JP3805617B2

JP3805617B2 - Cable fault detection device

Info

Publication number: JP3805617B2
Application number: JP2000351042A
Authority: JP
Inventors: 知之山形; 健七郎三島; 工山根; 秀樹吉武
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-11-17
Filing date: 2000-11-17
Publication date: 2006-08-02
Anticipated expiration: 2020-11-17
Also published as: JP2002159131A

Description

【０００１】
【発明の属する技術分野】
本発明は、高圧交流電路に布設する相毎に金属製遮蔽体を有するケ−ブルの故障を検知するケーブル故障検出装置に関する。
【０００２】
【従来の技術】
ここで従来のケーブル故障検出装置について説明する。図７は従来のケーブル故障検出装置のブロック構成図である。図７において、高圧交流電路１に布設された相ごとに金属製遮蔽体２１を有するケーブル２に開閉器３を介して負荷４が接続されている。このケーブル故障検出装置は、各金属製遮蔽体２１の接地線６−１の接地線電流を検出する電流検出手段５−１〜５−３の出力を入力とする各相接地線電流検出回路７３と、各接地線６−１を一括接続して接地した一括接地線６−２の接地線電流を検出する電流検出手段５−４の出力を入力とする地絡検出回路７２と、一括接地線６−２の接地線電流を検出する電流検出手段５−５の検出出力により電源接続部７６を接続状態とすることにより電池電源７５を定電圧電源部８３を介して地絡検出回路７２および各相接地線電流検出回路７３に接続する電源駆動手段７１と、地絡検出回路７２の地絡事故検出動作により機械的または磁気的に表示器の表示状態を継続する第一の表示手段７４−１と、計測値および事故経歴を表示する第二の表示手段７４−２と、点検時に電源駆動手段７１に信号を送り電源接続部７６を所定時間接続するように動作させる手動操作のスイッチ手段７７とで構成されている。なお、定電圧電源部８３は、電源接続部７６が接続状態のときに、電池電源７５から電圧の供給を受け、一定の電圧を地絡検出回路７２および各相接地線電流検出回路７３に供給する。
【０００３】
ケーブル２は、一例として導体部を中心（芯）とし、その外側に半導電層，絶縁体，半導電層，金属製遮蔽体２１，テープ，シースが順に巻かれた構成である。金属製遮蔽体２１はアルミや銅などの金属からなり、金属製遮蔽体２１を接地し、そこに流れる接地線電流の大きさからケーブル２の劣化等を判断できる。ここでいう地絡事故とは、ケーブル２で発生し、ケーブル２の導体部と接地された金属製遮蔽体２１とが接触してしまう状態となることであり、そのとき電流はケーブル２の導体部から金属製遮蔽体２１に接続された接地線６−１，６−２を通り、地面に流れる。帰還電流はまわりの接地線からケーブル２に戻る。
【０００４】
次に上記構成のケーブル故障検出装置の動作を説明する。地絡事故が発生した場合、地絡電流が金属製遮蔽体２１の接地線６−１に流れ、それによる電流が零相電流として一括接地線６−２に流れる。一括接地線６−２に流れる零相電流を接地線電流を検出する電流検出手段５−５が検出し、その出力が第一の規定値（電源駆動用規定値）以上の場合、電源駆動手段７１は電源接続部７６を接続状態にして地絡検出回路７２および各相接地線電流検出回路７３に定電圧電源部８３を介して電池電源７５を接続する。そして零相電流が第二の規定値（事故検出用規定値）以上の場合、地絡検出回路７２は地絡事故として検出し、その検出信号を第一の表示手段７４−１および第二の表示手段７４−２へ送る。この検出信号により第一の表示手段７４−１では機械的または磁気的に表示状態を継続する表示器を電池電源７５で動作させ、事故の発生を表示するとともに事故データを記録する。ここで、第一の表示手段７４−１は、前述の表示器や事故データを記録する媒体などを備えたものである。なお、第二の規定値は第一の規定値より大きい値である。
【０００５】
また、第一の表示手段７４−１は、手動操作のスイッチ手段７７から電源駆動手段７１への信号による電源起動時に、表示器の正常動作確認として表示器を一旦動作させた後、表示復帰という動作をしたり、事故経歴の消去時には表示復帰の動作も行う。
【０００６】
また、第二の表示手段７４−２は、事故入力または手動操作のスイッチ手段７７から電源駆動手段７１への信号による電源起動時に、各相接地線電流検出回路７３及び地絡検出回路７２の計測結果及び事故経歴を表示する。
【０００７】
なお、点検時に手動操作のスイッチ手段７７から電源駆動手段７１へ信号が送られると、電源駆動手段７１は電流検出手段５−５からの入力にかかわらず、電源接続部７６を接続状態にする。
【０００８】
【発明が解決しようとする課題】
上記従来の構成では、地絡事故が発生するたびに電源駆動手段７１が地絡検出回路７２に電池電源７５を接続するので、電池寿命に至るまで電源起動してしまい、点検時には電源起動することができないという課題があった。
【０００９】
また、地絡事故が発生した場合に流れる地絡電流による零相電流が第二の規定値以上となって、その零相電流が継続した場合に、地絡検出回路７２が動作したにもかかわらず電源駆動手段７１により地絡検出回路７２に電池電源７５が接続されたままとなり、電池が不必要に消費されるという課題があった。
【００１０】
また、地絡事故が発生した場合に流れる地絡電流による零相電流が地絡検出に至らず継続する場合には、電池寿命に至るまで電池電源７５が接続されたままとなり、電池が不必要に消費されるという課題があった。
【００１１】
また、地絡検出回路７２の動作によって機械的または磁気的に表示状態を継続する表示器を電池電源７５で動作させる場合、電池の瞬時大電流負荷時の電池電圧降下によりケーブル故障検出装置の動作が不安定となる課題があった。
【００１２】
本発明は、上記課題を解決することができるケーブル故障検出装置を提供することを目的とするものであり、第一の目的は、点検時には電池電源により必ず電源起動することができるケーブル故障検出装置を提供することであり、第二の目的は、電池電源の電池が不必要に消費されるのを防止することができるケーブル故障検出装置を提供することであり、第三の目的は、表示器の動作により瞬時に大きな負荷電流が流れても安定した動作が可能となるケーブル故障検出装置を提供することである。
【００１３】
【課題を解決するための手段】
本発明の請求項１記載のケーブル故障検出装置は、電池電源と、高圧交流電路に布設され相毎に金属製遮蔽体を有するケ−ブルの各金属製遮蔽体に接続された各接地線を一括して接地した一括接地線または前記各金属製遮蔽体に接続された各接地線に流れる接地線電流を検出する電流検出手段と、前記電流検出手段で検出した接地線電流が事故検出用規定値以上のときに地絡事故の検出を行う地絡検出回路と、前記電流検出手段で検出した接地線電流が前記事故検出用規定値より小さい値である電源駆動用規定値以上のときには前記電池電源を前記地絡検出回路に接続し、前記電源駆動用規定値未満のときには前記電池電源を前記地絡検出回路に非接続とする電源駆動手段とを備えたケ−ブル故障検出装置であって、前記電池電源の電池が点検のために確保すべき電源容量に至ると前記電流検出手段から前記電源駆動手段への入力を無効にし前記電池電源を非接続状態とするロック手段を設けたことを特徴とする。
【００１４】
この請求項１の構成によれば、ロック手段を設け、電池電源が電池寿命に至る前に電源駆動手段をロックすることで、以後の事故入力に対して電池の消耗を防ぐ一方、点検時に電池電源により電源起動することができる。
【００１５】
本発明の請求項２記載のケーブル故障検出装置は、電池電源と、高圧交流電路に布設され相毎に金属製遮蔽体を有するケ−ブルの各金属製遮蔽体に接続された各接地線を一括して接地した一括接地線または前記各金属製遮蔽体に接続された各接地線に流れる接地線電流を検出する電流検出手段と、前記電流検出手段で検出した接地線電流が事故検出用規定値以上のときに地絡事故の検出を行う地絡検出回路と、前記電流検出手段で検出した接地線電流が前記事故検出用規定値より小さい値である電源駆動用規定値以上のときには前記電池電源を前記地絡検出回路に接続し、前記電源駆動用規定値未満のときには前記電池電源を前記地絡検出回路に非接続とする電源駆動手段とを備えたケ−ブル故障検出装置であって、前記電流検出手段で検出した接地線電流が前記事故検出用規定値以上の状態が第一の特定時間継続したとき前記電流検出手段から前記電源駆動手段への入力を無効にし前記電池電源を非接続状態とするロック手段を設けたことを特徴とする。
【００１６】
この請求項２の構成によれば、ロック手段を設け、地絡事故検出後の地絡電流継続に対し電源駆動手段をロックすることで、電池の不必要な消費をなくすことができる。
【００１７】
本発明の請求項３記載のケーブル故障検出装置は、電池電源と、高圧交流電路に布設され相毎に金属製遮蔽体を有するケ−ブルの各金属製遮蔽体に接続された各接地線を一括して接地した一括接地線または前記各金属製遮蔽体に接続された各接地線に流れる接地線電流を検出する電流検出手段と、前記電流検出手段で検出した接地線電流が事故検出用規定値以上のときに地絡事故の検出を行う地絡検出回路と、前記電流検出手段で検出した接地線電流が前記事故検出用規定値より小さい値である電源駆動用規定値以上のときには前記電池電源を前記地絡検出回路に接続し、前記電源駆動用規定値未満のときには前記電池電源を前記地絡検出回路に非接続とする電源駆動手段とを備えたケ−ブル故障検出装置であって、前記電流検出手段で検出した接地線電流が前記電源駆動用規定値以上で前記事故検出用規定値未満の状態が第二の特定時間継続した後、前記電池電源の電池が点検のために確保すべき電源容量に至ると前記電流検出手段から前記電源駆動手段への入力を無効にし前記電池電源を非接続状態とするロック手段を設けたことを特徴とする。
【００１８】
この請求項３の構成によれば、ロック手段を設け、地絡検出に至らない地絡電流の継続に対し、電池寿命に至る前に電源駆動手段をロックすることで、電池の不必要な消費をなくすことができる。
【００１９】
本発明の請求項４記載のケーブル故障検出装置は、請求項１，請求項２または請求項３に記載のケ−ブル故障検出装置において、ロック手段はラッチングリレーを用い、ラッチングリレーにより電流検出手段から電源駆動手段への入力を無効にするようにしたことを特徴とする。このようにロック手段を構成できる。
【００２４】
【発明の実施の形態】
（第１の実施の形態）
本発明の第１の実施の形態について図１および図２を用いて説明する。図１は第１の実施の形態のケーブル故障検出装置のブロック構成図、図２は同ケーブル故障検出装置の動作説明用のフロー図である。
【００２５】
図１において、高圧交流電路１に布設された相ごとに金属製遮蔽体２１を有するケーブル２に開閉器３を介して負荷４が接続されている。このケーブル故障検出装置は、各金属製遮蔽体２１の接地線６−１の接地線電流を検出する電流検出手段５−１〜５−３の出力を入力とする各相接地線電流検出回路７３と、各接地線６−１を一括接続して接地した一括接地線６−２の接地線電流を検出する電流検出手段５−４の出力を入力とする地絡検出回路７２と、一括接地線６−２の接地線電流を検出する電流検出手段５−５の検出出力により電源接続部７６を接続状態とすることにより電池電源７５を定電圧電源部８３を介して地絡検出回路７２および各相接地線電流検出回路７３に接続する電源駆動手段７１と、地絡検出回路７２の地絡事故検出動作により機械的または磁気的に表示器の表示状態を継続する第一の表示手段７４−１と、計測値および事故経歴を表示する第二の表示手段７４−２と、点検時に電源駆動手段７１に信号を送り電源接続部７６を所定時間接続するように動作させる手動操作のスイッチ手段７７と、電源駆動手段７１をロックするロック手段８１とで構成されている。従来の構成との違いはロック手段８１を設けたことであり、図７と同等のものには同一符号を付している。
【００２６】
上記構成における動作を図２のフロー図を用いて説明する。地絡事故が発生した場合、地絡電流が金属製遮蔽体２１の接地線６−１に流れ、それによる電流が零相電流として一括接地線６−２に流れる。一括接地線６−２に流れる零相電流を接地線電流を検出する電流検出手段５−５が検出し、その出力が第一の規定値（電源駆動用規定値）以上の場合、電源駆動手段７１は電源接続部７６を非接続状態から接続状態にして地絡検出回路７２および各相接地線電流検出回路７３に定電圧電源部８３を介して電池電源７５を接続する（ステップＳ１１の電源起動）。また、電流検出手段５−５の出力が第一の規定値未満になると、電源駆動手段７１は電源接続部７６を接続状態から非接続状態にして地絡検出回路７２および各相接地線電流検出回路７３から電池電源７５を切り離す。
【００２７】
電流検出手段５−５の出力が第一の規定値以上となり、電池電源７５が接続された（ステップＳ１１の電源起動）場合について、以下説明する。電源駆動手段７１では、電池電源７５の電池使用開始からの累積動作時間を計算し（ステップＳ１２）、その累積動作時間が電池の規定残存容量にいたる時間より小さいか否かを判定し（ステップＳ１３）、電池の規定残存容量にいたる時間以上であれば、ロック手段８１を制御する。この電源駆動手段７１の制御によりロック手段８１が電源駆動手段７１をロックする（Ｓ１４）。この電源駆動手段７１をロックするということは、事故入力による電源起動をできなくすることであり、ロック手段８１が電流検出手段５−５からの電源駆動手段７１への入力を無効にする（電流検出手段５−５を電源駆動手段７１から電気的に切り離す）ことにより、電源接続部７６を非接続状態とすることである。したがって、電源駆動手段７１がロックされると、以後の事故入力は無効となり、電池電源７５の電池の消費はなくなる。なお、電池の規定残存容量とは、製品仕様で決まり、例えば、仕様で電池容量が「電池残存容量が３０％で動作回数５００回以上であること」とあれば、電池の規定残存容量を３０％にする。
【００２８】
また、上記の説明では、ステップＳ１２からステップＳ１４でロック手段８１を制御するまでの処理を、電源駆動手段７１により行うものとしたが、地絡検出回路７２で行うようにしてもよい。
【００２９】
なお、電源駆動手段７１がロックされていない場合に、零相電流が第二の規定値（事故検出用規定値）以上になったとき、地絡検出回路７２が地絡事故として検出し、その検出信号が第一の表示手段７４−１および第二の表示手段７４−２へ送られるのは、従来例で述べた通りである。
【００３０】
また、電源駆動手段７１がロックされている場合、点検時に手動操作のスイッチ手段７７から電源駆動手段７１へ信号が送られると、電源駆動手段７１はロック手段８１からの入力にかかわらず、電源接続部７６を接続状態にし、このとき、電流検出手段５−５からの入力はロック手段８１により無効にされたままである。
【００３１】
第１の実施の形態によれば、電池電源７５が電池寿命に至る前に、ロック手段８１により電流検出手段５−５からの電源駆動手段７１への入力（事故入力）を無効にすることにより電源駆動手段７１をロックするので、点検時には手動操作のスイッチ手段７７により電源を起動させ、事故経歴確認をすることができる。また、ロック手段８１としてラッチングリレーを使用した場合、手動操作のスイッチ手段７７により容易に電源駆動手段７１のロックを解除することができる。ここで、ラッチングリレーは、コイルに通電して接点が動作したら、電流を切っても接点の状態が保持されるリレーである。
【００３２】
また、ここでは一括接地線６−２に接続された接地線電流を検出する電流検出手段５−５の出力により電源起動する場合を記述したが、各相ケーブルの接地線６−１に接続された接地線電流を検出する電流検出手段５−１〜５−３の出力により電源駆動手段７１に信号を送り、電源起動してもよい。
【００３３】
上記のように、第一の規定値の比較対象として零相電流の代わりに各相ケーブルの接地線電流を比較対象としてもよいし、第二の規定値の比較対象についても零相電流の代わりに各相ケーブルの接地線電流を比較対象としてもよい。
【００３４】
（第２の実施の形態）
第２の実施の形態について図３を用いて説明する。図３は第２の実施の形態のケーブル故障検出装置の動作説明用のフロー図である。第２の実施の形態の構成図については第１の実施の形態を示す図１と同様なのでその説明を省略する。
【００３５】
次に動作を図３を用いて説明する。地絡事故が発生した場合、地絡電流が金属製遮蔽体２１の接地線６−１に流れ、それによる電流が零相電流として一括接地線６−２に流れる。一括接地線６−２に流れる零相電流を接地線電流を検出する電流検出手段５−５が検出し、その出力が第一の規定値（電源駆動用規定値）以上の場合、電源駆動手段７１は電源接続部７６を非接続状態から接続状態にして地絡検出回路７２および各相接地線電流検出回路７３に定電圧電源部８３を介して電池電源７５を接続する（ステップＳ２１の電源起動）。また、電流検出手段５−５の出力が第一の規定値未満になると、電源駆動手段７１は電源接続部７６を接続状態から非接続状態にして地絡検出回路７２および各相接地線電流検出回路７３から電池電源７５を切り離す。
【００３６】
電流検出手段５−５の出力が第一の規定値以上となり、電池電源７５が接続された（ステップＳ２１の電源起動）場合について、以下説明する。電源が起動すると、地絡検出回路７２では、電流検出手段５−４からの零相電流を計測して第二の規定値（事故検出用規定値）と比較し（ステップＳ２２，Ｓ２３）、その零相電流が第二の規定値以上の場合、地絡事故と判断し、その検出信号を第一の表示手段７４−１および第二の表示手段７４−２へ送る（ステップＳ２４）。
【００３７】
地絡検出回路７２は、事故検出動作後も、引き続き電流検出手段５−４からの零相電流を計測し、第二の規定値以上の零相電流が継続してるかどうかを判定する（ステップＳ２５，Ｓ２６）とともに、第二の規定値以上の零相電流の継続時間を算出し（ステップＳ２７）、その算出した継続時間が予め定めた第一の特定時間になると、ロック手段８１を制御する。この地絡検出回路７２の制御によりロック手段８１が電源駆動手段７１をロックする（ステップＳ２８，Ｓ２９）。電源駆動手段７１がロックされると、その後の地絡検出回路７２および各相接地線電流検出回路７３による不必要な電池の消費はなくなる。
【００３８】
第２の実施の形態によれば、電源駆動手段７１をロックすることにより、第二の規定値以上の零相電流の継続に対する地絡事故検出動作後の不必要な電池の消費をなくすことができる。また、ロック手段８１としてラッチングリレーを使用した場合、手動操作のスイッチ手段７７により容易に電源駆動手段７１のロックを解除することができる。
【００３９】
なお、上記の説明では、ステップＳ２２からステップＳ２９でロック手段８１を制御するまでの処理を、地絡検出回路７２により行うものとしたが、電源駆動手段７１で行うようにしてもよい。
【００４０】
また、ここでは第一の規定値および第二の規定値の比較対象として零相電流を用いたが、零相電流の代わりに各相ケーブルの接地線電流を比較対象としてもよい。
【００４１】
（第３の実施の形態）
第３の実施の形態について図４を用いて説明する。図４は第３の実施の形態のケーブル故障検出装置の動作説明用のフロー図である。第３の実施の形態の構成図については第１の実施の形態を示す図１と同様なのでその説明を省略する。
【００４２】
次に動作を図４を用いて説明する。地絡事故が発生した場合、地絡電流が金属製遮蔽体２１の接地線６−１に流れ、それによる電流が零相電流として一括接地線６−２に流れる。一括接地線６−２に流れる零相電流を接地線電流を検出する電流検出手段５−５が検出し、その出力が第一の規定値（電源駆動用規定値）を以上の場合、電源駆動手段７１は電源接続部７６を非接続状態から接続状態にして地絡検出回路７２および各相接地線電流検出回路７３に定電圧電源部８３を介して電池電源７５を接続する（ステップＳ３１の電源起動）。また、電流検出手段５−５の出力が第一の規定値未満になると、電源駆動手段７１は電源接続部７６を接続状態から非接続状態にして地絡検出回路７２および各相接地線電流検出回路７３から電池電源７５を切り離す。
【００４３】
電流検出手段５−５の出力が第一の規定値以上となり、電池電源７５が接続された（ステップＳ３１の電源起動）場合について、以下説明する。電源が起動すると、地絡検出回路７２では電池使用開始からの累積動作時間を計算する（ステップＳ３２）。次に、地絡検出回路７２は電流検出手段５−４で検出される零相電流が第二の規定値（事故検出用規定値）未満であるかどうか判定する（ステップＳ３３，Ｓ３４）。そして、第二の規定値未満の零相電流が継続しているかどうかを判定するとともに、第二の規定値未満の零相電流の継続時間を算出し（ステップＳ３５）、その算出した継続時間が予め定めた第二の特定時間になったかを判定する（ステップＳ３６）。予め定めた第二の特定時間になった後、累積動作時間が電池の規定残存容量にいたる時間より小さいか否か判定する（ステップＳ３７）。そして、累積動作時間が電池の規定残存容量にいたる時間以上である場合、地絡検出回路７２はロック手段８１を制御してロック手段８１により電源駆動手段７１をロックする（ステップＳ３８）。電源駆動手段７１がロックされると、第一の規定値以上で、第二の規定値未満の零相電流の継続に対する不必要な電池の消費はなくなる。
【００４４】
第３の実施の形態によれば、地絡検出に至らない零相電流の継続に対し、電池寿命に至る前に電源駆動手段７１をロックするので、不必要な電池の消費をなくすことができる。この実施の形態では、地絡検出には至っていないが、接地線電流（零相電流）の継続によりケーブルが劣化が進んでいることが判断できる。
【００４５】
また、ロック手段８１としてラッチングリレーを使用した場合、手動操作のスイッチ手段７７により容易に電源駆動手段７７のロックを解除することができる。
【００４６】
なお、上記の説明では、ステップＳ３２からステップＳ３８でロック手段８１を制御するまでの処理を、地絡検出回路７２により行うものとしたが、電源駆動手段７１で行うようにしてもよい。
【００４７】
また、ここでは第一の規定値および第二の規定値の比較対象として零相電流を用いたが、零相電流の代わりに各相ケーブルの接地線電流を比較対象としてもよい。
【００４８】
（第４の実施の形態）
第４の実施の形態について図５を用いて説明する。図５は第４の実施の形態のケーブル故障検出装置のブロック構成図である。
【００４９】
図５において、高圧交流電路１に布設された相ごとに金属製遮蔽体２１を有するケーブル２に開閉器３を介して負荷４が接続されている。このケーブル故障検出装置は、各金属製遮蔽体２１の接地線６−１の接地線電流を検出する電流検出手段５−１〜５−３の出力を入力とする各相接地線電流検出回路７３と、各接地線６−１を一括接続して接地した一括接地線６−２の接地線電流を検出する電流電流検出手段５−４の出力を入力とする地絡検出回路７２と、一括接地線６−２の接地線電流を検出する電流検出手段５−５の検出出力により電源接続部８２を接続状態とする電源駆動手段７１と、地絡検出回路７２の地絡事故検出動作により機械的または磁気的に表示器８６の表示状態を継続する第一の表示手段７４−１と、電池電源７５と、ケ−ブル故障検出装置の定電圧電源部８３と、電源駆動手段７１によって接続状態と非接続状態とが切り替えられる電源接続部８２と、ダイオ−ド８４およびコンデンサ回路８５とで構成されている。なお、図５では示していないが、図１の第二の表示手段７４−２と、スイッチ手段７７とが設けられてあってもよい。また、電源接続部８２は、図１の電源接続部７６と同様のものである。
【００５０】
この第４の実施の形態では、電源接続部８２が接続（導通）状態のときに、ダイオード８４を介して電池電源７５により充電されるコンデンサ回路８５を設け、コンデンサ回路８５の一端を表示器８６に接続して表示器８６をコンデンサ回路８５の充電電圧により動作させるようにしている。また、電源接続部８２を介して電池電源７５に接続された定電圧電源部８３は、電源接続部８２が接続状態のときに、電池電源７５から電圧の供給を受け、一定の電圧を地絡検出回路７２および各相接地線電流検出回路７３に供給する。
【００５１】
上記構成における動作を説明する。地絡事故が発生した場合、地絡電流が金属製遮蔽体２１の接地線６−１に流れ、それによる電流が零相電流として一括接地線６−２に流れる。一括接地線６−２に流れる零相電流を接地線電流を検出する電流検出手段５−５が検出し、その出力が第一の規定値（電源駆動用規定値）以上の場合、電源駆動手段７１は電源接続部７６を非接続（非導通）状態から接続状態に切替える。これにより、定電圧電源部８３から地絡検出回路７２および各相接地線電流検出回路７３に電圧が供給されるとともに、コンデンサ回路８５が充電される。そして電流検出手段５−４を介して検出された零相電流が第二の規定値（事故検出用規定値）以上の場合、地絡検出回路７２は地絡事故と判断し、その検出信号を第一の表示手段７４−１へ送る。この検出信号により第一の表示手段７４−１では表示器８６を動作させ、事故の発生を表示させる。この表示器８６が動作すると瞬時に大きな負荷電流が流れるが、表示器８６の電源電圧は充電されたコンデンサ回路８５から供給されるので、瞬時の大きな負荷電流による電池電源７５の電池電圧降下は小さくなる。
【００５２】
第４の実施の形態によれば、表示器８６の動作による瞬時大電流負荷時でも電池電源７５を安定化することができ、それにより定電圧電源部８３も安定するので、ケーブル故障検出装置の動作を安定化することができる。
【００５３】
また、上記動作説明では、零相電流が第二の規定値以上になったときの地絡検出回路７２による事故検出時に表示器８６が動作する場合を記述したが、手動操作のスイッチ手段（図１のスイッチ手段７７参照）による表示器８６の点検による動作および事故経歴の消去に伴う復帰表示動作の場合も同様に電池電圧降下を小さくできる。
【００５４】
また、ここでは第一の規定値および第二の規定値の比較対象として零相電流を用いたが、零相電流の代わりに各相ケーブルの接地線電流を比較対象としてもよい。
【００５５】
また、ここでは表示器８６の動作時、定電圧電源部８３を安定させるために、電源接続部８２と定電圧電源部８３との間から定電圧電源部８３と並列にダイオード８４を介したコンデンサ回路８５を接続し、コンデンサ回路８５に充電された電圧を表示器用電源とする構成としたが、図６に示すように、電源接続部８２と定電圧電源部８３との間にダイオード８４を挿入し、ダイオード８４と定電圧電源部８３との間から定電圧電源部８３と並列にコンデンサ回路８５を接続し、電源接続部８２とダイオード８４との間から表示器用電源を取り出す構成とすることで、定電圧電源部８３を安定させ、ケーブル故障検出装置の動作を安定化させることも可能である。この図６の場合、表示器８６の電源電圧は電池電源７５から供給され、事故の発生により表示器８６が動作すると瞬時に大きな負荷電流が流れ、電池電源７５の電池電圧降下は大きくなるが、このとき定電圧電源部８３にはコンデンサ回路８５の充電電圧が供給されるので、定電圧電源部８３を安定させ、ケーブル故障検出装置の動作を安定化させることが可能である。
【００５６】
上記の図５や図６の第４の実施の形態の構成と、第１，第２または第３の実施の形態の構成とを組み合わせることにより、両方の効果を得ることができる。
【００５７】
【発明の効果】
本発明の請求項１記載のケーブル故障検出装置によれば、電池電源の電池が規定残存容量に至ると電流検出手段から電源駆動手段への入力を無効にし電源駆動手段をロックするロック手段を設けたことを特徴とし、電池電源が電池寿命に至る前に電源駆動手段をロックすることができ、以後の事故入力に対して電池の消耗を防ぐ一方、点検時に電池電源により電源起動することができる。
【００５８】
本発明の請求項２記載のケーブル故障検出装置によれば、電流検出手段で検出した接地線電流が事故検出用規定値以上の状態が第一の特定時間継続したとき電流検出手段から電源駆動手段への入力を無効にし電源駆動手段をロックするロック手段を設けたことを特徴とし、地絡事故検出後の地絡電流継続に対し電源駆動手段をロックすることで、電池の不必要な消費をなくすことができる。
【００５９】
本発明の請求項３記載のケーブル故障検出装置によれば、電流検出手段で検出した接地線電流が電源駆動用規定値以上で事故検出用規定値未満の状態が第二の特定時間継続した後、電池電源の電池が規定残存容量に至ると電流検出手段から電源駆動手段への入力を無効にし電源駆動手段をロックするロック手段を設けたことを特徴とし、地絡検出に至らない地絡電流の継続に対し、電池寿命に至る前に電源駆動手段をロックすることで、電池の不必要な消費をなくすことができる。
【００６０】
本発明の請求項４記載のケーブル故障検出装置によれば、請求項１，請求項２または請求項３に記載のケ−ブル故障検出装置において、ロック手段はラッチングリレーを用い、ラッチングリレーにより電流検出手段から電源駆動手段への入力を無効にするようにしたことを特徴とし、このようにロック手段を構成でき、また、手動操作のスイッチ手段によりロックの解除が容易に可能となる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態のケーブル故障検出装置のブロック構成図。
【図２】本発明の第１の実施の形態における動作説明用のフロー図。
【図３】本発明の第２の実施の形態における動作説明用のフロー図。
【図４】本発明の第３の実施の形態における動作説明用のフロー図。
【図５】本発明の第４の実施の形態のケーブル故障検出装置のブロック構成図。
【図６】本発明の第４の実施の形態のケーブル故障検出装置のブロック構成図。
【図７】従来のケーブル故障検出装置のブロック構成図。
【符号の説明】
１高圧交流電路
２ケーブル
２１金属製遮蔽体
３開閉器
４負荷
５−１〜５−３電流検出手段
５−４〜５−５電流検出手段
６−１接地線
６−２一括接地線
７１電源駆動手段
７２地絡検出回路
７３各相接地線電流検出回路
７４−１第一の表示手段
７４−２第二の表示手段
７５電池電源
７６電源接続部
７７スイッチ手段
８１ロック手段
８２電源接続部
８３定電圧電源部
８４ダイオード
８５コンデンサ回路
８６表示器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cable failure detection device that detects a failure of a cable having a metal shield for each phase laid on a high-voltage AC circuit.
[0002]
[Prior art]
Here, a conventional cable failure detection apparatus will be described. FIG. 7 is a block diagram of a conventional cable failure detection apparatus. In FIG. 7, a load 4 is connected via a switch 3 to a cable 2 having a metal shield 21 for each phase laid in the high-voltage AC circuit 1. This cable failure detection apparatus is a circuit for detecting the phase grounding line current that receives the outputs of the current detection means 5-1 to 5-3 for detecting the grounding line current of the grounding line 6-1 of each metal shield 21. 73, a ground fault detection circuit 72 that receives the output of the current detection means 5-4 that detects the ground line current of the collective ground line 6-2 that is grounded by connecting the ground lines 6-1 together, and collective grounding The battery power supply 75 is connected to the ground fault detection circuit 72 through the constant voltage power supply unit 83 by setting the power supply connection unit 76 to the connected state by the detection output of the current detection unit 5-5 that detects the ground line current of the line 6-2. Power supply driving means 71 connected to each phase ground line current detection circuit 73, and first display means 74 that mechanically or magnetically continues the display state of the display device by the ground fault detection operation of the ground fault detection circuit 72. -1 and second display to display measured values and accident history And stage 74-2 is configured to power connections 76 sends a signal to the power drive means 71 by the switching means 77 manually operated to operate to connect a predetermined time during inspection. The constant voltage power supply unit 83 is supplied with a voltage from the battery power supply 75 when the power supply connection unit 76 is in a connected state, and supplies a constant voltage to the ground fault detection circuit 72 and each phase ground line current detection circuit 73. Supply.
[0003]
As an example, the cable 2 has a configuration in which a conductor portion is a center (core), and a semiconductive layer, an insulator, a semiconductive layer, a metal shield 21, a tape, and a sheath are wound around the outside in that order. The metal shield 21 is made of a metal such as aluminum or copper, and the metal shield 21 is grounded, and the deterioration of the cable 2 can be determined from the magnitude of the ground line current flowing therethrough. The ground fault here means that the cable 2 is in a state where the conductor portion of the cable 2 and the grounded metal shield 21 are in contact with each other. Flows through the ground lines 6-1 and 6-2 connected to the metal shield 21 from the section to the ground. The feedback current returns to the cable 2 from the surrounding ground line.
[0004]
Next, the operation of the cable failure detection apparatus having the above configuration will be described. When a ground fault occurs, a ground fault current flows to the ground line 6-1 of the metal shield 21, and the resulting current flows to the collective ground line 6-2 as a zero-phase current. When the current detection means 5-5 for detecting the ground line current detects the zero-phase current flowing through the collective ground line 6-2, and the output is equal to or higher than the first specified value (specified value for power supply drive), the power supply drive means 71 connects the battery power source 75 to the ground fault detection circuit 72 and each phase ground line current detection circuit 73 through the constant voltage power source unit 83 with the power source connection unit 76 connected. When the zero-phase current is greater than or equal to the second specified value (accident detection specified value), the ground fault detection circuit 72 detects a ground fault and detects the detected signal as the first display means 74-1 and the second Send to display means 74-2. In response to this detection signal, the first display means 74-1 operates a display device that continues the display state mechanically or magnetically with the battery power source 75 to display the occurrence of the accident and record the accident data. Here, the 1st display means 74-1 is provided with the above-mentioned indicator, the medium which records accident data, etc. Note that the second specified value is larger than the first specified value.
[0005]
Further, the first display means 74-1 is referred to as display restoration after once operating the display as a normal operation check of the display at the time of power activation by a signal from the manually operated switch means 77 to the power supply drive means 71. When the accident history is deleted, the display is restored.
[0006]
Further, the second display means 74-2 is configured such that each phase grounding line current detection circuit 73 and ground fault detection circuit 72 is activated when the power is activated by a signal from the accident input or manual operation switch means 77 to the power supply drive means 71. Display measurement results and accident history.
[0007]
When a signal is sent from the manually operated switch unit 77 to the power source driving unit 71 at the time of inspection, the power source driving unit 71 puts the power source connecting unit 76 into a connected state regardless of the input from the current detecting unit 5-5.
[0008]
[Problems to be solved by the invention]
In the above-described conventional configuration, the power source driving means 71 connects the battery power source 75 to the ground fault detection circuit 72 every time a ground fault occurs, so that the power source is activated until the battery life is reached, and the power source is activated at the time of inspection. There was a problem that it was not possible.
[0009]
Further, when the zero-phase current due to the ground-fault current that flows when the ground-fault accident occurs exceeds the second specified value and the zero-phase current continues, the ground-fault detection circuit 72 operates. Therefore, there is a problem that the battery power source 75 remains connected to the ground fault detection circuit 72 by the power source driving means 71 and the battery is unnecessarily consumed.
[0010]
In addition, when the zero-phase current due to the ground fault current that flows in the event of a ground fault does not reach the ground fault detection, the battery power supply 75 remains connected until the battery life is reached, and the battery is unnecessary. There was a problem of being consumed.
[0011]
In addition, when the battery power supply 75 is used to operate a display device that continues the display state mechanically or magnetically by the operation of the ground fault detection circuit 72, the operation of the cable fault detection device is caused by the battery voltage drop when the battery is instantaneously loaded with a large current There was a problem that became unstable.
[0012]
The present invention has an object to provide a cable failure detection device that can solve the above-mentioned problems, and a first object is to provide a cable failure detection device that can always be powered on by a battery power source at the time of inspection. The second object is to provide a cable failure detection device that can prevent the battery of the battery power source from being consumed unnecessarily, and the third object is to provide an indicator. It is an object of the present invention to provide a cable failure detection device capable of stable operation even when a large load current flows instantaneously.
[0013]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a cable failure detection apparatus comprising: a battery power source; and grounding wires connected to each metal shield of a cable laid on a high-voltage AC circuit and having a metal shield for each phase. Current detection means for detecting a ground line current flowing in a collective ground line collectively grounded or each ground line connected to each of the metal shields, and a ground line current detected by the current detection means is used for accident detection. A ground fault detection circuit for detecting a ground fault when the value is equal to or greater than a value, and the battery when a ground line current detected by the current detection means is equal to or greater than a specified value for power supply driving that is smaller than the specified value for accident detection. A cable failure detection device comprising: a power source connected to the ground fault detection circuit; and a power source drive means for disconnecting the battery power source from the ground fault detection circuit when the power source is less than a specified value for driving the power source. The battery power The battery reaches the power capacity that should be reserved for inspection And invalidate the input from the current detection means to the power supply drive means. Locking means for disconnecting the battery power source Is provided.
[0014]
According to the configuration of the first aspect of the present invention, the lock means is provided, and the power supply drive means is locked before the battery power reaches the battery life, thereby preventing the battery from being consumed with respect to the subsequent accident input. The power supply can be activated by the power supply.
[0015]
According to a second aspect of the present invention, there is provided a cable fault detection apparatus comprising: a battery power source; and grounding wires connected to the respective metal shields of the cable laid on the high-voltage AC circuit and having a metal shield for each phase. Current detection means for detecting a ground line current flowing in a collective ground line collectively grounded or each ground line connected to each of the metal shields, and a ground line current detected by the current detection means is used for accident detection. A ground fault detection circuit for detecting a ground fault when the value is equal to or greater than a value, and the battery when a ground line current detected by the current detection means is equal to or greater than a specified value for power supply driving that is smaller than the specified value for accident detection. A cable failure detection device comprising: a power source connected to the ground fault detection circuit; and a power source drive means for disconnecting the battery power source from the ground fault detection circuit when the power source is less than a specified value for driving the power source. Detected by the current detection means Grounding wire current disables inputs from said current detecting means when said fault detection for a specified value or more state continues first specific time to said power drive means Locking means for disconnecting the battery power source Is provided.
[0016]
According to the second aspect of the present invention, unnecessary consumption of the battery can be eliminated by providing the locking means and locking the power supply driving means against the continuation of the ground fault current after the detection of the ground fault.
[0017]
According to a third aspect of the present invention, there is provided a cable fault detection device comprising: a battery power source; and a ground wire connected to each metal shield of a cable laid on a high-voltage AC circuit and having a metal shield for each phase. Current detection means for detecting a ground line current flowing in a collective ground line collectively grounded or each ground line connected to each of the metal shields, and a ground line current detected by the current detection means is used for accident detection. A ground fault detection circuit for detecting a ground fault when the value is equal to or greater than a value, and the battery when a ground line current detected by the current detection means is equal to or greater than a specified value for power supply driving that is smaller than the specified value for accident detection. A cable failure detection device comprising: a power source connected to the ground fault detection circuit; and a power source drive means for disconnecting the battery power source from the ground fault detection circuit when the power source is less than a specified value for driving the power source. Detected by the current detection means After the ground wire current state of less than the fault detection for a specified value in the supply voltage driving the specified value or more has continued a second specific time, the battery power supply The battery reaches the power capacity that should be reserved for inspection And invalidate the input from the current detection means to the power supply drive means. Locking means for disconnecting the battery power source Is provided.
[0018]
According to the third aspect of the present invention, by providing the locking means and locking the power supply driving means before the battery life is reached, against the continuation of the ground fault current that does not lead to the detection of the ground fault, unnecessary consumption of the battery is achieved. Can be eliminated.
[0019]
The cable failure detection device according to claim 4 of the present invention is the cable failure detection device according to claim 1, 2 or 3, wherein the locking means uses a latching relay, and the current detection means by the latching relay. The input to the power source drive means is invalidated. In this way, the locking means can be configured.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the cable failure detection apparatus according to the first embodiment, and FIG. 2 is a flowchart for explaining the operation of the cable failure detection apparatus.
[0025]
In FIG. 1, a load 4 is connected via a switch 3 to a cable 2 having a metal shield 21 for each phase laid in the high-voltage AC circuit 1. This cable failure detection apparatus is a circuit for detecting the phase grounding line current that receives the outputs of the current detection means 5-1 to 5-3 for detecting the grounding line current of the grounding line 6-1 of each metal shield 21. 73, a ground fault detection circuit 72 that receives the output of the current detection means 5-4 that detects the ground line current of the collective ground line 6-2 that is grounded by connecting the ground lines 6-1 together, and collective grounding The battery power supply 75 is connected to the ground fault detection circuit 72 through the constant voltage power supply unit 83 by setting the power supply connection unit 76 to the connected state by the detection output of the current detection unit 5-5 that detects the ground line current of the line 6-2. Power supply driving means 71 connected to each phase ground line current detection circuit 73, and first display means 74 that mechanically or magnetically continues the display state of the display device by the ground fault detection operation of the ground fault detection circuit 72. -1 and second display to display measured values and accident history It comprises a stage 74-2, a manually operated switch means 77 that sends a signal to the power supply means 71 at the time of inspection and operates to connect the power supply connection portion 76 for a predetermined time, and a lock means 81 that locks the power supply means 71. Has been. The difference from the conventional configuration is that the locking means 81 is provided, and the same components as those in FIG.
[0026]
The operation in the above configuration will be described with reference to the flowchart of FIG. When a ground fault occurs, a ground fault current flows to the ground line 6-1 of the metal shield 21, and the resulting current flows to the collective ground line 6-2 as a zero-phase current. When the current detection means 5-5 for detecting the ground line current detects the zero-phase current flowing through the collective ground line 6-2, and the output is equal to or higher than the first specified value (specified value for power supply drive), the power supply drive means 71 connects the battery power supply 75 to the ground fault detection circuit 72 and each phase ground line current detection circuit 73 via the constant voltage power supply section 83 by changing the power supply connection section 76 from the non-connected state to the connected state (the power supply in step S11). Start-up). Further, when the output of the current detecting means 5-5 becomes less than the first specified value, the power supply driving means 71 changes the power supply connecting portion 76 from the connected state to the disconnected state, and the ground fault detection circuit 72 and each phase ground line current. The battery power source 75 is disconnected from the detection circuit 73.
[0027]
The case where the output of the current detection means 5-5 becomes equal to or higher than the first specified value and the battery power source 75 is connected (power activation in step S11) will be described below. The power source driving means 71 calculates the accumulated operation time from the start of battery use of the battery power source 75 (step S12), and determines whether or not the accumulated operation time is smaller than the time until the specified remaining capacity of the battery (step S13). If the time reaches the specified remaining capacity of the battery, the lock means 81 is controlled. Under the control of the power supply driving means 71, the locking means 81 locks the power supply driving means 71 (S14). Locking the power supply means 71 means that the power supply cannot be activated due to an accident input, and the lock means 81 invalidates the input from the current detection means 5-5 to the power supply means 71 (current By electrically disconnecting the detecting means 5-5 from the power supply driving means 71), the power supply connecting portion 76 is brought into a non-connected state. Therefore, when the power supply driving means 71 is locked, the subsequent accident input becomes invalid and the battery of the battery power supply 75 is not consumed. The specified remaining capacity of the battery is determined by the product specification. For example, if the battery capacity in the specification is “the remaining battery capacity is 30% and the number of operations is 500 times or more”, the specified remaining capacity of the battery is 30. %.
[0028]
In the above description, the processing from the step S12 to the control of the lock unit 81 in step S14 is performed by the power source drive unit 71, but may be performed by the ground fault detection circuit 72.
[0029]
When the power source driving means 71 is not locked and the zero-phase current becomes equal to or greater than the second specified value (specified value for accident detection), the ground fault detection circuit 72 detects that a ground fault has occurred. The detection signal is sent to the first display means 74-1 and the second display means 74-2 as described in the conventional example.
[0030]
Further, when the power supply driving means 71 is locked, when a signal is sent from the manually operated switch means 77 to the power supply driving means 71 during inspection, the power supply driving means 71 is connected to the power supply regardless of the input from the lock means 81. At this time, the input from the current detection means 5-5 is disabled by the lock means 81.
[0031]
According to the first embodiment, before the battery power supply 75 reaches the battery life, the lock means 81 invalidates the input (accident input) from the current detection means 5-5 to the power supply drive means 71. Since the power supply driving means 71 is locked, the power history can be checked by manually operating the switch means 77 at the time of inspection to check the accident history. When a latching relay is used as the lock unit 81, the power source drive unit 71 can be easily unlocked by the manually operated switch unit 77. Here, the latching relay is a relay that maintains the state of the contact even when the current is turned off when the contact is operated by energizing the coil.
[0032]
Further, here, the case where the power source is started by the output of the current detection means 5-5 for detecting the ground line current connected to the collective ground line 6-2 has been described, but it is connected to the ground line 6-1 of each phase cable. The power supply may be activated by sending a signal to the power supply drive means 71 by the outputs of the current detection means 5-1 to 5-3 for detecting the ground line current.
[0033]
As described above, the ground line current of each phase cable may be compared instead of the zero-phase current as the comparison target of the first specified value, and the zero-phase current is also compared for the comparison target of the second specified value. In addition, the ground line current of each phase cable may be used as a comparison target.
[0034]
(Second Embodiment)
A second embodiment will be described with reference to FIG. FIG. 3 is a flowchart for explaining the operation of the cable failure detection apparatus according to the second embodiment. Since the configuration diagram of the second embodiment is the same as that of FIG. 1 showing the first embodiment, the description thereof is omitted.
[0035]
Next, the operation will be described with reference to FIG. When a ground fault occurs, a ground fault current flows to the ground line 6-1 of the metal shield 21, and the resulting current flows to the collective ground line 6-2 as a zero-phase current. When the current detection means 5-5 for detecting the ground line current detects the zero-phase current flowing through the collective ground line 6-2, and the output is equal to or higher than the first specified value (specified value for power supply drive), the power supply drive means 71 connects the power source connecting unit 76 from the non-connected state to the connected state, and connects the battery power source 75 to the ground fault detecting circuit 72 and each phase ground line current detecting circuit 73 via the constant voltage power source unit 83 (the power source of step S21). Start-up). Further, when the output of the current detecting means 5-5 becomes less than the first specified value, the power supply driving means 71 changes the power supply connecting portion 76 from the connected state to the disconnected state, and the ground fault detection circuit 72 and each phase ground line current. The battery power source 75 is disconnected from the detection circuit 73.
[0036]
The case where the output of the current detection means 5-5 becomes equal to or higher than the first specified value and the battery power source 75 is connected (power activation in step S21) will be described below. When the power supply is activated, the ground fault detection circuit 72 measures the zero-phase current from the current detection means 5-4 and compares it with the second specified value (specified value for accident detection) (steps S22 and S23). If the zero-phase current is greater than or equal to the second specified value, it is determined that a ground fault has occurred, and the detection signal is sent to the first display means 74-1 and the second display means 74-2 (step S24).
[0037]
The ground fault detection circuit 72 continues to measure the zero-phase current from the current detection means 5-4 after the accident detection operation, and determines whether the zero-phase current equal to or greater than the second specified value continues (step). Along with S25 and S26), the duration of the zero-phase current equal to or greater than the second specified value is calculated (step S27), and the lock means 81 is controlled when the calculated duration reaches a predetermined first specific time. . Under the control of the ground fault detection circuit 72, the lock unit 81 locks the power source drive unit 71 (steps S28 and S29). When the power supply driving means 71 is locked, unnecessary battery consumption by the subsequent ground fault detection circuit 72 and each phase ground line current detection circuit 73 is eliminated.
[0038]
According to the second embodiment, by locking the power supply driving means 71, unnecessary battery consumption after the ground fault detection operation for the continuation of the zero-phase current exceeding the second specified value can be eliminated. it can. When a latching relay is used as the lock unit 81, the power source drive unit 71 can be easily unlocked by the manually operated switch unit 77.
[0039]
In the above description, the processing from the step S22 to the control of the lock unit 81 in step S29 is performed by the ground fault detection circuit 72, but may be performed by the power source drive unit 71.
[0040]
Here, the zero-phase current is used as a comparison target between the first specified value and the second specified value, but the ground line current of each phase cable may be used as a comparison target instead of the zero-phase current.
[0041]
(Third embodiment)
A third embodiment will be described with reference to FIG. FIG. 4 is a flowchart for explaining the operation of the cable failure detection apparatus according to the third embodiment. Since the configuration diagram of the third embodiment is the same as that of FIG. 1 showing the first embodiment, the description thereof is omitted.
[0042]
Next, the operation will be described with reference to FIG. When a ground fault occurs, a ground fault current flows to the ground line 6-1 of the metal shield 21, and the resulting current flows to the collective ground line 6-2 as a zero-phase current. When the current detection means 5-5 for detecting the ground line current detects the zero-phase current flowing through the collective ground line 6-2, and the output exceeds the first specified value (specified value for power supply drive), the power supply is driven. The means 71 connects the battery power source 75 to the ground fault detection circuit 72 and each phase ground line current detection circuit 73 via the constant voltage power source unit 83 by changing the power source connection unit 76 from the non-connected state to the connected state (in step S31). Power on). Further, when the output of the current detecting means 5-5 becomes less than the first specified value, the power supply driving means 71 changes the power supply connecting portion 76 from the connected state to the disconnected state, and the ground fault detection circuit 72 and each phase ground line current. The battery power source 75 is disconnected from the detection circuit 73.
[0043]
The case where the output of the current detection means 5-5 becomes equal to or higher than the first specified value and the battery power source 75 is connected (power activation in step S31) will be described below. When the power supply is activated, the ground fault detection circuit 72 calculates the accumulated operation time from the start of battery use (step S32). Next, the ground fault detection circuit 72 determines whether or not the zero-phase current detected by the current detection means 5-4 is less than the second specified value (accident detection specified value) (steps S33 and S34). Then, it is determined whether or not the zero-phase current less than the second specified value continues, the duration of the zero-phase current less than the second specified value is calculated (step S35), and the calculated duration is calculated. It is determined whether a predetermined second specific time has come (step S36). After the predetermined second specific time is reached, it is determined whether or not the accumulated operation time is shorter than the time to reach the specified remaining capacity of the battery (step S37). When the accumulated operation time is equal to or longer than the time required for the specified remaining capacity of the battery, the ground fault detection circuit 72 controls the lock unit 81 and locks the power source drive unit 71 by the lock unit 81 (step S38). When the power supply driving means 71 is locked, unnecessary battery consumption is eliminated for the continuation of zero-phase current that is greater than or equal to the first specified value and less than the second specified value.
[0044]
According to the third embodiment, since the power supply driving means 71 is locked before the battery life is reached with respect to the continuation of the zero-phase current that does not lead to the ground fault detection, unnecessary battery consumption can be eliminated. . In this embodiment, although the ground fault has not been detected, it can be determined that the cable has deteriorated due to the continuation of the ground line current (zero phase current).
[0045]
When a latching relay is used as the lock unit 81, the power source drive unit 77 can be easily unlocked by the manually operated switch unit 77.
[0046]
In the above description, the processing from the step S32 to the control of the lock unit 81 in step S38 is performed by the ground fault detection circuit 72, but may be performed by the power source drive unit 71.
[0047]
Here, the zero-phase current is used as a comparison target between the first specified value and the second specified value, but the ground line current of each phase cable may be used as a comparison target instead of the zero-phase current.
[0048]
(Fourth embodiment)
A fourth embodiment will be described with reference to FIG. FIG. 5 is a block diagram of a cable failure detection apparatus according to the fourth embodiment.
[0049]
In FIG. 5, a load 4 is connected via a switch 3 to a cable 2 having a metal shield 21 for each phase laid in the high-voltage AC circuit 1. This cable failure detection apparatus is a circuit for detecting the phase grounding line current that receives the outputs of the current detection means 5-1 to 5-3 for detecting the grounding line current of the grounding line 6-1 of each metal shield 21. 73, a ground fault detection circuit 72 that receives the output of the current / current detection means 5-4 for detecting the ground line current of the collective ground line 6-2 that is grounded by connecting the ground lines 6-1 together, The power supply drive means 71 for connecting the power supply connection portion 82 with the detection output of the current detection means 5-5 for detecting the ground line current of the ground line 6-2 and the ground fault detection operation of the ground fault detection circuit 72 Connected by the first display means 74-1 that continuously or magnetically continues the display state of the display 86, the battery power source 75, the constant voltage power source 83 of the cable failure detection device, and the power source drive means 71. And a power supply connection portion 82 that can be switched between a disconnected state and a disconnected state, Io - it is composed of a de 84 and the capacitor circuit 85. Although not shown in FIG. 5, the second display unit 74-2 and the switch unit 77 in FIG. 1 may be provided. Moreover, the power supply connection part 82 is the same as the power supply connection part 76 of FIG.
[0050]
In the fourth embodiment, a capacitor circuit 85 that is charged by the battery power source 75 via the diode 84 when the power supply connecting portion 82 is in a connected (conducting) state is provided, and one end of the capacitor circuit 85 is connected to the display 86. The display 86 is operated by the charging voltage of the capacitor circuit 85. Further, the constant voltage power supply unit 83 connected to the battery power supply 75 via the power supply connection unit 82 is supplied with a voltage from the battery power supply 75 when the power supply connection unit 82 is in a connected state, and a constant voltage is supplied to the ground. This is supplied to the detection circuit 72 and each phase ground line current detection circuit 73.
[0051]
The operation in the above configuration will be described. When a ground fault occurs, a ground fault current flows to the ground line 6-1 of the metal shield 21, and the resulting current flows to the collective ground line 6-2 as a zero-phase current. When the current detection means 5-5 for detecting the ground line current detects the zero-phase current flowing through the collective ground line 6-2, and the output is equal to or higher than the first specified value (specified value for power supply drive), the power supply drive means 71 switches the power supply connection part 76 from a non-connection (non-conduction) state to a connection state. As a result, a voltage is supplied from constant voltage power supply unit 83 to ground fault detection circuit 72 and each phase ground line current detection circuit 73, and capacitor circuit 85 is charged. If the zero-phase current detected via the current detection means 5-4 is equal to or greater than the second specified value (accident detection specified value), the ground fault detection circuit 72 determines that there is a ground fault and detects the detected signal. The data is sent to the first display means 74-1. In response to this detection signal, the first display means 74-1 operates the display 86 to display the occurrence of an accident. When the display 86 is operated, a large load current flows instantaneously. However, since the power supply voltage of the display 86 is supplied from the charged capacitor circuit 85, the battery voltage drop of the battery power supply 75 due to the instantaneous large load current is small. Become.
[0052]
According to the fourth embodiment, the battery power supply 75 can be stabilized even during an instantaneous large current load due to the operation of the display 86, and the constant voltage power supply unit 83 is also stabilized. The operation can be stabilized.
[0053]
In the above description of the operation, a case has been described in which the indicator 86 operates when an accident is detected by the ground fault detection circuit 72 when the zero-phase current becomes equal to or greater than the second specified value. Similarly, the battery voltage drop can be reduced in the case of the operation by inspection of the indicator 86 by the switch means 77 of 1) and the return display operation accompanying the deletion of the accident history.
[0054]
Here, the zero-phase current is used as a comparison target between the first specified value and the second specified value, but the ground line current of each phase cable may be used as a comparison target instead of the zero-phase current.
[0055]
Further, here, in order to stabilize the constant voltage power supply unit 83 during the operation of the display 86, a capacitor is interposed between the power supply connection unit 82 and the constant voltage power supply unit 83 through the diode 84 in parallel with the constant voltage power supply unit 83. Although the circuit 85 is connected and the voltage charged in the capacitor circuit 85 is used as the power supply for the display, a diode 84 is inserted between the power supply connection portion 82 and the constant voltage power supply portion 83 as shown in FIG. The capacitor circuit 85 is connected in parallel with the constant voltage power supply unit 83 from between the diode 84 and the constant voltage power supply unit 83, and the display power supply is taken out between the power supply connection unit 82 and the diode 84. It is also possible to stabilize the constant voltage power supply unit 83 and stabilize the operation of the cable failure detection device. In the case of FIG. 6, the power supply voltage of the display 86 is supplied from the battery power supply 75. When the display 86 is operated due to the occurrence of an accident, a large load current flows instantaneously, and the battery voltage drop of the battery power supply 75 increases. At this time, since the charging voltage of the capacitor circuit 85 is supplied to the constant voltage power supply unit 83, the constant voltage power supply unit 83 can be stabilized and the operation of the cable failure detection apparatus can be stabilized.
[0056]
By combining the configuration of the fourth embodiment in FIG. 5 and FIG. 6 described above with the configuration of the first, second, or third embodiment, both effects can be obtained.
[0057]
【The invention's effect】
According to the cable failure detection apparatus of the first aspect of the present invention, there is provided the lock means for invalidating the input from the current detection means to the power supply drive means and locking the power supply drive means when the battery of the battery power supply reaches the specified remaining capacity. The power supply drive means can be locked before the battery power reaches the end of its battery life, and it is possible to start up the power supply by the battery power supply at the time of inspection while preventing the battery from being consumed for subsequent accident inputs. .
[0058]
According to the cable fault detection apparatus of the second aspect of the present invention, when the state where the ground line current detected by the current detection means is equal to or greater than the specified value for accident detection continues for the first specific time, the current detection means to the power supply drive means. It is characterized by providing a lock means that disables input to the power supply and locks the power supply drive means, and locks the power supply drive means against continuation of the ground fault current after detection of a ground fault, thereby reducing unnecessary consumption of the battery. Can be eliminated.
[0059]
According to the cable fault detection device of the third aspect of the present invention, after the ground line current detected by the current detection means is equal to or greater than the power supply drive specified value and less than the accident detection specified value continues for the second specific time. A ground fault current that does not lead to ground fault detection, characterized by providing a lock means for disabling the input from the current detection means to the power drive means when the battery of the battery power source reaches the specified remaining capacity, and locking the power drive means In contrast, unnecessary power consumption of the battery can be eliminated by locking the power supply driving means before the battery life is reached.
[0060]
According to the cable fault detection device of claim 4 of the present invention, in the cable fault detection device of claim 1, claim 2 or claim 3, the locking means uses a latching relay, and the current is generated by the latching relay. It is characterized in that the input from the detection means to the power supply drive means is invalidated, and thus the lock means can be configured, and the lock can be easily released by the manually operated switch means.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram of a cable failure detection apparatus according to a first embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation in the first embodiment of the present invention.
FIG. 3 is a flowchart for explaining operations in the second embodiment of the present invention;
FIG. 4 is a flowchart for explaining the operation in the third embodiment of the present invention.
FIG. 5 is a block configuration diagram of a cable failure detection device according to a fourth embodiment of the present invention.
FIG. 6 is a block configuration diagram of a cable failure detection apparatus according to a fourth embodiment of the present invention.
FIG. 7 is a block diagram of a conventional cable failure detection device.
[Explanation of symbols]
1 High voltage AC circuit
2 Cable
21 Metal shield
3 Switch
4 Load
5-1-5-3 Current detection means
5-4 to 5-5 Current detection means
6-1 Ground wire
6-2 Collective grounding wire
71 Power supply means
72 Ground fault detection circuit
73 Each phase ground line current detection circuit
74-1 First display means
74-2 Second display means
75 Battery power
76 Power connection
77 Switch means
81 Locking means
82 Power connection
83 Constant voltage power supply
84 Diode
85 Capacitor circuit
86 Display

Claims

Battery power,
Connected to each ground shield wire collectively grounded each ground wire connected to each metal shield of the cable laid on the high-voltage AC circuit and having a metal shield for each phase, or connected to each metal shield. Current detecting means for detecting a ground line current flowing through each ground line;
A ground fault detection circuit for detecting a ground fault when the ground line current detected by the current detection means is equal to or greater than a specified value for fault detection;
When the ground line current detected by the current detection means is equal to or greater than a specified value for power supply driving, which is smaller than the specified value for accident detection, the battery power supply is connected to the ground fault detection circuit, and less than the specified value for driving the power supply. A cable failure detection device comprising power supply driving means for disconnecting the battery power supply from the ground fault detection circuit,
When the battery of the battery power supply reaches a power capacity that should be ensured for inspection, there is provided a lock means that disables the input from the current detection means to the power supply driving means and disconnects the battery power supply. A cable fault detection device.

Battery power,
Connected to each ground shield wire collectively grounded each ground wire connected to each metal shield of the cable laid on the high-voltage AC circuit and having a metal shield for each phase, or connected to each metal shield. Current detecting means for detecting a ground line current flowing through each ground line;
A ground fault detection circuit for detecting a ground fault when the ground line current detected by the current detection means is equal to or greater than a specified value for fault detection;
When the ground line current detected by the current detection means is equal to or greater than a specified value for power supply driving, which is smaller than the specified value for accident detection, the battery power supply is connected to the ground fault detection circuit, and less than the specified value for driving the power supply. A cable failure detection device comprising power supply driving means for disconnecting the battery power supply from the ground fault detection circuit,
When the ground line current detected by the current detection unit is equal to or greater than the specified value for accident detection continues for a first specific time, the input from the current detection unit to the power source drive unit is invalidated and the battery power source is not connected. A cable failure detection apparatus comprising a lock means for setting a state .

Battery power,
Connected to each ground shield wire collectively grounded each ground wire connected to each metal shield of the cable laid on the high-voltage AC circuit and having a metal shield for each phase, or connected to each metal shield. Current detecting means for detecting a ground line current flowing through each ground line;
A ground fault detection circuit for detecting a ground fault when the ground line current detected by the current detection means is equal to or greater than a specified value for fault detection;
When the ground line current detected by the current detection means is equal to or greater than a specified value for power supply driving, which is smaller than the specified value for accident detection, the battery power supply is connected to the ground fault detection circuit, and less than the specified value for driving the power supply. A cable failure detection device comprising power supply driving means for disconnecting the battery power supply from the ground fault detection circuit,
After the ground line current detected by the current detecting means is not less than the specified value for power supply drive and less than the specified value for accident detection continues for a second specific time, the battery of the battery power supply is secured for inspection. The cable failure detection device is provided with a lock means for disabling the input from the current detection means to the power supply drive means when the power supply capacity is reached , so that the battery power supply is disconnected .

The locking means uses a latching relay, and the input from the current detection means to the power supply driving means is invalidated by the latching relay. Cable fault detection device.