JP3649660B2

JP3649660B2 - Leakage current exploration device

Info

Publication number: JP3649660B2
Application number: JP2000294550A
Authority: JP
Inventors: 英倫吉田; 英明高田
Original assignee: 英倫吉田; 株式会社戸上電機製作所
Priority date: 2000-09-27
Filing date: 2000-09-27
Publication date: 2005-05-18
Anticipated expiration: 2020-09-27
Also published as: JP2002098729A

Description

【０００１】
【発明の属する技術分野】
本発明は、低圧配線路の漏電箇所を探査し、特に活線状態において漏洩電流を検出する漏洩電流探査方法に関する。
【０００２】
【従来の技術】
従来、この種の漏洩電流探査装置は特開平３−９６８７４公報に示すものがあった。図８は前記従来の漏洩電流探査装置の構成図、図９は従来の漏洩電流探査装置の動作確認試験説明図、図１０(a)、(b)は従来の漏洩電流探査装置の漏電探査説明図である。
【０００３】
前記従来の漏洩電流探査装置１００は、漏洩電流を検出する電流検出部(クランプ型ZCT)３００と、この検出した前記漏洩電流を演算処理して表示する検出部本体５００と、この検出部本体５００外部に絶縁物１９０を介して検出部本体５００に固定された導電性の部材からなり、検出部本体５００内部に内蔵される試験回路２７０に接続される取手２１０とを備える構成である。この試験回路２７０は、低周波信号を発振する発振回路１７０と、この発振回路１７０に直列に接続される抵抗２３０及びスイッチ２５０とを備え、前記取手２１０にこの抵抗２３０、発振回路１７０及びスイッチ２５０が直列に接続されてループ回路を形成する構成である。
【０００４】
以下、前記構成に基づく従来の漏洩電流探査装置１００の具体的な動作について説明する。まず、漏洩電流探査装置１００の動作試験時に図９に示すように電流検出部３００を取手２１０にクランプして結合し、低周波の監視信号を発振回路１７０よりこの取手２１０に流す。この際、電流検出部３００により測定される電流値を漏洩電流探査装置１００自体で測定し、この測定された電流値が所定値以上検出することができるか否かを判定することにより漏洩電流探査装置１００の動作確認を行うものである。
【０００５】
次に、前記電流検出部３００を取手２１０から取り外し、図１０(a)に示すようにこの電流検出部３００を既存の配線路７００にクランプし、この電流検出部３００がクランプされた配線路７００の接地線９００に発振器１１０を接続し、この発振器１１０から発振される監視信号を配線路７００に印加し、この配線路７００に流れる前記監視信号電流の大きさを前記漏洩電流探査装置１００により測定する。前記発振器１１０は発信出力を調整して変化させ、この配線路７００に印加する発振周波数を変動させることによって、この配線路７００に流れる監視信号電流の大きさを変化させながら前記監視信号電流値の検出精度を求め、この検出精度を求められる範囲内で対象となる配線路７００の漏洩電流を検出するものである。
【０００６】
図１０(b)に示すように、配線路７００のB−C間に於いて絶縁劣化が発生している場合には、配線路７００中の測定箇所をA→B→Cと順次変更して漏電探査を行うと、A点及びB点における監視信号の検出値は高く、C点に於ける監視信号の検出値は低下する。したがって、配線路７００の任意の箇所における監視信号の測定値を知ることにより絶縁不良箇所を探査することができる。以上のように、従来の漏洩電流探査装置１００は、事前にこの従来の漏洩電流探査装置１００自体で従来の漏洩電流探査装置１００の動作確認を行い配線路７００の漏洩箇所の探査を行うものである。
【０００７】
その他、従来の漏洩電流探査装置は、特開平６−２７１６５公報や特開平１０−６８７４９公報に示すものがある。
一般的に、漏洩電流探査装置の対象となる漏洩電流については、負荷機器等が存在する配線路と大地間には静電容量成分が存在し、またコンピュータ等の電子機器に設置される電源雑音防止フィルタ等にも静電容量成分が存在し、また配線路や負荷機器等の絶縁劣化により抵抗成分も存在する。前記静電容量成分や前記抵抗成分が存在することから、配線路と大地間で漏洩電流が流れる。漏洩電流は、場合によっては火災等の重大事故の原因となる為、漏洩電流の発生を未然に防止する必要があり、漏洩電流の原因を適確かつ迅速に発見することが重要である。
【０００８】
【発明が解決しようとする課題】
従来の漏洩電流探査装置は以上のように構成されていたことから、電流検出部３００又は検出部本体５００に検出誤差、検出精度の差異がある場合には、予め試験回路２７０で動作確認を実行しても、この検出誤差又は検出精度の差異により動作確認結果自体に誤認の虞れがあり、配線路７００に生じる漏洩電流を確実且つ正確に検出できないという課題を有する。
【０００９】
また、単相の漏電ブレーカを接続して共通線で接地相の配線路を構成している場合には、配線路７００の電圧相配線路と接地相配線路とを一括してクランプすることができないという課題を有する。本発明は前記課題を解消するためになされたもので、二つの電流検出手段の検出誤差の有無及び検出精度の相違にも拘わらずこの誤差を相殺して確実に漏洩電流を検出できると共に、探査作業におけるクランプの作業性を向上させることができる漏洩電流探査方法を提供することを目的とする。
【００１０】
【課題を解決するための手段】
本発明に係る漏洩電流探査方法は、単相の電源電圧が一対の配線路に印加された状態で、当該一対の配線路にクランプして配線路に流れる電流を検出する二つの電流検出手段と、前記二つの電流検出手段で検出した電流値の差分を演算する差分演算部と、前記検出した二つの電流値を一致させるように前記二つの電流検出手段の検出精度を調整する調整部とを備える漏洩電流探査装置を用いて配線路の漏電電流を検出する漏洩電流探査方法であって、前記一対の配線路のうち第一の配線路に前記二つの電流検出手段をクランプした状態で、前記第一の配線路に流れる電流を検出し、前記二つの電流検出手段で検出した検出電流の差分を前記差分演算部が演算し、当該演算結果に基づいて前記調整部が前記二つの電流検出手段で検出する電流値を一致させるように前記二つの電流検出手段の検出精度を調整し、前記一方の電流検出手段を前記第一の配線路にクランプした状態を維持し、他方の電流検出手段を前記第一の配線路から取り外して前記第二の配線路にクランプし、前記二つの電流検出手段を各々異なる第一又は第二の配線路にクランプした状態で電流を検出して当該各電流の電流差分を差分演算部が演算し、当該差分演算部で演算した電流差分から、前記一対の配線路の漏洩電流を測定して前記一対の配線路の漏洩状態を検出するものである。
【００１１】
このように本発明によれば、同一の電源配線路に当該二つの電流検出手段を同時にクランプして当該二つの電流検出手段から検出される各電流値の差分を差分演算部が演算し、この差分がなくなるように各電流値を一致させるように調整部で調整し、一方の電流検出手段をそのまま第一の配線路にクランプしたまま他方の電流検出手段を第二の配線路側にクランプしてその差異を検出するようにしているので、相互の誤差を相殺するように調整して一致させた状態で探査動作を行えることとなり、この相対的な検出の差異によって漏電の有無を判断することができる。また、電圧相に単相の漏電ブレーカを接続し、接地相を共通線として各配線が離れて構成されている場合においても、電圧相及び接地相に別々に電流検出手段を作業性よくクランプして、各検出された電流値の差分から漏洩電流を検出することができる。
【００１２】
また、本発明に係る漏洩電流探査方法は必要に応じて、前記調整部が、前記二つの電流検出手段で検出する電流値を振幅及び/又は位相を調整することにより一致させるものである。このように本発明によれば、前記一対の配線路のうち前記第一の配線路に流れる電流を前記二つの電流検出手段で検出して当該電流値を振幅及び/又は位相について一致させるようにしているので、調整部による電流値の一致調整を緻密に実行できることとなり、漏洩電流を高精度に検出できる。
【００１４】
【発明の実施の形態】
（本発明の第１の実施形態）以下、本発明の第１の実施形態に係る漏洩電流探査方法の形態を図１、図２及び図３に基づいて説明する。図１は本発明の第１の実施形態に係る漏洩電流探査方法の動作説明図、図２は本発明の第１の実施形態に係る漏洩電流探査方法を実施するための漏洩電流探査装置の概略ブロック構成図、図３(a)は本発明の第１の実施形態に係る漏洩電流探査装置を同一配線路に接続した概略図、図３(b)は本発明の第１の実施形態に係る漏洩電流探査装置を一対の配線路に接続した概略図である。
【００１５】
本発明の第１の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置１は、一対の配線路１０にクランプして配線路１０に流れる電流を検出する二つの電流検出部２a、２bからなる電流検出手段２と、これらの二つの電流検出部２a、２bでそれぞれ検出した検出電流を入力してこの検出電流の差分を演算処理する検出部本体３とで構成される。電流検出部２a（２b）は、分割された円環状に形成され、配線路１０にクランプするクランプ部２１a（２１b）と、このクランプ部２１a（２１b）を一端に支持する取手部２２a（２２b）と、この取手部２２a（２２b）の一側端にクランプ部２１a（２１b）を開放自在に制御するレバー２３a（２３b）と、取手部２２a（２２b）の他端側から検出部本体３に接続されるコード２４a（２４b）とから構成される。
【００１６】
検出部本体３は、図２に示すように、二つの電流検出部２a、２bから二つの検出電流が入力され、この二つの検出電流を各々電圧に変換する電流/電圧変換部４a、４bと、変換された二つの変換電圧を一致するように調整する調整値が設定され、この調整値に基づいて二つの変換電圧をそれぞれ補正する調整部５a、５bと、この調整部５a、５bで補正された二つの変換電圧を演算処理して差分を出力する差分演算部６と、この差分演算部６から出力した差分電圧を増幅する増幅部７と、この増幅部７で増幅された変換電圧をさらにアナログ値からデジタル値に変換する出力A/D変換部８とを備える構成である。調整部５a、５bは、前記ケース３aの外側面に配設された操作部を回動させることにより前記調整値が設定され、この調整値により二つの電流検出部２a、２bから入力される検出電流を補正することにより、それぞれ二つの電流検出部２a、２bの検出精度を調整する構成である。
【００１７】
以下、前記構成に基づく本実施形態の具体的な動作について説明する。まず、図３(a)に示すように、電圧相と接地相との一対からなる配線路１０のうちの電圧相配線路１０aにこの二つの電流検出部２a、２bを同時にクランプしてこの電圧相配線路１０aに流れる電流がこの二つの電流検出部２a、２bによってそれぞれ検出される。この検出電流が検出部本体３に入力されて二つの検出電流が各々電圧に変換され、変換された二つの変換電圧がそれぞれ調整部５a、５bを介して差分演算部６に入力して演算処理されて上記二つの変換電圧の差分が出力され、この差分電圧が増幅されさらにA/D変換されて出力される。
【００１８】
電圧相配線路１０aにこの二つの電流検出部２a、２bを同時にクランプしているときの前記差分の出力結果に基づいてこの差分値がゼロとなるように調整部５a、５bを調整する。すなわち、それぞれ二つの電流検出部２a、２bで検出する検出電流を一致させるように調整部５a、５bの調整値が設定される。このとき調整値が設定されるのは、調整部５aだけであっても調整部５bだけであってもよく、また調整部５aと調整部５b両方に同一又は異なる調整値が設定されて二つの電流検出部２a、２bで検出する検出電流を一致させてもよい。
【００１９】
次に、図３(b)に示すように、一方の電流検出部２aを電圧相配線路１０aにクランプした状態を維持し、他方の電流検出部２bを電圧相配線路１０aから取り外して接地相配線路１０bにクランプし、二つの電流検出部２a、２bを各々異なる電圧相配線路１０aと接地相配線路１０bとにクランプした状態で電圧相配線路１０aと接地相配線路１０bとに流れる各電流がこの二つの電流検出部２a、２bによってそれぞれ検出される。この二つの電流検出部２a、２bによってそれぞれ検出された検出電流が、検出部本体３に入力されて二つの検出電流が各々電圧に変換され、変換された二つの変換電圧がそれぞれ調整部５a、５bの調整値で補正されて差分演算部６に入力され、この差分演算部６で演算処理されて二つの変換電圧の差分が出力され、この差分が増幅されさらにA/D変換されて出力されるものである。この差分値が一対の電圧相配線路１０aと接地相配線路１０bとの電流値の差分であり、この電流値の差分が判明することによってこの一対の電圧相と接地相からなる配線路１０の漏洩状態を検出する。
【００２０】
本発明の第１の実施形態に係るこの漏洩電流探査方法は、電圧相に単相の漏電ブレーカを接続し、接地相を共通線として各配線が離れて構成されている場合においても、電圧相及び接地相に別々に電流検出部２a、２bを作業性よくクランプして、各検出された電流値の差分から漏洩電流を検出することができる。
（本発明の第２の実施形態）以下、本発明の第２の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置の形態を図４及び図５に基づいて説明する。図４は本発明の第２の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置の形態図、図５は本発明の第２の実施形態に係る漏洩電流探査装置の概略ブロック構成図である。
【００２１】
本発明の第２の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置１は、検出部本体３が図４及び図５に示すように本発明の第１の実施例の検出部本体３の構成を異にし、前記調整部５a、５bに換え、振幅調整部５１a、５１bと位相調整部５２a、５２bとを備える構成である。以下、前記構成に基づく本実施形態の具体的な動作について説明する。電圧相と接地相との一対からなる配線路１０のうちの電圧相配線路１０aにこの二つの電流検出部２a、２bを同時にクランプしてこの電圧相配線路１０aに流れる電流がこの二つの電流検出部２a、２bによってそれぞれ検出される。この二つの電流検出部２a、２bによってそれぞれ検出された検出電流が検出部本体３内に入力され、差分演算部６によって二つの電流検出部２a、２bにそれぞれ検出された検出電流の差分が出力A/D変換部８から出力されるまでは本発明の第１の実施形態の動作と全く同様である。
【００２２】
電圧相配線路１０aにこの二つの電流検出部２a、２bを同時にクランプしているときに、振幅調整部５１a、５１b及び位相調整部５２a、５２bは、二つの電流検出部２a、２bで各々検出され、検出電流の振幅及び位相の差がゼロとなるように振幅調整値及び位相調整値を設定する。このとき振幅調整値を設定するのは、振幅調整部５１aと振幅調整部５１bとのいずれか一方又は双方であってもよく、位相調整値を設定するのは、位相調整部５２aと位相調整部５２bとのいずれか一方又は双方であってもよい。
【００２３】
次に、一方の電流検出部２aを電圧相配線路１０aにクランプした状態を維持し、他方の電流検出部２bを電圧相配線路１０aから取り外して接地相配線路１０bにクランプし、二つの電流検出部２a、２bを各々異なる電圧相配線路１０aと接地相配線路１０bとにクランプした状態で電圧相配線路１０aと接地相配線路１０bとに流れる各電流を二つの電流検出部２a、２bによってそれぞれ検出する。この検出された各電流が検出部本体３に入力し、出力A/D変換部８から検出電流を振幅調整部５１a、５１bが振幅調整値に基づいて振幅を補正し、さらに位相調整部５２a、５２bが位相調整値に基づいて位相を補正する。この各々補正された検出電流が差分演算部６により差分が出力され、電流値の差分が判明することによってこの電圧相と接地相との一対からなる配線路１０の漏洩状態を検出する動作まで本発明の第１の実施形態と同様である。
【００２４】
本発明の第２の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置は、電圧相配線路１０aにこの二つの電流検出部２a、２bを同時にクランプしているときにこのこの二つの電流検出部２a、２bで検出する電流値を一致させるように振幅調整部５１a、５１bと位相調整部５２a、５２bとを調整するので、本発明の第１の実施例のように調整部５a、５bだけを調整するときよりもより厳密に二つの電流検出部２a、２bで検出する電流値を一致させることができ、これにより、より正確に電圧相と接地相との一対からなる配線路１０の漏洩電流値を検出することができる。
【００２５】
（本発明の第３の実施形態）以下、本発明の第３の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置の形態を図６及び図７に基づいて説明する。図６は本発明の第３の実施形態に係る漏洩電流探査装置の形態図、図７は本発明の第３の実施形態に係る漏洩電流探査装置の概略ブロック構成図である。
【００２６】
本発明の第３の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置１は、検出部本体３が図６及び図７に示すように本発明の第２の実施例の検出部本体３の構成に加え、検出部本体３に、二つの電流検出部２a、２bによってそれぞれ検出された検出電流を表示する電流表示部９a、９bと、二つの電流検出部２a、２bによってそれぞれ検出された検出電流の差分を表示する差分表示部１１とを備える構成である。
【００２７】
電流表示部９a、９bは、二つの電流検出部２a、２bによってそれぞれ検出された検出電流が、検出部本体３に入力されて二つの検出電流がそれぞれ電圧に変換され、変換された二つの変換電圧がそれぞれ振幅調整部５１a、５１bと位相調整部５２a、５２bを介して調整され、この調整された変換電圧がそれぞれ増幅部７a、７bで増幅され、出力A/D変換部８a、８bからデジタル信号としてそれぞれ出力されることにより、二つの電流検出部２a、２bでそれぞれ検出された検出電流を表示するものである。差分表示部１１は、二つの電流検出部２a、２bによってそれぞれ検出された検出電流が検出部本体３内に入力され、差分演算部６によって二つの電流検出部２a、２bにそれぞれ検出された検出電流の差分が出力A/D変換部８からデジタル信号として出力されることにより、二つの電流検出部２a、２bにそれぞれ検出された検出電流値の差分を表示するものである。
【００２８】
本発明の第３の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置は、二つの電流検出部２a、２bにそれぞれ検出された検出電流値及びその検出電流値の差分値を視認することができ、この表示された差分値に基づいて調整部５a、５bにおける調整が正確且つ簡易に行えることとなり、電圧相と接地相との一対からなる配線路１０における漏洩電流の検出をより確実に実行できる。ここでは、電流検出用クランプの向きを各々同一方向にクランプすることで説明したが、片方のクランプの向きを逆にした場合、差分演算部６の演算は加算演算を行うことになる。
【００２９】
【発明の効果】
以上のように本発明においては、同一の電源配線路に当該二つの電流検出手段を同時にクランプして当該二つの電流検出手段から検出される各電流値の差分を差分演算部が演算し、この差分がなくなるように各電流値を一致させるように調整部で調整し、一方の電流検出手段をそのまま第一の配線路にクランプしたまま他方の電流検出手段を第二の配線路側にクランプしてその差異を検出するようにしているので、相互の誤差を相殺するように調整して一致させた状態で探査動作を行えることとなり、この相対的な検出の差異によって漏電の有無を判断することができるという効果を有し、電圧相に単相の漏電ブレーカを接続し、接地相を共通線として各配線が離れて構成されている場合においても、電圧相及び接地相に別々に電流検出手段を作業性よくクランプして、各検出された電流値の差分から漏洩電流を検出することができるという効果を有する。
【００３０】
また、本発明においては、前記一対の配線路のうち前記第一の配線路に流れる電流を前記二つの電流検出手段で検出して当該電流値を振幅及び/又は位相について一致させるようにしているので、調整部による電流値の一致調整を緻密に実行できることとなり、漏洩電流を高精度に検出できるという効果を有する。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係る漏洩電流探査方法の動作説明図である。
【図２】本発明の第１の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置の概略ブロック構成図である。
【図３】本発明の第１の実施形態に係る漏洩電流探査装置を同一配線路に接続した概略図(a)及び本発明の第１の実施形態に係る漏洩電流探査装置を一対の配線路に接続した概略図(b)である。
【図４】本発明の第２の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置の形態図である。
【図５】本発明の第２の実施形態に係る漏洩電流探査装置の概略ブロック構成図である
【図６】本発明の第３の実施形態に係る漏洩電流探査方法を実行する漏洩電流探査装置の形態図である。
【図７】本発明の第３の実施形態に係る漏洩電流探査装置の概略ブロック構成図である。
【図８】従来の漏洩電流探査装置の動作確認試験説明図である。
【図９】従来の漏洩電流探査装置の動作確認試験説明図である。
【図１０】従来の漏洩電流探査装置の漏電探査説明図(a)、(b)である。
【符号の説明】
１、１００漏洩電流探査装置
２電流検出手段
２a、２b、３００電流検出部
２１a、２１b クランプ部
２２a、２２b 取手部
２３a、２３b レバー
２４a、２４b コード
３、５００検出部本体
３b ケース
４a、４b 電流/電圧変換部
５a、５b 調整部
５１a、５１b 振幅調整部
５２a、５２b 位相調整部
６差分演算部
７、７a、７b 増幅部
８、８a、８b 出力A/D変換部
９a、９b 電流表示部
１０、７００配線路
１０a 電圧相配線路
１０b 接地相配線路
１１差分表示部
１１０発振器
１７０発信回路
１９０絶縁物
２１０取手
２３０抵抗
２５０スイッチ
２７０試験回路
９００接地線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a leakage current search method for searching for a leakage point in a low-voltage wiring line and detecting a leakage current particularly in a live line state.
[0002]
[Prior art]
Conventionally, this type of leakage current exploration device has been disclosed in Japanese Patent Laid-Open No. 3-96874. FIG. 8 is a configuration diagram of the conventional leakage current exploration device, FIG. 9 is an operation confirmation test explanatory diagram of the conventional leakage current exploration device, and FIGS. 10A and 10B are explanations of electric leakage exploration of the conventional leakage current exploration device. FIG.
[0003]
The conventional leakage current exploration device 100 includes a current detection unit (clamp type ZCT) 300 that detects a leakage current, a detection unit main body 500 that displays the detected leakage current by calculation processing, and the detection unit main body 500. It is configured to include a handle 210 made of a conductive member fixed to the detection unit main body 500 via an insulator 190 and connected to a test circuit 270 built in the detection unit main body 500. The test circuit 270 includes an oscillation circuit 170 that oscillates a low-frequency signal, a resistor 230 and a switch 250 connected in series to the oscillation circuit 170, and the handle 210 includes the resistor 230, the oscillation circuit 170, and the switch 250. Are connected in series to form a loop circuit.
[0004]
Hereinafter, a specific operation of the conventional leakage current exploration device 100 based on the above configuration will be described. First, as shown in FIG. 9, the current detection unit 300 is clamped and coupled to the handle 210 during the operation test of the leakage current exploration device 100, and a low-frequency monitoring signal is sent from the oscillation circuit 170 to the handle 210. At this time, the leakage current exploration is performed by measuring the current value measured by the current detection unit 300 using the leakage current exploration device 100 itself and determining whether or not the measured current value can be detected above a predetermined value. The operation of the apparatus 100 is checked.
[0005]
Next, the current detection unit 300 is detached from the handle 210, the current detection unit 300 is clamped to the existing wiring path 700 as shown in FIG. 10A, and the wiring path 700 in which the current detection unit 300 is clamped. An oscillator 110 is connected to the ground line 900, a monitoring signal oscillated from the oscillator 110 is applied to the wiring line 700, and the magnitude of the monitoring signal current flowing through the wiring line 700 is measured by the leakage current exploration device 100. To do. The oscillator 110 adjusts and changes the transmission output, and varies the oscillation frequency applied to the wiring line 700, thereby changing the magnitude of the monitoring signal current flowing through the wiring line 700 while changing the magnitude of the monitoring signal current. The detection accuracy is obtained, and the leakage current of the target wiring path 700 is detected within the range in which the detection accuracy is obtained.
[0006]
As shown in FIG. 10B, when insulation deterioration occurs between B and C of the wiring path 700, the measurement points in the wiring path 700 are changed in order of A → B → C. When the earth leakage survey is performed, the detection value of the monitoring signal at points A and B is high, and the detection value of the monitoring signal at point C decreases. Therefore, by knowing the measurement value of the monitoring signal at an arbitrary location on the wiring path 700, it is possible to search for an insulation failure location. As described above, the conventional leakage current exploration device 100 checks the operation of the conventional leakage current exploration device 100 in advance with the conventional leakage current exploration device 100 in advance and searches for a leakage point in the wiring path 700. is there.
[0007]
Other conventional leakage current exploration devices include those disclosed in JP-A-6-27165 and JP-A-10-68749.
In general, the leakage current that is the target of the leakage current exploration device is that there is a capacitance component between the wiring path where the load equipment and the like exist and the ground, and the power supply noise that is installed in electronic equipment such as computers. An electrostatic capacitance component exists also in a prevention filter etc., and a resistance component also exists by insulation degradation, such as a wiring path and load equipment. Since the capacitance component and the resistance component exist, a leakage current flows between the wiring path and the ground. Since the leakage current may cause a serious accident such as a fire in some cases, it is necessary to prevent the leakage current from occurring, and it is important to find the cause of the leakage current accurately and quickly.
[0008]
[Problems to be solved by the invention]
Since the conventional leakage current exploration device is configured as described above, if there is a difference in detection error or detection accuracy between the current detection unit 300 or the detection unit main body 500, an operation check is performed in advance by the test circuit 270. However, there is a possibility that the operation confirmation result itself may be misidentified due to the difference in detection error or detection accuracy, and there is a problem that the leakage current generated in the wiring path 700 cannot be detected reliably and accurately.
[0009]
In addition, when a ground-phase wiring path is configured with a common line by connecting a single-phase leakage breaker, the voltage-phase wiring path and the ground-phase wiring path of the wiring path 700 cannot be collectively clamped. Has a problem. The present invention has been made to solve the above-mentioned problems. In spite of the presence or absence of detection error and the difference in detection accuracy of the two current detection means, it is possible to cancel this error and reliably detect the leakage current, and to An object of the present invention is to provide a leakage current exploration method capable of improving the workability of the clamp in the work.
[0010]
[Means for Solving the Problems]
Leakage current exploration method according to the present invention, while the power voltage of the single phase is applied to the pair of wiring lines, and two current detecting means for detecting a current flowing through the distribution line and clamped to the pair of wiring lines A difference calculation unit that calculates a difference between the current values detected by the two current detection units, and an adjustment unit that adjusts the detection accuracy of the two current detection units so as to match the two detected current values. a leakage current exploration method for detecting the leakage current of the wiring path with the leakage current locator Ru provided, while clamping the two current detection means to the first wiring path of the pair of wiring lines, The current flowing through the first wiring path is detected, the difference between the detected currents detected by the two current detecting means is calculated by the difference calculation unit, and the adjustment unit detects the two current detections based on the calculation result Current value detected by means The detection accuracy of the two current detection means is adjusted so as to coincide with each other, the state where the one current detection means is clamped to the first wiring path, and the other current detection means is set to the first wiring path. And is clamped to the second wiring path, the current is detected in a state where the two current detection means are clamped to different first or second wiring paths, and the current difference between the currents is calculated as a difference calculation unit. Is calculated, and the leakage current of the pair of wiring paths is measured from the current difference calculated by the difference calculation unit to detect the leakage state of the pair of wiring paths.
[0011]
As described above, according to the present invention, the difference calculation unit calculates the difference between the current values detected from the two current detection means by simultaneously clamping the two current detection means to the same power supply wiring path. The adjustment unit adjusts the current values to match each other so that there is no difference, and clamps the other current detection means on the second wiring path side while clamping one current detection means on the first wiring path as it is. Since the difference is detected, the exploration operation can be performed in a state in which the differences are adjusted and matched so as to cancel out the mutual errors, and it is possible to determine the presence or absence of leakage by the relative detection difference. it can. In addition, even when a single-phase leakage breaker is connected to the voltage phase and the wiring is separated from the ground phase as a common line, the current detection means is clamped separately to the voltage phase and the ground phase with good workability. Thus, the leakage current can be detected from the difference between the detected current values.
[0012]
Also, in the leakage current search method according to the present invention, the adjustment unit matches the current values detected by the two current detection means by adjusting the amplitude and / or phase as necessary. As described above, according to the present invention, the current flowing through the first wiring path of the pair of wiring paths is detected by the two current detection means, and the current values are made to coincide with each other in amplitude and / or phase. Therefore, the adjustment of the current value by the adjustment unit can be performed precisely, and the leakage current can be detected with high accuracy.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
(First Embodiment of the Present Invention) A form of a leakage current exploration method according to a first embodiment of the present invention will be described below with reference to FIG. 1, FIG. 2, and FIG. 1 are views for explaining the operation of the leakage current exploration method according to the first embodiment of the present invention, schematically in Figure 2 is the leakage current locator for carrying the leakage current exploration method according to the first embodiment of the present invention 3 is a block diagram, FIG. 3 (a) is a schematic diagram in which the leakage current exploration device according to the first embodiment of the present invention is connected to the same wiring path, and FIG. 3 (b) is according to the first embodiment of the present invention. It is the schematic which connected the leakage current investigation apparatus to a pair of wiring path.
[0015]
The leakage current exploration device 1 that executes the leakage current exploration method according to the first embodiment of the present invention includes two current detection units 2a and 2b that clamp a pair of wiring paths 10 and detect a current flowing through the wiring paths 10. And a detection unit main body 3 that inputs detection currents detected by the two current detection units 2a and 2b and calculates a difference between the detection currents. The current detection unit 2a (2b) is formed in a divided annular shape, and a clamp unit 21a (21b) that clamps the wiring path 10, and a handle unit 22a (22b) that supports the clamp unit 21a (21b) at one end. And a lever 23a (23b) for controlling the clamp portion 21a (21b) to be freely opened at one end of the handle portion 22a (22b), and the other end side of the handle portion 22a (22b) connected to the detector main body 3 Code 24a (24b).
[0016]
As shown in FIG. 2, the detection unit body 3 receives two detection currents from the two current detection units 2a and 2b, and current / voltage conversion units 4a and 4b for converting the two detection currents into voltages, respectively. An adjustment value for adjusting the two converted voltages to be matched is set, and adjustment units 5a and 5b for correcting the two conversion voltages based on the adjustment values, respectively, and correction by the adjustment units 5a and 5b The difference calculation unit 6 that calculates the difference between the two converted voltages and outputs the difference, the amplification unit 7 that amplifies the difference voltage output from the difference calculation unit 6, and the conversion voltage amplified by the amplification unit 7 Further, the output A / D converter 8 for converting an analog value into a digital value is provided. The adjustment units 5a and 5b set the adjustment value by rotating the operation unit disposed on the outer surface of the case 3a, and the detection values input from the two current detection units 2a and 2b by the adjustment value. By correcting the current, the detection accuracy of each of the two current detectors 2a and 2b is adjusted.
[0017]
The specific operation of the present embodiment based on the above configuration will be described below. First, as shown in FIG. 3 (a), the two current detectors 2a and 2b are clamped simultaneously on the voltage phase wiring path 10a of the wiring path 10 consisting of a pair of voltage phase and ground phase, and this voltage phase distribution is obtained. The currents flowing through the line 10a are detected by the two current detectors 2a and 2b, respectively. This detection current is input to the detection unit main body 3, the two detection currents are converted into voltages, and the two converted conversion voltages are input to the difference calculation unit 6 via the adjustment units 5a and 5b, respectively, to perform calculation processing. Then, the difference between the two conversion voltages is output, the difference voltage is amplified, further A / D converted, and output.
[0018]
The adjustment units 5a and 5b are adjusted so that the difference value becomes zero based on the output result of the difference when the two current detection units 2a and 2b are simultaneously clamped to the voltage phase wiring line 10a. That is, the adjustment values of the adjustment units 5a and 5b are set so that the detection currents detected by the two current detection units 2a and 2b are matched. At this time, the adjustment value may be set only in the adjustment unit 5a or only in the adjustment unit 5b, and the same or different adjustment values are set in both the adjustment unit 5a and the adjustment unit 5b. The detection currents detected by the current detection units 2a and 2b may be matched.
[0019]
Next, as shown in FIG. 3 (b), one current detection unit 2a is maintained clamped to the voltage phase wiring path 10a, and the other current detection unit 2b is removed from the voltage phase wiring path 10a and the ground phase wiring path 10b. The currents flowing in the voltage phase wiring path 10a and the ground phase wiring path 10b in a state where the two current detection units 2a and 2b are clamped to the different voltage phase wiring path 10a and the ground phase wiring path 10b, respectively, are detected by these two currents. Detected by the units 2a and 2b, respectively. The detection currents detected by the two current detection units 2a and 2b are respectively input to the detection unit body 3, and the two detection currents are converted into voltages, respectively. The two converted voltages are converted into the adjustment units 5a and 5a, respectively. The difference is corrected with the adjustment value 5b and input to the difference calculation unit 6. The difference calculation unit 6 performs calculation processing to output a difference between the two conversion voltages. The difference is amplified and further A / D converted and output. Is. This difference value is the difference between the current values of the pair of voltage phase wiring paths 10a and the ground phase wiring path 10b, and the leakage state of the wiring path 10 composed of the pair of voltage phases and the ground phase is determined by determining the difference between the current values. Is detected.
[0020]
In this leakage current exploration method according to the first embodiment of the present invention, even when a single-phase leakage breaker is connected to the voltage phase and each wiring is separated from the ground phase as a common line, the voltage phase In addition, the current detection units 2a and 2b can be clamped separately to the ground phase with good workability, and the leakage current can be detected from the difference between the detected current values.
(Second Embodiment of the Present Invention) The form of a leakage current exploration apparatus for executing the leakage current exploration method according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a configuration diagram of a leakage current exploration apparatus that executes a leakage current exploration method according to the second embodiment of the present invention, and FIG. 5 is a schematic block configuration diagram of the leakage current exploration apparatus according to the second embodiment of the present invention. It is.
[0021]
In the leakage current exploration apparatus 1 for executing the leakage current exploration method according to the second embodiment of the present invention, the detection unit main body 3 has a detection unit main body according to the first embodiment of the present invention as shown in FIGS. 3 is different, and instead of the adjustment units 5a and 5b, amplitude adjustment units 51a and 51b and phase adjustment units 52a and 52b are provided. The specific operation of the present embodiment based on the above configuration will be described below. The two current detectors 2a and 2b are clamped simultaneously on the voltage phase wiring path 10a of the wiring path 10 consisting of a pair of voltage phase and ground phase, and the current flowing through the voltage phase wiring path 10a is the two current detection sections. Detected by 2a and 2b, respectively. The detection currents detected by the two current detection units 2a and 2b are input into the detection unit main body 3, and the difference between the detection currents detected by the difference calculation unit 6 is output to the two current detection units 2a and 2b, respectively. The operation until the output from the A / D converter 8 is exactly the same as the operation of the first embodiment of the present invention.
[0022]
When the two current detection units 2a and 2b are simultaneously clamped to the voltage phase wiring line 10a, the amplitude adjustment units 51a and 51b and the phase adjustment units 52a and 52b are detected by the two current detection units 2a and 2b, respectively. The amplitude adjustment value and the phase adjustment value are set so that the difference between the amplitude and the phase of the detection current becomes zero. At this time, the amplitude adjustment value may be set by either or both of the amplitude adjustment unit 51a and the amplitude adjustment unit 51b, and the phase adjustment value is set by the phase adjustment unit 52a and the phase adjustment unit. Either one or both of 52b may be used.
[0023]
Next, the state where one current detection unit 2a is clamped to the voltage phase wiring path 10a is maintained, the other current detection unit 2b is detached from the voltage phase wiring path 10a and clamped to the ground phase wiring path 10b, and the two current detection units 2a Each current flowing in the voltage phase wiring path 10a and the ground phase wiring path 10b in a state where 2b is clamped to the different voltage phase wiring path 10a and the ground phase wiring path 10b is detected by the two current detectors 2a and 2b, respectively. Each detected current is input to the detection unit main body 3, the amplitude adjustment units 51a and 51b correct the detection current from the output A / D conversion unit 8 based on the amplitude adjustment value, and the phase adjustment unit 52a and 52b corrects the phase based on the phase adjustment value. A difference is output from each of the corrected detection currents by the difference calculation unit 6, and the difference between the current values is clarified, so that the operation until the leakage state of the wiring line 10 consisting of a pair of the voltage phase and the ground phase is detected. This is the same as the first embodiment of the invention.
[0024]
The leakage current exploration apparatus that executes the leakage current exploration method according to the second embodiment of the present invention is configured to clamp the two current detection units 2a and 2b on the voltage phase wiring line 10a at the same time. Since the amplitude adjustment units 51a and 51b and the phase adjustment units 52a and 52b are adjusted so that the current values detected by the detection units 2a and 2b coincide with each other, the adjustment units 5a and 5b as in the first embodiment of the present invention. Therefore, the current values detected by the two current detectors 2a and 2b can be made to coincide more strictly than when adjusting only the voltage of the wiring path 10 consisting of a pair of a voltage phase and a ground phase. The leakage current value can be detected.
[0025]
(Third Embodiment of the Present Invention) A form of a leakage current exploration apparatus for executing a leakage current exploration method according to a third embodiment of the present invention will be described below with reference to FIGS. FIG. 6 is a schematic diagram of a leakage current exploration device according to the third embodiment of the present invention, and FIG. 7 is a schematic block configuration diagram of the leakage current exploration device according to the third embodiment of the present invention.
[0026]
In the leakage current exploration apparatus 1 for executing the leakage current exploration method according to the third embodiment of the present invention, as shown in FIGS. 6 and 7, the detection portion main body 3 of the second embodiment of the present invention is used. In addition to the configuration of 3, the detection unit body 3 is detected by the current display units 9a and 9b for displaying the detected currents respectively detected by the two current detection units 2a and 2b, and the two current detection units 2a and 2b. The difference display unit 11 displays the difference between the detected currents.
[0027]
In the current display units 9a and 9b, the detection currents detected by the two current detection units 2a and 2b are input to the detection unit main body 3, and the two detection currents are converted into voltages, respectively. The voltages are adjusted via the amplitude adjusters 51a and 51b and the phase adjusters 52a and 52b, respectively, and the adjusted conversion voltages are amplified by the amplifiers 7a and 7b, respectively, and digitally output from the output A / D converters 8a and 8b. By outputting each as a signal, the detected current detected by each of the two current detectors 2a and 2b is displayed. In the difference display unit 11, detection currents detected by the two current detection units 2a and 2b are input into the detection unit main body 3, and detection detected by the difference calculation unit 6 in the two current detection units 2a and 2b, respectively. By outputting the current difference as a digital signal from the output A / D conversion unit 8, the difference between the detected current values is displayed on each of the two current detection units 2a and 2b.
[0028]
The leakage current exploration apparatus that executes the leakage current exploration method according to the third embodiment of the present invention visually recognizes the detected current value detected by the two current detection units 2a and 2b and the difference value between the detected current values. Therefore, the adjustment in the adjustment units 5a and 5b can be performed accurately and easily based on the displayed difference value, and the leakage current in the wiring line 10 consisting of a pair of the voltage phase and the ground phase can be detected more reliably. Can be executed. Here, the direction of the current detection clamp is described as being clamped in the same direction. However, when the direction of one of the clamps is reversed, the calculation of the difference calculation unit 6 performs an addition calculation.
[0029]
【The invention's effect】
As described above, in the present invention, the difference calculation unit calculates the difference between the current values detected from the two current detection means by simultaneously clamping the two current detection means to the same power supply wiring path. The adjustment unit adjusts the current values to match each other so that there is no difference, and clamps the other current detection means on the second wiring path side while clamping one current detection means on the first wiring path as it is. Since the difference is detected, the exploration operation can be performed in a state of being adjusted and matched so as to cancel out the mutual errors, and it is possible to determine the presence / absence of leakage by the relative detection difference. Even when a single-phase earth leakage breaker is connected to the voltage phase and each wiring is separated from the ground phase as a common line, current detection means are separately provided for the voltage phase and the ground phase. And good workability clamp has the effect that it is possible to detect the leakage current from the difference between the detected current value.
[0030]
Further, in the present invention, the current flowing through the first wiring path of the pair of wiring paths is detected by the two current detection means, and the current values are matched with respect to amplitude and / or phase. As a result, the adjustment of the current value by the adjustment unit can be precisely performed, and the leakage current can be detected with high accuracy .
[Brief description of the drawings]
FIG. 1 is an operation explanatory diagram of a leakage current search method according to a first embodiment of the present invention.
FIG. 2 is a schematic block diagram of a leakage current exploration apparatus that executes the leakage current exploration method according to the first embodiment of the present invention.
FIG. 3A is a schematic diagram in which the leakage current exploration device according to the first embodiment of the present invention is connected to the same wiring path, and the leakage current exploration device according to the first embodiment of the present invention is a pair of wiring paths; It is the schematic (b) connected to.
FIG. 4 is a configuration diagram of a leakage current exploration apparatus that executes a leakage current exploration method according to a second embodiment of the present invention.
FIG. 5 is a schematic block configuration diagram of a leakage current exploration device according to a second embodiment of the present invention. FIG. 6 is a leakage current exploration device that executes a leakage current exploration method according to a third embodiment of the present invention. FIG.
FIG. 7 is a schematic block diagram of a leakage current exploration device according to a third embodiment of the present invention.
FIG. 8 is an explanatory diagram of an operation confirmation test of a conventional leakage current exploration device.
FIG. 9 is an explanatory diagram of an operation confirmation test of a conventional leakage current exploration device.
FIGS. 10A and 10B are explanatory diagrams (a) and (b) of a leakage current exploration of a conventional leakage current investigation device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,100 Leakage current exploration apparatus 2 Current detection means 2a, 2b, 300 Current detection part 21a, 21b Clamp part 22a, 22b Handle part 23a, 23b Lever 24a, 24b Code 3, 500 Detection part main body 3b Case 4a, 4b Current / Voltage conversion unit 5a, 5b Adjustment unit 51a, 51b Amplitude adjustment unit 52a, 52b Phase adjustment unit 6 Difference calculation unit 7, 7a, 7b Amplification unit 8, 8a, 8b Output A / D conversion unit 9a, 9b Current display unit 10, 700 Wiring path 10a Voltage phase wiring path 10b Ground phase wiring path 11 Difference display section 110 Oscillator 170 Transmission circuit 190 Insulator 210 Handle 230 Resistance 250 Switch 270 Test circuit 900 Ground line

Claims

While the power voltage of the single phase is applied to the pair of wiring lines, and two current detecting means for detecting a current flowing clamped to the pair of wiring lines and the distribution lines,
A difference calculation unit for calculating a difference between current values detected by the two current detection means;
In the leakage current exploration method for detecting the leakage current of the wiring path by using the two current leakage current exploration device Ru and an adjustment unit for adjusting the detection accuracy of the detection means to match the two current values the detected There,
In a state where the two current detection means are clamped to the first wiring path among the pair of wiring paths, the current flowing through the first wiring path is detected,
The difference calculation unit calculates the difference between the detected currents detected by the two current detection means,
Adjusting the detection accuracy of the two current detection means so that the adjustment unit matches the current value detected by the two current detection means based on the calculation result,
Maintaining the state where the one current detection means is clamped to the first wiring path, the other current detection means is removed from the first wiring path and clamped to the second wiring path,
The current is detected in a state where the two current detection means are clamped to different first or second wiring paths, and the difference calculation unit calculates the current difference between the currents.
A leakage current exploration method, comprising: measuring a leakage current of the pair of wiring paths from a current difference calculated by the difference calculation unit to detect a leakage state of the pair of wiring paths.

In the leakage current exploration method according to claim 1,
The leakage current exploration method , wherein the adjustment unit matches current values detected by the two current detection means by adjusting amplitude and / or phase.