12 is a configuration diagram showing an outline of the configuration of the power output apparatus 120 of the second embodiment. As shown in the figure, the power output apparatus 120 of the second embodiment includes a motor 122 that is rotationally driven by three-phase AC, an inverter circuit 124 that can convert DC power into three-phase AC power and supply the three-phase AC power, and an inverter. The first DC power supply 130 connected to the positive bus 126 and the negative bus 128 of the circuit 124, the second DC power supply 132 connected to the neutral bus 128 of the inverter circuit 124 and the neutral point of the motor 122, and the entire apparatus And an electronic control unit 140 for controlling.
[0051]
Similarly to the motor 22 of the power output apparatus 20 of the first embodiment, the motor 122 is a synchronization capable of generating electricity, which includes a rotor having a permanent magnet attached to the outer surface and a stator wound with a three-phase coil. It is configured as a generator motor.
[0052]
The inverter circuit 124 includes six transistors T1 to T6 and six diodes D1 to D6. The six transistors T1 to T6 are arranged in pairs so as to be on the source side and the sink side with respect to the positive electrode bus 126 and the negative electrode bus 128, respectively, and a three-phase coil (uvw) of the motor 122 is connected to the connection point. Each of which is connected. Accordingly, if the on-time ratio of the transistors T1 to T6 that make a pair is controlled while the voltage is acting on the positive electrode bus 126 and the negative electrode bus 128, the voltage of the positive electrode bus 126 and the voltage of the negative electrode bus 128 are two stages. By the PWM control based on the voltage level, a rotating magnetic field can be formed by the three-phase coil of the motor 122 and the motor 122 can be driven to rotate.
[0053]
Similarly to the first DC power supply 30 and the second DC power supply 32 of the power output apparatus 20 of the first embodiment, the first DC power supply 130 and the second DC power supply 132 are, for example, nickel-hydrogen or lithium ion secondary batteries. The inter-terminal voltage V1 of the first DC power supply 130 is adjusted to be approximately twice the inter-terminal voltage V2 of the second DC power supply 132. Therefore, if the neutral point of the motor 122 is used as a reference, the potential of the positive electrode bus 126 is V1-V2 and the potential of the negative electrode bus 128 is -V2, as in the case of the power output device 20 of the first embodiment. Become. Hereinafter, it is assumed that the voltage of the positive electrode bus 126 is ½ VB, and the voltage of the negative electrode bus 128 is −½ VB.
[0054]
Similarly to the electronic control unit 40 of the power output apparatus 20 of the first embodiment, the electronic control unit 140 is also configured as a microprocessor centered on the CPU 142, and temporarily stores data in the ROM 144 storing the processing program. A RAM 146 for storage and an input / output port (not shown) are provided. The electronic control unit 140 includes a current of each phase from the current sensors 152 to 156 attached to each phase of the uvw of the three-phase coil of the motor 122 and a current sensor 158 attached to the neutral point of the motor 122. The neutral point current, the rotation angle of the rotor of the motor 122 from the rotation angle sensor 160 attached to the rotation shaft of the motor 122, a command value related to the operation of the motor 122, and the like are input via the input port. Further, a control signal for performing switching control of the transistors T1 to T6 of the inverter circuit 124 is output from the electronic control unit 140 through an output port.
[0055]
Next, the operation of the power output apparatus 120 of the second embodiment configured as described above, particularly the formation of pseudo three-phase alternating current applied to the motor 122 by the inverter circuit 124 will be described. FIG. 13 is an explanatory diagram illustrating each phase modulated wave and each phase carrier wave used in the PWM control by the electronic control unit 140 of the power output apparatus 120 of the second embodiment. As shown in the figure, the u-phase carrier, the v-phase carrier, and the w-phase carrier are all triangular waves and have phases different by 120 degrees. The u-phase modulated wave, the v-phase modulated wave, and the w-phase modulated wave are all formed based on each phase command. Since each phase is the same, although the phase is different, the u phase will be described. When the u-phase modulated wave is larger than the u-phase carrier wave, the transistor T1 is turned on and the transistor T2 is turned off to apply the voltage (1/2 VB) of the positive bus 126 to the u-phase of the three-phase coil of the motor 122. On the other hand, when the u-phase modulated wave is smaller than the u-phase carrier wave, the transistor T1 is turned off and the transistor T2 is turned on so that the voltage (−½ VB) of the negative electrode bus 128 acts on the u-phase of the three-phase coil of the motor 122. . By performing such switching control, as shown in FIG. 6, it is possible to perform PWM control with two voltage levels as in the conventional power output apparatus. Similarly, with respect to the v phase and the w phase, PWM control waveforms can be obtained using the respective phase modulated waves and the respective phase carrier waves. However, by making each phase carrier wave 120 degrees out of phase, each phase ( Vu, Vv, Vw) are not generated, and the zero voltage vector appears less frequently.
[0056]
FIG. 14 is an explanatory diagram showing currents flowing through the neutral points of the respective phases and the motor 122 when switching is performed based on the respective phase-modulated waves and the respective phase carriers in FIG. As shown in the figure, each phase current is a pseudo three-phase AC current having a phase of 120 degrees, and the current at the neutral point of the motor 122 settles in the vicinity of zero with a small amplitude.
[0057]
According to the power output device 120 of the second embodiment described above, the transistors of the respective phases of the inverter circuit 24 are switched based on the respective phase carrier waves whose phases are different by 120 degrees and the respective phase modulated waves based on the respective phase commands. Thus, the appearance frequency of the zero voltage vector can be reduced. As a result, the current pulsation that can occur at the neutral point of the motor 122 with the output of the zero voltage vector can be reduced and the loss of the motor 122 can be suppressed.
[0058]
In the power output apparatus 120 of the second embodiment, the second DC power supply 132 is attached so as to connect the negative bus 128 of the inverter circuit 124 and the neutral point of the motor 122, but the positive bus 126 of the inverter circuit 124 and the motor 122 are connected. It is good also as what attaches the 2nd DC power supply 132 so that it may connect with a neutral point. In the power output apparatus 120 of the second embodiment, the first DC power supply 130 having a voltage V1 that is twice the voltage V2 of the second DC power supply 132 is connected to the positive bus 126 and the negative bus 128 of the inverter circuit 124. 15, the first DC power supply 130B having the same voltage as the voltage V2 of the second DC power supply 132 is connected to the positive bus 126 of the inverter circuit 124 and the motor 122 as shown in the power output device 120B of the modification of FIG. It is good also as what attaches so that a neutral point may be connected. This is because the power output device 120B of the modification is electrically equivalent to the power output device 120 of the embodiment.
[0059]
The power output apparatus 120 of the second embodiment includes the first DC power supply 130 that connects the positive bus 126 and the negative bus 128 of the inverter circuit 124. The power output apparatus 120C of the modification of FIG. As described above, a capacitor 130 </ b> C may be provided instead of the first DC power supply 130. Note that the power output apparatus 120C of the modified example illustrated in FIG. 16 includes a voltage sensor 162 that detects a voltage Vc between terminals of the capacitor 130C, and a detection signal from the voltage sensor 162 is electronically controlled via an input port. Input to the unit 140. FIG. 17 is a circuit diagram of a power output apparatus 120 </ b> C of a modified example focusing on the leakage inductance of the three-phase coil of the motor 122. This circuit diagram has a configuration in which the transistors TU1 and TU2 are replaced with one transistor T1 and the transistors TU3 and TU4 are replaced with one transistor T2 in the circuit diagram illustrated in FIG. Accordingly, the circuit shown in FIG. 17 can charge the second DC power supply 132 by using the potential of the capacitor 130C while boosting and storing the energy of the second DC power supply 132 in the capacitor 130C, similarly to the circuit illustrated in FIG. It can be regarded as a simple buck-boost chopper circuit. Similarly to the u phase, the vw phase of the three-phase coil of the motor 122 can also be regarded as a step-up / step-down chopper circuit. It can be used to charge the second DC power source 132. The control of the inter-terminal voltage Vc of the capacitor 130C and the drive control of the motor 122 are performed by offsetting the pseudo three-phase AC potential to the plus side or the minus side, as described in the modification of the power output device 20C. Can be done at the same time.
[0060]
Therefore, in the power output device 120C of the modification, the same control as the PWM control of each phase of the power output device 120 of the second embodiment is performed by offsetting each phase modulated wave in FIG. 13 to the plus side or the minus side. The voltage Vc between terminals of the capacitor 130C can be controlled. As a result, the power output device 120C of the modified example can obtain the same effects as those of the power output device 120 of the second embodiment.
[0061]
The power output apparatus 120 of the second embodiment is provided with the first DC power supply 130 that connects the positive electrode bus 126 and the negative electrode bus 128 of the inverter circuit 124. The power output apparatus 120D of the modified example of FIG. Thus, instead of the first DC power supply 130, a capacitor 130 </ b> D that connects the positive bus 126 of the inverter circuit 124 and the neutral point of the motor 122 may be provided. 18 includes a voltage sensor 162 that detects the inter-terminal voltage Vc of the capacitor 130D, and the detection signal from the voltage sensor 162 is electronically controlled via the input port. Input to the unit 140. FIG. 19 is a circuit diagram of a power output apparatus 120D of a modified example focusing on the leakage inductance of the three-phase coil of the motor 122. This circuit diagram has a configuration in which the transistors TU1 and TU2 are replaced with one transistor T1 and the transistors TU3 and TU4 are replaced with one transistor T2 in the circuit diagram illustrated in FIG. Therefore, like the circuit illustrated in FIG. 11, the circuit shown in FIG. 19 stores the energy of the second DC power supply 132 in the capacitor 130D and can charge the second DC power supply 132 using the potential of the capacitor 130D. Can be considered. Similarly to the u phase, the vw phase of the three-phase coil of the motor 122 can also be regarded as a step-up / step-down chopper circuit. The second DC power supply 132 can be charged. The control of the inter-terminal voltage Vc of the capacitor 130D and the drive control of the motor 122 are performed by offsetting the pseudo three-phase AC potential to the plus side or the minus side as described in the modified power output device 20D. Can be done at the same time.
[0062]
Therefore, in the power output apparatus 120D of the modification, the same control as the PWM control of each phase of the power output apparatus 120 of the second embodiment is performed by offsetting each phase modulated wave in FIG. 13 to the plus side or the minus side. It is possible to control the voltage Vc between terminals of the capacitor 130D. As a result, the power output device 120D of the modified example can obtain the same effects as those of the power output device 120 of the second embodiment.
[0063]
In the power output device 120 of the second embodiment and its modification, the phase of each phase carrier wave is different by 120 degrees. However, if an n-phase motor is used, the phase difference is 360 / n degrees. Good. Moreover, since the phase of each phase carrier wave should just be in the tolerance | permissible_range of a current pulsation, it should just be an angle within the tolerance | permissible_range containing 120 degree | times or 360 / n degree | times. Furthermore, the phase of each phase carrier may be any number of times as long as the frequency of appearance of the zero voltage vector can be reduced.
[0064]
In the power output device 20 of the first embodiment, the power output device 120 of the second embodiment, and the modified example thereof, a synchronous generator motor driven by a three-phase AC rectangular wave voltage is used as the motors 22 and 122. Any type of electric motor driven by a rectangular wave voltage may be used.
[0065]
The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of a configuration of a power output apparatus 20 according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of a power output apparatus 20 of an embodiment focusing on a u phase in a state where transistors TU1 and TU2 are turned on and transistors TU3 and TU4 are turned off.
FIG. 3 is a circuit diagram of the power output apparatus 20 of the embodiment focusing on the u phase in a state where the transistors TU1 and TU2 are turned off and the transistors TU3 and TU4 are turned on.
FIG. 4 is a circuit diagram of the power output apparatus 20 of the embodiment focusing on the u phase in a state where the transistors TU1 and TU4 are turned off and the transistors TU2 and TU3 are turned on.
FIG. 5 is an explanatory diagram for explaining how pseudo three-phase alternating current is obtained by switching of transistors TU1 to TU4, TV1 to TV4, and TW1 to TW4 of the inverter circuit 24;
FIG. 6 is an explanatory diagram showing output of each phase command, triangular carrier wave, PWM waveform of each phase (Vu, Vv, Vw), and zero voltage vector in the conventional power output apparatus.
FIG. 7 is a configuration diagram showing an outline of a configuration of a power output apparatus 20B of a modified example.
FIG. 8 is a configuration diagram showing an outline of a configuration of a power output apparatus 20C according to a modified example.
9 is a circuit diagram of a power output apparatus 20C according to an embodiment focusing on leakage inductance of a three-phase coil of a motor 22. FIG.
FIG. 10 is a configuration diagram showing an outline of a configuration of a power output apparatus 20D according to a modified example.
FIG. 11 is a circuit diagram of a power output apparatus 20D of an embodiment focusing on leakage inductance of a three-phase coil of a motor 22.
FIG. 12 is a configuration diagram showing an outline of a configuration of a power output apparatus 120 of a second embodiment.
FIG. 13 is an explanatory diagram illustrating each phase modulated wave and each phase carrier wave used in PWM control by the electronic control unit 140 of the power output apparatus 120 of the second embodiment.
14 is an explanatory diagram showing currents that flow to the neutral point of each phase and motor 122 when switching is performed based on each phase-modulated wave and each phase carrier wave of FIG.
FIG. 15 is a configuration diagram showing an outline of a configuration of a power output apparatus 120B of a modified example.
FIG. 16 is a configuration diagram showing an outline of a configuration of a power output apparatus 120C according to a modified example.
17 is a circuit diagram of a power output apparatus 120C according to an embodiment focusing on leakage inductance of a three-phase coil of a motor 122. FIG.
FIG. 18 is a configuration diagram showing an outline of a configuration of a power output apparatus 120D of a modified example.
FIG. 19 is a circuit diagram of a power output apparatus 120D of an embodiment focusing on leakage inductance of a three-phase coil of a motor 122.
[Explanation of symbols]
20, 20B, 20C, 20D, 120, 120B, 120C, 120D Power output device, 22, 122 Motor, 24, 124 Inverter circuit, 26, 126 Positive bus, 28, 128 Negative bus, 30, 30B, 130, 130B 1 DC power supply, 30C, 30D, 130C, 130D capacitor, 32, 132 2nd DC power supply, 34 connection line, 40, 140 electronic control unit, 42, 142 CPU, 44, 144 ROM, 46, 146 RAM, 52-58 , 152 to 158 Current sensor, 60, 160 Rotation angle sensor, 62, 162 Voltage sensor, T1 to T6, TU1 to TU4, TV1 to TV4, TW1 to TW4 Transistors, D1 to D6, DU1 to DU6, DV1 to DV6, DW1 ~ DW6 diode, C1, C2 capacitor

Claims (20)

An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying pseudo multi-phase AC power to three or more voltage levels to the motor by switching operations of a plurality of switching elements;
A first power source connected to the positive and negative buses of the inverter circuit;
A second power source connected to one of the positive bus and the negative bus of the inverter circuit and a neutral point of the motor;
Switching control means for controlling switching of a plurality of switching elements of the inverter circuit ,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the electric motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled. Power output device.   2. The power output apparatus according to claim 1, wherein the first power source is a chargeable / dischargeable power storage unit that is charged using electric power from the second power source. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying pseudo multi-phase AC power to three or more voltage levels to the motor by switching operations of a plurality of switching elements;
A first power source connected to the positive bus of the inverter circuit and a neutral point of the motor;
A second power source connected to the negative bus of the inverter circuit and a neutral point of the motor;
Switching control means for controlling switching of a plurality of switching elements of the inverter circuit ,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled. Power output device.   The power output apparatus according to claim 3, wherein the first power source is a chargeable / dischargeable power storage unit that is charged using electric power from the second power source.   The power output apparatus according to claim 3, wherein the second power source is a chargeable / dischargeable power storage unit that is charged by using electric power from the first power source.   The power output device according to any one of claims 1 to 5, wherein the inverter circuit is a circuit for supplying pseudo multiphase AC power with three voltage levels. Each phase of the inverter circuit includes four switching elements that connect a positive bus and a negative bus in series, and two switching elements in the middle of the four switching elements. and two diodes connected in series as a forward, according to claim 6, and an intermediate voltage supplying means for supplying an intermediate voltage level of said three stages the voltage level of the intermediate contact point of the two said diodes Power output device.   The intermediate voltage supply means includes two capacitors for connecting a positive electrode bus and a negative electrode bus in series, and connects an intermediate contact of the two capacitors to an intermediate contact of the two diodes. 7. The power output device according to 7.   The power output apparatus according to claim 7 or 8, wherein the intermediate voltage supply means is means for connecting a neutral point of the electric motor to an intermediate contact of the two diodes.   The switching control means switches a plurality of switching elements of the inverter circuit based on a plurality of carrier waves hierarchically provided between the voltage levels of the three or more stages and a voltage command of each phase. The power output apparatus according to any one of claims 1 to 9, which is means for controlling.   The switching control means sets a voltage level of each phase of the inverter circuit based on which of the layers formed by the plurality of carriers the voltage command of each phase, and sets the voltage level of each phase of the inverter circuit 11. The power output apparatus according to claim 10, which is means for controlling switching of a plurality of switching elements of the inverter circuit so that a voltage level becomes the set voltage level. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying pseudo multiphase AC power to the electric motor by switching operations of a plurality of switching elements;
A first power source connected to the positive and negative buses of the inverter circuit;
A second power source connected to one of the positive bus and the negative bus of the inverter circuit and a neutral point of the motor;
Switching of a plurality of switching elements of the inverter circuit based on each phase modulated wave based on the voltage command of each phase of the polyphase AC and each phase carrier wave corresponding to each phase of the polyphase AC and having a predetermined phase difference and a switching control means for controlling,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled. Power output device.   The power output apparatus according to claim 12, wherein the first power source is a chargeable / dischargeable power storage unit that is charged by using electric power from the second power source. An electric motor that is rotationally driven by polyphase alternating current;
An inverter circuit capable of supplying pseudo multiphase AC power to the electric motor by switching operations of a plurality of switching elements;
A first power source connected to the positive bus of the inverter circuit and a neutral point of the motor;
A second power source connected to the negative bus of the inverter circuit and a neutral point of the motor;
Switching of a plurality of switching elements of the inverter circuit based on each phase modulated wave based on the voltage command of each phase of the polyphase AC and each phase carrier wave corresponding to each phase of the polyphase AC and having a predetermined phase difference and a switching control means for controlling,
By controlling on / off of a plurality of switching elements of the inverter circuit, the inverter circuit and the coil of the motor are operated as a chopper circuit, and the movement of power between the first power source and the second power source is controlled. Power output device.   15. The power output apparatus according to claim 14, wherein the first power source is a chargeable / dischargeable power storage unit that is charged by using electric power from the second power source.   15. The power output apparatus according to claim 14, wherein the second power source is a chargeable / dischargeable power storage unit that is charged by using electric power from the first power source.   The power output apparatus according to any one of claims 12 to 16, wherein the predetermined phase difference is a phase difference that cancels a current ripple at a neutral point of the electric motor.   The power output device according to any one of claims 12 to 16, wherein the predetermined phase difference is an angle in a predetermined range including an angle obtained by dividing 360 degrees by the number of phases of the electric motor.   The power output apparatus according to any one of claims 12 to 16, wherein the predetermined phase difference is an angle obtained by dividing 360 degrees by the number of phases of the electric motor.   20. The power output apparatus according to any one of claims 1 to 19, wherein the electric motor is a generator motor capable of generating electricity by inputting power, and the first power source and / or the second power source can be charged / discharged. And switching the plurality of switching elements of the inverter circuit to drive the electric motor as a generator and charge the electric power generated by the electric motor to the first power source and / or the second power source. A power output device comprising a charge control means for controlling the power.

Images