JP2004072886A

JP2004072886A - Ac -ac direct conversion device

Info

Publication number: JP2004072886A
Application number: JP2002228331A
Authority: JP
Inventors: Junichi Ito; 伊東　淳一; Ikuya Sato; 佐藤　以久也
Original assignee: Fuji Electric Holdings Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2002-08-06
Filing date: 2002-08-06
Publication date: 2004-03-04

Abstract

<P>PROBLEM TO BE SOLVED: To provide an AC-AC direct conversion device capable of realizing cost reduction and a simple structure by using a small number of power supplies with independent potentials. <P>SOLUTION: A plurality of AC switch circuits connected between AC inputs and outputs include a first and a second solid state switching devices 11, 12. An emitter of the plurality of first solid state switching elements 11 are connected to the same AC input phase, and the plurality of first solid state switching devices 11 are driven by using a first common power supply 64 with the potential of the AC input phase taken as a reference potential. The emitter of the plurality of secondary solid state switching devices 12 are connected to the same AC output phase, and the plurality of secondary solid state switching devices 12 are driven by using a second common power supply 64 with the potential of the AC output phase taken as the reference potential. Any AC switch circuit (e.g. 10RU) of the same structure is constituted by connecting the first and second solid state switching devices 11, 12 in reversed parallel. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、交流スイッチ回路のスイッチング動作により交流入力から直流に変換することなく直接、交流出力を得る交流交流直接変換装置に関し、特に、交流スイッチ回路及びその駆動用電源の接続構成に特徴を有する交流交流直接変換装置に関するものである。
【０００２】
【従来の技術】
図４は、３相入力／３相出力の交流交流直接変換装置としての、いわゆるマトリクスコンバータの構成を示している。ここで、マトリクスコンバータをはじめとする交流交流直接変換装置は、直流段を必要とせず、大容量のコンデンサやリアクトル等のエネルギー蓄積要素が不要であって装置の小型軽量化、低価格化が可能であるため、多相交流電動機等の電源としてしばしば用いられている。
以下では、マトリクスコンバータの３相交流電源２００側の交流入力相をＲ，Ｓ，Ｔ相、負荷３００側の交流出力相をＵ，Ｖ，Ｗ相と称して説明する。
【０００３】
一般に、マトリクスコンバータでは、図４に示すように２個の単方向の半導体スイッチング素子１０３，１０４を組み合わせて交流スイッチ回路（双方向スイッチ回路）１０２を構成し、出力電圧波形や入力電流波形を制御している。なお、各スイッチング素子１０３，１０４は、例えば、環流ダイオードが逆並列接続されたＩＧＢＴ（絶縁ゲートバイポーラトランジスタ）によって構成されている。
【０００４】
ここで、各スイッチング素子１０３，１０４は、電源の短絡や誘導性負荷の開放を防止するべく電源電圧や負荷電流の極性に応じてそれぞれ独立にスイッチングを行う必要があるため、個別の駆動回路１０６，１０７によって駆動されるようになっている。
また、駆動回路１０６，１０７の電源は絶縁電源１０８から供給されており、これらの駆動回路１０６，１０７及び絶縁電源１０８によって駆動ユニット１０５が構成されている。駆動回路１０６，１０７の入力ｐは、図示されていない制御装置により、所望の出力電圧や入力電流を得るために生成されたＰＷＭパルスである。
【０００５】
そして、交流スイッチ回路１０２及び駆動ユニット１０５が３相分設けられて一つのスイッチ群１０１Ｒが構成され、このスイッチ群１０１Ｒ内の３個の交流スイッチ回路１０２の一端が一括してＲ相端子に接続されると共に、３個の交流スイッチ回路１０２の他端がそれぞれＵ，Ｖ，Ｗ相端子に接続されている。
また、スイッチ群１０１Ｒと同一構成のスイッチ群１０１Ｓ，１０１Ｔが構成され、内部の各交流スイッチ回路１０２は、スイッチ群１０１Ｒと同様にしてＳ，Ｔ相端子、Ｕ，Ｖ，Ｗ相端子にそれぞれ接続されている。
【０００６】
このように、図４の構成では、スイッチ群１０１Ｒ，１０１Ｓ，１０１Ｔについて、各３個の交流スイッチ回路１０２と同数の絶縁電源１０８が必要であり、全体では合計９個の絶縁電源１０８が必要となる。
【０００７】
なお、図４では省略したが、絶縁電源１０８の入力は、絶縁電源の方式に応じて交流電圧でも直流電圧でもよく、いずれにしても共通の電源から各絶縁電源１０８へ電力が供給されるようになっている。
【０００８】
【発明が解決しようとする課題】
上記のように、従来の交流交流直接変換装置では、交流スイッチ回路一つにつき一つの独立電位の電源（前述した絶縁電源１０８）を必要とするため、駆動用電源の数が多く、コスト高の原因となっていた。
そこで本発明は、少数の独立電位の電源を使用して半導体スイッチング素子を駆動可能とした、低コストかつ構成簡単な交流交流直接変換装置を提供しようとするものである。
【０００９】
【課題を解決するための手段】
上記課題を解決するため、請求項１に記載した発明は、交流スイッチ回路のスイッチング動作により交流入力を直接、交流出力に変換する交流交流直接変換装置において、
交流入力相と交流出力相との間にそれぞれ接続される複数の交流スイッチ回路が第１，第２の半導体スイッチング素子を備え、複数の第１の半導体スイッチング素子の電流流出側電極を同一の交流入力相に接続すると共に、当該交流入力相の電位を基準電位とする第１の共通電源を用いて前記複数の第１の半導体スイッチング素子を駆動し、かつ、複数の第２の半導体スイッチング素子の電流流出側電極を同一の交流出力相に接続すると共に、当該交流出力相の電位を基準電位とする第２の共通電源を用いて前記複数の第２の半導体スイッチング素子を駆動する交流交流直接変換装置であって、
前記交流スイッチ回路を、第１の半導体スイッチング素子と第２の半導体スイッチング素子とを逆並列接続して構成したものである。
【００１０】
請求項２に記載した発明は、前記交流スイッチ回路を、第１の半導体スイッチング素子と第１のダイオードとの順方向直列接続回路と、第２の半導体スイッチング素子と第２のダイオードとの順方向直列接続回路とを、逆並列接続して構成したものである。
【００１１】
請求項３に記載した発明は、前記交流スイッチ回路を、第１の半導体スイッチング素子と第１のダイオードとの逆並列接続回路と、第２の半導体スイッチング素子と第２のダイオードとの逆並列接続回路とによって構成し、第１，第２のダイオードのカソード同士を接続したものである。
【００１２】
請求項４に記載した発明では、請求項１，２または３に記載した交流交流直接変換装置において、交流入力相（例えばＲ，Ｓ，Ｔの３相とする）の各相と交流出力相（例えばＵ，Ｖ，Ｒの３相とする）の各相との間にそれぞれ交流スイッチ回路を接続する。
更に、同一の交流入力相（例えばＲ相）にそれぞれ接続される交流出力相数（３相）分の交流スイッチ回路内の第１の半導体スイッチング素子の電流流出側電極（例えばエミッタ）を、当該交流入力相（Ｒ相）にそれぞれ接続し、同一の交流出力相（例えばＵ相）にそれぞれ接続される交流入力相数（３相）分の交流スイッチ回路内の第２の半導体スイッチング素子の電流流出側電極を、当該交流出力相（Ｕ相）にそれぞれ接続する。同様にして、他の交流入力相（Ｓ，Ｔ相）または他の交流出力相（Ｖ，Ｗ相）に接続される交流スイッチ回路についても、第１，第２の半導体スイッチング素子の電流流出側電極を該当する交流入力相（Ｓ相またはＴ相）、交流出力相（Ｖ相またはＷ相）にそれぞれ接続するものである。
【００１３】
【発明の実施の形態】
以下、図に沿って本発明の実施形態を説明する。
図１は本発明の第１実施形態を示す構成図であり、請求項１，４に記載した発明の実施形態に相当する。この実施形態に係る交流交流直接変換装置は、図４と同様に３相入力／３相出力のマトリクスコンバータであり、３相交流電源２００側のＲ，Ｓ，Ｔ相端子と負荷３００側のＵ，Ｖ，Ｗ相端子との間に接続される。
【００１４】
図１において、１０ＲＵ，１０ＲＶ，１０ＲＷ，１０ＳＵ，１０ＳＶ，１０ＳＷ，１０ＴＵ，１０ＴＶ，１０ＴＷは何れも同一構成の交流スイッチ回路であり、これらのスイッチ回路は、ＩＧＢＴ等の単方向の半導体スイッチング素子１１，１２を逆並列に接続して構成されている。なお、便宜的に、半導体スイッチング素子１１を第１の半導体スイッチング素子、同１２を第２の半導体スイッチング素子とする。
【００１５】
これらの半導体スイッチング素子１１，１２の駆動回路の基準電位は、各々の電流流出側電極としてのエミッタの電位に等しくなるため、Ｒ，Ｓ，Ｔ相、Ｕ，Ｖ，Ｗ相の各相について、図示するように半導体スイッチング素子１１のエミッタ、半導体スイッチング素子１２のエミッタをそれぞれ共通接続してこれらのエミッタが各駆動回路の基準電位となるようにすれば、この基準電位を有する共通の電源を各駆動回路の電源とすることができる。
【００１６】
図１において、６０Ｒ，６０Ｓ，６０Ｔ，６０Ｕ，６０Ｖ，６０Ｗは同一構成の駆動ユニットであり、駆動ユニット６０Ｒとして例示されているように、駆動回路６１，６２，６３及び絶縁電源６４から構成されている。また、駆動回路６１，６２，６３の入力ｐは、前記同様に制御装置（図示せず）によって所望の出力電圧や入力電流を得るために生成されたＰＷＭパルスである。
【００１７】
ここで、各交流スイッチ回路と駆動ユニットとの接続状態を説明すると、例えば３相交流電源２００のＲ相端子に、交流スイッチ回路１０ＲＵ，１０ＲＶ，１０ＲＷ内の半導体スイッチング素子１１，１１，１１のエミッタを接続し、このエミッタを、駆動ユニット６０Ｒ内の駆動回路６１，６２，６３に接続して基準電位とする。なお、駆動回路６１，６２，６３は、それぞれ交流スイッチ回路１０ＲＵ，１０ＲＶ，１０ＲＷ内の半導体スイッチング素子１１，１１，１１を駆動するためのものである。
また、前記エミッタは単一かつ共通の絶縁電源６４の基準電位としてこの絶縁電源６４に接続されており、絶縁電源６４から各駆動回路６１，６２，６３に電源が供給されている。
【００１８】
同様にして、３相交流電源２００のＳ相端子に、交流スイッチ回路１０ＳＵ，１０ＳＶ，１０ＳＷ内の半導体スイッチング素子１１，１１，１１のエミッタを接続し、このエミッタを、駆動ユニット６０Ｓ内の駆動回路６１，６２，６３（図示せず）に接続して基準電位とする。また、これらのエミッタを駆動ユニット６０Ｓ内の単一の絶縁電源６４（図示せず）の基準電位として接続し、この絶縁電源６４から各駆動回路６１，６２，６３に電源を供給するものである。
３相交流電源２００のＴ相端子についても同様であり、駆動ユニット６０Ｔ内の単一の絶縁電源６４により、駆動回路６１，６２，６３（何れも図示せず）を介して交流スイッチ回路１０ＴＵ，１０ＴＶ，１０ＴＷ内の半導体スイッチング素子１１，１１，１１が駆動される。
【００１９】
ここで、駆動ユニット６０Ｒ，６０Ｓ，６０Ｔ内の絶縁電源６４は、請求項に記載した第１の共通電源に相当している。
【００２０】
更に、負荷３００側のＵ，Ｖ，Ｗ相については、例えば、Ｕ相端子に交流スイッチ回路１０ＲＵ，１０ＳＵ，１０ＴＵ内の半導体スイッチング素子１２，１２，１２のエミッタが共通接続され、このエミッタが駆動ユニット６０Ｕ内の駆動回路６１，６２，６３（図示せず）に接続されて基準電位となる。前記エミッタは駆動ユニット６０Ｕ内の単一の絶縁電源６４（図示せず）の基準電位としてこの絶縁電源６４に接続され、絶縁電源６４から各駆動回路６１，６２，６３に電源が供給されている。
【００２１】
他のＶ相，Ｗ相についても同様であり、駆動ユニット６０Ｖ，６０Ｗ内のそれぞれ単一の絶縁電源６４により駆動回路６１，６２，６３（何れも図示せず）を介して交流スイッチ回路１０ＲＶ，１０ＳＶ，１０ＴＶ、及び１０ＲＷ，１０ＳＷ，１０ＴＷ内の半導体スイッチング素子１２，１２，１２が駆動されるものである。
【００２２】
ここで、駆動ユニット６０Ｕ，６０Ｖ，６０Ｗ内の絶縁電源６４は、請求項に記載した第２の共通電源に相当している。
【００２３】
以上のようにこの実施形態では、３相電源２００のＲ相にエミッタが接続される第１の半導体スイッチング素子１１，１１，１１の絶縁電源６４（第１の共通電源）の基準電位をＲ相電位とし、Ｓ相にエミッタが接続される第１の半導体スイッチング素子１１，１１，１１の絶縁電源６４（第１の共通電源）の基準電位をＳ相電位とし、Ｔ相にエミッタが接続される第１の半導体スイッチング素子１１，１１，１１の絶縁電源６４（第１の共通電源）の基準電位をＴ相電位としている。
また、負荷３００のＵ相にエミッタが接続される第２の半導体スイッチング素子１２，１２，１２の絶縁電源６４（第２の共通電源）の基準電位をＵ相電位とし、Ｖ相にエミッタが接続される第２の半導体スイッチング素子１２，１２，１２の絶縁電源６４（第２の共通電源）の基準電位をＶ相電位とし、Ｗ相にエミッタが接続される第２の半導体スイッチング素子１２，１２，１２の絶縁電源６４（第２の共通電源）の基準電位をＷ相電位としている。
これにより、３相入力／３相出力の場合に、基準電位として独立電位を有する電源を従来の９個から６個に減少させることができ、コストの低減や回路構成の簡略化が可能になる。
【００２４】
次に、図２は本発明の第２実施形態を示すものであり、請求項２，４に記載した発明の実施形態に相当する。
図２において、３０ＲＵ，３０ＲＶ，３０ＲＷ，３０ＳＵ，３０ＳＶ，３０ＳＷ，３０ＴＵ，３０ＴＶ，３０ＴＷは何れも同一構成の交流スイッチ回路であり、これらのスイッチ回路は、ＩＧＢＴ等の単方向の半導体スイッチング素子１１，１２とダイオード２１，２２とから構成されている。すなわち、半導体スイッチング素子１１のコレクタにダイオード２１のカソードを接続し、そのアノードを半導体スイッチング素子１２のエミッタに接続すると共に、半導体スイッチング素子１２のコレクタにダイオード２２のカソードを接続し、そのアノードを半導体スイッチング素子１１のエミッタに接続して構成される。
なお、半導体スイッチング素子１１を第１の半導体スイッチング素子、同１２を第２の半導体スイッチング素子、ダイオード２１を第１のダイオード、ダイオード２２を第２のダイオードとする。
【００２５】
交流スイッチ回路３０ＲＵ，３０ＲＶ，３０ＲＷ内の半導体スイッチング素子１１のエミッタをＲ相端子に共通接続して駆動ユニット６０Ｒ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路３０ＳＵ，３０ＳＶ，３０ＳＷ内の半導体スイッチング素子１１のエミッタをＳ相端子に共通接続して駆動ユニット６０Ｓ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路３０ＴＵ，３０ＴＶ，３０ＴＷ内の半導体スイッチング素子１１のエミッタをＴ相端子に共通接続して駆動ユニット６０Ｔ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点は、図１の実施形態と同様である。
【００２６】
また、交流スイッチ回路３０ＲＵ，３０ＳＵ，３０ＴＵ内の半導体スイッチング素子１２のエミッタをＵ相端子に共通接続して駆動ユニット６０Ｕ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路３０ＲＶ，３０ＳＶ，３０ＴＶ内の半導体スイッチング素子１２のエミッタをＶ相端子に共通接続して駆動ユニット６０Ｖ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路３０ＲＷ，３０ＳＷ，３０ＴＷ内の半導体スイッチング素子１２のエミッタをＷ相端子に共通接続して駆動ユニット６０Ｗ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点も、図１の実施形態と同様である。
【００２７】
この実施形態は、単方向の半導体スイッチング素子１１，１２の逆耐圧能力が低い場合のものであり、各スイッチング素子１１，１２にそれぞれ順方向接続されるダイオード２１，２２によって逆耐圧特性を向上させている。
本実施形態においても、３相入力／３相出力の場合に、基準電位として独立電位を有する電源を６個にすることができ、コストの低減や回路構成の簡略化が可能になる。
【００２８】
次いで、図３は本発明の第３実施形態を示しており、請求項３，４に記載した発明の実施形態に相当する。
図３において、４０ＲＵ，４０ＲＶ，４０ＲＷ，４０ＳＵ，４０ＳＶ，４０ＳＷ，４０ＴＵ，４０ＴＶ，４０ＴＷは何れも同一構成の交流スイッチ回路であり、これらのスイッチ回路は、半導体スイッチング素子１１，１２を逆方向に直列接続し、各スイッチング素子１１，１２に対して逆並列に還流ダイオード２１，２２をそれぞれ接続して構成されている。
なお、図２と同様に半導体スイッチング素子１１を第１の半導体スイッチング素子、同１２を第２の半導体スイッチング素子、ダイオード２１を第１のダイオード、ダイオード２２を第２のダイオードとする。
【００２９】
交流スイッチ回路４０ＲＵ，４０ＲＶ，４０ＲＷ内の半導体スイッチング素子１１のエミッタをＲ相端子に共通接続して駆動ユニット６０Ｒ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路４０ＳＵ，４０ＳＶ，４０ＳＷ内の半導体スイッチング素子１１のエミッタをＳ相端子に共通接続して駆動ユニット６０Ｓ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路４０ＴＵ，４０ＴＶ，４０ＴＷ内の半導体スイッチング素子１１のエミッタをＴ相端子に共通接続して駆動ユニット６０Ｔ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点は、図１、図２の実施形態と同様である。
【００３０】
また、交流スイッチ回路４０ＲＵ，４０ＳＵ，４０ＴＵ内の半導体スイッチング素子１２のエミッタをＵ相端子に共通接続して駆動ユニット６０Ｕ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路４０ＲＶ，４０ＳＶ，４０ＴＶ内の半導体スイッチング素子１２のエミッタをＶ相端子に共通接続して駆動ユニット６０Ｖ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点、交流スイッチ回路４０ＲＷ，４０ＳＷ，４０ＴＷ内の半導体スイッチング素子１２のエミッタをＷ相端子に共通接続して駆動ユニット６０Ｗ内の駆動回路６１，６２，６３及び絶縁電源６４に接続する点も、図１、図２の実施形態と同様である。
【００３１】
この実施形態においても、３相入力／３相出力の場合に、基準電位として独立電位を有する電源を６個にすることができ、コストの低減や回路構成の簡略化が可能になる。また、交流スイッチ回路４０ＲＵ，４０ＲＶ，４０ＲＷ，４０ＳＵ，４０ＳＶ，４０ＳＷ，４０ＴＵ，４０ＴＶ，４０ＴＷとして、図４に示した従来技術の交流スイッチ回路１０２をそのまま利用可能である。
【００３２】
なお、上記各実施形態では、共通電源として絶縁電源６４を用いているが、線間電圧を利用したシリーズレギュレータ等の電源でもよい。
また、各実施形態では半導体スイッチング素子１１，１２としてＩＧＢＴを使用した場合を説明したが、ＭＯＳＦＥＴ等の電圧駆動型デバイスを使用しても良い。
更に、本発明は、３相入力／３相出力に限定されるものではなく、それ以外の多相入力／多相出力の交流交流直接変換装置に適用可能である。
【００３３】
【発明の効果】
以上のように本発明によれば、交流交流直接変換装置において単方向の半導体スイッチング素子を用いて交流スイッチ回路を構成する際に、各半導体スイッチング素子の電流流出側電極を交流入力相（交流電源側）及び交流出力相（負荷側）に接続することにより、電流流出側電極の電位を電源の基準電位とすることができ、独立電位を有する電源の数を従来よりも減少させることができる。
この結果、交流交流直接変換装置の回路構成の簡略化、並びにコストの低減が可能になる。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示す回路構成図である。
【図２】本発明の第２実施形態を示す回路構成図である。
【図３】本発明の第３実施形態を示す回路構成図である。
【図４】従来技術としてのマトリクスコンバータの回路構成図である。
【符号の説明】
１０ＲＵ，１０ＲＶ，１０ＲＷ，１０ＳＵ，１０ＳＶ，１０ＳＷ，１０ＴＵ，１０ＴＶ，１０ＴＷ：交流スイッチ回路
１１，１２：半導体スイッチング素子
２１，２２：ダイオード
３０ＲＵ，３０ＲＶ，３０ＲＷ，３０ＳＵ，３０ＳＶ，３０ＳＷ，３０ＴＵ，３０ＴＶ，３０ＴＷ：交流スイッチ回路
４０ＲＵ，４０ＲＶ，４０ＲＷ，４０ＳＵ，４０ＳＶ，４０ＳＷ，４０ＴＵ，４０ＴＶ，４０ＴＷ：交流スイッチ回路
６０Ｒ，６０Ｓ，６０Ｔ，６０Ｕ，６０Ｖ，６０Ｗ：駆動ユニット
６１，６２，６３：駆動回路
６４：絶縁電源
２００：３相交流電源
３００：負荷[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an AC / AC direct conversion device that directly obtains an AC output without converting an AC input to a DC by a switching operation of an AC switch circuit, and particularly has a feature in a connection configuration of an AC switch circuit and a power supply for driving the AC switch circuit. The present invention relates to an AC / AC direct conversion device.
[0002]
[Prior art]
FIG. 4 shows a configuration of a so-called matrix converter as a three-phase input / 3-phase output AC / AC direct conversion device. Here, AC / AC direct conversion devices such as matrix converters do not require a DC stage, and do not require energy storage elements such as large-capacity capacitors and reactors, making it possible to reduce the size, weight, and cost of the device. Therefore, it is often used as a power source for a polyphase AC motor or the like.
Hereinafter, the AC input phase on the three-phase AC power supply 200 side of the matrix converter will be referred to as R, S, T phases, and the AC output phase on the load 300 side will be referred to as U, V, W phases.
[0003]
Generally, in a matrix converter, an AC switch circuit (bidirectional switch circuit) 102 is formed by combining two unidirectional semiconductor switching elements 103 and 104 as shown in FIG. 4 to control an output voltage waveform and an input current waveform. are doing. Each of the switching elements 103 and 104 is configured by, for example, an IGBT (insulated gate bipolar transistor) in which a free-wheeling diode is connected in anti-parallel.
[0004]
Here, since each of the switching elements 103 and 104 needs to perform switching independently according to the polarity of the power supply voltage and the load current in order to prevent the short circuit of the power supply and the opening of the inductive load, the individual drive circuits 106 , 107.
The power of the drive circuits 106 and 107 is supplied from an insulated power supply 108, and the drive circuits 106 and 107 and the insulated power supply 108 constitute a drive unit 105. Inputs p of the drive circuits 106 and 107 are PWM pulses generated by a control device (not shown) to obtain desired output voltages and input currents.
[0005]
The AC switch circuit 102 and the drive unit 105 are provided for three phases to form one switch group 101R. One end of the three AC switch circuits 102 in the switch group 101R is collectively connected to the R-phase terminal. In addition, the other ends of the three AC switch circuits 102 are connected to U, V, and W phase terminals, respectively.
Also, switch groups 101S and 101T having the same configuration as the switch group 101R are configured, and the respective internal AC switch circuits 102 are connected to S, T phase terminals, U, V, and W phase terminals in the same manner as the switch group 101R. Have been.
[0006]
As described above, in the configuration of FIG. 4, the switch groups 101R, 101S, and 101T require the same number of insulated power supplies 108 as the three AC switch circuits 102, and a total of nine insulated power supplies 108 are required. Become.
[0007]
Although not shown in FIG. 4, the input of the insulated power supply 108 may be an AC voltage or a DC voltage depending on the type of the insulated power supply. In any case, power is supplied from the common power supply to each of the insulated power supplies 108. It has become.
[0008]
[Problems to be solved by the invention]
As described above, the conventional AC / AC direct converter requires one power supply having an independent potential (the above-described insulated power supply 108) for each AC switch circuit, so that the number of driving power supplies is large and cost is high. Was the cause.
Accordingly, an object of the present invention is to provide a low-cost and simple-structure AC / AC direct conversion device that can drive a semiconductor switching element using a small number of power supplies with independent potentials.
[0009]
[Means for Solving the Problems]
In order to solve the above problem, an invention according to claim 1 is an AC / AC direct conversion device that directly converts an AC input into an AC output by a switching operation of an AC switch circuit,
A plurality of AC switch circuits respectively connected between the AC input phase and the AC output phase include first and second semiconductor switching elements, and a current outflow side electrode of the plurality of first semiconductor switching elements is connected to the same AC. Connected to the input phase, and driving the plurality of first semiconductor switching elements using a first common power supply having the potential of the AC input phase as a reference potential; AC / AC direct conversion in which a current outflow side electrode is connected to the same AC output phase, and the plurality of second semiconductor switching elements are driven using a second common power supply having a potential of the AC output phase as a reference potential. A device,
The AC switch circuit is configured by connecting a first semiconductor switching element and a second semiconductor switching element in antiparallel.
[0010]
According to a second aspect of the present invention, the AC switch circuit includes a forward series connection circuit of a first semiconductor switching element and a first diode, and a forward connection of a second semiconductor switching element and a second diode. And a series connection circuit connected in anti-parallel.
[0011]
According to a third aspect of the present invention, the AC switch circuit includes an anti-parallel connection circuit of a first semiconductor switching element and a first diode, and an anti-parallel connection of a second semiconductor switching element and a second diode. And a circuit in which the cathodes of the first and second diodes are connected to each other.
[0012]
According to the invention described in claim 4, in the AC-AC direct conversion device described in claim 1, 2, or 3, each of the AC input phases (for example, three phases of R, S, and T) and the AC output phase ( An AC switch circuit is connected to each of the three phases (for example, three phases of U, V, and R).
Further, the current outflow-side electrodes (eg, emitters) of the first semiconductor switching elements in the AC switch circuits for the number of AC output phases (three phases) connected to the same AC input phase (eg, R phase) are connected to the same. The current of the second semiconductor switching element in the AC switch circuit for the number of AC input phases (three phases) connected to the AC input phase (R phase) and connected to the same AC output phase (for example, U phase). The outflow-side electrodes are connected to the AC output phase (U-phase). Similarly, for an AC switch circuit connected to another AC input phase (S, T phase) or another AC output phase (V, W phase), the current outflow side of the first and second semiconductor switching elements is also used. The electrodes are connected to the corresponding AC input phase (S phase or T phase) and the AC output phase (V phase or W phase).
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing a first embodiment of the present invention, and corresponds to the first and fourth embodiments of the present invention. The AC / AC direct conversion device according to this embodiment is a three-phase input / three-phase output matrix converter as in FIG. , V, W phase terminals.
[0014]
1, 10RU, 10RV, 10RW, 10SU, 10SV, 10SW, 10TU, 10TV, 10TW are all AC switch circuits having the same configuration. These switch circuits are unidirectional semiconductor switching elements 11, such as IGBTs. 12 are connected in anti-parallel. Note that, for convenience, the semiconductor switching element 11 is a first semiconductor switching element, and the semiconductor switching element 12 is a second semiconductor switching element.
[0015]
Since the reference potential of the drive circuit of these semiconductor switching elements 11 and 12 becomes equal to the potential of the emitter as each current outflow side electrode, for each of the R, S, T, U, V, and W phases, As shown, if the emitter of the semiconductor switching element 11 and the emitter of the semiconductor switching element 12 are commonly connected so that these emitters become the reference potential of each drive circuit, a common power supply having this reference potential is connected to each It can be used as a power supply for a driving circuit.
[0016]
In FIG. 1, 60R, 60S, 60T, 60U, 60V, and 60W are drive units having the same configuration, and include drive circuits 61, 62, 63 and an insulated power supply 64 as exemplified as the drive unit 60R. I have. The input p of the drive circuits 61, 62, 63 is a PWM pulse generated in order to obtain a desired output voltage or input current by a control device (not shown) as described above.
[0017]
Here, the connection state between each AC switch circuit and the drive unit will be described. For example, the emitters of the semiconductor switching elements 11, 11, 11 in the AC switch circuits 10RU, 10RV, 10RW are connected to the R-phase terminal of the three-phase AC power supply 200. And this emitter is connected to the drive circuits 61, 62, and 63 in the drive unit 60R to make it a reference potential. The drive circuits 61, 62, 63 are for driving the semiconductor switching elements 11, 11, 11 in the AC switch circuits 10RU, 10RV, 10RW, respectively.
Further, the emitter is connected to the insulation power supply 64 as a reference potential of a single and common insulation power supply 64, and power is supplied from the insulation power supply 64 to each of the drive circuits 61, 62, 63.
[0018]
Similarly, the emitters of the semiconductor switching elements 11, 11, 11 in the AC switch circuits 10SU, 10SV, 10SW are connected to the S-phase terminal of the three-phase AC power supply 200, and this emitter is connected to the drive circuit in the drive unit 60S. 61, 62, and 63 (not shown) to set a reference potential. Further, these emitters are connected as a reference potential of a single insulated power supply 64 (not shown) in the drive unit 60S, and power is supplied from the insulated power supply 64 to each of the drive circuits 61, 62, 63. .
The same applies to the T-phase terminal of the three-phase AC power supply 200. The single insulated power supply 64 in the drive unit 60T drives the AC switch circuits 10TU, 10TU, via drive circuits 61, 62, 63 (none of which are shown). The semiconductor switching elements 11, 11, 11 in 10TV, 10TW are driven.
[0019]
Here, the insulated power supply 64 in the drive units 60R, 60S, 60T corresponds to a first common power supply described in claims.
[0020]
Further, for the U, V, and W phases on the load 300 side, for example, the emitters of the semiconductor switching elements 12, 12, and 12 in the AC switch circuits 10RU, 10SU, and 10TU are commonly connected to the U-phase terminal, and this emitter is driven. It is connected to the drive circuits 61, 62, 63 (not shown) in the unit 60U and becomes a reference potential. The emitter is connected to a single insulation power supply 64 (not shown) in the drive unit 60U as a reference potential of the insulation power supply 64, and power is supplied from the insulation power supply 64 to each of the drive circuits 61, 62, and 63. .
[0021]
The same applies to other V-phases and W-phases. The AC switch circuits 10RV, 10RV, are driven by drive circuits 61, 62, 63 (all not shown) by a single insulated power supply 64 in the drive units 60V, 60W. The semiconductor switching elements 12, 12, 12 in 10SV, 10TV, and 10RW, 10SW, 10TW are driven.
[0022]
Here, the insulated power supply 64 in the drive units 60U, 60V, 60W corresponds to a second common power supply described in claims.
[0023]
As described above, in this embodiment, the reference potential of the insulated power supply 64 (first common power supply) of the first semiconductor switching elements 11, 11, 11 whose emitters are connected to the R phase of the three-phase power supply 200 is set to the R phase. Potential, the reference potential of the insulated power supply 64 (first common power supply) of the first semiconductor switching elements 11, 11, 11 whose emitters are connected to the S phase is the S phase potential, and the emitter is connected to the T phase. The reference potential of the insulated power supply 64 (first common power supply) of the first semiconductor switching elements 11, 11, 11 is a T-phase potential.
The reference potential of the insulated power supply 64 (second common power supply) of the second semiconductor switching elements 12, 12, 12 whose emitters are connected to the U phase of the load 300 is set to the U phase potential, and the emitter is connected to the V phase. The reference potential of the insulated power supply 64 (second common power supply) of the second semiconductor switching elements 12, 12, 12 is set to the V-phase potential, and the second semiconductor switching elements 12, 12, the emitters of which are connected to the W-phase. , 12 have a W-phase potential as a reference potential.
As a result, in the case of three-phase input / three-phase output, the number of power supplies having independent potentials as reference potentials can be reduced from nine to six in the related art, which enables cost reduction and simplification of the circuit configuration. .
[0024]
Next, FIG. 2 shows a second embodiment of the present invention, and corresponds to the second and fourth embodiments of the present invention.
2, 30RU, 30RV, 30RW, 30SU, 30SV, 30SW, 30TU, 30TV, 30TW are all AC switch circuits having the same configuration, and these switch circuits are unidirectional semiconductor switching elements 11, such as IGBTs. 12 and diodes 21 and 22. That is, the cathode of the diode 21 is connected to the collector of the semiconductor switching element 11, the anode is connected to the emitter of the semiconductor switching element 12, the cathode of the diode 22 is connected to the collector of the semiconductor switching element 12, and the anode is connected to the semiconductor. The switching element 11 is connected to the emitter.
The semiconductor switching element 11 is a first semiconductor switching element, the semiconductor switching element 12 is a second semiconductor switching element, the diode 21 is a first diode, and the diode 22 is a second diode.
[0025]
The point that the emitters of the semiconductor switching elements 11 in the AC switch circuits 30RU, 30RV, 30RW are commonly connected to the R-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60R. , 30SV, 30SW in that the emitters of the semiconductor switching elements 11 are commonly connected to the S-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60S, and the AC switch circuits 30TU, 30TV, 30TW. 1 is similar to the embodiment of FIG. 1 in that the emitter of the semiconductor switching element 11 is commonly connected to the T-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60T.
[0026]
Also, the point that the emitters of the semiconductor switching elements 12 in the AC switch circuits 30RU, 30SU, 30TU are commonly connected to the U-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60U, The point that the emitters of the semiconductor switching elements 12 in the circuits 30RV, 30SV, 30TV are commonly connected to the V-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60V, and the AC switch circuits 30RW, 30SW. , 30TW, the emitters of the semiconductor switching elements 12 are commonly connected to the W-phase terminals and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60W in the same manner as in the embodiment of FIG. .
[0027]
In this embodiment, the unidirectional semiconductor switching elements 11 and 12 have a low reverse withstand voltage capability. Diodes 21 and 22 connected to the respective switching elements 11 and 12 in the forward direction improve the reverse withstand voltage characteristics. ing.
Also in this embodiment, in the case of three-phase input / three-phase output, the number of power supplies having independent potentials as reference potentials can be reduced to six, so that cost can be reduced and the circuit configuration can be simplified.
[0028]
Next, FIG. 3 shows a third embodiment of the present invention, which corresponds to the third and fourth embodiments of the present invention.
In FIG. 3, 40RU, 40RV, 40RW, 40SU, 40SV, 40SW, 40TU, 40TV, 40TW are all AC switch circuits having the same configuration, and these switch circuits connect the semiconductor switching elements 11 and 12 in series in opposite directions. The switching diodes 11 and 12 are connected in reverse parallel to the switching elements 11 and 12, respectively.
2, the semiconductor switching element 11 is a first semiconductor switching element, the semiconductor switching element 12 is a second semiconductor switching element, the diode 21 is a first diode, and the diode 22 is a second diode.
[0029]
The point that the emitters of the semiconductor switching elements 11 in the AC switch circuits 40RU, 40RV, 40RW are commonly connected to the R-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60R. , 40SV, 40SW, the emitters of the semiconductor switching elements 11 are commonly connected to the S-phase terminals and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60S, and the AC switch circuits 40TU, 40TV, 40TW. 1 and FIG. 2 in that the emitters of the semiconductor switching elements 11 are commonly connected to the T-phase terminals and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60T. is there.
[0030]
Also, the point that the emitters of the semiconductor switching elements 12 in the AC switch circuits 40RU, 40SU, and 40TU are commonly connected to the U-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60U. The point that the emitters of the semiconductor switching elements 12 in the circuits 40RV, 40SV, 40TV are commonly connected to the V-phase terminal and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60V, and the AC switch circuits 40RW, 40SW. , 40TW, the emitters of the semiconductor switching elements 12 are commonly connected to the W-phase terminals and connected to the drive circuits 61, 62, 63 and the insulated power supply 64 in the drive unit 60W. The same is true.
[0031]
Also in this embodiment, in the case of three-phase input / three-phase output, the number of power supplies having independent potentials as reference potentials can be reduced to six, so that cost can be reduced and the circuit configuration can be simplified. Further, the AC switch circuit 102 of the related art shown in FIG. 4 can be used as it is as the AC switch circuits 40RU, 40RV, 40RW, 40SU, 40SV, 40SW, 40TU, 40TV, 40TW.
[0032]
In the above embodiments, the insulated power supply 64 is used as the common power supply, but a power supply such as a series regulator using line voltage may be used.
In each embodiment, the case where the IGBT is used as the semiconductor switching elements 11 and 12 has been described. However, a voltage-driven device such as a MOSFET may be used.
Furthermore, the present invention is not limited to three-phase input / three-phase output, but can be applied to other multi-phase input / multi-phase output AC / AC direct conversion devices.
[0033]
【The invention's effect】
As described above, according to the present invention, when configuring an AC switch circuit using unidirectional semiconductor switching elements in an AC / AC direct converter, the current outflow-side electrodes of each semiconductor switching element are connected to an AC input phase (AC power supply). Side) and the AC output phase (load side), the potential of the current outflow side electrode can be used as the reference potential of the power supply, and the number of power supplies having independent potentials can be reduced as compared with the conventional case.
As a result, the circuit configuration of the AC / AC direct conversion device can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a circuit configuration diagram showing a second embodiment of the present invention.
FIG. 3 is a circuit configuration diagram showing a third embodiment of the present invention.
FIG. 4 is a circuit diagram of a conventional matrix converter.
[Explanation of symbols]
10RU, 10RW, 10RW, 10SU, 10SV, 10SW, 10TU, 10TV, 10TW: AC switch circuits 11, 12: Semiconductor switching elements 21, 22: Diode 30RU, 30RV, 30RW, 30SU, 30SV, 30SW, 30TU, 30TV, 30TW : AC switch circuits 40RU, 40RV, 40RW, 40SU, 40SV, 40SW, 40TU, 40TV, 40TW: AC switch circuits 60R, 60S, 60T, 60U, 60V, 60W: Drive units 61, 62, 63: Drive circuit 64: Insulation Power supply 200: three-phase AC power supply 300: load

Claims

In an AC / AC direct conversion device that directly converts an AC input into an AC output by a switching operation of an AC switch circuit,
A plurality of AC switch circuits respectively connected between the AC input phase and the AC output phase include first and second semiconductor switching elements, and a current outflow side electrode of the plurality of first semiconductor switching elements is connected to the same AC. The plurality of first semiconductor switching elements are connected to an input phase and are driven by a first common power supply having a potential of the AC input phase as a reference potential, and a plurality of second semiconductor switching elements are driven. AC / AC direct conversion in which a current outflow side electrode is connected to the same AC output phase, and the plurality of second semiconductor switching elements are driven using a second common power supply having a potential of the AC output phase as a reference potential. A device,
An AC / AC direct conversion device, wherein the AC switch circuit is configured by connecting a first semiconductor switching element and a second semiconductor switching element in antiparallel.

In an AC / AC direct conversion device that directly converts an AC input into an AC output by a switching operation of an AC switch circuit,
A plurality of AC switch circuits respectively connected between the AC input phase and the AC output phase include first and second semiconductor switching elements, and a current outflow side electrode of the plurality of first semiconductor switching elements is connected to the same AC. Connected to the input phase, and driving the plurality of first semiconductor switching elements using a first common power supply having the potential of the AC input phase as a reference potential; AC / AC direct conversion in which a current outflow side electrode is connected to the same AC output phase, and the plurality of second semiconductor switching elements are driven using a second common power supply having a potential of the AC output phase as a reference potential. A device,
The AC switch circuit is connected in reverse parallel to a forward series connection circuit of a first semiconductor switching element and a first diode, and a forward series connection circuit of a second semiconductor switching element and a second diode. An AC / AC direct conversion device characterized by being configured as follows.

In an AC / AC direct conversion device that directly converts an AC input into an AC output by a switching operation of an AC switch circuit,
A plurality of AC switch circuits respectively connected between the AC input phase and the AC output phase include first and second semiconductor switching elements, and a current outflow side electrode of the plurality of first semiconductor switching elements is connected to the same AC. The plurality of first semiconductor switching elements are connected to an input phase and are driven by a first common power supply having a potential of the AC input phase as a reference potential, and a plurality of second semiconductor switching elements are driven. AC / AC direct conversion in which a current outflow side electrode is connected to the same AC output phase, and the plurality of second semiconductor switching elements are driven using a second common power supply having a potential of the AC output phase as a reference potential. A device,
The AC switch circuit includes an anti-parallel connection circuit of a first semiconductor switching element and a first diode, and an anti-parallel connection circuit of a second semiconductor switching element and a second diode. An AC / AC direct conversion device, wherein cathodes of a second diode are connected to each other.

The AC / AC direct conversion device according to claim 1, 2, or 3,
An AC switch circuit is connected between each phase of the AC input phase and each phase of the AC output phase,
Connecting the current outflow-side electrodes of the first semiconductor switching elements in the AC switch circuits for the number of AC output phases respectively connected to the same AC input phase to the AC input phases;
AC AC direct current characterized in that the current outflow-side electrodes of the second semiconductor switching elements in the AC switch circuits for the number of AC input phases respectively connected to the same AC output phase are connected to the AC output phases, respectively. Conversion device.