JP3830669B2

JP3830669B2 - Power converter

Info

Publication number: JP3830669B2
Application number: JP23763998A
Authority: JP
Inventors: 秀樹綾野; 仲田　　清; 知伊東; 彰三島; 阿佐子小柳
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1998-08-24
Filing date: 1998-08-24
Publication date: 2006-10-04
Anticipated expiration: 2018-08-24
Also published as: JP2000069766A

Description

【０００１】
【発明の属する技術分野】
本発明は、鉄道車両用等一般に利用される電力変換装置に係わり、特に、直流平滑用コンデンサとインバータ部分間の配線インダクタンスを低減させた電力変換装置に関する。
【０００２】
【従来の技術】
通常、電力変換装置において、配線インダクタンスが大きい場合には、半導体素子のスイッチング時に半導体素子に過大な電圧が印加されるため、半導体素子を保護するためのスナバ回路が必要となり、装置を小型化することが困難である。
【０００３】
ところで、配線インダクタンスを低減する方法としては、電流の経路である導体をできるだけ幅広の板状とし、かつ往路と復路の導体をできるだけ近接して接続するいわゆる平行平板状にすれば良いことが知られている。これは、往路と復路を流れる電流によって発生する磁束の変化が互いに相殺し、見かけ上磁束の変化がほとんどなくなるからである。
【０００４】
電力変換装置の配線においてもこのような原理を利用して、配線インダクタンスの低減が図られており、特にインバータ部分とコンデンサ部分の接続部のインダクタンスの低減方法が、特開平５−２９２７５６号公報、特開平６−３８５０７号公報、特開平７−２４５９５１号公報、および特開平９−１１７１２６号公報などに開示されている。これらにはいずれも上述の平行平板の配線を利用したものであり、接続端子が一方の導体や両導体間に設けられる絶縁層の貫通穴を通って他方の導体に接続されている。また、特開平６−２２５５４５号公報に開示されていいるものは、上述の平行平板の配線を利用するものであるが、導体を曲げることによって貫通穴を避けるように構成されている。
【０００５】
【発明が解決しようとする課題】
上記従来技術の貫通穴を設ける構造では、貫通穴を有する導体と貫通穴を通って他方の導体に接続するため接続端子との絶縁距離を確保するために前記貫通穴を大きくとる必要がある。この場合には、貫通穴周辺の導体の狭くなった部分に電流が集中し、インピーダンスの増大、局所的な発熱等の問題が生じる。さらに、貫通穴付近では電流分布に偏りが生じるため、インダクタンスの低減効果は小さいという問題がある。
【０００６】
また、特開平６−２２５５４５号公報に記載のものは、導体を曲げるなどの加工が必要であり、コストの上昇を免れない。さらに、導体が一部の接続端子を覆うように配置されているため、直流平滑用コンデンサの取り外しが極めて困難である。
【０００７】
本発明の目的は、上記の問題点に鑑みて、直流平滑用コンデンサとインバータ部分を接続する配線インダクタンスの低減を簡単な構成で実現した電力変換装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記目的を達成するために、本発明の電力変換装置は以下の特徴を有する。
【０００９】
少なくとも、複数の半導体素子が組み合わされて構成され、入力側を構成する正側端子と負側端子および出力側を構成する交流端子とを備えるインバータ部と、前記正側端子および負側端子間にそれぞれ正極側導体および負極側導体を介して接続される直流平滑用コンデンサとからなる電力変換装置において、前記正極側導体および前記負極側導体を、対角の位置に１組の接続部を有するとともに平板状に形成し、前記１組の接続部を結ぶ線が交差するように各導体面を同方向で互いに平行に配置し、前記各導体の一方の接続部を前記直流平滑用コンデンサに接続するとともに、前記各導体の他方の接続部を前記正側端子および前記負側端子に接続したことを特徴とする。
【００１０】
また、請求項１に記載の電力変換装置において、前記正極側導体および負極側導体の前記一方の接続部間を結ぶ線と平行な幅が、前記各導体の前記一方の接続部間の距離より大きいことを特徴とする。
【００１１】
また、少なくとも、複数の半導体素子が組み合わされて構成され、入力側を構成する正側端子と負側端子および出力側を構成する交流端子とを備える複数相のインバータ部から構成される多相インバータ部と、前記各相のインバータ部の前記正側端子および負側端子間にそれぞれ正極側導体および負極側導体を介して接続される直流平滑用コンデンサとからなる電力変換装置において、前記正極側導体および前記負極側導体を、前記各導体の一辺の一端側に片寄って分散配置された一方の複数の接続部および前記各導体の前記一辺に対向する辺の他端側に片寄って分散配置された他方の複数の接続部を有するとともに平板状に形成し、前記各導体のそれぞれの前記一端側と前記他端側とを結ぶ線が互いに交差するように各導体面を同方向に平行に配置し、前記各導体の前記一方の複数の接続部を各相のそれぞれの直流平滑用コンデンサに接続するとともに、前記各導体の他方の複数の接続部をそれぞれの各相インバータ部の前記正側端子および前記負側端子に接続したことを特徴とする。
【００１２】
また、少なくとも、複数の半導体素子が組み合わされて構成され、入力側を構成する正側端子と負側端子および出力側を構成する交流端子とを備える複数相のインバータ部から構成される多相インバータ部と、前記各相のインバータ部の前記正側端子および負側端子間に正極側導体および負極側導体を介して接続される直流平滑用コンデンサとからなる電力変換装置において、前記正極側導体および前記負極側導体を、前記各導体の一辺の一端側に片寄って配置された一方の接続部および前記各導体の前記一辺に対向する辺の他端側に片寄って分散配置された他方の複数の接続部を有するとともに平板状に形成し、前記各導体のそれぞれの前記一端側と前記他端側とを結ぶ線が互いに交差するように各導体面を同方向に平行に配置し、前記各導体の前記一方の接続部を直流平滑用コンデンサに接続するとともに、前記各導体の他方の複数の接続部をそれぞれの各相インバータ部の前記正側端子および前記負側端子に接続したことを特徴とする。
【００１３】
また、請求項１ないしは請求項４のいずれか１つの請求項に記載の電力変換装置おいて、前記正極側導体と負極側導体を略同一形状のものを用いることを特徴とする。
【００１４】
【発明の実施の形態】
はじめに、本発明の第１の実施形態を図１から図６を用いて説明する。
【００１５】
図３は、本実施形態に係わる電力変換装置に電源、整流器、およびモータ負荷を接続した状態を示す回路構成図である。
【００１６】
同図において、１１は電力変換装置、１４は三相交流電源、１５はこの三相交流電源１４の交流電圧を直流電圧に変換する整流器、１６はモータ負荷、６および７はそれぞれ整流器１５と電力変換装置１１を接続する正側導体および負側導体、８は電力変換装置１１とモータ負荷１６を接続する交流側導体である。
【００１７】
ここで、電力変換装置１１は、Ｕ相変換装置１１１、Ｖ相変換装置１１２、およびＷ相変換装置１１３の３相の変換装置から構成される。
【００１８】
図１および図２は、図３に示す各相の変換装置１１１〜１１３のうちの１つの内部構造を示す図であり、図４は各相変換装置１１１〜１１３のうちの１つの等価回路図である。
【００１９】
これらの図において、１は整流器１５の出力側に接続されるとともに、各相変換装置１１１（１１２〜１１３）内の半導体素子９，１０の入力側に接続される直流平滑用コンデンサ、２は正側導体６と直流平滑用コンデンサ１の正極端子間を接続する正極側導体、３は負側導体７と直流平滑用コンデンサ１の負極端子間を接続する負極側導体、４は正極側導体２と直流平滑用コンデンサ１の正極端子間を接続する接続部、５は負極側導体２と直流平滑用コンデンサ１の負極端子間を接続する接続部、９および１０はそれぞれ正側の半導体素子および負側の半導体素子、１２は正極側導体２と正側導体６との接続部、１３は負極側導体３と負側導体７との接続部である。
【００２０】
ここで、正側の半導体素子９、負側の半導体素子１０、正側導体６、負側導体７、および交流導体８でインバータ部分を構成する。
【００２１】
このインバータ部は、正側の半導体素子９および負側の半導体素子１０が、図示していない制御装置によってオンオフ制御され、正側導体６および負側導体７間から供給される直流の電力を交流に変換して交流側導体８に出力する。
【００２２】
また、直流平滑用コンデンサ１は正極側導体２および負極側導体３を介してインバータ部分と接続されており、正側の半導体素子９あるいは負側の半導体素子１０がスイッチオンした瞬間に電流を供給し、半導体素子９，１０の応答速度を補償している。さらに、正側の半導体素子９あるいは負側の半導体素子１０がスイッチオフした際の過渡電流を吸収する。
【００２３】
また、図１に示すように、正極側導体３は、長方形の一方の対角部分に突出部を有し、一方の突出部上の接続部５において直流平滑用コンデンサ１の負極端子と接続され、もう一方の突出部上の接続部１３において負側導体７と接続される。また、正極側導体２は、負極側導体３の左右を反転した形状の導体板であり、負極側導体３の裏面側に設けられる。正極側導体２も負極側導体３と同様に、接続部４において直流平滑用コンデンサ１の正極端子と接続され、接続部１２において正側導体６と接続される。さらに、正極側導体２と負極側導体３は、互いに平行にかつ中央の長方形の部分が重なりあうように配置され、接続部５と接続部１３、接続部４と接続部１２は互い違いに位置するように配置される。また、正極側導体２と負極側導体３の重なり合った部分の横幅Ｗは直流平滑用コンデンサ１の正極端子と負極端子間の間隔Ｌよりも長く、また、正極側導体２と負極側導体３間は電圧印加時に放電が生じないように間隙が設けられる。ここで、導体２，３間に絶縁材の板を配置すれば、導体間隔を狭めることも可能となる。
【００２４】
図５および図６は、それぞれ正極側導体２および負極側導体３の電流分布を示す図である。
【００２５】
同図において、曲線は電流の流線を示し、この間隔が狭いほど電流密度が大きいことを表している。図５では、直流平滑用コンデンサ１の正極端子との接続部４から流入した電流が、正側導体６との接続部１２に流出している。図６では、負側導体７との接続部１３から流入した電流が直流平滑用コンデンサ１の負極端子との接続部５に流出している。このように、正極側導体２および負極側導体３の電流流線は各導体面内に広がって分布する。これは、一方の導体に流れる電流が、他方の導体の電流密度の高い部分、つまり直流平滑用コンデンサ１の接続部とインバータ側導体の接続部に引き寄せられるためと考えられる。電流流線が面内に広がることにより、直流平滑用コンデンサ１とインバータ部分間の配線インダクタンスが減少する。さらに、正極側導体２の電流と負極側導体３の電流は互いに逆向きになっているため、発生する磁束が互いに相殺され、配線インダクタンスを低減させれることができる。
【００２６】
図７は、本発明の第２の実施形態に係わる正極側導体２１および負極側導体３１の形状を示す図である。
【００２７】
本実施形態の正極側導体２１および負極側導体３１は、第１の実施形態の図１に示したものに比べて、正極側導体２１および負極側導体３１の重なり合う部分の幅を狭くした点で相違する。本実施形態においても、第１の実施形態と同様に、負極側導体３１と正極側導体２１は、図示するように、長方形部分が重なり合うように構成され、また、各導体２１，３１間に電圧が印加されても放電が生じないように間隙が設けられる。なお、その他の構成は第１の実施形態のものと同じであるので説明を省略する。
【００２８】
本実施形態によれば、第１の実施形態の正極側導体２および負極側導体３に比べて、重なり合う部分の幅が狭くなっているので、装置の軽量化が図られる。また、幅が狭い長方形部分において電流の流路が両導体間で互いに逆向きになり発生する磁束が相殺されるので、第１の実施形態と同様に配線インダクタンスを低減することができる。
【００２９】
図８は、本発明の第３の実施形態に係わる正極側導体２２および負極側導体３２の形状を示す図である。
【００３０】
本実施形態の正極側導体２２および負極側導体３２は、第１の実施形態の図１に示したものに比べて、正極側導体２２および負極側導体３２の対角部分の一部を削った点で相違する。第１の実施形態の正極側導体２および負極側導体３が、図５および図６に示すように、正極側導体２と負極側導体３とが重なり合う部分の対角部分の電流分布が少ないことを考慮して、この対角部分の一部を削り取ったものである。本実施形態においても、第１の実施形態と同様に、負極側導体３２と正極側導体２２間は電圧を印加した際に放電が生じないように間隙が設けられる。なお、その他の構成は第１の実施形態のものと同じである。
【００３１】
本実施形態によれば、第１の実施形態の正極側導体２および負極側導体３に比べて、上記対角部分が削除されているので、装置の軽量化が図られる。また、第１の実施形態と同様に、電流の流路が両導体間で互いに逆向きになり発生する磁束が相殺されるので、第１の実施形態と同様に配線インダクタンスを低減することができる。
【００３２】
図９は、本発明の第４の実施形態に係わる正極側導体２３および負極側導体３３の形状を示す図である。
【００３３】
本実施形態の正極側導体２３および負極側導体３３は、第１の実施形態の図１に示したものに比べて、負極側導体３３は接続部５，１３と接続するための突出部を有さない長方形とするが、正極側導体２３は負極側導体３３と同じ大きさの長方形であって、同図の点線で示すように、負極側導体３３と直流平滑用コンデンサ１との接続部分５、インバータ部分との接続部分１３の部分にあたる角の部分のみを切り取った形状とする。ここで切り取る大きさは、両導体２３，３３間に電圧を印加した場合に正極側導体２３と接続部５および接続部１３間で放電が生じないような大きさである。なお、その他の構成は第１の実施形態のものと同じである。
【００３４】
本実施形態によれば、第１の実施形態の正極側導体２および負極側導体３に比べて、両導体２３，３３を作成するための加工数を減少させることができる。また、第１の実施形態と同様に、配線インダクタンスの低減効果が得られる。
【００３５】
図１０は、本発明の第５の実施形態に係わる正極側導体２４および負極側導体３４の形状を示す図である。
【００３６】
本実施形態の正極側導体２４および負極側導体３４は、第１の実施形態の図１に示したものに比べて、正極側導体２４および負極側導体３４の重なり合う部分の幅を狭くするとともに、両導体２４，３４の形状をＳ字型としたものである。なお、その他の構成は第１の実施形態のものと同じである。
【００３７】
本実施形態によれば、第１の実施形態の正極側導体２および負極側導体３に比べて重なり合う部分の幅が狭くなっているので装置の軽量化が図られるとともに、第１の実施形態と同様に、配線インダクタンスの低減効果が得られる。
【００３８】
図１１は、本発明の第６の実施形態に係わる正極側導体２５および負極側導体３５の形状を示す図である。
【００３９】
同図において、正極側導体２５は、各相の電力変換装置１１１〜１１３のそれぞれの直流平滑用コンデンサ１の正極端子との接続部４ｕ，４ｖ，４ｗ、およびＵ相変換装置１１１の正極側との接続部１２ｕ、Ｖ相変換装置１１２の正極側との接続部１２ｖ、およびＷ相変換装置１１３の正極側との接続部１２ｗにそれぞれ相応して設けられる突出部を備え、負極側導体３４も、上記のそれぞれの直流平滑用コンデンサ１の負極端子との接続部５ｕ，５ｖ，５ｗ、およびＵ相変換装置１１１の負極側との接続部１３ｕ、Ｖ相変換装置１１２の負極側との接続部１３ｖ、およびＷ相変換装置１１３の負極側との接続部１３ｗに相応して設けられる突出部を備えている。
【００４０】
本実施形態と第１の実施形態を比べると、第１の実施形態のものが、各相毎の直流平滑用コンデンサ１と各相の変換装置１１１〜１１３間にそれぞれ正極側導体２および負極側導体３を設けているのに対して、本実施形態では、各相毎の直流平滑用コンデンサと各相の変換装置１１１〜１１３間に共用する１組の正極側導体２５および負極側導体３５が設けられている点で相違する。
【００４１】
図１２（ａ）および図１２（ｂ）は、それぞれ図１１に示す正極側導体２５および負極側導体３５の電流分布の一例を示す図であり、図１２（ａ）は、各相のそれぞれの直流平滑用コンデンサ１の正極端子の接続部４ｕ，４ｖ，４ｗからＵ相，Ｖ相，Ｗ相の各変換装置１１１〜１１３の正極側の接続部１２ｕ，１２ｖ，１２ｗへの電流分布、図１２（ｂ）は、Ｕ相，Ｖ相，Ｗ相の各変換装置１１１〜１１３の負極側の接続部１３ｕ，１３ｖ，１３ｗから各相のそれぞれの直流平滑用コンデンサ１の負極端子の接続部５ｕ，５ｖ，５ｗへの電流分布を示す。
【００４２】
本実施形態によれば、Ｕ相，Ｖ相，Ｗ相の各変換装置１１１〜１１３に共用の１組の正極側導体２４と負極側導体３４を用いるので、第１から第５の実施形態の電力変換装置に比べて部品点数を減らすことができ、また、第１の実施形態と同様に、電流が広がって分布するので、配線インダクタンスの逓減効果が得られる。さらに、本実施形態によれば、直流平滑用コンデンサ１の３組の正極側の接続部４ｕ，４ｖ，４ｗ、および負極側の接続部５ｕ，５ｖ，５ｗから電流が供給されるので、さらに配線インダクタンスを低減することができる。また、インバータ部のＵ相，Ｖ相，Ｗ相の各電力変換装置１１１〜１１３への電流供給のバランスも良くなる。
【００４３】
図１３は、本発明の第７の実施形態に係わる正極側導体２６および負極側導体３６の形状を示す図である。
【００４４】
同図において、正極側導体２６は、各相の変換装置１１１〜１１３に図示されていない共用の直流平滑用コンデンサの正極端子との接続部４、Ｕ相変換装置１１１の正極側との接続部１２ｕ、Ｖ相変換装置１１２の負極側との接続部１２ｖ、およびＷ相変換装置１１３の負極側との接続部１２ｗに相応して設けられる突出部を備え、負極側導体３６は、上記共用の直流平滑用コンデンサの負極端子との接続部５、Ｕ相変換装置１１１の負極側との接続部１３ｕ、Ｖ相変換装置１１２の負極側との接続部１３ｖ、およびＷ相変換装置１１３の負極側との接続部１３ｗに相応して設けられる突出部を備えている。
【００４５】
本実施形態と第１の実施形態を比べると、第１の実施形態のものが、各相毎の直流平滑用コンデンサ１と各相の変換装置１１１〜１１３間にそれぞれ正極側導体２および負極側導体３が設けられているのに対して、本実施形態では、各相に共用する直流平滑用コンデンサと各相の変換装置１１１〜１１３に共用する１組の正極側導体２６および負極側導体３６が設けられている点で相違する。
【００４６】
図１４（ａ）および図１４（ｂ）は、それぞれ図１３に示す正極側導体２６および負極側導体３６の電流分布の一例を示す図であり、図１４（ａ）は、１つの直流平滑用コンデンサの正極端子の接続部４からＵ相，Ｖ相，Ｗ相の各変換装置１１１〜１１３の正極側の接続部１２ｕ，１２ｖ，１２ｗへの電流分布を示し、図１４（ｂ）は、Ｕ相，Ｖ相，Ｗ相の各変換装置１１１〜１１３の負極側の接続部１３ｕ，１３ｖ，１３ｗから前記１つの直流平滑用コンデンサの負極端子の接続部５への電流分布を示す。
【００４７】
【発明の効果】
本発明の電力変換装置によれば、簡単な構成で直流平滑用コンデンサとインバータ部分の間のインダクタンスを低減でき、半導体素子の能力を最大限に利用できる。さらに、過電圧を抑制して半導体素子を保護するためのスナバ回路の容量低減、もしくはスナバレス化にも寄与する。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係わる各相の変換装置１１１〜１１３のうちの１つの内部構造を示す正面図である。
【図２】図１に示す上記内部構造の側面図である。
【図３】本実施形態に係わる電力変換装置に電源、整流器、およびモータ負荷を接続した状態を示す回路構成図である。
【図４】図３に示す各相の変換装置１１１〜１１３のうちの１つの等価回路図である。
【図５】図１および図２に示す正極側導体２の電流分布を示す図である。
【図６】図１および図２に示す負極側導体３の電流分布を示す図である。
【図７】本発明の第２の実施形態に係わる正極側導体２１および負極側導体３１の形状を示す図である。
【図８】本発明の第３の実施形態に係わる正極側導体２２および負極側導体３２の形状を示す図である。
【図９】本発明の第４の実施形態に係わる正極側導体２３および負極側導体３３の形状を示す図である。
【図１０】本発明の第５の実施形態に係わる正極側導体２４および負極側導体３４の形状を示す図である。
【図１１】本発明の第６の実施形態に係わる正極側導体２５および負極側導体３５の形状を示す図である。
【図１２】図１１に示す正極側導体２５および負極側導体３５の電流分布を示す図である。
【図１３】本発明の第７の実施形態に係わる正極側導体２６および負極側導体３６の形状を示す図である。
【図１４】図１３に示す正極側導体２６および負極側導体３６の電流分布を示す図である。
【符号の説明】
１直流平滑用コンデンサ
２，２１，２２，２３，２４，２５，２６正極側導体
３，３１，３２，３３，３４，３５，３６負極側導体
４，４ｕ，４ｖ，４ｗ正極側導体における直流平滑用コンデンサの正極端子との接続部分
５，５ｕ，５ｖ，５ｗ負極側導体における直流平滑用コンデンサの負極端子との接続部分
６正側導体
７負側導体
８交流側導体
９正側の半導体素子
１０負側の半導体素子
１１電力変換装置
１１１，１１２，１１３Ｕ相，Ｖ相，Ｗ相の電力変換装置
１２，１２ｕ，１２ｖ，１２ｗ正極側導体と正側導体との接続部
１３，１３ｕ，１３ｖ，１３ｗ負極側導体と負側導体との接続部
１４三相交流電源
１５整流器
１６モータ負荷[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power conversion device that is generally used for railway vehicles, and more particularly to a power conversion device that reduces wiring inductance between a DC smoothing capacitor and an inverter portion.
[0002]
[Prior art]
Usually, in a power conversion device, when the wiring inductance is large, an excessive voltage is applied to the semiconductor element when the semiconductor element is switched. Therefore, a snubber circuit for protecting the semiconductor element is required, and the apparatus is downsized. Is difficult.
[0003]
By the way, as a method for reducing the wiring inductance, it is known that the conductor which is a current path is made as wide as possible and the so-called parallel plate shape which connects the forward and return conductors as close as possible is known. ing. This is because changes in the magnetic flux generated by the current flowing in the forward path and the return path cancel each other, and apparently there is almost no change in the magnetic flux.
[0004]
The wiring inductance of the power converter is also reduced by using such a principle, and in particular, a method for reducing the inductance of the connection portion between the inverter portion and the capacitor portion is disclosed in JP-A-5-292756, It is disclosed in JP-A-6-38507, JP-A-7-245951, JP-A-9-117126, and the like. Each of these uses the above-described parallel plate wiring, and the connection terminal is connected to the other conductor through a through hole of an insulating layer provided between one conductor and both conductors. Moreover, what is disclosed in Japanese Patent Application Laid-Open No. 6-225545 uses the above-described parallel plate wiring, but is configured to avoid a through hole by bending a conductor.
[0005]
[Problems to be solved by the invention]
In the structure provided with the through hole according to the prior art, it is necessary to make the through hole large in order to secure an insulation distance between the conductor having the through hole and the connection terminal through the through hole. In this case, the current concentrates on the narrowed portion of the conductor around the through hole, causing problems such as an increase in impedance and local heat generation. Furthermore, since the current distribution is biased in the vicinity of the through hole, there is a problem that the effect of reducing the inductance is small.
[0006]
Moreover, the thing of Unexamined-Japanese-Patent No. 6-225545 requires processing, such as bending a conductor, and cannot avoid an increase in cost. Furthermore, since the conductor is disposed so as to cover a part of the connection terminals, it is extremely difficult to remove the DC smoothing capacitor.
[0007]
In view of the above problems, an object of the present invention is to provide a power converter that realizes a reduction in wiring inductance connecting a DC smoothing capacitor and an inverter part with a simple configuration.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the power conversion device of the present invention has the following characteristics.
[0009]
At least an inverter unit comprising a combination of a plurality of semiconductor elements, a positive side terminal constituting the input side, a negative side terminal and an AC terminal constituting the output side, and between the positive side terminal and the negative side terminal In a power conversion device comprising a DC smoothing capacitor connected through a positive electrode side conductor and a negative electrode side conductor, respectively, the positive electrode side conductor and the negative electrode side conductor have a pair of connecting portions at diagonal positions. Each conductor surface is formed in a flat plate shape and arranged parallel to each other in the same direction so that the lines connecting the one set of connection portions intersect, and one connection portion of each conductor is connected to the DC smoothing capacitor. In addition, the other connecting portion of each conductor is connected to the positive terminal and the negative terminal.
[0010]
Further, in the power conversion device according to claim 1, a width parallel to a line connecting the one connection portions of the positive electrode side conductor and the negative electrode side conductor is greater than a distance between the one connection portions of the conductors. It is large.
[0011]
In addition, a multi-phase inverter composed of a plurality of inverter sections each including at least a positive terminal that constitutes the input side, a negative terminal, and an AC terminal that constitutes the output side, which is configured by combining a plurality of semiconductor elements. And a DC smoothing capacitor connected between the positive side terminal and the negative side terminal of the inverter part of each phase via a positive side conductor and a negative side conductor, respectively, the positive side conductor And the negative electrode side conductors are arranged in a distributed manner on the other end side of the side facing the one side of each conductor and the plurality of connection parts arranged in a distributed manner on one side of the one side of each conductor. Each of the conductor surfaces is flat in the same direction so that the lines connecting the one end side and the other end side of each conductor intersect each other. And connecting the one plurality of connection portions of the conductors to the DC smoothing capacitors of the respective phases, and connecting the other plurality of connection portions of the conductors to the positive terminals of the respective phase inverter portions. It is connected to the side terminal and the negative side terminal.
[0012]
In addition, a multi-phase inverter composed of a plurality of inverter sections each including at least a positive terminal that constitutes the input side, a negative terminal, and an AC terminal that constitutes the output side, which is configured by combining a plurality of semiconductor elements. And a DC smoothing capacitor connected between the positive side terminal and the negative side terminal of the inverter part of each phase via a positive side conductor and a negative side conductor, the positive side conductor and The negative electrode-side conductor is connected to one end of one side of each conductor, and the other plurality of other terminals arranged in a distributed manner toward the other end of the side opposite to the one side of each conductor. Each conductor surface is arranged in parallel in the same direction so that a line connecting the one end side and the other end side of each conductor intersects each other, having a connecting portion and having a flat plate shape, The one connection part of the body is connected to a DC smoothing capacitor, and the other plurality of connection parts of the conductors are connected to the positive terminal and the negative terminal of each phase inverter part. And
[0013]
Further, in the power conversion device according to any one of claims 1 to 4, the positive electrode side conductor and the negative electrode side conductor have substantially the same shape.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
First, a first embodiment of the present invention will be described with reference to FIGS.
[0015]
FIG. 3 is a circuit configuration diagram showing a state where a power supply, a rectifier, and a motor load are connected to the power conversion apparatus according to the present embodiment.
[0016]
In the figure, 11 is a power converter, 14 is a three-phase AC power source, 15 is a rectifier that converts the AC voltage of the three-phase AC power source 14 into DC voltage, 16 is a motor load, and 6 and 7 are the rectifier 15 and power, respectively. A positive-side conductor and a negative-side conductor that connect the converter 11, and 8 are AC-side conductors that connect the power converter 11 and the motor load 16.
[0017]
Here, the power converter 11 includes a three-phase converter, that is, a U-phase converter 111, a V-phase converter 112, and a W-phase converter 113.
[0018]
1 and FIG. 2 are diagrams showing an internal structure of one of the phase conversion devices 111 to 113 shown in FIG. 3, and FIG. 4 is an equivalent circuit diagram of one of the phase conversion devices 111 to 113. It is.
[0019]
In these figures, 1 is connected to the output side of the rectifier 15, and DC smoothing capacitor connected to the input side of the semiconductor elements 9 and 10 in each phase converter 111 (112 to 113). Positive conductor 3 connecting the side conductor 6 and the positive electrode terminal of the DC smoothing capacitor 1, 3 Negative electrode conductor connecting the negative conductor 7 and the negative electrode terminal of the DC smoothing capacitor 1, 4 Positive electrode conductor 2 Connection part for connecting the positive electrode terminals of the DC smoothing capacitor 1, 5 is a connection part for connecting the negative electrode side conductor 2 and the negative electrode terminal of the DC smoothing capacitor 1, and 9 and 10 are the semiconductor element on the positive side and the negative side, respectively. Reference numeral 12 denotes a connection portion between the positive-side conductor 2 and the positive-side conductor 6, and reference numeral 13 denotes a connection portion between the negative-side conductor 3 and the negative-side conductor 7.
[0020]
Here, the positive semiconductor element 9, the negative semiconductor element 10, the positive conductor 6, the negative conductor 7, and the AC conductor 8 constitute an inverter part.
[0021]
In this inverter unit, the positive-side semiconductor element 9 and the negative-side semiconductor element 10 are on / off controlled by a control device (not shown), and direct-current power supplied from between the positive-side conductor 6 and the negative-side conductor 7 is exchanged. And output to the AC side conductor 8.
[0022]
Further, the DC smoothing capacitor 1 is connected to the inverter part via the positive-side conductor 2 and the negative-side conductor 3, and supplies current when the positive-side semiconductor element 9 or the negative-side semiconductor element 10 is switched on. The response speed of the semiconductor elements 9 and 10 is compensated. Further, the transient current when the positive-side semiconductor element 9 or the negative-side semiconductor element 10 is switched off is absorbed.
[0023]
Moreover, as shown in FIG. 1, the positive electrode side conductor 3 has a protrusion part at one diagonal part of the rectangle, and is connected to the negative electrode terminal of the DC smoothing capacitor 1 at the connection part 5 on the one protrusion part. The connection portion 13 on the other protrusion is connected to the negative conductor 7. Further, the positive electrode side conductor 2 is a conductor plate having a shape in which the left and right sides of the negative electrode side conductor 3 are reversed, and is provided on the back surface side of the negative electrode side conductor 3. Similarly to the negative electrode side conductor 3, the positive electrode side conductor 2 is connected to the positive electrode terminal of the DC smoothing capacitor 1 at the connection portion 4, and is connected to the positive side conductor 6 at the connection portion 12. Further, the positive electrode side conductor 2 and the negative electrode side conductor 3 are arranged in parallel with each other so that the central rectangular portions overlap each other, and the connection portion 5 and the connection portion 13 and the connection portion 4 and the connection portion 12 are alternately arranged. Are arranged as follows. Further, the width W of the overlapping portion of the positive electrode side conductor 2 and the negative electrode side conductor 3 is longer than the interval L between the positive electrode terminal and the negative electrode terminal of the DC smoothing capacitor 1 and between the positive electrode side conductor 2 and the negative electrode side conductor 3. Is provided with a gap so that no discharge occurs when a voltage is applied. Here, if an insulating material plate is disposed between the conductors 2 and 3, the conductor interval can be reduced.
[0024]
5 and 6 are diagrams showing current distributions of the positive electrode side conductor 2 and the negative electrode side conductor 3, respectively.
[0025]
In the figure, the curve shows the streamline of current, and the smaller the interval, the greater the current density. In FIG. 5, the current flowing from the connection portion 4 with the positive electrode terminal of the DC smoothing capacitor 1 flows out to the connection portion 12 with the positive conductor 6. In FIG. 6, the current flowing from the connection portion 13 with the negative conductor 7 flows out to the connection portion 5 with the negative electrode terminal of the DC smoothing capacitor 1. Thus, the current stream lines of the positive electrode side conductor 2 and the negative electrode side conductor 3 are spread and distributed in the respective conductor surfaces. This is presumably because the current flowing through one conductor is attracted to the portion where the other conductor has a high current density, that is, the connection portion of the DC smoothing capacitor 1 and the inverter-side conductor. By spreading the current flow lines in the plane, the wiring inductance between the DC smoothing capacitor 1 and the inverter portion is reduced. Furthermore, since the current of the positive electrode side conductor 2 and the current of the negative electrode side conductor 3 are opposite to each other, the generated magnetic fluxes cancel each other and the wiring inductance can be reduced.
[0026]
FIG. 7 is a diagram showing the shapes of the positive electrode side conductor 21 and the negative electrode side conductor 31 according to the second embodiment of the present invention.
[0027]
The positive electrode side conductor 21 and the negative electrode side conductor 31 of this embodiment are the points which narrowed the width | variety of the part which the positive electrode side conductor 21 and the negative electrode side conductor 31 overlap compared with what was shown in FIG. 1 of 1st Embodiment. Is different. Also in the present embodiment, as in the first embodiment, the negative electrode side conductor 31 and the positive electrode side conductor 21 are configured such that the rectangular portions overlap as shown in the figure, and a voltage is applied between the conductors 21 and 31. A gap is provided so that no electric discharge occurs even when is applied. Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0028]
According to the present embodiment, since the width of the overlapping portion is narrower than that of the positive electrode side conductor 2 and the negative electrode side conductor 3 of the first embodiment, the weight of the device can be reduced. In addition, since the current flow paths are opposite to each other between the two conductors in the rectangular portion having a narrow width and the generated magnetic flux is canceled, the wiring inductance can be reduced as in the first embodiment.
[0029]
FIG. 8 is a diagram showing the shapes of the positive electrode side conductor 22 and the negative electrode side conductor 32 according to the third embodiment of the present invention.
[0030]
The positive electrode side conductor 22 and the negative electrode side conductor 32 of this embodiment cut off some diagonal portions of the positive electrode side conductor 22 and the negative electrode side conductor 32 as compared with the one shown in FIG. 1 of the first embodiment. It is different in point. As shown in FIGS. 5 and 6, the positive-side conductor 2 and the negative-side conductor 3 of the first embodiment have a small current distribution in the diagonal portion where the positive-side conductor 2 and the negative-side conductor 3 overlap each other. In consideration of this, a part of this diagonal portion is cut off. Also in the present embodiment, as in the first embodiment, a gap is provided between the negative electrode side conductor 32 and the positive electrode side conductor 22 so that no discharge occurs when a voltage is applied. Other configurations are the same as those of the first embodiment.
[0031]
According to the present embodiment, the diagonal portion is eliminated as compared with the positive electrode side conductor 2 and the negative electrode side conductor 3 of the first embodiment, so that the weight of the device can be reduced. Further, as in the first embodiment, the current flow paths are opposite to each other between the two conductors, and the generated magnetic flux is canceled out, so that the wiring inductance can be reduced as in the first embodiment. .
[0032]
FIG. 9 is a diagram showing the shapes of the positive electrode side conductor 23 and the negative electrode side conductor 33 according to the fourth embodiment of the present invention.
[0033]
The positive electrode side conductor 23 and the negative electrode side conductor 33 of the present embodiment have protrusions for connecting to the connecting portions 5 and 13 as compared with the one shown in FIG. 1 of the first embodiment. However, the positive electrode side conductor 23 is a rectangle having the same size as the negative electrode side conductor 33, and as shown by the dotted line in the figure, the connecting portion 5 between the negative electrode side conductor 33 and the DC smoothing capacitor 1. , Only the corner portion corresponding to the connection portion 13 with the inverter portion is cut out. The size cut out here is such that no discharge occurs between the positive electrode side conductor 23 and the connecting portion 5 and the connecting portion 13 when a voltage is applied between the conductors 23 and 33. Other configurations are the same as those of the first embodiment.
[0034]
According to this embodiment, compared with the positive electrode side conductor 2 and the negative electrode side conductor 3 of 1st Embodiment, the number of processes for producing both the conductors 23 and 33 can be reduced. In addition, as in the first embodiment, the effect of reducing the wiring inductance can be obtained.
[0035]
FIG. 10 is a diagram showing the shapes of the positive electrode side conductor 24 and the negative electrode side conductor 34 according to the fifth embodiment of the present invention.
[0036]
The positive electrode side conductor 24 and the negative electrode side conductor 34 of the present embodiment are narrower in width than the overlapping portion of the positive electrode side conductor 24 and the negative electrode side conductor 34 compared to the one shown in FIG. 1 of the first embodiment, The shape of both the conductors 24 and 34 is S-shaped. Other configurations are the same as those of the first embodiment.
[0037]
According to this embodiment, since the width of the overlapping portion is narrower than that of the positive electrode side conductor 2 and the negative electrode side conductor 3 of the first embodiment, the weight of the apparatus can be reduced, and the first embodiment and Similarly, the effect of reducing the wiring inductance can be obtained.
[0038]
FIG. 11 is a diagram showing the shapes of the positive electrode side conductor 25 and the negative electrode side conductor 35 according to the sixth embodiment of the present invention.
[0039]
In the figure, the positive electrode side conductor 25 is connected to the positive terminals of the DC smoothing capacitors 1 of the power converters 111 to 113 of each phase and the positive electrode side of the U phase converter 111. Of the V-phase conversion device 112, the connection portion 12v to the positive electrode side of the V-phase conversion device 112, and the projection portion provided corresponding to the connection portion 12w of the W-phase conversion device 113 to the positive electrode side. , Connecting portions 5u, 5v, 5w to the negative electrode terminal of each of the DC smoothing capacitors 1 described above, connecting portions 13u to the negative electrode side of the U-phase converter 111, and connecting portions to the negative electrode side of the V-phase converter 112 13v, and a protrusion provided corresponding to the connecting portion 13w with the negative electrode side of the W-phase converter 113.
[0040]
Comparing this embodiment with the first embodiment, the first embodiment is that the DC-side smoothing capacitor 1 for each phase and the converters 111 to 113 for each phase are respectively connected to the positive-side conductor 2 and the negative-side Whereas the conductor 3 is provided, in the present embodiment, a set of the positive electrode side conductor 25 and the negative electrode side conductor 35 shared between the DC smoothing capacitor for each phase and the conversion devices 111 to 113 for each phase are provided. It differs in that it is provided.
[0041]
12 (a) and 12 (b) are diagrams showing an example of the current distribution of the positive electrode side conductor 25 and the negative electrode side conductor 35 shown in FIG. 11, respectively, and FIG. 12 (a) shows each of the phases. Current distribution from the connecting portions 4u, 4v and 4w of the positive electrode terminal of the DC smoothing capacitor 1 to the connecting portions 12u, 12v and 12w on the positive side of the U-phase, V-phase and W-phase converters 111 to 113, FIG. (B) shows the connection portions 5u of the negative electrode terminals of the DC smoothing capacitors 1 of the respective phases from the connection portions 13u, 13v, 13w on the negative electrode side of the converters 111 to 113 of the U phase, the V phase, and the W phase. The current distribution to 5v and 5w is shown.
[0042]
According to the present embodiment, the common positive electrode side conductor 24 and negative electrode side conductor 34 are used for each of the U-phase, V-phase, and W-phase converters 111 to 113, so that the first to fifth embodiments are used. Compared to the power converter, the number of parts can be reduced, and the current is spread and distributed as in the first embodiment, so that the effect of decreasing the wiring inductance can be obtained. Furthermore, according to the present embodiment, since current is supplied from the three sets of positive electrode side connection portions 4u, 4v, 4w and negative electrode side connection portions 5u, 5v, 5w of the DC smoothing capacitor 1, further wiring is performed. Inductance can be reduced. In addition, the balance of current supply to the U-phase, V-phase, and W-phase power converters 111 to 113 of the inverter section is improved.
[0043]
FIG. 13 is a diagram showing the shapes of the positive electrode side conductor 26 and the negative electrode side conductor 36 according to the seventh embodiment of the present invention.
[0044]
In the figure, the positive side conductor 26 is connected to the positive terminal of a common DC smoothing capacitor not shown in the converters 111 to 113 for each phase, and connected to the positive side of the U-phase converter 111. 12u, a projecting portion provided corresponding to the connection portion 12v to the negative electrode side of the V phase conversion device 112 and the connection portion 12w to the negative electrode side of the W phase conversion device 113, and the negative electrode side conductor 36 Connection portion 5 with the negative electrode terminal of the DC smoothing capacitor, connection portion 13u with the negative electrode side of U-phase converter 111, connection portion 13v with the negative electrode side of V-phase converter 112, and negative electrode side of W-phase converter 113 The protrusion part provided according to the connection part 13w is provided.
[0045]
Comparing this embodiment with the first embodiment, the first embodiment is that the DC-side smoothing capacitor 1 for each phase and the converters 111 to 113 for each phase are respectively connected to the positive-side conductor 2 and the negative-side Whereas the conductor 3 is provided, in the present embodiment, a set of the positive electrode side conductor 26 and the negative electrode side conductor 36 shared by the DC smoothing capacitor shared by each phase and the converters 111 to 113 of each phase. Is different in that it is provided.
[0046]
14 (a) and 14 (b) are diagrams showing an example of the current distribution of the positive electrode side conductor 26 and the negative electrode side conductor 36 shown in FIG. 13, respectively, and FIG. 14 (a) is for one DC smoothing. FIG. 14B shows a current distribution from the connection portion 4 of the positive terminal of the capacitor to the connection portions 12u, 12v, and 12w on the positive side of the U-phase, V-phase, and W-phase converters 111 to 113. The current distribution from the connection part 13u, 13v, 13w by the side of the negative electrode of each converter 111-113 of a phase, V phase, and W phase to the connection part 5 of the negative electrode terminal of said one DC smoothing capacitor is shown.
[0047]
【The invention's effect】
According to the power conversion device of the present invention, the inductance between the DC smoothing capacitor and the inverter portion can be reduced with a simple configuration, and the capacity of the semiconductor element can be utilized to the maximum. Furthermore, it contributes to the reduction of the capacity of the snubber circuit for protecting the semiconductor element by suppressing the overvoltage or the snubber-less operation.
[Brief description of the drawings]
FIG. 1 is a front view showing an internal structure of one of phase conversion devices 111 to 113 according to a first embodiment of the present invention.
FIG. 2 is a side view of the internal structure shown in FIG.
FIG. 3 is a circuit configuration diagram showing a state where a power supply, a rectifier, and a motor load are connected to the power conversion apparatus according to the present embodiment.
4 is an equivalent circuit diagram of one of the phase conversion devices 111 to 113 shown in FIG. 3; FIG.
5 is a diagram showing a current distribution of the positive electrode side conductor 2 shown in FIGS. 1 and 2. FIG.
6 is a diagram showing a current distribution of the negative electrode side conductor 3 shown in FIGS. 1 and 2. FIG.
7 is a diagram showing shapes of a positive electrode side conductor 21 and a negative electrode side conductor 31 according to a second embodiment of the present invention. FIG.
FIG. 8 is a diagram showing shapes of a positive electrode side conductor 22 and a negative electrode side conductor 32 according to a third embodiment of the present invention.
FIG. 9 is a diagram showing shapes of a positive electrode side conductor and a negative electrode side conductor 33 according to a fourth embodiment of the present invention.
FIG. 10 is a diagram showing shapes of a positive electrode side conductor and a negative electrode side conductor according to a fifth embodiment of the present invention.
FIG. 11 is a diagram showing shapes of a positive electrode side conductor 25 and a negative electrode side conductor 35 according to a sixth embodiment of the present invention.
12 is a diagram showing a current distribution of the positive electrode side conductor 25 and the negative electrode side conductor 35 shown in FIG.
FIG. 13 is a diagram showing the shapes of a positive electrode side conductor and a negative electrode side conductor according to a seventh embodiment of the present invention.
14 is a diagram showing a current distribution of the positive electrode side conductor 26 and the negative electrode side conductor 36 shown in FIG.
[Explanation of symbols]
1 DC smoothing capacitor 2, 21, 22, 23, 24, 25, 26 Positive side conductor 3, 31, 32, 33, 34, 35, 36 Negative side conductor 4, 4u, 4v, 4w DC smoothing on positive side conductor Connection part 5, 5u, 5v, 5w with capacitor positive electrode terminal Connection part with negative electrode terminal of DC smoothing capacitor in negative electrode side conductor 6 Positive side conductor 7 Negative side conductor 8 AC side conductor 9 Positive side semiconductor element 10 Negative-side semiconductor element 11 Power converters 111, 112, 113 U-phase, V-phase, W-phase power converters 12, 12u, 12v, 12w Connection portions 13, 13u, 13v between the positive-side conductor and the positive-side conductor 13w Connection portion 14 between negative electrode side conductor and negative side conductor 14 Three-phase AC power supply 15 Rectifier 16 Motor load

Claims

At least an inverter unit comprising a combination of a plurality of semiconductor elements, a positive side terminal constituting the input side, a negative side terminal and an AC terminal constituting the output side, and between the positive side terminal and the negative side terminal In the power conversion device consisting of a DC smoothing capacitor connected via a positive electrode side conductor and a negative electrode side conductor,
The positive electrode side conductor and the negative electrode side conductor have a pair of connection portions at diagonal positions and are formed in a flat plate shape, and the conductor surfaces are arranged in the same direction so that the lines connecting the one set of connection portions intersect each other. Arranged in parallel with each other, and one connecting portion of each conductor is connected to the DC smoothing capacitor, and the other connecting portion of each conductor is connected to the positive terminal and the negative terminal. A power converter.

2. The power conversion according to claim 1, wherein a width parallel to a line connecting the one connection portions of the positive electrode side conductor and the negative electrode side conductor is larger than a distance between the one connection portions of the conductors. apparatus.

A multi-phase inverter unit composed of a plurality of inverter units each including at least a positive terminal that constitutes the input side, a negative side terminal, and an AC terminal that constitutes the output side; In the power converter comprising a DC smoothing capacitor connected between the positive terminal and the negative terminal of the inverter part of each phase via a positive conductor and a negative conductor, respectively.
The positive electrode side conductor and the negative electrode side conductor are shifted toward one end side of one side of each conductor, and the plurality of connection parts arranged in a distributed manner and the other end side of the side opposite to the one side of each conductor. Each conductor surface is formed in the same direction so that the lines connecting the one end side and the other end side of each conductor intersect with each other, having a plurality of other connection portions distributed and arranged in a flat plate shape. Arranged in parallel, and connecting the one plurality of connection portions of the conductors to the DC smoothing capacitors of the respective phases, and connecting the other plurality of connection portions of the conductors to the phase inverter portions of the respective phase inverter portions. A power converter connected to a positive terminal and the negative terminal.

A multi-phase inverter unit composed of a plurality of inverter units each including at least a positive terminal that constitutes the input side, a negative side terminal, and an AC terminal that constitutes the output side; In the power conversion device comprising a DC smoothing capacitor connected between the positive side terminal and the negative side terminal of the inverter part of each phase via a positive side conductor and a negative side conductor,
The positive electrode side conductor and the negative electrode side conductor are arranged in a distributed manner toward one end of one side of each conductor and the other end side of the side opposite to the one side of each conductor. In addition, the conductor surfaces are formed in a flat plate shape, and the conductor surfaces are arranged in parallel in the same direction so that the lines connecting the one end side and the other end side of each conductor intersect each other. And connecting the one connecting portion of each conductor to a DC smoothing capacitor and connecting the other plurality of connecting portions of each conductor to the positive terminal and the negative terminal of each phase inverter portion The power converter characterized by having performed.

5. The power conversion device according to claim 1, wherein the positive electrode side conductor and the negative electrode side conductor have substantially the same shape.