JP4051866B2

JP4051866B2 - Mobile power circuit for contactless power supply

Info

Publication number: JP4051866B2
Application number: JP2000242308A
Authority: JP
Inventors: 勝幸森田; 直近藤; 勲渡辺
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2000-08-10
Filing date: 2000-08-10
Publication date: 2008-02-27
Anticipated expiration: 2020-08-10
Also published as: JP2002058179A

Description

【０００１】
【発明の属する技術分野】
本発明は、交流電力の供給されている給電線から非接触状態で電磁誘導により交流電力を受け、移動体側の負荷（制御回路、モータ等）に直流電力を出力供給する非接触給電装置の移動体側電源回路に関するものである。
【０００２】
【従来の技術】
移動体（例えば、レールに沿って走行する台車等）の駆動源へ電力を供給する方式として、接触給電方式（トロリ方式）と非接触給電方式とがある。しかし、接触給電方式の場合、接触部における金属摩耗粉やスパークの発生、接触不良による瞬停の発生、さらに使用環境によっては、短絡や感電等の発生もあり得る。また、定期的なメンテナンスや部品交換等も必要である。そこで、クリーンかつ安全でメンテナンスフリーな非接触給電方式を利用した移動体が普及しつつある。
この非接触方式による給電装置（非接触給電装置）は、通常、高周波電源から交流電力が供給されている給電線と、給電線の発生する交番磁束に鎖交するコイル（コアを含む）を配設した受電部と、該コイルで受電された交流電力を整流する整流回路とを備え、その整流後の直流電力を移動体側の負荷（制御回路、モータ等）に供給できるようになっている。
【０００３】
ところで、その非接触給電装置中の移動体側に配設される電源回路（整流回路等）として、種々のものが開発されており、例えば、特開２００−７８７６４号公報や特開２０００−１３４８２９号公報にその開示がある。
▲１▼特開２０００−７８７６４号公報では、図４に示すように、直列接続した２つの受電部の両端を整流回路にそのまま接続して、交流を直流に整流した後、１つのコンデンサを充電して、そのコンデンサの両端電圧を出力電圧とする電源回路（以下、「直列電源回路」と称する。）が開示されている。
この直列電源回路は、回路構成が簡単なため、信頼性やコスト性に優れる。
【０００４】
▲２▼特開２０００−１３４８２９号公報では、図５に示すように、直列接続した２つの受電部の両端を整流回路に接続すると共にその中間点を、整流回路後の直列接続した２つのコンデンサの中間点に接続した電源回路（以下、「倍電圧電源回路」と称する。）が開示されている。この倍電圧電源回路では、それぞれの受電部から発生した整流後の直流電圧によって２つのコンデンサが交互に充電され、各コンデンサの両端電圧の和が出力電圧となる。
この倍電圧電源回路も、回路構成が簡単なため、信頼性やコスト性に優れる。
【０００５】
【発明が解決しようとする課題】
ところで、移動体の移動距離が長くなると、必然的に長い給電線が必要となるが、給電効率や給電線の定格等から１組の給電線の長さには限界がある。そこで、移動体の移動距離が長い場合、複数組の給電線を敷設して、各給電線毎に別の高周波電源から交流電力を供給することが多い。ただ、別の高周波電源から交流電力が供給されている給電線間では、その位相が一般に異なるため、１つの受電部が２組の給電線に跨り、それらから同時に交流電力の供給を受けると、受電部の受ける交流電力、特に交流電圧が不安定となり、移動体の動作も不安定になってしまう。このため、特開平１１−１２２８４７号公報にも開示されているように、隣接する別組の給電線間に各受電部（コイルまたはコア）の長さよりも長い「無給電線区間」を設け、隣接する別組の給電線間の干渉を防止している。
【０００６】
▲１▼ところが、この無給電線区間を移動体の受電部が通過するとき、その受電部は電力供給を受けられない。このため、前述の直列電源回路の場合、受電部が直列接続されているために、移動体へ供給される交流電圧は半減してしまう。たとえ通過時の短時間といえ、移動体の動作、特にその制御回路の動作が不安定になってしまうことは好ましくない。勿論、前述の特開２０００−１３４８２９号公報にもあるように、ＤＣ／ＤＣコンバータ等を設けて所定電圧を確保することも可能であるが、コスト高となってしまう。
【０００７】
▲２▼一方、前述の倍電圧電源回路では、１つの受電部が無給電線区間にあっても、各受電部に生じる電圧の正負に従って直列接続されたコンデンサが交互に充電されるから、全体としては半波整流状態となるものの、各コンデンサの両端電圧の和が出力電圧となるため、出力電圧が大きく低下することはない。従って、移動体が無給電線区間に位置するときでも、その動作が不安定になることもない。
但し、倍電圧電源回路の場合、直列電源回路と異なり各受電部を流れる電流は相互に独立しているため、受電部に生じる電圧によって、両コイル間を流れる電流にアンバランスが生じ得る。このため、たとえ両受電部が同一組の給電線から交流電力を供給されていたとしても、一方の受電部のコイルのみに過大な電流が流れ、予想以上に発熱してしまうことも考えられる。
【０００８】
本発明は、このような事情に鑑みて為されたものである。つまり、受電部の位置に拘らず、移動体側に必要な電圧を出力できると共に、各受電部を流れる電流の定常的なアンバランスを防止できる非接触給電装置の移動体側電源回路を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明者は、この課題を解決すべく鋭意研究し、試行錯誤を重ねた結果、電源回路に切替部を設けて２種類の電源回路を切替えることを思いつき、本発明の非接触給電装置の移動体側電源回路を開発するに至ったものである。
すなわち、本発明の非接触給電装置の移動体側電源回路は、交流電力が供給されている複数組の給電線の少なくとも１組の給電線から非接触状態で電磁誘導により交流電力を受ける受電部と、該受電部が受電した交流電力を直流電力に整流する整流部と、該整流部から得られた直流電力を端子間に接続されたコンデンサを介して負荷に出力する出力部と、からなる非接触給電装置の移動体側電源回路において、
前記受電部は少なくとも２つの直列接続された第１受電部と第２受電部とからなり、前記出力部のコンデンサは直列接続された第１コンデンサと第２コンデンサとからなり、該第１受電部と該第２受電部との受電側中間点と、該第１コンデンサと該第２コンデンサとのコンデンサ側中間点との連結または遮断を切替えることができる切替部と、を有することを特徴とする。
【００１０】
切替部により、第１受電部と第２受電部との受電側中間点と第１コンデンサと第２コンデンサとのコンデンサ側中間点とが遮断されると、前述した直列電源回路と実質的に同様の回路が形成される。このとき、第１受電部と第２受電部とは直列接続されているため、両者に同一の電流が流れ、受電部の存在位置に拘らず、電流のアンバランスを防止できる。そして、直列接続された第１コンデンサと第２コンデンサとは、一体となって平滑コンデンサとして機能し、リプル率の低減、つまり平滑化が図られる。
一方、切替部により、第１受電部と第２受電部との受電側中間点と第１コンデンサと第２コンデンサとのコンデンサ側中間点とが連結されると、前述した倍電圧電源回路と実質的に同様の回路が形成される。このとき、第１受電部と第２受電部とが独立に、それらに生じる電圧の正負に応じて、第１コンデンサと第２コンデンサとを交互に充電する。言換えると、仮に、一方の受電部からの電力供給がなくなったとしても、他方の受電部のみで、第１コンデンサと第２コンデンサとの両方のコンデンサが充電される。そして、第１コンデンサと第２コンデンサとが直列接続されているために、各コンデンサの両端電圧の和が出力電圧となり、出力電圧が大きく低下することはない。
このように、非接触給電装置の移動体側電源回路が切替部を有することにより、従来の直列電源回路と倍電圧電源回路との短所が相互に補完される。つまり、コストが低く信頼性が高いと共に、受電部における電流の定常的なアンバランスや移動体の移動に伴う出力電圧の低下を防止できる移動体側電源回路が得られる。
【００１１】
特に、前記切替部は、前記第１受電部または前記第２受電部が隣接する別組の給電線間に形成される無給電線区間またはその付近に位置するときに連結され、該第１受電部および該第２受電部が同一組の給電線区間に位置するときに遮断されると、好適である。
【００１２】
このように切替部を制御することにより、本発明の非接触給電装置の移動体側電源回路は、一方の受電部が無給電線区間またはその付近に位置するときに実質的な倍電圧電源回路として必要電圧を出力し、また、第１受電部および第２受電部が同一組の給電線区間に存在するときに実質的な直列電源回路として電流のアンバランスを解消する。従って、移動体の位置に拘らず、必要電圧が移動体側の負荷に出力され、また、受電部における想定外の発熱等が防止される。
なお、受電部が無給電線区間に位置するときのみならず、その付近に位置するときも切替部を連結して倍電圧電源回路とすることにより、出力電圧をより安定化させることができる。
【００１３】
さらに、前記第１コンデンサと並列接続された第１抵抗と前記第２コンデンサと並列接続された第２抵抗とを備えると、好適である。
【００１４】
各コンデンサに抵抗がそれぞれ並列接続されているため、切替部を切替えて遮断状態としたときでも、第１コンデンサと第２コンデンサとのそれぞれの両端に印可される電圧は、第１抵抗と第２抵抗の抵抗値に応じて分圧される。このため、第１コンデンサと第２コンデンサとの各々の許容電圧を超えて、過電圧がいずれか一方のコンデンサに印可されることを防止できる。
なお、切替部が連結されているときは、抵抗値に関わりなく第１受電部と第２受電部とにより生じる電圧が第１コンデンサと第２コンデンサとにそれぞれ交互に印可されるため、各コンデンサに許容電圧を超えた過電圧が印可されることはない。
【００１５】
【発明の実施の形態】
本発明の非接触給電装置の移動体側電源回路に係る実施形態を以下に挙げ、本発明を具体的に説明する。
図１に本発明の移動体側電源回路を用いた非接触給電装置の全体図を示した。非接触給電装置は、高周波電源から高周波の交流電力が供給されている給電線と、この給電線から交流電力を受けて動作する移動体とからなる。
【００１６】
高周波電源として、例えば、サイリスタインバータ式発振器やトランジスタインバータ式発振器等を使用できる。そして、１組の給電線ごとに高周波電源が設けられている。
給電線は、図１に示すように、一本の給電線が中央部で折返されて２本の給電線となり、各給電線が平行を保って移動体の軌道レール（図示せず）に敷設されている。本実施形態では、この状態を１組の給電線と称している。但し、１組の給電線は、これに限られるものではなく、１本の環状ループを形成していても、また、２本を超える平行な給電線から構成されていても良い。従って、複数組の給電線は、移動体の種類やその移動経路に応じて、様々な形態をとり得る。
【００１７】
移動体は、本発明に係る移動体側電源回路と、この電源回路から出力された直流電力により動作する制御回路を備えた制御部と、電源回路から受けた直流電力をインバータを介してＡＣモータに供給し、移動体を走行等させる駆動部とからなる。なお、制御部は、駆動部を制御して移動体の走行速度等を制御すると共に、後述する移動体側電源回路の切替部の切替えを制御する。
【００１８】
ところで、移動体側電源回路は、図１に示すように、第１受電部と第２受電部とを備えた受電部と、この受電部から受けた交流電力を整流する整流部と、整流後の直流電力を蓄電する第１コンデンサと第２コンデンサとを備える出力部と、第１受電部と第２受電部との受電側中間点と第１コンデンサと第２コンデンサとのコンデンサ側中間点との連結または遮断を切替える切替部とからなる。
【００１９】
この移動体側電源回路の具体的な回路構成を図２に示した。
受電部を構成する第１受電部と第２受電部とは共に、図３に示すように、断面Ｅ型のコア１１と、コア１１の中央突起に巻回されたコイル１２とからなる。コイル１２は、その両側に非接触状態で延在する平行な１組の給電線１と給電線２がつくる磁束に鎖交するように巻回されている。このため、給電線１および給電線２に高周波の交流電力が供給されると、電磁誘導によりコイル１２に交流の起電力が生じ、給電線１、２からコイル１２に交流電力が非接触状態で給電されることとなる。そして、このコイル１２の両端が、図２に示した第１受電部の入力端Ｕ１、Ｖ１および第２受電部の入力端Ｕ２、Ｖ２に結線されている。また、本実施形態では、入力端Ｖ１と入力端Ｕ２とが接続されている。
受電部の次にある整流部は、４つのダイオードＤ１〜Ｄ４からなり、ブリッジ整流回路を形成している。このブリッジ整流回路の入力端は前述の入力端Ｕ１、Ｖ２に接続され、ブリッジ整流回路の出力端は、次の出力部の第１コンデンサＣａと第２コンデンサＣｂとに接続されている。
【００２０】
出力部は、直列接続された第１コンデンサＣａと第２コンデンサＣｂと、第１コンデンサＣａに並列接続された第１抵抗Ｒａと、第２コンデンサＣｂに並列接続された第２抵抗Ｒｂとからなり、第１コンデンサＣａ（第１抵抗Ｒａ）の一端が正側の出力端Ｐに接続され、第２コンデンサＣｂ（第２抵抗Ｒｂ）の一端が負側の出力端Ｎに接続されている。そして、出力端ＰＮの両端間で所定の出力電圧Ｖｏｕｔが出力される。
【００２１】
切替部は、スイッチＳＷからなり、スイッチＳＷの一端は前述した第１受電部の入力端Ｖ１と第２受電部の入力端Ｕ２との中間にある受電側中間点Ｍｉに接続されていると共に、スイッチＳＷの他端は第１コンデンサＣａと第２コンデンサＣｂとの中間にあるコンデンサ側中間点Ｍｃに接続されている。従って、このスイッチＳＷの断続により、受電側中間点Ｍｉとコンデンサ側中間点Ｍｃとの連結、遮断が切替えられ、移動体側電源回路の回路構成を変更できるようになっている。
なお、このスイッチＳＷの断続は、制御部により制御され、制御部は、図１に示す移動体に設けた検出部のセンサからの信号に基づいてスイッチＳＷを断続させる。具体的には、検出部のセンサが無給電線区間を検出すると、制御部はその信号を受けてスイッチＳＷを連結（ＯＮ）して、移動体側電源回路をいわゆる倍電圧電源回路に切替える。逆に、検出部のセンサにより無給電線区間が検出されないと、制御部はスイッチＳＷを遮断（ＯＦＦ）状態として、移動体側電源回路をいわゆる直列電源回路に切替える。
【００２２】
次に、この移動体側電源回路の動作について説明する。
▲１▼スイッチＳＷがＯＦＦのとき
前述したように移動体側電源回路は直列電源回路として作動する。このとき、直列接続された第１受電部と第２受電部とは共に同一組の給電線上にあるから、両受電部へは同位相の交流電力が供給されている。
従って、受電部の入力端Ｕ１と入力端Ｖ２との間には、第１受電部の両端電圧と第２受電部の両端電圧とを加えた交流電圧が生じる。例えば、第１受電部の入力端間でＡＣ１００Ｖが発生し、第２受電部の入力端間でＡＣ１００Ｖが発生していると、入力端Ｕ１と入力端Ｖ２との間にＡＣ２００Ｖが発生する。これが整流部で全波整流された後、出力部の第１コンデンサＣａと第２コンデンサＣｂとによって平滑化されて、出力端ＰＮから直流電圧として出力される。
【００２３】
ところで一般に、一方の受電部が無給電線区間に存在する時間よりも、両方の受電部が同一組の給電線上に存在する時間の方が長い。つまり、スイッチＳＷがＯＦＦ状態にあるときの方が長い。本発明の移動体側電源回路は、この長時間側で直列電源回路を構成して電流のアンバランスを防止しているので、受電部の一方側のみが過剰に発熱することがない。
また、第１コンデンサＣａと第２コンデンサＣｂとの両端に印可される電圧は、第１抵抗Ｒａと第２抵抗Ｒｂとにより分圧されているので、各コンデンサに過電圧が印可されることも防止できる。
【００２４】
▲２▼スイッチＳＷがＯＮのとき
前述したように移動体側電源回路は倍電圧電源回路として作動する。本発明の移動体側電源回路では、受電部の一方が無給電線区間にあるときの動作が特に重要である。そこで、第２受電部が無給電線区間にあるときを例にとり、以下説明する。
第２受電部が無給電線区間にあるとき、第１受電部のみが給電線から交流電力の供給を受ける。第１受電部が「正電圧（Ｕ１＞Ｖ１）」を出力すると、入力端Ｕ１→ダイオードＤ１→第１コンデンサＣａ→コンデンサ側中間点Ｍｃ→スイッチＳＷ→受電側中間点Ｍｉ→入力端Ｖ１と電流が流れて第１コンデンサＣａが充電される。
【００２５】
逆に、第１受電部が「負電圧（Ｕ１＜Ｖ１）」を出力すると、入力端Ｖ１→受電側中間点Ｍｉ→スイッチＳＷ→コンデンサ側中間点Ｍｃ→第２コンデンサＣｂ→ダイオードＤ２→入力端Ｕ１と電流が流れて第２コンデンサＣｂが充電される。このように、一方の受電部が無給電線区間にあるときでも、両方の第１コンデンサＣａと第２コンデンサＣｂとが充電されるため、出力端ＰＮ間の出力電圧Ｖｏｕｔは、大きく低減することもなく、前述のスイッチＳＷがＯＦＦ状態のときとほぼ同様の出力電圧Ｖｏｕｔ（最大電圧）を得ることができる。
【００２６】
なお、移動体の動作を常に安定させるためには、出力電圧の低下を早めに回避することが好ましい。従って、受電部が無給電線区間に差掛かったときにスイッチＳＷを早めにＯＮとすることが好ましい。なお、スイッチＳＷを早めにＯＮ状態としても、その時間は僅かであるため、第１受電部と第２受電部との間で電流のアンバランスが生じたとしても、実質的な問題はない。
また、第１受電部と第２受電部との取付間隔と無給電線区間の長さとの関係によって、第１受電部と第２受電部とがそれぞれ隣接する別組の給電線から交流電力を供給されることも起り得る。つまり、第１受電部と第２受電部との間で、供給される交流電力に位相差を生じることも考えられる。しかし、第１受電部と第２受電部とが、それぞれ交互に、第１コンデンサＣａと第２コンデンサＣｂとを充電することに変わりないため、移動体の安定動作に必要な出力電圧Ｖｏｕｔは維持される。
【００２７】
以上、本発明に係る非接触給電装置の移動体側電源回路の一実施形態を説明したが、これに限らず、例えば、次のような実施形態も考えることができる。
▲１▼上述の移動体側電源回路の実施形態では、受電部が２つの場合を考えたが、３つ以上でも良く、そのときは、任意に選択した受電部を第１受電部と第２受電部とすれば良い。このことは、第１コンデンサ、第２コンデンサ、第１抵抗および第２抵抗についても、同様である。
【００２８】
▲２▼上述の実施形態で使用したダイオード、コンデンサ、抵抗等は、非接触給電装置の種類に応じた許容容量内であれば、種々のものが使用可能である。
【００２９】
▲３▼スイッチも、リレースイッチ、半導体スイッチ等、種々のものを使用できる。また、スイッチの切替えに必ずしも制御部を介在させる必要はない。むしろ、制御部を介在させずに、検出部の出力信号を基に直接切替えられるようにすると、誤動作をより確実に防止できる。
【００３０】
▲４▼さらに、スイッチの切替えタイミングも、専用の検出センサを設ける以外に、例えば、ロータリエンコーダ等の信号から移動体の位置を随時演算して求めておき、無給電線区間との相対位置を判別するようにしても良い。また、スイッチがＯＦＦ状態のとき、移動体側電源回路は直列電源回路となっているので、一方の受電部が無給電線区間に差掛かると、出力電圧が低下し始める。その出力電圧の低下を制御部で検出して、スイッチＳＷをＯＮに切替えるようにすると、別途、センサを設ける必要はなくなる。
【００３１】
【発明の効果】
本発明の非接触給電装置の移動体側電源回路によれば、受電部の位置に拘らず、移動体側に必要な電圧を出力できると共に、各受電部を流れる電流の定常的なアンバランスを防止できる。
【図面の簡単な説明】
【図１】本発明に係る非接触給電装置の全体図である。
【図２】本発明に係る非接触給電装置の移動体側電源回路の実施形態を示す回路図である。
【図３】本発明に係る移動体側電源回路の受電部の拡大図である。
【図４】従来の非接触給電装置の移動体側電源回路（直列電源回路）を示す回路図である。
【図５】従来の非接触給電装置の移動体側電源回路（倍電圧電源回路）を示す回路図である。
【符号の説明】
Ｃａ第１コンデンサ
Ｃｂ第２コンデンサ
Ｒａ第１抵抗
Ｒｂ第２抵抗
ＳＷスイッチ（切替部）[0001]
BACKGROUND OF THE INVENTION
The present invention moves a non-contact power supply device that receives AC power by electromagnetic induction in a non-contact state from a power supply line to which AC power is supplied, and outputs DC power to a load (control circuit, motor, etc.) on the moving body side. The present invention relates to a body side power supply circuit.
[0002]
[Prior art]
As a method of supplying electric power to a driving source of a moving body (for example, a cart traveling along a rail), there are a contact power supply method (trolley method) and a non-contact power supply method. However, in the case of the contact power supply method, metal wear powder and sparks at the contact portion, instantaneous power failure due to poor contact, and short circuit or electric shock may occur depending on the usage environment. Also, regular maintenance and parts replacement are necessary. In view of this, mobile objects using a non-contact power supply method that is clean, safe, and maintenance-free are becoming popular.
This non-contact type power supply device (non-contact power supply device) usually includes a power supply line to which AC power is supplied from a high-frequency power source and a coil (including a core) interlinked with an alternating magnetic flux generated by the power supply line. The power receiving unit is provided, and a rectifier circuit that rectifies the AC power received by the coil, and the rectified DC power can be supplied to a load (control circuit, motor, etc.) on the mobile body side.
[0003]
By the way, various types of power supply circuits (rectifier circuits and the like) arranged on the moving body side in the non-contact power feeding device have been developed. For example, Japanese Patent Laid-Open Nos. 200-78764 and 2000-134829 are disclosed. The gazette has that disclosure.
(1) In Japanese Patent Laid-Open No. 2000-78764, as shown in FIG. 4, both ends of two power receiving units connected in series are directly connected to a rectifier circuit to rectify alternating current to direct current, and then charge one capacitor. Thus, a power supply circuit (hereinafter referred to as “series power supply circuit”) that uses the voltage across the capacitor as an output voltage is disclosed.
Since this series power supply circuit has a simple circuit configuration, it is excellent in reliability and cost.
[0004]
(2) In Japanese Patent Application Laid-Open No. 2000-134829, as shown in FIG. 5, both ends of two power receiving units connected in series are connected to a rectifier circuit, and the middle point thereof is two capacitors connected in series after the rectifier circuit. A power supply circuit (hereinafter referred to as a “double voltage power supply circuit”) connected to an intermediate point is disclosed. In this voltage doubler power supply circuit, the two capacitors are alternately charged by the rectified DC voltage generated from each power receiving unit, and the sum of the voltages at both ends of each capacitor becomes the output voltage.
This voltage doubler power supply circuit is also excellent in reliability and cost because of its simple circuit configuration.
[0005]
[Problems to be solved by the invention]
By the way, when the moving distance of the moving body becomes long, a long power supply line is inevitably required. However, the length of one set of power supply lines is limited due to the power supply efficiency and the rating of the power supply line. Therefore, when the moving distance of the moving body is long, a plurality of sets of power supply lines are laid and AC power is often supplied from a separate high-frequency power source for each power supply line. However, since the phases are generally different between the feeding lines to which AC power is supplied from different high-frequency power sources, when one power receiving unit straddles two sets of feeding lines and receives AC power from them simultaneously, The AC power received by the power receiving unit, in particular the AC voltage, becomes unstable, and the operation of the moving body also becomes unstable. For this reason, as disclosed in Japanese Patent Application Laid-Open No. 11-122847, a “non-feed line section” longer than the length of each power receiving unit (coil or core) is provided between adjacent pairs of feed lines. This prevents interference between different sets of feeders.
[0006]
(1) However, when the power receiving unit of the moving body passes through the non-feed line section, the power receiving unit cannot receive power supply. For this reason, in the case of the above-mentioned series power supply circuit, the AC voltage supplied to the moving body is halved because the power receiving units are connected in series. Even if it is a short time during passage, it is not preferable that the operation of the moving body, particularly the operation of its control circuit, becomes unstable. Of course, as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2000-134829, a DC / DC converter or the like can be provided to secure a predetermined voltage, but the cost increases.
[0007]
(2) On the other hand, in the above-mentioned voltage doubler power supply circuit, even if one power receiving unit is in the parasitic line section, capacitors connected in series are alternately charged according to the positive / negative of the voltage generated in each power receiving unit. Although the half-wave rectification state is set, the output voltage is not greatly reduced because the sum of the voltages across the capacitors becomes the output voltage. Therefore, even when the moving body is located in the parasitic line section, the operation does not become unstable.
However, in the case of the voltage doubler power supply circuit, unlike the series power supply circuit, the currents flowing through the power receiving units are independent of each other, and therefore the current flowing between the two coils can be unbalanced due to the voltage generated at the power receiving unit. For this reason, even if both power receiving units are supplied with AC power from the same set of power supply lines, it is possible that an excessive current flows only in the coil of one power receiving unit and heat is generated more than expected.
[0008]
The present invention has been made in view of such circumstances. That is, it is possible to provide a moving body side power supply circuit of a non-contact power feeding device that can output a necessary voltage to the moving body side regardless of the position of the power receiving section and can prevent a steady unbalance of a current flowing through each power receiving section. Objective.
[0009]
[Means for Solving the Problems]
The present inventor has intensively studied to solve this problem, and as a result of repeated trial and error, the inventor has conceived that a switching unit is provided in the power supply circuit to switch between two types of power supply circuits, and the movement of the non-contact power feeding device of the present invention It came to develop the body side power supply circuit.
That is, the moving body side power supply circuit of the non-contact power feeding device of the present invention includes a power receiving unit that receives AC power by electromagnetic induction in a non-contact state from at least one pair of power feeding lines to which AC power is supplied. A rectifying unit that rectifies the AC power received by the power receiving unit into DC power, and an output unit that outputs the DC power obtained from the rectifying unit to a load via a capacitor connected between the terminals. In the mobile power supply circuit of the contact power supply device,
The power receiving unit includes at least two first power receiving units and a second power receiving unit connected in series, and the capacitor of the output unit includes a first capacitor and a second capacitor connected in series, the first power receiving unit. And a power receiving side intermediate point between the first power receiving unit and the second power receiving unit, and a switching unit capable of switching connection or disconnection between the first capacitor and the capacitor intermediate point between the second capacitor and the second power receiving unit. .
[0010]
When the switching unit cuts off the power receiving side intermediate point between the first power receiving unit and the second power receiving unit and the capacitor side intermediate point between the first capacitor and the second capacitor, it is substantially the same as the series power supply circuit described above. Circuit is formed. At this time, since the first power receiving unit and the second power receiving unit are connected in series, the same current flows through both, and current imbalance can be prevented regardless of the position of the power receiving unit. And the 1st capacitor | condenser and 2nd capacitor | condenser connected in series function as a smoothing capacitor | condenser integrally, and reduction of a ripple rate, ie, smoothing, is achieved.
On the other hand, when the power receiving side intermediate point between the first power receiving unit and the second power receiving unit and the capacitor side intermediate point between the first capacitor and the second capacitor are connected by the switching unit, Thus, a similar circuit is formed. At this time, the first power receiving unit and the second power receiving unit independently charge the first capacitor and the second capacitor according to the sign of the voltage generated in them. In other words, even if power supply from one power receiving unit is lost, both the first capacitor and the second capacitor are charged only by the other power receiving unit. And since the 1st capacitor and the 2nd capacitor are connected in series, the sum of the both-ends voltage of each capacitor turns into an output voltage, and an output voltage does not fall large.
As described above, the moving body side power supply circuit of the non-contact power supply apparatus includes the switching unit, thereby complementing the disadvantages of the conventional series power supply circuit and the voltage doubler power supply circuit. That is, it is possible to obtain a moving body-side power supply circuit that is low in cost and high in reliability, and that can prevent a steady imbalance of current in the power receiving unit and a decrease in output voltage due to movement of the moving body.
[0011]
In particular, the switching unit is connected when the first power receiving unit or the second power receiving unit is located at or near a non-feed line section formed between adjacent sets of power feed lines, and the first power receiving unit It is preferable that the second power receiving unit is cut off when the second power receiving unit is located in the same set of feeder line sections.
[0012]
By controlling the switching unit in this way, the mobile-side power supply circuit of the non-contact power feeding device of the present invention is necessary as a substantial voltage doubler power supply circuit when one power receiving unit is located in or near the non-feeding line section. Voltage is output, and current imbalance is eliminated as a substantial series power supply circuit when the first power receiving unit and the second power receiving unit exist in the same set of feeder line sections. Accordingly, the necessary voltage is output to the load on the moving body regardless of the position of the moving body, and unexpected heat generation or the like in the power receiving unit is prevented.
Note that the output voltage can be further stabilized by connecting the switching unit to form a voltage doubler power supply circuit not only when the power receiving unit is positioned in the non-feed line section but also when the power receiving unit is positioned in the vicinity thereof.
[0013]
Furthermore, it is preferable that a first resistor connected in parallel with the first capacitor and a second resistor connected in parallel with the second capacitor are provided.
[0014]
Since the resistors are connected in parallel to the capacitors, even when the switching unit is switched to the cut-off state, the voltages applied to both ends of the first capacitor and the second capacitor are the first resistor and the second resistor. The voltage is divided according to the resistance value of the resistor. For this reason, it is possible to prevent the overvoltage from being applied to any one of the capacitors beyond the allowable voltage of each of the first capacitor and the second capacitor.
When the switching unit is connected, the voltage generated by the first power receiving unit and the second power receiving unit is alternately applied to the first capacitor and the second capacitor regardless of the resistance value. An overvoltage exceeding the allowable voltage is not applied to the.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the moving body side power supply circuit of the non-contact power feeding device of the present invention will be described below, and the present invention will be specifically described.
FIG. 1 shows an overall view of a non-contact power feeding apparatus using a moving body side power supply circuit of the present invention. The non-contact power supply device includes a power supply line to which high-frequency AC power is supplied from a high-frequency power source, and a moving body that operates by receiving AC power from the power supply line.
[0016]
For example, a thyristor inverter type oscillator or a transistor inverter type oscillator can be used as the high frequency power source. A high-frequency power source is provided for each set of feeder lines.
As shown in FIG. 1, a single feed line is folded at the center to form two feed lines, and each feed line is kept parallel and laid on a track rail (not shown) of the moving body. Has been. In the present embodiment, this state is referred to as a set of feeder lines. However, the set of feed lines is not limited to this, and may form one annular loop or may be composed of more than two parallel feed lines. Therefore, the plurality of sets of power supply lines can take various forms depending on the type of the moving body and its moving path.
[0017]
The mobile unit includes a mobile unit side power supply circuit according to the present invention, a control unit including a control circuit that operates by direct current power output from the power supply circuit, and direct current power received from the power supply circuit to an AC motor via an inverter. And a drive unit that feeds and moves the moving body. The control unit controls the driving unit to control the traveling speed of the moving body and the like, and also controls switching of the switching unit of the moving body side power supply circuit described later.
[0018]
By the way, as shown in FIG. 1, the mobile-side power supply circuit includes a power receiving unit including a first power receiving unit and a second power receiving unit, a rectifying unit that rectifies AC power received from the power receiving unit, An output unit including a first capacitor and a second capacitor for storing DC power, a power receiving side intermediate point between the first power receiving unit and the second power receiving unit, and a capacitor side intermediate point between the first capacitor and the second capacitor And a switching unit that switches between connection and disconnection.
[0019]
A specific circuit configuration of this mobile unit side power supply circuit is shown in FIG.
As shown in FIG. 3, each of the first power receiving unit and the second power receiving unit constituting the power receiving unit includes a core 11 having an E-shaped cross section and a coil 12 wound around a central protrusion of the core 11. The coil 12 is wound on both sides so as to interlink with a magnetic flux generated by a pair of parallel feed lines 1 and 2 extending in a non-contact state. For this reason, when high-frequency AC power is supplied to the power supply line 1 and the power supply line 2, AC electromotive force is generated in the coil 12 by electromagnetic induction, and AC power is not contacted from the power supply lines 1 and 2 to the coil 12. Power will be supplied. Then, both ends of the coil 12 are connected to the input terminals U1 and V1 of the first power receiving unit and the input terminals U2 and V2 of the second power receiving unit shown in FIG. In the present embodiment, the input terminal V1 and the input terminal U2 are connected.
The rectification unit next to the power reception unit includes four diodes D1 to D4, and forms a bridge rectification circuit. The input terminal of the bridge rectifier circuit is connected to the input terminals U1 and V2, and the output terminal of the bridge rectifier circuit is connected to the first capacitor Ca and the second capacitor Cb of the next output unit.
[0020]
The output unit includes a first capacitor Ca and a second capacitor Cb connected in series, a first resistor Ra connected in parallel to the first capacitor Ca, and a second resistor Rb connected in parallel to the second capacitor Cb. One end of the first capacitor Ca (first resistor Ra) is connected to the positive output terminal P, and one end of the second capacitor Cb (second resistor Rb) is connected to the negative output terminal N. A predetermined output voltage Vout is output between both ends of the output terminal PN.
[0021]
The switching unit is composed of a switch SW, and one end of the switch SW is connected to the power receiving side intermediate point Mi located between the input terminal V1 of the first power receiving unit and the input terminal U2 of the second power receiving unit. The other end of the switch SW is connected to a capacitor side intermediate point Mc located between the first capacitor Ca and the second capacitor Cb. Therefore, the connection / disconnection of the power receiving side intermediate point Mi and the capacitor side intermediate point Mc is switched by the switching of the switch SW, and the circuit configuration of the mobile unit side power supply circuit can be changed.
The on / off state of the switch SW is controlled by the control unit, and the control unit turns on / off the switch SW based on a signal from the sensor of the detecting unit provided in the moving body shown in FIG. Specifically, when the sensor of the detection unit detects a parasitic line section, the control unit receives the signal and connects (ON) the switch SW to switch the mobile unit side power supply circuit to a so-called voltage doubler power supply circuit. On the contrary, when the parasitic line section is not detected by the sensor of the detection unit, the control unit switches the moving body side power supply circuit to a so-called series power supply circuit by turning off the switch SW.
[0022]
Next, the operation of this mobile unit side power supply circuit will be described.
(1) When the switch SW is OFF, the moving body side power supply circuit operates as a series power supply circuit as described above. At this time, since the first power receiving unit and the second power receiving unit connected in series are both on the same set of power supply lines, AC power having the same phase is supplied to both power receiving units.
Therefore, an AC voltage is generated between the input terminal U1 and the input terminal V2 of the power reception unit, which is the sum of the voltage across the first power reception unit and the voltage across the second power reception unit. For example, when AC100V is generated between the input terminals of the first power receiving unit and AC100V is generated between the input terminals of the second power receiving unit, AC200V is generated between the input terminal U1 and the input terminal V2. After this is full-wave rectified by the rectification unit, it is smoothed by the first capacitor Ca and the second capacitor Cb of the output unit, and is output as a DC voltage from the output terminal PN.
[0023]
By the way, generally, the time during which both power reception units exist on the same set of power supply lines is longer than the time during which one power reception unit exists in the non-feed line section. That is, it is longer when the switch SW is in the OFF state. Since the mobile power supply circuit of the present invention forms a series power supply circuit on this long time side to prevent current imbalance, only one side of the power receiving unit does not generate excessive heat.
Further, since the voltage applied to both ends of the first capacitor Ca and the second capacitor Cb is divided by the first resistor Ra and the second resistor Rb, it is possible to prevent an overvoltage from being applied to each capacitor. it can.
[0024]
(2) When the switch SW is ON, the moving body side power supply circuit operates as a voltage doubler power supply circuit as described above. In the mobile-side power supply circuit of the present invention, the operation when one of the power reception units is in the parasitic line section is particularly important. Therefore, the case where the second power receiving unit is in the parasitic line section will be described below as an example.
When the second power receiving unit is in the non-feed line section, only the first power receiving unit is supplied with AC power from the feed line. When the first power receiving unit outputs “positive voltage (U1> V1)”, the input terminal U1, the diode D1, the first capacitor Ca, the capacitor side intermediate point Mc, the switch SW, the power receiving side intermediate point Mi, the input terminal V1, and the current. Flows to charge the first capacitor Ca.
[0025]
Conversely, when the first power receiving unit outputs “negative voltage (U1 <V1)”, the input terminal V1 → the power receiving side intermediate point Mi → the switch SW → the capacitor side intermediate point Mc → the second capacitor Cb → the diode D2 → the input terminal. A current flows through U1, and the second capacitor Cb is charged. Thus, even when one power receiving unit is in the parasitic line section, both the first capacitor Ca and the second capacitor Cb are charged, so that the output voltage Vout between the output terminals PN can be greatly reduced. The output voltage Vout (maximum voltage) almost the same as that when the switch SW is in the OFF state can be obtained.
[0026]
In order to always stabilize the operation of the moving body, it is preferable to avoid a decrease in the output voltage as soon as possible. Therefore, it is preferable to turn on the switch SW early when the power receiving unit reaches the non-feed line section. Note that even if the switch SW is turned on early, the time is very short, so even if a current imbalance occurs between the first power receiving unit and the second power receiving unit, there is no substantial problem.
Also, AC power is supplied from another set of power supply lines adjacent to the first power receiving section and the second power receiving section, depending on the relationship between the mounting interval between the first power receiving section and the second power receiving section and the length of the non-feed line section. It can happen. That is, it is conceivable that a phase difference is generated in the supplied AC power between the first power receiving unit and the second power receiving unit. However, since the first power receiving unit and the second power receiving unit alternately charge the first capacitor Ca and the second capacitor Cb, the output voltage Vout necessary for stable operation of the moving body is maintained. Is done.
[0027]
As mentioned above, although one Embodiment of the mobile body side power supply circuit of the non-contact electric power feeder which concerns on this invention was described, not only this but the following embodiment can also be considered, for example.
(1) In the above-described embodiment of the mobile unit side power supply circuit, the case where there are two power receiving units is considered. However, three or more power receiving units may be used, and in this case, arbitrarily selected power receiving units are the first power receiving unit and the second power receiving unit. Part. The same applies to the first capacitor, the second capacitor, the first resistor, and the second resistor.
[0028]
{Circle around (2)} Various diodes, capacitors, resistors, and the like used in the above embodiments can be used as long as they are within an allowable capacity corresponding to the type of the non-contact power feeding device.
[0029]
(3) Various switches such as relay switches and semiconductor switches can be used. Further, it is not always necessary to interpose a control unit for switching the switch. Rather, malfunction can be prevented more reliably by switching directly based on the output signal of the detection unit without interposing a control unit.
[0030]
(4) In addition to providing a dedicated detection sensor, the switching timing of the switch is obtained by calculating the position of the moving body from time to time, for example, from a signal from a rotary encoder, etc., and determining the relative position with respect to the parasitic line section. You may make it do. In addition, when the switch is in the OFF state, the moving body side power supply circuit is a series power supply circuit, and therefore when one power receiving unit reaches the non-feed line section, the output voltage starts to decrease. If the drop in the output voltage is detected by the control unit and the switch SW is switched ON, it is not necessary to provide a separate sensor.
[0031]
【The invention's effect】
According to the mobile body side power supply circuit of the non-contact power feeding device of the present invention, it is possible to output a necessary voltage to the mobile body regardless of the position of the power receiving unit, and to prevent steady unbalance of the current flowing through each power receiving unit. .
[Brief description of the drawings]
FIG. 1 is an overall view of a non-contact power feeding device according to the present invention.
FIG. 2 is a circuit diagram showing an embodiment of a mobile unit side power supply circuit of the non-contact power feeding device according to the present invention.
FIG. 3 is an enlarged view of a power receiving unit of a mobile unit side power supply circuit according to the present invention.
FIG. 4 is a circuit diagram showing a moving body side power supply circuit (series power supply circuit) of a conventional non-contact power feeding device.
FIG. 5 is a circuit diagram showing a moving body side power supply circuit (double voltage power supply circuit) of a conventional non-contact power supply apparatus.
[Explanation of symbols]
Ca first capacitor Cb second capacitor Ra first resistor Rb second resistor SW switch (switching unit)

Claims

A power receiving unit that receives AC power by electromagnetic induction in a non-contact state from at least one set of power supply lines to which AC power is supplied, and rectification that rectifies the AC power received by the power receiving unit into DC power A mobile unit power circuit of a non-contact power feeding device comprising: an output unit that outputs DC power obtained from the rectifying unit to a load via a capacitor connected between terminals;
The power receiving unit includes at least two first power receiving units and a second power receiving unit connected in series,
The output capacitor is composed of a first capacitor and a second capacitor connected in series.
A switching unit capable of switching connection or disconnection between a power receiving side intermediate point between the first power receiving unit and the second power receiving unit and a capacitor side intermediate point between the first capacitor and the second capacitor;
A moving body side power supply circuit for a non-contact power feeding device.

The switching unit is connected when the first power receiving unit or the second power receiving unit is located in or near a non-feed line section formed between another set of adjacent feed lines, and the first power receiving unit and the second power receiving unit The mobile body side power supply circuit of the non-contact power feeding device according to claim 1, wherein the power receiving circuit is cut off when the second power receiving unit is located in the same set of power feeding line sections.

The mobile-side power supply circuit of the non-contact power feeding device according to claim 1, further comprising a first resistor connected in parallel with the first capacitor and a second resistor connected in parallel with the second capacitor.