JP2004103308A

JP2004103308A - Circuit breaker

Info

Publication number: JP2004103308A
Application number: JP2002260879A
Authority: JP
Inventors: Koichi Nishimura; 西村　貢一; Takashi Kurosaki; 黒崎　剛史; Koji Hirotsune; 広常　弘二
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2002-09-06
Filing date: 2002-09-06
Publication date: 2004-04-02
Anticipated expiration: 2022-09-06
Also published as: CN1481058A; JP4096668B2; CN1309135C

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker allowing automatic setting of a time-limited tripping operation according to a switching state of a circuit breaker contact and a flowing state of a load current. <P>SOLUTION: In this circuit breaker 2a, the load current flowing through a cable way 1 is detected, a detection signal thereof is subjected to an arithmetic process by a calculation part 6 to cut off the load current by the circuit breaker contacts 3. The circuit breaker is provided with: a first delay means 10 for outputting a signal delayed by a predetermined time based on a voltage inputted from the cable way 1; and a determination part 11 for determining the switching states of the contacts 3 and the flowing state of the load current based on the signal inputted from the delay means 10 and a signal inputted from a signal conversion part 5 to output the determination result thereof to the calculation part 6; and is so structured that the calculation part 6 sets the time-limited tripping operation based on the determination result of the determination part 11. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、電路に流れる負荷電流に応じて引外し動作を行う回路遮断器に関し、特に遮断器接点の開閉状態、負荷電流の通電状態に応じて限時引外し動作（長限時引外し動作、短限時引外し動作、及び瞬時引外し動作）の設定を変更可能にした回路遮断器に関するものである。
【０００２】
【従来の技術】
図６は、例えば特開平６−２４５３６２号公報に示されたような従来の回路遮断器の構成を示すブロック図である。
図において、１は電路、２は回路遮断器、３は電路１に流れる電流を開閉する遮断器接点、４は電路１に流れる電流を検出する電流検出手段である電流センサ、５は電流センサ４で検出した信号を所定の信号に変換する信号変換部、６は信号変換部５から出力された信号を演算処理し、この信号に応じた引外し信号を後述のトリップコイル７に出力する演算部で、電路１に過電流が流れたときに電流センサ２から信号変換部５を介して入力された信号に応じた引外し信号をトリップコイル７に出力する。
【０００３】
７は周知のごとく電磁石からなる機構部を有し、演算部６から出力された限時動作信号を受けてプランジャー（可動部分）の動きによって遮断器接点３を引外し動作させるトリップコイル、８は電路１を流れる電流によって電源回路９に電流を供給する変流器で、電源回路９は変流器８から入力された電流により信号処理部５及び演算部６に供給する電力を生成する。
【０００４】
以上のように構成された回路遮断器２は、電路１に流れる負荷電流の大きさに応じ、回路遮断器の周知の限時引外し動作である長限時引外し動作、短限時引外し動作、及び瞬時引外し動作の３つの動作を行う。
【０００５】
【発明が解決しようとする課題】
従来の回路遮断器は以上のように構成されており、電路に流れる負荷電流の大きさに応じて長限時引外し動作、短限時引外し動作、及び瞬時引外し動作の３つの動作を行うように設定されているが、例えば、電路に接続された負荷がトランスなどの突入電流が比較的大きなものが接続された場合、突入電流による誤動作を防ぐために回路遮断器を投入した時には、瞬時引外し動作をさせなくする必要がある。
【０００６】
しかし、ただ単に瞬時引外しの動作をさせなくするようにした場合、回路遮断器投入後、負荷側において短絡事故などが起きた場合には回路遮断器本来の機能である電路を保護することができないため、回路遮断器を投入した時のみ瞬時引外し機能を動作させるようにする必要がある。この対応として回路遮断器の投入動作を機械的に検出し、検出結果に基づいて瞬時引外し動作をさせなくするという方式のものがあったが、この方式のものは、レバー、スプリング、分銅、スイッチなどの機構部品を組み合わせた構成であり、構造が複雑でコストが高くなると共に、機構部品で構成しているため、耐久性が劣るという問題があった。
【０００７】
この発明は上記のような問題を解決するためになされたもので、構造が簡素で且つ信頼性の高い構成で、遮断器接点の開閉状態、負荷電流の通電状態に応じた限時引外し動作の設定を自動的に行うことができる回路遮断器を提供することを目的としている。
【０００８】
【課題を解決するための手段】
この発明に係わる回路遮断器は、電路に流れる電流を開閉する遮断器接点と、この遮断器接点を引外し動作させるトリップコイルと、前記電路に流れる電流を検出する電流検出手段と、この電流検出手段で検出した信号を所定の信号に変換する信号変換部と、この信号変換部から出力された信号を演算処理しこの信号に応じた引外し信号を前記トリップコイルに出力する演算部とを備えた回路遮断器において、前記電路の前記遮断器接点より負荷側に配設され前記電路から入力された電圧に基づいて所定の時間遅らせた信号を出力する第１の遅延手段と、この第１の遅延手段から入力された信号と前記信号変換部から入力された信号に基づいて前記遮断器接点の開閉状態、負荷電流の通電状態を判定し、この判定結果を前記演算部に出力する判定部とを備え、前記演算部が前記判定部の判定結果に基づいて限時引外し動作の設定を行うものである。
【０００９】
また、電路が負荷電流通電状態で遮断器接点をＯＮにしたときに、演算部に長限時引外し動作、短限時引外し動作、及び瞬時引外し動作が設定された後、所定の時間後に長限時引外し動作、短限時引外し動作が設定されるものである。
【００１０】
また、第１の遅延手段は、電路の電圧を整流する整流回路と、この整流回路から入力された信号を遅延させて出力する遅延回路とにより構成されるものである。
【００１１】
また、遅延回路は電圧制限手段を備えたものである。
【００１２】
また、電路の遮断器接点より電源側に配設され前記電路から入力された電圧に基づいて所定の時間遅らせた信号を出力する第２の遅延手段を備え、
判定部は第１の遅延手段、前記第２の遅延手段から入力された信号、及び信号変換部から入力された信号に基づいて遮断器接点の開閉状態、負荷電流の通電状態を判定し、この判定結果を演算部に出力し、この演算部が前記判定部の判定結果に基づいて限時引外し動作の設定を行うものである。
【００１３】
また、電路が負荷電流通電状態で遮断器接点をＯＮにしたときに、演算部に長限時引外し動作、短限時引外し動作、及び瞬時引外し動作が設定された後、所定の時間後に長限時引外し動作、短限時引外し動作が設定されるものである。
【００１４】
【発明の実施の形態】
実施の形態１．
図１はこの発明の実施の形態１における回路遮断器の構成を示すブロック図である。
図において、１は電路、２ａは回路遮断器、３は電路１に流れる電流を開閉する遮断器接点、４は電路１に流れる電流を検出する電流検出手段である電流センサ、５は電流センサ４で検出した信号を所定の信号に変換する信号変換部である。
【００１５】
６は後述の判定部１１の判定結果に基づいて、長限時引外し動作、短限時引外し動作、及び瞬時引外し動作の３つの限時引外し動作の中から所定の限時引外し動作を選択し設定を行うと共に、電路１に過電流が流れたときに電流センサ２から信号変換部５を介して入力された信号に応じた引外し信号を後述のトリップコイル７に出力する演算部である。
【００１６】
７は周知のごとく電磁石からなる機構部を有し、演算部６から出力された限時動作信号を受けてプランジャー（可動部分）の動きによって遮断器接点３を引外し動作させるトリップコイル、８は電路１を流れる電流によって電源回路９に電流を供給する変流器で、電源回路９は変流器８から入力された電流により信号処理部５、演算部６、及び後述の判定部１１に供給する電力を生成する。
【００１７】
１０は第１の遅延手段で、整流回路１０ａ及び遅延回路１０ｂにより構成され、電路１の負荷側から入力された電圧を整流した後平滑する整流回路１０ａ、整流回路１０ａから入力された電圧を所定の時間、例えば１００ｍＳ程度遅らせる機能を有する遅延回路１０ｂから構成されている。１１は第１の遅延手段１０Ｂから入力された信号と信号変換部５から入力された信号に基づいて、遮断器接点３の開閉状態、負荷電流の通電状態を判定し、判定結果を演算部６に送る判定部である。
【００１８】
図２は第１の遅延手段１０の回路構成を示すもので、整流回路１０ａはブリッジダイオード１０ａ１及び平滑コンデンサ１０ａ２、遅延回路１０ｂは抵抗１０ｂ１、電解コンデンサ１０ｂ２及び電圧制限手段である定電圧ダイオード１０ｂ３により構成され、抵抗１０ｂ１及び電解コンデンサ１０ｂ２の夫々の値は、信号変換部５が出力を開始する時間（例えば１０ｍｓ）よりも第１の遅延手段１０の出力が所定の時間、例えば１００ｍｓ遅延するように設定されている。
【００１９】
なお、定電圧ダイオード１０ｂ３の定電圧特性は、第１の遅延手段１０から出力される電圧が所定の値（例えば１０Ｖ）以上にならないと出力されないように設定されており、この定電圧ダイオード１０ｂ３を配設することにより、電路１から入力されたノイズ信号による判定部１１の誤動作を防止することができる。
【００２０】
図３は、この発明の実施の形態１における回路遮断器の動作を示すタイムチャートである。
次に以上のように構成されたこの発明の実施の形態１における回路遮断器の動作について説明する。
【００２１】
最初に、電路１に負荷を接続状態（負荷電流通電状態）で回路遮断器２ａを投入した場合について図３（ａ）を用いて説明する。
（１）遮断器接点３がＯＮ（Ｓ１）になる。
（２）変流器８が電路１を流れる負荷電流を検出し、電源回路９に電流を供給する。
【００２２】
（３）電源回路９が電圧を発生（Ｓ２）し、信号変換部５、演算部６及び判定部１２に電力を供給する。
（４）電路１に流れる負荷電流を電流センサ４が検出し、負荷電流に応じた信号を信号変換部５へ送出する。
【００２３】
（５）信号変換部５は入力された信号を所定の信号に変換し、演算部６に出力すると共に、電路１に負荷電流が流れているという信号を判定部１１に送出（Ｓ３）する。
（６）判定部１１は第１の遅延手段１０から入力された信号（出力信号なし）と信号変換部５から入力された信号（出力信号あり）により、遮断器接点３が投入されたことを検知し、結果を演算部６に送る（Ｓ４）。
【００２４】
（７）演算部６に判定部１１からの信号に基づいて、所定の時間（Ｔ２）、例えば１００ｍｓ、長限時引外し動作、短限時引外し動作及び瞬時引外し動作を行う設定（Ｓ５）がされる。このとき、瞬時引外し動作を行うレベルの電流が電路１に流れていれば、トリップコイル７を駆動させ、遮断器接点３をＯＦＦにする。
（８）所定の時間（Ｔ２）後、演算部６に長限時引外し動作及び短限時引外し動作を行う設定（Ｓ６）がされる。
【００２５】
（９）第１の遅延手段１０は入力された電路１の電圧を整流回路１０ａのダイオードブリッジ１０ａ１で整流した後、平滑コンデンサ１０ａ２で平滑し、遅延回路１０ｂに入力され、抵抗１０ｂ１を介して電解コンデンサ１０ｂ２に充電される。電解コンデンサ１０ｂ２の電圧は抵抗１０ｂ１及び電解コンデンサ１０ｂ２で決定される時定数で徐々に増加し、電圧が定電圧ダイオード１０ｂ３の定電圧値に達する（Ｔ２）と、判定部１１へ信号を出力（Ｓ７）する。
なお、この時点においては演算部６での設定処理を完了しており、出力信号（Ｓ７）は無視される。
【００２６】
次に、回路遮断器２ａが投入状態で無負荷から負荷状態になった場合について図３（ｂ）を用いて説明する。
（１）無負荷（電路１に電圧が印加された状態で負荷電流が流れていない状態）においては、第１の遅延手段１０が電圧を出力（Ｓ１１）する。
（２）電路１に負荷電流が通電（Ｓ１２）される。
【００２７】
（３）電源回路９が電圧を発生（Ｓ１３）し、信号変換部５、演算部６及び判定部１１に電力を供給する。
（４）電路１に流れる負荷電流を電流センサ４が検出し、負荷電流に応じた信号を信号変換部５へ送出する。
【００２８】
（５）信号変換部５は入力された信号を所定の信号に変換し、演算部６に出力すると共に、電路１に負荷電流が流れているという信号を判定部１１に送出（Ｓ１４）する。
（６）判定部１１は第１の遅延手段１０から入力された信号（出力信号あり）と信号変換部５から入力された信号（出力信号あり）により、遮断器接点３が投入状態の時に電路１に負荷電流が流れたことを検知し、結果を演算部６に送る（Ｓ１５）。
【００２９】
（７）演算部６に長限時引外し動作及び短限時引外し動作を行う設定（Ｓ１６）がされる。
以上のように、この発明の実施の形態１における回路遮断器は、構造が簡素で且つ、信頼性の高い構成で、遮断器接点の開閉状態、負荷電流の通電状態に応じた限時引外し動作の設定を自動的に行うことができる。
【００３０】
実施の形態２
図４はこの発明の実施の形態２における回路遮断器の構成を示すブロック図、図５は、この発明の実施の形態２における回路遮断器の動作を示すタイムチャートである。
【００３１】
図において、２ｂは回路遮断器、１２は整流回路１２ａ、及び遅延回路１２ｂにより構成された第２の遅延手段で、この第２の遅延手段１２ｂの回路構成は上述した実施の形態１における第１の遅延手段１０と同様である。
なお、１，３〜１１については上述した実施の形態１と同様であり、同一の番号を付し説明を省略する。
【００３２】
次に以上のように構成されたこの発明の実施の形態２おける回路遮断器の動作について説明する。
最初に、電路１に負荷を接続状態（負荷電流通電状態）で回路遮断器２ｂ投入した場合について図５（ａ）を用いて説明する。
【００３３】
（１）遮断器接点３がＯＮ（Ｓ２１）になる。
（２）第２の遅延手段１２は電路１に電圧が印加された状態であり、電圧を出力（Ｓ２２）中である。
（３）変流器８が電路１を流れる負荷電流を検出し、電源回路９に電流を供給する。
【００３４】
（４）電源回路９が電圧を発生（Ｓ２３）し、信号変換部５、演算部６及び判定部１２に電力を供給する。
（５）電路１に流れる負荷電流を電流センサ４が検出し、負荷電流に応じた信号を信号変換部５へ送出する。
【００３５】
（６）信号変換部５は入力された信号を所定の信号に変換し、演算部６に出力すると共に、電路１に負荷電流が流れているという信号を判定部１１に送出（Ｓ２４）する。
（７）判定部１１は第１の遅延手段１０から入力された信号（出力信号なし）、第２の遅延手段１２から入力された信号（出力信号あり）、及び信号変換部５から入力された信号（出力信号あり）により、遮断器接点３が投入されたことを検知し、結果を演算部６に送る（Ｓ２５）。
【００３６】
（８）演算部６に判定部１１からの信号に基づいて、所定の時間（Ｔ３）、例えば１００ｍｓ、長限時引外し動作、短限時引外し動作及び瞬時引外し動作を行う設定（Ｓ２６）がされる。このとき、瞬時引外し動作を行うレベルの電流が電路１に流れていれば、トリップコイル７を駆動させ、遮断器接点３をＯＦＦにする。
（８）所定の時間（Ｔ３）後、演算部６に長限時引外し動作及び短限時引外し動作を行う設定（Ｓ２７）がされる。
【００３７】
（９）第１の遅延手段１０は入力された電路１の電圧を整流回路１０ａのダイオードブリッジ１０ａ１で整流した後、平滑コンデンサ１０ａ２で平滑し、遅延回路１０ｂに入力され、抵抗１０ｂ１を介して電解コンデンサ１０ｂ２に充電される。電解コンデンサ１０ｂ２の電圧は抵抗１０ｂ１及び電解コンデンサ１０ｂ２で決定される時定数で徐々に増加し、電圧が定電圧ダイオード１０ｂ３の定電圧値に達する（Ｔ４）と、判定部１１へ信号を出力（Ｓ２８）する。
なお、この時点においては演算部６での設定処理を完了しており、出力信号（Ｓ２８）は無視される。
【００３８】
次に、回路遮断器２ａが投入状態で無負荷から負荷状態になった場合について図５（ｂ）を用いて説明する。
（１）無負荷（電路１に電圧が印加された状態で負荷電流が流れていない状態）においては、第１の遅延手段１０及び第２の遅延手段１２が電圧を出力（Ｓ３１，３２）する。
（２）電路１に負荷電流が通電（Ｓ３３）される。
【００３９】
（３）電源回路９が電圧を発生（Ｓ３４）し、信号変換部５、演算部６及び判定部１１に電力を供給する。
（４）電路１に流れる負荷電流を電流センサ４が検出し、負荷電流に応じた信号を信号変換部５へ送出する。
【００４０】
（５）信号変換部５は入力された信号を所定の信号に変換し、演算部６に出力すると共に、電路１に負荷電流が流れているという信号を判定部１１に送出（Ｓ３５）する。
（６）判定部１１は第１の遅延手段１０から入力された信号（出力信号あり）、第２の遅延手段１２から入力された信号（出力信号あり）、及び信号変換部５から入力された信号（出力信号あり）により、遮断器接点３が投入状態の時に電路１に負荷電流が流れたことを検知し、結果を演算部６に送る（Ｓ３６）。
（７）演算部６に長限時引外し動作及び短限時引外し動作を行う設定（Ｓ３７）がされる。
【００４１】
なお、この発明の実施の形態２における回路遮断器は、図４に示すように電源側、負荷側の両方に遅延手段である第１の遅延手段１０、第２の遅延手段１２が配設されており、回路遮断器２ｂを電路１に対して逆接続した場合においても、上述と同様の動作を行う。
【００４２】
以上のように、この発明の実施の形態２における回路遮断器は、発明の実施の形態１における回路遮断器が負荷側にのみ遅延手段を配設していたものに対して、電源側、負荷側の両方に遅延手段が配設されているので、回路遮断器２ｂを電路１に対して逆接続した場合においても、構造が簡素で且つ、信頼性の高い構成で、遮断器接点の開閉状態、負荷電流の通電状態に応じ限時引外し動作の設定を自動的に行うことができる。
【００４３】
【発明の効果】
この発明によれば、電路に流れる電流を開閉する遮断器接点と、この遮断器接点を引外し動作させるトリップコイルと、電路に流れる電流を検出する電流検出手段と、この電流検出手段で検出した信号を所定の信号に変換する信号変換部と、この信号変換部から出力された信号を演算処理しこの信号に応じた引外し信号をトリップコイルに出力する演算部とを備えた回路遮断器において、電路の前記遮断器接点より負荷側に配設され電路から入力された電圧に基づいて所定の時間遅らせた信号を出力する第１の遅延手段と、この第１の遅延手段から入力された信号と前記信号変換部から入力された信号に基づいて遮断器接点の開閉状態、負荷電流の通電状態を判定し、この判定結果を演算部に出力する判定部とを備え、演算部が判定部の判定結果に基づいて限時引外し動作の設定を行うので、構造が簡素で且つ、信頼性の高い構成で、遮断器接点の開閉状態、負荷電流の通電状態に応じた引外し動作の設定を自動的に行うことができる。
【００４４】
また、電路が負荷電流通電状態で遮断器接点をＯＮにしたときに、演算部に長限時引外し動作、短限時引外し動作、及び瞬時引外し動作が設定された後、所定の時間後に長限時引外し動作、短限時引外し動作が設定されるので、電路に接続された負荷がトランスなどの突入電流が比較的大きなものが接続された場合に突入電流による誤動作がない。
【００４５】
また、第１の遅延手段は、電路の電圧を整流する整流回路と、この整流回路から入力された信号を遅延させて出力する遅延回路とにより構成されるので、簡素な構成で遅延信号を生成できる。
【００４６】
また、遅延回路は電圧制限手段を備えたので、電路から入力されたノイズ信号による判定部の誤動作を防止することができる。
【００４７】
また、電路の遮断器接点より電源側に配設され前記電路から入力された電圧に基づいて所定の時間遅らせた信号を出力する第２の遅延手段を備え、判定部は第１の遅延手段、前記第２の遅延手段から入力された信号、及び信号変換部から入力された信号に基づいて遮断器接点の開閉状態、負荷電流の通電状態を判定し、この判定結果を演算部に出力し、この演算部が前記判定部の判定結果に基づいて限時引外し動作の設定を行うので、回路遮断器を電路に対して逆接続した場合においても、構造が簡素で且つ、信頼性の高い構成で、遮断器接点の開閉状態、負荷電流の通電状態に応じ限時引外し動作の設定を自動的に行うことができる。
【００４８】
また、電路が負荷電流通電状態で遮断器接点をＯＮにしたときに、演算部に長限時引外し動作、短限時引外し動作、及び瞬時引外し動作が設定された後、所定の時間後に長限時引外し動作、短限時引外し動作が設定されるので、電路に接続された負荷がトランスなどの突入電流が比較的大きなものが接続された場合に突入電流による誤動作がない。
【図面の簡単な説明】
【図１】この発明の実施の形態１における回路遮断器の構成を示すブロック図である。
【図２】図１の回路遮断器を構成する第１の遅延手段の回路構成である。
【図３】この発明の実施の形態１における回路遮断器の動作を示すタイムチャートである。
【図４】この発明の実施の形態２における回路遮断器の構成を示すブロック図である。
【図５】この発明の実施の形態２における回路遮断器の動作を示すタイムチャートである。
【図６】従来の回路遮断器の構成を示すブロック図である。
【符号の説明】
１　電路、２ａ，２ｂ　回路遮断器、３　遮断器接点、
４　電流センサ（電流検出手段）、５　信号変換部、６　演算部、
７　トリップコイル、１０　第１の遅延手段、１０ａ　整流回路、
１０ｂ　遅延回路、１０ｂ３　電圧制限手段、１１　判定部、
１２　第２の遅延手段。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit breaker that performs a tripping operation according to a load current flowing through an electric circuit, and particularly to a timed tripping operation (a long timed tripping operation, a short timed trip operation, and a short-time tripping operation according to an open / close state of a circuit breaker contact and a load current energizing state). The present invention relates to a circuit breaker capable of changing settings of a timed trip operation and an instantaneous trip operation.
[0002]
[Prior art]
FIG. 6 is a block diagram showing a configuration of a conventional circuit breaker as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-245362.
In the figure, 1 is an electric circuit, 2 is a circuit breaker, 3 is a circuit breaker contact for opening and closing a current flowing in the electric circuit 1, 4 is a current sensor as current detecting means for detecting a current flowing in the electric circuit 1, and 5 is a current sensor 4. A signal conversion unit for converting the signal detected in step 1 into a predetermined signal; and a calculation unit 6 for processing the signal output from the signal conversion unit 5 and outputting a trip signal corresponding to the signal to a trip coil 7 described later. Then, when an overcurrent flows through the electric circuit 1, a trip signal corresponding to a signal input from the current sensor 2 via the signal converter 5 is output to the trip coil 7.
[0003]
As is well known, a trip coil 7 has a mechanism unit composed of an electromagnet, and trips the breaker contact 3 by the movement of a plunger (movable part) in response to a timed operation signal output from the calculation unit 6. The current transformer supplies a current to the power supply circuit 9 by a current flowing through the electric circuit 1. The power supply circuit 9 generates power to be supplied to the signal processing unit 5 and the arithmetic unit 6 by the current input from the current transformer 8.
[0004]
The circuit breaker 2 configured as described above, according to the magnitude of the load current flowing through the electric circuit 1, a long time trip operation, a short time trip operation, which is a known time trip operation of the circuit breaker, and Three operations of instantaneous trip operation are performed.
[0005]
[Problems to be solved by the invention]
The conventional circuit breaker is configured as described above, and performs three operations of a long time trip operation, a short time trip operation, and an instantaneous trip operation according to the magnitude of the load current flowing through the electric circuit. However, for example, if the load connected to the circuit is connected to a load with a relatively large rush current, such as a transformer, the instantaneous trip is performed when the circuit breaker is turned on to prevent malfunction due to the rush current. It is necessary to stop operation.
[0006]
However, if the instantaneous trip operation is simply disabled, if the circuit breaker is turned on and a short-circuit accident occurs on the load side, it is necessary to protect the electric circuit, which is the original function of the circuit breaker. Therefore, it is necessary to operate the instantaneous trip function only when the circuit breaker is turned on. As a countermeasure, there was a system that mechanically detects the closing operation of the circuit breaker and does not perform the instantaneous trip operation based on the detection result.However, this system uses a lever, spring, weight, This is a configuration in which mechanical parts such as switches are combined, and has a problem that the structure is complicated and the cost is high, and durability is inferior because it is composed of mechanical parts.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has a simple and highly reliable structure, and has a timed tripping operation in accordance with an open / closed state of a circuit breaker contact and an energized state of a load current. It is an object of the present invention to provide a circuit breaker that can automatically perform setting.
[0008]
[Means for Solving the Problems]
A circuit breaker according to the present invention comprises: a circuit breaker contact for opening and closing a current flowing in an electric circuit; a trip coil for tripping the circuit breaker contact; current detecting means for detecting a current flowing in the electric circuit; A signal conversion unit for converting a signal detected by the means into a predetermined signal; and a calculation unit for performing arithmetic processing on a signal output from the signal conversion unit and outputting a trip signal corresponding to the signal to the trip coil. Circuit breaker, the first delay means being disposed on the load side of the circuit path from the circuit breaker contact and outputting a signal delayed by a predetermined time based on the voltage input from the circuit path; and Based on the signal input from the delay unit and the signal input from the signal conversion unit, the open / close state of the breaker contact and the load current conduction state are determined, and the determination result is output to the arithmetic unit. And a tough, the arithmetic unit is used to set the time limit tripping based on the determination result of the determination unit.
[0009]
Also, when the circuit breaker contact is turned on while the circuit is energized with the load current, a long time trip operation, a short time trip operation, and an instantaneous trip operation are set in the calculation unit, and after a predetermined time, a long time trip operation is set. The timed trip operation and the short timed trip operation are set.
[0010]
Further, the first delay means includes a rectifier circuit for rectifying the voltage of the electric circuit, and a delay circuit for delaying and outputting a signal input from the rectifier circuit.
[0011]
Further, the delay circuit has a voltage limiting means.
[0012]
A second delay unit that is disposed closer to the power supply than the circuit breaker contact of the electric circuit and outputs a signal delayed by a predetermined time based on the voltage input from the electric circuit;
The determination unit determines the open / close state of the circuit breaker contact and the load current conduction state based on the signal input from the first delay unit, the second delay unit, and the signal input from the signal conversion unit. The determination result is output to a calculation unit, and the calculation unit sets the time-limited trip operation based on the determination result of the determination unit.
[0013]
Also, when the circuit breaker contact is turned on while the circuit is energized with the load current, a long time trip operation, a short time trip operation, and an instantaneous trip operation are set in the calculation unit, and after a predetermined time, a long time trip operation is set. The timed trip operation and the short timed trip operation are set.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a circuit breaker according to Embodiment 1 of the present invention.
In the figure, 1 is an electric circuit, 2a is a circuit breaker, 3 is a circuit breaker contact for opening and closing a current flowing in the electric circuit 1, 4 is a current sensor as current detecting means for detecting a current flowing in the electric circuit 1, and 5 is a current sensor 4. Is a signal conversion unit that converts the signal detected in step 1 into a predetermined signal.
[0015]
6 selects a predetermined timed trip operation from three timed trip operations, a long timed trip operation, a short timed trip operation, and an instantaneous trip operation, based on the judgment result of the judgment unit 11 described later. This is a calculation unit that performs setting and outputs a trip signal according to a signal input from the current sensor 2 via the signal conversion unit 5 to an after-mentioned trip coil 7 when an overcurrent flows through the electric circuit 1.
[0016]
As is well known, a trip coil 7 has a mechanism unit composed of an electromagnet, and trips the breaker contact 3 by the movement of a plunger (movable part) in response to a timed operation signal output from the calculation unit 6. A current transformer that supplies a current to a power supply circuit 9 by a current flowing through the electric circuit 1. The power supply circuit 9 supplies a current input from the current transformer 8 to a signal processing unit 5, a calculation unit 6, and a determination unit 11 described below. To generate power.
[0017]
Reference numeral 10 denotes a first delay unit, which includes a rectifier circuit 10a and a delay circuit 10b. The rectifier circuit 10a rectifies a voltage input from the load side of the electric circuit 1 and then smoothes the rectified voltage. , For example, about 100 mS. 11 determines the open / close state of the breaker contact 3 and the load current supply state based on the signal input from the first delay unit 10B and the signal input from the signal conversion unit 5, and calculates the determination result by the calculation unit 6. It is a determination unit to send to.
[0018]
FIG. 2 shows a circuit configuration of the first delay means 10. The rectifier circuit 10a includes a bridge diode 10a1 and a smoothing capacitor 10a2, and the delay circuit 10b includes a resistor 10b1, an electrolytic capacitor 10b2, and a constant voltage diode 10b3 serving as a voltage limiting means. The respective values of the resistor 10b1 and the electrolytic capacitor 10b2 are configured such that the output of the first delay unit 10 is delayed by a predetermined time, for example, 100 ms, from the time (for example, 10 ms) at which the signal conversion unit 5 starts outputting. Is set.
[0019]
The constant voltage characteristics of the constant voltage diode 10b3 are set so that the voltage is not output unless the voltage output from the first delay unit 10 exceeds a predetermined value (for example, 10 V). By arranging, it is possible to prevent a malfunction of the determination unit 11 due to a noise signal input from the electric circuit 1.
[0020]
FIG. 3 is a time chart illustrating the operation of the circuit breaker according to Embodiment 1 of the present invention.
Next, the operation of the circuit breaker thus configured according to the first embodiment of the present invention will be described.
[0021]
First, a case where the circuit breaker 2a is turned on with the load connected to the electric circuit 1 (load current energized state) will be described with reference to FIG.
(1) The breaker contact 3 is turned ON (S1).
(2) The current transformer 8 detects a load current flowing through the electric circuit 1 and supplies a current to the power supply circuit 9.
[0022]
(3) The power supply circuit 9 generates a voltage (S2), and supplies power to the signal conversion unit 5, the operation unit 6, and the determination unit 12.
(4) The current sensor 4 detects a load current flowing through the electric circuit 1 and sends a signal corresponding to the load current to the signal conversion unit 5.
[0023]
(5) The signal conversion unit 5 converts the input signal into a predetermined signal, outputs the signal to the calculation unit 6, and sends a signal indicating that a load current is flowing through the electric circuit 1 to the determination unit 11 (S3).
(6) The determination unit 11 determines that the circuit breaker contact 3 has been turned on by the signal input from the first delay unit 10 (no output signal) and the signal input from the signal conversion unit 5 (output signal present). It detects and sends the result to the arithmetic unit 6 (S4).
[0024]
(7) Based on the signal from the determination unit 11, the arithmetic unit 6 performs a setting for performing a predetermined time (T2), for example, 100 ms, a long time trip operation, a short time trip operation, and an instantaneous trip operation (S5). Is done. At this time, if a current at a level for performing an instantaneous trip operation is flowing in the electric circuit 1, the trip coil 7 is driven and the circuit breaker contact 3 is turned off.
(8) After a predetermined time (T2), the arithmetic unit 6 is set to perform the long time trip operation and the short time trip operation (S6).
[0025]
(9) The first delay means 10 rectifies the input voltage of the electric circuit 1 by the diode bridge 10a1 of the rectifier circuit 10a, smoothes the rectified voltage by the smoothing capacitor 10a2, inputs the rectified voltage to the delay circuit 10b, and performs electrolysis via the resistor 10b1. The capacitor 10b2 is charged. The voltage of the electrolytic capacitor 10b2 gradually increases with a time constant determined by the resistor 10b1 and the electrolytic capacitor 10b2, and when the voltage reaches the constant voltage value of the constant voltage diode 10b3 (T2), a signal is output to the determination unit 11 (S7). ).
At this point, the setting process in the calculation unit 6 has been completed, and the output signal (S7) is ignored.
[0026]
Next, a case where the circuit breaker 2a changes from a no-load state to a load state in the closed state will be described with reference to FIG.
(1) When there is no load (in a state where a load current is not flowing while a voltage is applied to the electric circuit 1), the first delay unit 10 outputs a voltage (S11).
(2) A load current is supplied to the electric circuit 1 (S12).
[0027]
(3) The power supply circuit 9 generates a voltage (S13), and supplies power to the signal conversion unit 5, the operation unit 6, and the determination unit 11.
(4) The current sensor 4 detects a load current flowing through the electric circuit 1 and sends a signal corresponding to the load current to the signal conversion unit 5.
[0028]
(5) The signal conversion unit 5 converts the input signal into a predetermined signal, outputs the signal to the calculation unit 6, and sends a signal indicating that a load current is flowing through the electric circuit 1 to the determination unit 11 (S14).
(6) The determination unit 11 determines whether or not the circuit when the breaker contact 3 is in the closed state, based on the signal (with output signal) input from the first delay unit 10 and the signal (with output signal) input from the signal conversion unit 5. 1 is detected, and the result is sent to the calculation unit 6 (S15).
[0029]
(7) The arithmetic unit 6 is set to perform the long time limit trip operation and the short time limit trip operation (S16).
As described above, the circuit breaker according to the first embodiment of the present invention has a simple structure and a highly reliable configuration, and the timed trip operation according to the open / closed state of the breaker contact and the energized state of the load current. Can be set automatically.
[0030]
Embodiment 2
FIG. 4 is a block diagram illustrating a configuration of a circuit breaker according to Embodiment 2 of the present invention, and FIG. 5 is a time chart illustrating an operation of the circuit breaker according to Embodiment 2 of the present invention.
[0031]
In the figure, 2b is a circuit breaker, 12 is a second delay means composed of a rectifier circuit 12a and a delay circuit 12b, and the circuit configuration of the second delay means 12b is the first delay means in the first embodiment described above. Is the same as that of the delay means 10.
It should be noted that 1, 3 to 11 are the same as those in the first embodiment described above, and are denoted by the same reference numerals and description thereof is omitted.
[0032]
Next, the operation of the circuit breaker according to Embodiment 2 of the present invention configured as described above will be described.
First, a case where the circuit breaker 2b is turned on in a state where a load is connected to the electric circuit 1 (a state where a load current is supplied) will be described with reference to FIG.
[0033]
(1) The breaker contact 3 is turned on (S21).
(2) The second delay means 12 is in a state where a voltage is applied to the electric circuit 1, and is outputting a voltage (S22).
(3) The current transformer 8 detects a load current flowing through the electric circuit 1 and supplies a current to the power supply circuit 9.
[0034]
(4) The power supply circuit 9 generates a voltage (S23), and supplies power to the signal conversion unit 5, the operation unit 6, and the determination unit 12.
(5) The current sensor 4 detects a load current flowing through the electric circuit 1 and sends a signal corresponding to the load current to the signal conversion unit 5.
[0035]
(6) The signal conversion unit 5 converts the input signal into a predetermined signal, outputs the signal to the calculation unit 6, and sends a signal indicating that a load current is flowing through the electric circuit 1 to the determination unit 11 (S24).
(7) The determination unit 11 receives the signal input from the first delay unit 10 (without an output signal), the signal input from the second delay unit 12 (with an output signal), and the signal input from the signal conversion unit 5. Based on the signal (there is an output signal), it is detected that the circuit breaker contact 3 has been turned on, and the result is sent to the calculation unit 6 (S25).
[0036]
(8) Based on the signal from the determination unit 11, the arithmetic unit 6 sets a predetermined time (T3), for example, 100 ms, to perform a long time trip operation, a short time trip operation, and an instantaneous trip operation (S26). Is done. At this time, if a current at a level for performing an instantaneous trip operation is flowing in the electric circuit 1, the trip coil 7 is driven and the circuit breaker contact 3 is turned off.
(8) After a predetermined time (T3), the arithmetic unit 6 is set to perform the long time trip operation and the short time trip operation (S27).
[0037]
(9) The first delay means 10 rectifies the input voltage of the electric circuit 1 by the diode bridge 10a1 of the rectifier circuit 10a, smoothes the rectified voltage by the smoothing capacitor 10a2, inputs the rectified voltage to the delay circuit 10b, and performs electrolysis via the resistor 10b1. The capacitor 10b2 is charged. The voltage of the electrolytic capacitor 10b2 gradually increases with a time constant determined by the resistor 10b1 and the electrolytic capacitor 10b2, and when the voltage reaches the constant voltage value of the constant voltage diode 10b3 (T4), a signal is output to the determination unit 11 (S28). ).
At this point, the setting process in the calculation unit 6 has been completed, and the output signal (S28) is ignored.
[0038]
Next, a case where the circuit breaker 2a changes from a no-load state to a load state in the closed state will be described with reference to FIG.
(1) When there is no load (in a state where a voltage is applied to the electric circuit 1 and no load current flows), the first delay unit 10 and the second delay unit 12 output a voltage (S31, 32). .
(2) A load current is supplied to the electric circuit 1 (S33).
[0039]
(3) The power supply circuit 9 generates a voltage (S34), and supplies power to the signal conversion unit 5, the operation unit 6, and the determination unit 11.
(4) The current sensor 4 detects a load current flowing through the electric circuit 1 and sends a signal corresponding to the load current to the signal conversion unit 5.
[0040]
(5) The signal conversion unit 5 converts the input signal into a predetermined signal, outputs the signal to the calculation unit 6, and sends a signal indicating that a load current is flowing through the electric circuit 1 to the determination unit 11 (S35).
(6) The determination unit 11 receives the signal (with an output signal) input from the first delay unit 10, the signal (with an output signal) input from the second delay unit 12, and the signal input from the signal conversion unit 5. Based on the signal (with output signal), it is detected that a load current has flowed through the electric circuit 1 when the circuit breaker contact 3 is in the closed state, and the result is sent to the calculation unit 6 (S36).
(7) The arithmetic unit 6 is set to perform the long time limit trip operation and the short time limit trip operation (S37).
[0041]
In the circuit breaker according to Embodiment 2 of the present invention, as shown in FIG. 4, a first delay unit 10 and a second delay unit 12, which are delay units, are provided on both the power supply side and the load side. Therefore, even when the circuit breaker 2b is reversely connected to the electric circuit 1, the same operation as described above is performed.
[0042]
As described above, the circuit breaker according to the second embodiment of the present invention is different from the circuit breaker according to the first embodiment in which delay means is provided only on the load side, in that the power supply side and the load Since the delay means is provided on both sides, even when the circuit breaker 2b is reversely connected to the electric circuit 1, the open / close state of the circuit breaker contacts is simple and highly reliable. In addition, the setting of the timed trip operation can be automatically performed in accordance with the state of the load current.
[0043]
【The invention's effect】
According to the present invention, a circuit breaker contact that opens and closes a current flowing through an electric circuit, a trip coil that trips the circuit breaker contact and operates, a current detecting unit that detects a current flowing through the electric circuit, and a current detected by the current detecting unit A circuit breaker comprising: a signal conversion unit that converts a signal into a predetermined signal; and a calculation unit that performs arithmetic processing on a signal output from the signal conversion unit and outputs a trip signal corresponding to the signal to a trip coil. A first delay means disposed on the load side of the circuit breaker contact for outputting a signal delayed by a predetermined time based on a voltage input from the circuit, and a signal input from the first delay means; And a determining unit that determines the open / closed state of the circuit breaker contact and the energized state of the load current based on the signal input from the signal conversion unit, and outputs a result of the determination to the arithmetic unit. Judgment The timed trip operation is set based on the results, so the structure is simple and the configuration is highly reliable, and the tripping operation is automatically set according to the open / close state of the breaker contacts and the load current conduction state. Can be done.
[0044]
Also, when the circuit breaker contact is turned on while the circuit is energized with the load current, a long time trip operation, a short time trip operation, and an instantaneous trip operation are set in the calculation unit, and after a predetermined time, a long time trip operation is set. Since the timed trip operation and the short timed trip operation are set, there is no malfunction due to the rush current when the load connected to the electric circuit is a transformer or the like having a relatively large rush current.
[0045]
Further, the first delay means includes a rectifier circuit for rectifying the voltage of the electric circuit and a delay circuit for delaying and outputting a signal input from the rectifier circuit, so that the delay signal is generated with a simple configuration. it can.
[0046]
In addition, since the delay circuit includes the voltage limiting means, it is possible to prevent a malfunction of the determination unit due to the noise signal input from the electric circuit.
[0047]
A second delay unit that is disposed closer to the power supply than the circuit breaker contact of the electric circuit and outputs a signal delayed by a predetermined time based on the voltage input from the electric circuit, the determination unit includes a first delay unit; A signal input from the second delay unit and a switching state of the circuit breaker contact based on the signal input from the signal conversion unit, and a conduction state of the load current are determined, and the determination result is output to a calculation unit. Since this calculation unit sets the timed trip operation based on the determination result of the determination unit, even when the circuit breaker is reversely connected to the electric circuit, the structure is simple and the configuration is highly reliable. The timed trip operation can be automatically set in accordance with the open / close state of the circuit breaker contacts and the load current supply state.
[0048]
Also, when the circuit breaker contact is turned on while the circuit is energized with the load current, a long time trip operation, a short time trip operation, and an instantaneous trip operation are set in the calculation unit, and after a predetermined time, a long time trip operation is set. Since the timed trip operation and the short timed trip operation are set, there is no malfunction due to the rush current when the load connected to the electric circuit is a transformer or the like having a relatively large rush current.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a circuit breaker according to Embodiment 1 of the present invention.
FIG. 2 is a circuit configuration of a first delay unit included in the circuit breaker of FIG. 1;
FIG. 3 is a time chart illustrating an operation of the circuit breaker according to Embodiment 1 of the present invention.
FIG. 4 is a block diagram showing a configuration of a circuit breaker according to Embodiment 2 of the present invention.
FIG. 5 is a time chart showing an operation of the circuit breaker according to Embodiment 2 of the present invention.
FIG. 6 is a block diagram showing a configuration of a conventional circuit breaker.
[Explanation of symbols]
1 circuit, 2a, 2b circuit breaker, 3 breaker contact,
4 current sensor (current detection means), 5 signal conversion unit, 6 arithmetic unit,
7 trip coil, 10 first delay means, 10a rectifier circuit,
10b delay circuit, 10b3 voltage limiting means, 11 determination unit,
12 Second delay means.

Claims

A circuit breaker contact for opening and closing the current flowing through the electric circuit;
A trip coil for tripping and operating the circuit breaker contact;
Current detection means for detecting a current flowing in the electric circuit,
A signal conversion unit that converts a signal detected by the current detection unit into a predetermined signal;
A circuit breaker comprising: an arithmetic unit that arithmetically processes a signal output from the signal conversion unit and outputs a trip signal corresponding to the signal to the trip coil;
A first delay unit that is arranged on the load side of the circuit breaker contact of the circuit and outputs a signal delayed by a predetermined time based on a voltage input from the circuit;
Based on the signal input from the first delay unit and the signal input from the signal conversion unit, an open / close state of the circuit breaker contact and a load current conduction state are determined, and the determination result is output to the arithmetic unit. And a determination unit that performs
The circuit breaker, wherein the calculation unit sets a time-limited trip operation based on a result of the determination by the determination unit.

When the circuit breaker contact is turned on while the load circuit is energized, the long time trip operation, short time trip operation, and instantaneous trip operation are set in the calculation unit, and then a long time 2. The circuit breaker according to claim 1, wherein a trip operation and a short time trip operation are set.

A first delay unit configured to rectify a voltage of the electric circuit;
2. The circuit breaker according to claim 1, further comprising a delay circuit that delays a signal input from the rectifier circuit and outputs the delayed signal.

4. The circuit breaker according to claim 3, wherein the delay circuit includes voltage limiting means.

A second delay unit that is disposed closer to the power supply than the circuit breaker contact of the electric circuit and outputs a signal delayed by a predetermined time based on the voltage input from the electric circuit;
The determination unit determines the open / close state of the circuit breaker contact and the load current conduction state based on the signal input from the first delay unit, the second delay unit, and the signal input from the signal conversion unit. 2. The circuit breaker according to claim 1, wherein a result of the determination is output to a calculation unit, and the calculation unit sets the timed trip operation based on the result of the determination by the determination unit.

When the circuit breaker contact is turned on while the load circuit is energized, the long time trip operation, short time trip operation, and instantaneous trip operation are set in the calculation unit, and then a long time 6. The circuit breaker according to claim 5, wherein a trip operation and a short time trip operation are set.