JP4054700B2

JP4054700B2 - Device for reducing lightning damage in buildings

Info

Publication number: JP4054700B2
Application number: JP2003071081A
Authority: JP
Inventors: 正憲小林
Original assignee: Sanki Engineering Co Ltd
Current assignee: Sanki Engineering Co Ltd
Priority date: 2003-03-14
Filing date: 2003-03-14
Publication date: 2008-02-27
Anticipated expiration: 2023-03-14
Also published as: JP2004278118A

Description

【０００１】
【発明の属する技術分野】
本発明は建物における雷障害の低減装置に関する。
【０００２】
【従来の技術】
【特許文献１】
特許第３１４３８８２号公報
【特許文献２】
特開平９−４１７２３号公報
【特許文献３】
特開平７−１９２７８４号公報
【特許文献４】
特公平７−８９７１２号公報
【特許文献５】
特許第２７６４００８号公報
【０００３】
特許文献１には、無線中継所や情報化対応ビルディング、ハイテク機器を備えた工場など、半導体システムなどの電気設備を備えた建物を雷サージから保護するため、図１３に示すような、建物１００を囲む環状接地線１０１を設け、その環状接地線に避雷針１０２を接続する防雷方法が開示されている。前記環状接地線１０１には、所望の間隔で地中に埋めた接地極１０３を接続しており、建物内の電気設備の接地１０４を環状接地線１０１内に設けている。なお符号１０５は外部から建物内に入る電源線であり、耐雷変圧器１０６を経由して電気設備１０７に電源供給している。
【０００４】
この防雷方法によれば、避雷針１０２に落雷したとき、建物１００内を通過する雷電流をできる限り抑制することができるので、建物内部の電気設備１０７を雷サージから保護することができる。なお、特許文献２および特許文献３にも、ほぼ同様の建物への雷のサージ電流の侵入を防止する装置ないし構造が開示されている。
【０００５】
他方、特許文献４には、図１４に示すような、入力側巻線１１０と出力側巻線１１１の間に３層のシールド板１１２、１１３、１１４を設けた耐雷変圧器１１５を設け、各シールド板を異なるサージインピーダンスを介して接地する耐雷方法が開示されている。出力側巻線１１１のシールド板１１４は、保護すべき負荷機器１１６に接続されるケーブル１１７のシース１１８と共に接地している。
【０００６】
さらに特許文献５には、図１５に示すような、特許文献４とほぼ同様の耐雷変圧器１２０を設け、出力側巻線のシールド板（静電遮蔽板）１１４を負荷機器１１６の主接地１２１に接続し、入力側巻線のシールド板１１２を入力電源線１２２、１２３のうちのゼロ電位線１２３に接続する耐雷方法が開示されている。なお符号１２４は柱上変圧器であり、符号１２５は架空地線、符号１２６はその架空地線の接地線である。前記ゼロ電位線１２３は柱上変圧器のケースと共にその接地線１２５に接続されている。
【０００７】
この耐雷方法では、入力側巻線のシールド板１１２の接地工事が不要である利点があり、しかも建物１００の避雷針１０２に落雷したときでも、主接地１２１側に流れ、入力電源線１２２、１２３のゼロ電位線１２３に伝わってくる電流も、架空地線の接地（第Ｂ種接地）１２６と架空地線１２５に分流されるので、高圧電線側への影響が少ないとされている。
【０００８】
【発明が解決しようとする課題】
前記いずれの防雷方法あるいは耐雷方法・装置も、一旦、雷が落ちてからの機器の保護を目的とするものであり、雷が落ちにくくすることについては、あまり考慮されていない。本発明はこのような状況に鑑み、落雷をできるだけ少なくすることができる雷障害の低減装置を提供することを第１の技術課題とするものである。さらに本発明は、落雷をできるだけ避けることができ、しかも落雷があった場合の建物内の電気機器の障害をできるだけ少なくすることができる雷障害の低減装置を提供することを第２の課題としている。
【０００９】
【課題を解決するための手段】
本発明の建物における雷障害の低減装置（請求項１）は、建物を囲むように接地されている複数の周囲接地極と、それらの周囲接地極同士を導通する導線と、その建物から離れた位置に設けられる遠隔接地極と、前記周囲接地極ないし導線と前記遠隔接地極とを接続する接続線とを備えており、前記遠隔接地極が、建物から離れて配置された複数本の電柱の近辺に接地され、電柱の上端に沿って架設される架空地線と接続されていることを特徴としている。このような雷障害の低減装置においては、前記周囲接地極と異なる他の遠隔接地極が、建物を矩形状に囲んでおり、前記遠隔接地極が、周囲接地極のコーナー部から放射状に離れた個所に設けられているものが好ましい（請求項２）。
【００１０】
さらに、前記いずれの場合も、建物に避雷針が設けられており、その避雷針と前記周囲接地極とが接続されているものが好ましい（請求項３）。また、遠隔接地極を前述の電柱の近くの地面に設けられる接地極とする場合は、電柱に架設されている架設電線が建物内に引き込まれ、建物内の電気設備に接続されているものが一層好ましい（請求項４）。
【００１１】
【作用および発明の効果】
本発明の低減装置（請求項１）では、周囲接地極が敷地の電位と同電位である。そして接地極同士が導線で導通しているので、接地極が並んで立っている範囲もほぼ同電位である。さらにそれらの接地極と接続線で接続されている遠隔接地極の地面も同電位である。したがって電気が流れていない限り、建物を囲む敷地から遠隔接地極が及ぶ範囲の全体が広い範囲で同電位となり、広い範囲で電気的に平坦な領域が実現できる。それにより落雷し易い電気的に突出する部位がなく、いわばエンロトピーが大きくなる。そのため落雷自体を防止することができる。また、雷雲が建物に近づいていくとき、建物に接近するよりも早くその建物と同電位の遠隔接地極に接近する。そのため、仮に落雷する場合でも、建物より早く遠隔接地極に落雷する。したがって建物への落雷を避けることができる。
また、前記遠隔接地極が建物から離れて配置された複数本の電柱の近辺に接地され、電柱の上端に沿って架設される架空地線と接続されているので、建物の周囲の周囲接地極が電柱の近辺の接地極と同電位であり、しかもその電柱の頭部同士を連接する架空地線とも同電位である。したがって建物を囲む敷地および電柱が立っている帯状の広い範囲で同電位となり、広い範囲で電気的に平坦な領域が実現できる。それにより、落雷し易い電気的に突出する部位がなく、建物への落雷を避けることができる。なお、電柱の側についても、隣接する多くの土地所有者の周囲地線と接続することにより、電柱への落雷の危険性を低減することができる利点がある。
【００１２】
前記周囲接地極が建物を矩形状に囲んでおり、前記遠隔接地極と異なる他の遠隔接地極が周囲接地極のコーナー部から放射状に離れた個所に設けられている場合（請求項２）は、建物からかなり離れた位置に遠隔接地極を設けることができる。さらに周囲接地極同士を接続する導線も、接地極と同様の避雷作用を奏するので、建物を矩形状に囲んでいるほうが安全である。
【００１４】
さらに建物に避雷針を設け、その避雷針と周囲接地線とを接続する場合（請求項３）は、立体的な範囲で同電位の領域が実現する。そのため、一層落雷の危険性を低減することができ、しかも仮に落雷があっても、建物を通らずに避雷針から地面へ、あるいは地面から避雷針へ電流が流れるので、建物内の電気機器が保護される。
【００１５】
前記電柱に架設されている架設電線が建物内に引き込まれ、建物内の電気設備に接続されている場合（請求項４）は、前記落雷の危険性を低減する利点に加えて、落雷があったときの被害を少なくする利点がある。すなわち落雷があると、建物の周囲の周囲接地極および導線を通じて建物内に誘導起電力が生じ、電流が流れようとするが、同時に同じレベルだけ、架空地線に基づいて電源線に誘導起電力が生ずる。したがって電源線と建物内の電気設備との間には、起電力同士が相殺され、落雷による相対的な電位差がなく、誘導起電力に基づく障害（落雷による誘導サージ）が低減される。
【００１６】
【発明の実施の形態】
つぎに図面を参照しながら本発明の雷障害の低減装置の実施の形態を説明する。図１は本発明の低減装置の一実施形態を示す要部平面図、図２はその低減装置の立面図、図３は本発明の低減装置の他の実施形態を示す要部平面図、図４は本発明の低減装置の実施形態の全体を示す平面図、図５は図４の低減装置の立面図、図６はその低減装置の作用を模式的に示すグラフ、図７は本発明の低減装置のさらに他の実施形態を示す立面図、図８ａ〜ｃはその低減装置の作用を模式的に示すグラフ、図９および図１０は架空地線への落雷時における従来の低減装置と本発明の低減装置の作用を対比して示す概略斜視図、図１１および図１２は建物の避雷針への落雷時における従来の低減装置と本発明の低減装置の作用を対比して示す概略斜視図である。
【００１７】
図１の低減装置１は、建物２を囲むように敷地３内に所望の間隔で埋設された複数個の周囲接地極４と、それらの周囲接地極４同士を接続している導線（周囲接地線）５と、矩形状のコーナ部の周囲接地極４ａから放射状に長く延びる接続線６を介して接続される複数の遠隔接地極７とを備えている。なお遠隔接地極は、矩形のコーナー部だけでなく、たとえば符号７ａで示すように、矩形の一辺（図１では左辺）の途中と接続線６ａで導通するようにしてもよい。図１では電柱およびその電柱との接続線は省略している。
【００１８】
図２に示すように、前記周囲接地極４、４ａは、敷地３の地中に深く埋め込まれた金属製、とくに銅製の棒などで構成することができ、それらの上端に前記導線５が接続されている。また、導線５や遠隔接地極７、７ａ、接続線６、６ａも地中に埋め込まれる。しかし導線５や接続線６、６ａは地面の上を通してもよく、空中に懸架してもよい。導線５は被覆せずに直接地中に接地してもよく、被覆電線を用いて接地極のみによって接地してもよい。さらに導線５を、地中に埋めた配線用の配管（非金属配管）に通すようにしてもよい。
【００１９】
図１では隣接する周囲接地極４、４ａ同士を導線５で接続し、導線５は建物２を囲むように矩形状に配線しているが、周囲接地極４、４ａが建物の回りを囲むように配置されていれば、導線５自体は環状や矩形状にする必要はない。さらに導線５は建物２を囲むように配線する必要もなく、図３のように建物２の内部あるいは下方を通って放射状に配線されていてもよい。ただし導線５には落雷時、雷電流が流れ、サージ電圧が発生する。よって導線５の敷設場所は、保護対象機器が地面と接触しているところより、離間距離をとることが必要である。これを満足する限り、導線５は、建物を囲むように設けられる周囲接地極４同士を互いに導通させるものであればどのようなものでもよい。
【００２０】
前記遠隔接地極７、７ａは、建物２の敷地３内に限らず、可能であれば隣接する他人の土地あるいは公道に埋め込むこともできる。図４に示す本発明の低減装置１０では、建物２の近辺に配置された複数本の電柱１４を利用して遠隔接地極を構成している。すなわちこの低減装置１０は、図１の場合と同様の、建物２の周囲に配置される周囲接地極４と、それらの周囲接地極４同士を接続する導線５と、近接する電柱１４の架空地線１５と周囲接地極４とを接続する接続線１６とから構成される。
【００２１】
また、図４および図５に示すように、この実施形態では、さらに建物２の頂部に避雷針１８が立てられており、その避雷針１８から建物２の天面および壁面に沿って延びている第１の導線１９が、地面に埋め込まれた避雷針用の接地極２０に直接接続されている。さらに避雷針１８から延びている第２の導線２１は、建物２の壁面を経由して前述の導線５または周囲接地極４に接続されている。
【００２２】
前記電柱１４の架空地線１５は、電柱１４が本来目的とする架線（図示省略）、たとえば高圧電線、電話線などの架設電線を落雷から保護するものであり、それぞれの電柱１４の上端から電柱に沿って下方に延びる導線２２によって、電柱１４の根元近辺に埋め込まれた棒状の接地極（遠隔接地極）２３に接続されている。そしてもっとも建物２あるいは敷地に近い電柱１４ａの接地極２３ａと、前記周囲地極４または導線５とが前述の接続線１６で接続されている。その接続線１６は、空中に架設されていてもよいが、通常は地中に埋め込まれている。
【００２３】
上記のように構成される低減装置１０では、周囲接地極４によって建物１１の周囲の敷地３の電位が同じになる。さらにその敷地の大地電位と電柱１４周りの大地電位との電位差が少なくなる。とくに電柱１４は遠くまで列設されているので、図１の場合の接続線６ａを極めて遠くまで延ばす場合と同等の効果がある。たとえば、図６に示すように、電柱が埋め込まれている周囲の元の大地電位がＶ1であり、建物の周囲の元の大地電位がＶ2であった場合に、図４および図５に示す建物２の周囲に周囲接地極４を設け、接続線１６で架空地線１５に接続することにより、全体の電位がＶaに平均化される。それによって建物周囲の大地と大気（雷雲）との間で放電が起こりにくくなり、落雷の可能性が大きく低減する。すなわち雷雲から見れば、いわば建物２を含めた大地の全体が電気的に平坦になっており、一個所に突出している部位が見えない。それにより落雷が防止される。
【００２４】
さらにこの実施形態では、避雷針１８と建物周囲の大地との電位差が少ないため、雷雲から見れば、避雷針１８によって建物２が隠された状態になる。それによっても建物への落雷が防止される。
【００２５】
図７は電柱１４に架設されている架設電線２４が建物２内に引き込まれている場合を示している。すなわち先述のように電柱１４には架設地線１５で保護される電力線や電話線などの架設電線が配線されているが、通常はそのような架設電線２４は近くの電柱１４ａから分岐した分岐線２５によって建物２内に引き込まれる。そしてその分岐線２５は建物２内のコンピュータ設備や電話などの通信機器に接続されている。前述の低減装置１０はこのような場合に、落雷の危険性を低減するのに加えて、電柱１４に落雷があったときの被害を少なくする利点がある。
【００２６】
すなわち図７の左端に示すように、電柱１４に落雷があると、落雷による誘導サージが発生し、その誘導サージ波Ｉ_DTが架空電線２４を伝わって建物２内の電気設備などの電位を上昇させる（上昇量Ｖ_DT：図８ａ参照）。他方、架空地線１５にも同様の誘導サージが発生し、誘導サージ波Ｉ_Gが架空地線１５、接続線１６および周囲接地極４を伝わって建物周囲の大地電位を上昇させる（上昇量Ｖ_G：図８ｂ参照）。したがって電気設備の各機器に実際に加わる電位上昇Ｖは、両者の差、すなわちＶ＝Ｖ_DT−Ｖ_Gとなる（図８ｃ参照）。なお、架空電線２４を伝わる誘導サージ波Ｉ_VDと架空地線１５を伝わる誘導サージ波Ｖ_Gとは、大きさや周期がずれているが、それでも周囲接地極４と接続線１６がない場合よりも大幅に低減する。それによって電気設備が誘導サージによる電位上昇から保護される。とくにコンピュータなどのＩＣ機器は、誘導サージにより破壊される可能性が高いため、このような低減装置は有効である。
【００２７】
図１０は、図７の状態を大地側から電流が流れる観点から示しており、ここでは図９の接続線および遠隔接地極がない場合と対比して説明する。図９の接続線がない場合は、架空地線１５に落雷があると、周辺の大地２７から落雷した架空地線１５の近辺の電柱１４の接地極２３に向かって矢印Ｉのように電流が流れ、架空地線１５から雷雲２８に向かって放電する。また、架空地線１５についても、矢印Ｉのように雷電流が流れる。そのとき、建物２の周囲の大地２７の電位Ｖ_G1と架空地線１５および接地極２３の電位Ｖ_G2との間で電位差があり、また、同電位Ｖ_G1の範囲が限定されるので、周囲接地極４、４ａを環状に接続する導線５があるにもかかわらず、導線５で囲まれる大地２７にも電流が流れる。他方、建物２内の受電設備２９は電柱の架設電線（電力・通信線）２４と接続されているので、その架設電線２４を伝わって雷電流が流れ、電気機器接地３０から雷電流が進入する。それにより電気機器を経由して受電設備２９に向かって雷電流が流れ、電気機器および受電設備２９が障害を受ける。
【００２８】
他方、図１０のように、建物の周囲の導線５とその近辺の電柱１４の接地極２３とが接続線６ａで接続され、しかも周囲接地極４ａから遠隔接地極７まで接続線６で接続されている場合は、電柱１４の近辺の電離Ｖ_G2と建物の周囲の電位Ｖ_G1と差がなくなり、しかも建物の周囲の同電位Ｖ_G1の範囲が広くなる。したがって架空地線１５に落雷したとき環状の導線５内には雷電流が流れない。そして架空地線１５に落雷したとしても、電気機器接地３０の電位上昇が少しであるため、電気機器への影響が少ない。また、遠隔接地極７に接続している接続線６に落雷しても、前述と同様に電気機器接地３０の電位上昇が少しであるため、電気機器への影響が少ない。
【００２９】
図１１は接続線および遠隔接地極がない場合において、建物２の避雷針１８に落雷した場合を電流の観点から示している。この場合も建物２の周囲の大地２７の電位Ｖ_G1と架空地線１５および接地極２３の電位Ｖ_G2との間で電位差があり、また、同電位Ｖ_G1の範囲が限定される。そのため、雷雲２８と建物２の周囲の電位Ｖ_G1との間に落雷発生条件ができると、建物２の避雷針１８に落雷が集中することになる。
【００３０】
他方、図１２のように、建物２の周囲の導線５とその近辺の電柱１４の接地極２３とが接続線６ａで接続され、しかも周囲接地極４ａから遠隔接地極７まで接続線６で接続されている場合は、電柱１４の近辺の電離ＶＧ２と建物の周囲の電位ＶＧ１と差がなくなり、しかも建物の周囲の同電位ＶＧ１の範囲が広くなる。そのため、建物２の避雷針１８に落雷する確率が下がる。また、雷雲２８と建物の周囲の電位ＶＧ１との間に落雷発生条件ができても、周囲接地極４、４ａ、遠隔接地極７、７ａ、電柱の接地極２３など、接地極のポイントが多いため、建物２の避雷針１８に落雷する確率が少ない。
【００３１】
図１、図４の実施形態では、導線５は全体が連続した四角形の環状を呈しているが、一個所が切れていてもよい。また、台形、円形など、建物２を囲む平面形状であれば、他の平面形状であってもよい。さらにこの実施形態では周囲接地極４および導線５が１周だけであるが、二重に配線するようにしてもよい。さらに図４、図５の場合は、１本の接続線１６で周囲接地極４と電柱１４の接地極２３ａとを接続しているが、複数本の電柱の接地極あるいは架空地線と別個の接続線によって接続するようにしてもよい。
【図面の簡単な説明】
【図１】本発明の低減装置の一実施形態を示す要部平面図である。
【図２】その低減装置の立面図である。
【図３】本発明の低減装置のさらに他の実施形態を示す要部平面図である。
【図４】本発明の低減装置の実施形態の全体を示す平面図である。
【図５】図４の低減装置の立面図である。
【図６】その低減装置の作用を模式的に示すグラフである。
【図７】本発明の低減装置のさらに他の実施形態を示す立面図である。
【図８】図８ａ〜ｃはその低減装置の作用を模式的に示すグラフである。
【図９】架空地線針への落雷時における従来の低減装置の作用を示す概略斜視図である。
【図１０】架空地線針への落雷時における本発明の低減装置の作用を示す概略斜視図である。
【図１１】建物への落雷時における従来の低減装置の作用を示す概略斜視図である。
【図１２】建物への落雷時における本発明の低減装置の作用を示す概略斜視図である。
【図１３】従来の防雷方法の一例を示す斜視図である。
【図１４】従来の耐雷方法に用いられる耐雷変圧器の一例を示す電気回路図である。
【図１５】その耐雷変圧器を用いた耐雷方法の一例を示す電気回路図である。
【符号の説明】
１低減装置
２建物
３敷地
４、４ａ周囲接地極
５、５ａ導線
６、６ａ接続線
７、７ａ遠隔接地極
１０低減装置
１４電柱
１４ａもっとも近い電柱
１５架空地線
１８避雷針
１９第１の導線
２０接地極
２１第２の導線
２２導線
２３接地極
２３ａもっとも近い電柱の接地極
２４架設電線
２５分岐線
Ｉ_DT 誘導サージ波
Ｖ_DT 電位上昇
Ｉ_G 誘導サージ波
Ｖ_G 電位上昇
Ｖ実際の電位上昇
２７大地
２８雷雲
２９受電設備
３０電気機器接地
Ｖ_G1 建物周囲の大地電位
Ｖ_G2 架空地線の電位[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device for reducing lightning damage in a building.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent No. 3143882 [Patent Document 2]
Japanese Patent Laid-Open No. 9-41723 [Patent Document 3]
JP-A-7-192784 [Patent Document 4]
Japanese Patent Publication No. 7-89712 [Patent Document 5]
Japanese Patent No. 2764088
Patent Document 1 discloses a building 100 as shown in FIG. 13 in order to protect a building equipped with electrical equipment such as a semiconductor system such as a wireless relay station, an information-enabled building, and a factory equipped with high-tech equipment from lightning surges. A lightning protection method is disclosed in which an annular grounding wire 101 is provided surrounding the lightning rod 102 and a lightning rod 102 is connected to the annular grounding wire. A ground electrode 103 buried in the ground at a desired interval is connected to the annular ground wire 101, and a ground 104 of electrical equipment in the building is provided in the annular ground wire 101. Reference numeral 105 denotes a power supply line that enters the building from the outside, and supplies power to the electrical equipment 107 via the lightning resistant transformer 106.
[0004]
According to this lightning protection method, when lightning strikes the lightning rod 102, the lightning current passing through the building 100 can be suppressed as much as possible, so that the electrical equipment 107 inside the building can be protected from lightning surge. Note that Patent Document 2 and Patent Document 3 also disclose devices or structures that prevent lightning surge current from entering a similar building.
[0005]
On the other hand, Patent Document 4 is provided with a lightning-resistant transformer 115 having three layers of shield plates 112, 113, 114 between the input side winding 110 and the output side winding 111 as shown in FIG. A lightning protection method for grounding a shield plate via different surge impedances is disclosed. The shield plate 114 of the output side winding 111 is grounded together with the sheath 118 of the cable 117 connected to the load device 116 to be protected.
[0006]
Further, Patent Document 5 is provided with a lightning-resistant transformer 120 substantially the same as Patent Document 4 as shown in FIG. 15, and a shield plate (electrostatic shield plate) 114 of the output side winding is connected to the main ground 121 of the load device 116. A lightning protection method is disclosed in which the shield plate 112 of the input side winding is connected to the zero potential line 123 of the input power supply lines 122 and 123. Reference numeral 124 denotes a pole transformer, reference numeral 125 denotes an overhead ground wire, and reference numeral 126 denotes a ground wire of the overhead ground wire. The zero potential line 123 is connected to the ground line 125 together with the case of the pole transformer.
[0007]
This lightning protection method has an advantage that the grounding work of the shield plate 112 of the input side winding is unnecessary, and even when a lightning strikes the lightning rod 102 of the building 100, it flows to the main ground 121 side, and the input power lines 122 and 123 The current transmitted to the zero potential line 123 is also shunted to the grounding (type B grounding) 126 of the overhead ground wire 126 and the overhead ground wire 125, so that the influence on the high voltage electric wire side is considered to be small.
[0008]
[Problems to be solved by the invention]
Any of the lightning protection methods or the lightning protection methods / devices are intended to protect the device once the lightning has been dropped, and little consideration has been given to making it difficult for lightning to fall. In view of such a situation, it is a first technical object of the present invention to provide a lightning failure reduction device capable of reducing lightning strikes as much as possible. Furthermore, it is a second object of the present invention to provide a lightning failure reduction device that can avoid a lightning strike as much as possible and can reduce the failure of electrical equipment in a building when a lightning strike occurs. .
[0009]
[Means for Solving the Problems]
The apparatus for reducing lightning damage in a building according to the present invention (Claim 1) is separated from a plurality of surrounding grounding electrodes grounded so as to surround the building, a conductive wire conducting between the surrounding grounding electrodes, and the building. A remote grounding pole provided at a position, and a connection line connecting the surrounding grounding pole or lead and the remote grounding pole , wherein the remote grounding pole is a plurality of utility poles arranged away from the building. It is characterized by being grounded in the vicinity and connected to an aerial ground wire constructed along the upper end of the utility pole . In such a lightning failure reduction device, another remote grounding electrode different from the surrounding grounding electrode surrounds the building in a rectangular shape, and the remote grounding electrode is radially separated from the corner of the surrounding grounding electrode . those provided in the individual plants are preferred (claim 2).
[0010]
Furthermore, in any case prior to reporting, the building has a lightning rod is provided, which with its lightning rod and the surrounding earth electrode is connected preferably (claim 3). In addition, when the remote grounding pole is a grounding pole provided on the ground near the above-mentioned power pole, the cable installed in the power pole is drawn into the building and connected to the electrical equipment in the building. More preferred (Claim 4 ).
[0011]
[Operation and effect of the invention]
In the reduction device of the present invention (Claim 1), the surrounding ground electrode has the same potential as the site potential. And since the grounding electrodes are electrically connected with each other, the range where the grounding electrodes stand side by side is almost the same potential. Further, the ground of the remote ground electrode connected to the ground electrode by a connecting line has the same potential. Therefore, as long as electricity is not flowing, the entire range from the site surrounding the building to the remote grounding electrode is the same potential in a wide range, and an electrically flat region can be realized in a wide range. As a result, there is no electrically projecting portion that is easily subjected to lightning, so that the entropy is increased. Therefore, it is possible to prevent a lightning strike itself. In addition, when a thundercloud approaches a building, it approaches the remote ground electrode having the same potential as the building faster than approaching the building. Therefore, even if lightning strikes, lightning strikes the remote ground pole earlier than the building. Therefore, lightning strikes to the building can be avoided.
Further, since the remote grounding pole is grounded near a plurality of power poles arranged away from the building and connected to an overhead ground wire built along the upper end of the power pole, the surrounding grounding pole around the building Is the same potential as the grounding pole in the vicinity of the utility pole, and is also the same potential as the overhead ground wire connecting the heads of the utility pole. Therefore, the same potential is obtained in a wide band-like range where the site surrounding the building and the utility pole stand, and an electrically flat region can be realized in a wide range. As a result, there are no electrically projecting parts that are likely to strike lightning, and lightning strikes on the building can be avoided. In addition, there is an advantage that the risk of lightning strikes to the utility pole can be reduced by connecting to the surrounding ground lines of many adjacent land owners on the side of the utility pole.
[0012]
If the ambient ground electrode surrounds the building in a rectangular shape, the remote ground electrode is different from other remote earth electrode is provided in pieces plant spaced radially from the corner portion of the surrounding earth electrode (claim 2) Can be provided with a remote grounding pole at a location that is far away from the building. Furthermore, since the lead wire connecting the surrounding ground electrodes also has the same lightning protection as the ground electrode, it is safer to surround the building in a rectangular shape.
[0014]
Furthermore, when a lightning rod is provided in a building and the lightning rod is connected to the surrounding ground line (Claim 3 ), a region having the same potential is realized in a three-dimensional range. As a result, the risk of lightning can be further reduced, and even if there is a lightning strike, current flows from the lightning rod to the ground or from the ground to the lightning rod without passing through the building, so that the electrical equipment in the building is protected. The
[0015]
When the installation electric wire installed on the power pole is drawn into the building and connected to the electrical equipment in the building (Claim 4 ), in addition to the advantage of reducing the risk of lightning strike, there is a lightning strike. There is an advantage to reduce the damage. In other words, when there is a lightning strike, an induced electromotive force is generated in the building through the surrounding ground poles and conductors around the building, and an electric current tends to flow, but at the same level, an induced electromotive force is generated on the power line based on the overhead ground wire. Will occur. Therefore, the electromotive forces are offset between the power line and the electrical equipment in the building, there is no relative potential difference due to lightning strikes, and failures based on the induced electromotive force (inductive surge due to lightning strikes) are reduced.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the lightning failure reduction apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a main part plan view showing an embodiment of a reduction apparatus of the present invention, FIG. 2 is an elevation view of the reduction apparatus, FIG. 3 is a main part plan view showing another embodiment of the reduction apparatus of the present invention, 4 is a plan view showing the whole embodiment of the reduction device of the present invention, FIG. 5 is an elevation view of the reduction device of FIG. 4, FIG. 6 is a graph schematically showing the action of the reduction device, and FIG. FIG. 8A to FIG. 8C are graphs schematically showing the operation of the reduction device, and FIGS. 9 and 10 are conventional reductions during a lightning strike to an overhead ground wire. FIG. 11 and FIG. 12 are schematic views showing the operation of the conventional reduction device and the reduction device of the present invention in comparison with each other during a lightning strike on a lightning rod in a building. It is a perspective view.
[0017]
The reduction device 1 of FIG. 1 includes a plurality of surrounding ground electrodes 4 embedded at a desired interval in a site 3 so as to surround a building 2, and a conductive wire (surrounding ground) that connects the surrounding ground electrodes 4 to each other. Line) 5 and a plurality of remote grounding poles 7 connected via a connection line 6 extending radially from the surrounding grounding pole 4a of the rectangular corner portion. The remote grounding electrode may be connected not only to the rectangular corner portion but also to the middle of one side of the rectangle (left side in FIG. 1) via the connecting line 6a as indicated by reference numeral 7a, for example. In FIG. 1, the utility pole and the connection line with the utility pole are omitted.
[0018]
As shown in FIG. 2, the surrounding ground electrodes 4 and 4a can be made of metal, particularly copper bars, deeply embedded in the ground of the site 3, and the conductor 5 is connected to the upper ends thereof. Has been. Moreover, the conducting wire 5, the remote grounding electrodes 7 and 7a, and the connection lines 6 and 6a are also embedded in the ground. However, the conducting wire 5 and the connecting wires 6 and 6a may pass over the ground or may be suspended in the air. The conducting wire 5 may be directly grounded without being covered, or may be grounded only by a grounding electrode using a covered electric wire. Furthermore, you may make it let the conducting wire 5 pass through the piping (non-metallic piping) for wiring buried in the ground.
[0019]
In FIG. 1, adjacent surrounding grounding electrodes 4, 4 a are connected to each other by a conducting wire 5, and the conducting wire 5 is wired in a rectangular shape so as to surround the building 2, but the surrounding grounding electrodes 4, 4 a surround the building. If it is arrange | positioned, it does not need to make conducting wire 5 itself cyclic | annular or rectangular shape. Furthermore, it is not necessary to wire the conductive wire 5 so as to surround the building 2, and the conductive wire 5 may be wired radially through the inside of the building 2 or below as shown in FIG. 3. However, a lightning current flows through the conductor 5 during a lightning strike, and a surge voltage is generated. Therefore, the laying place of the conducting wire 5 needs to be separated from the place where the protection target device is in contact with the ground. As long as this is satisfied, the conductive wire 5 may be any wire as long as the surrounding ground electrodes 4 provided so as to surround the building are connected to each other.
[0020]
The remote grounding poles 7 and 7a are not limited to the site 3 of the building 2 but can be embedded in the land or public road of an adjacent person if possible. In the reduction device 10 of the present invention shown in FIG. 4, a remote grounding pole is configured using a plurality of utility poles 14 arranged in the vicinity of the building 2. That is, this reduction device 10 is similar to the case of FIG. 1, and includes a grounding ground 4 disposed around the building 2, a conductive wire 5 connecting the surrounding grounding poles 4, and an imaginary ground of the adjacent power pole 14. The connection line 16 connects the line 15 and the surrounding ground electrode 4.
[0021]
As shown in FIGS. 4 and 5, in this embodiment, a lightning rod 18 is further erected on the top of the building 2, and the lightning rod 18 extends along the top surface and the wall surface of the building 2. The lead wire 19 is directly connected to a grounding pole 20 for a lightning rod embedded in the ground. Further, the second conductor 21 extending from the lightning rod 18 is connected to the aforementioned conductor 5 or the surrounding ground electrode 4 via the wall surface of the building 2.
[0022]
The overhead ground wire 15 of the utility pole 14 protects an overhead wire (not shown) originally intended for the utility pole 14, for example, a built-in electric wire such as a high-voltage electric wire or a telephone line from lightning strikes. Is connected to a rod-shaped grounding electrode (remote grounding electrode) 23 embedded in the vicinity of the base of the utility pole 14 by a conductive wire 22 extending downward along the line. The ground electrode 23a of the utility pole 14a closest to the building 2 or the site and the surrounding ground electrode 4 or the conductive wire 5 are connected by the connection line 16 described above. The connecting line 16 may be erected in the air, but is usually buried in the ground.
[0023]
In the reduction device 10 configured as described above, the potential of the site 3 around the building 11 becomes the same by the surrounding ground electrode 4. Furthermore, the potential difference between the ground potential of the site and the ground potential around the utility pole 14 is reduced. In particular, since the utility poles 14 are arranged far away, there is an effect equivalent to the case where the connection line 6a in FIG. For example, as shown in FIG. 6, when the original ground potential around the power pole is embedded is V1, and the original ground potential around the building is V2, the buildings shown in FIGS. 2 is provided with a surrounding ground electrode 4 and connected to the overhead ground wire 15 by a connection line 16, whereby the entire potential is averaged to Va. This makes it difficult for electrical discharge to occur between the ground around the building and the atmosphere (thunderclouds), greatly reducing the possibility of lightning strikes. In other words, from the thundercloud, the entire ground including the building 2 is electrically flat, and a portion protruding in one place cannot be seen. This prevents lightning strikes.
[0024]
Furthermore, in this embodiment, since the potential difference between the lightning rod 18 and the ground around the building is small, the building 2 is hidden by the lightning rod 18 when viewed from the thundercloud. This also prevents lightning strikes on the building.
[0025]
FIG. 7 shows a case where the installation electric wire 24 installed on the utility pole 14 is drawn into the building 2. That is, as described above, the power pole 14 is wired with a built-in electric wire such as a power line or a telephone line that is protected by the installation ground wire 15, but normally such a built-in electric cable 24 is a branch line branched from a nearby power pole 14a. 25 is drawn into the building 2. The branch line 25 is connected to communication equipment such as computer equipment and a telephone in the building 2. In such a case, the above-described reducing device 10 has an advantage of reducing damage caused by lightning strikes on the utility pole 14 in addition to reducing the risk of lightning strikes.
[0026]
That is, as shown at the left end of FIG. 7, when there is a lightning strike on the utility pole 14, an induced surge is generated by the lightning strike, and the induced surge wave I _DT is transmitted through the overhead wire 24 to increase the potential of the electrical equipment in the building 2. (Increase amount V _DT : See FIG. 8a). On the other hand, a similar inductive surge is also generated in the overhead ground wire 15, and the induced surge wave I _G is transmitted through the overhead ground wire 15, the connection line 16 and the surrounding ground electrode 4 to increase the ground potential around the building (amount of increase V _G : See FIG. 8b). Actually applied potential increase V to each device of the electrical equipment therefore, the difference therebetween, that is, V = V _DT -V _G (see FIG. 8c). The induced surge wave I _VD transmitted through the overhead electric wire 24 and the induced surge wave V _G transmitted through the overhead ground wire 15 are shifted in size and period, but still more than in the case where the surrounding ground electrode 4 and the connection line 16 are not provided. Reduce significantly. This protects the electrical equipment from potential increases due to inductive surges. In particular, since an IC device such as a computer is highly likely to be destroyed by an inductive surge, such a reduction device is effective.
[0027]
FIG. 10 shows the state of FIG. 7 from the viewpoint of current flowing from the ground side, and here, it will be described in comparison with the case where the connection line and the remote grounding electrode of FIG. 9 are not provided. In the case where there is no connection line in FIG. 9, if there is a lightning strike on the overhead ground wire 15, a current flows as shown by an arrow I from the surrounding ground 27 toward the ground pole 23 of the utility pole 14 near the overhead ground wire 15. The electric current flows from the imaginary ground wire 15 toward the thundercloud 28. A lightning current also flows through the overhead ground wire 15 as indicated by an arrow I. At that time, there is a potential difference between the potential V _G1 of the ground 27 around the building 2 and the potential V _G2 of the overhead ground wire 15 and the ground electrode 23, and the range of the same potential V _G1 is limited. In spite of the presence of the conductive wire 5 that connects the ground electrodes 4 and 4 a in a ring shape, a current also flows through the ground 27 surrounded by the conductive wire 5. On the other hand, since the power receiving facility 29 in the building 2 is connected to a power pole erection wire (power / communication line) 24, lightning current flows through the erection wire 24 and lightning current enters from the electrical equipment ground 30. . As a result, a lightning current flows toward the power receiving facility 29 via the electric device, and the electric device and the power receiving facility 29 are damaged.
[0028]
On the other hand, as shown in FIG. 10, the conductor 5 around the building and the ground pole 23 of the power pole 14 in the vicinity thereof are connected by the connection line 6 a, and are further connected by the connection line 6 from the surrounding ground pole 4 a to the remote ground pole 7. If there is a difference, the difference between the ionization V _{G2 in} the vicinity of the utility pole 14 and the potential V _G1 around the building disappears, and the range of the same potential V _G1 around the building becomes wider. Therefore, when lightning strikes the overhead ground wire 15, no lightning current flows in the annular conductor 5. Even if lightning strikes the aerial ground wire 15, the potential rise of the electrical equipment ground 30 is slight, so that the electrical equipment is less affected. Further, even if lightning strikes the connection line 6 connected to the remote grounding electrode 7, since the potential rise of the electrical equipment ground 30 is slight as described above, the influence on the electrical equipment is small.
[0029]
FIG. 11 shows a case where lightning strikes the lightning rod 18 of the building 2 from the viewpoint of current when there is no connection line and no remote grounding pole. Also in this case, there is a potential difference between the potential V _G1 of the ground 27 around the building 2 and the potential V _G2 of the overhead ground wire 15 and the ground electrode 23, and the range of the same potential V _G1 is limited. Therefore, if a lightning strike condition is established between the thundercloud 28 and the electric potential V _G1 around the building 2, lightning strikes concentrate on the lightning rod 18 of the building 2.
[0030]
On the other hand, as shown in FIG. 12, the conductive wire 5 around the building 2 and the ground pole 23 of the power pole 14 in the vicinity thereof are connected by the connection line 6a, and are connected by the connection line 6 from the peripheral ground pole 4a to the remote ground pole 7. If there is a difference, the difference between the ionization VG2 near the utility pole 14 and the potential VG1 around the building disappears, and the range of the same potential VG1 around the building becomes wider. Therefore, the probability that lightning strikes the lightning rod 18 of the building 2 is reduced. Further, even if a lightning strike condition is established between the thundercloud 28 and the electric potential VG1 around the building, there are many points of the grounding pole such as the surrounding grounding poles 4, 4a, the remote grounding poles 7, 7a, and the grounding pole 23 of the utility pole. Therefore, the probability of lightning strikes on the lightning rod 18 of the building 2 is small.
[0031]
In the embodiment of FIGS. 1 and 4, the conducting wire 5 has a continuous quadrangular annular shape as a whole, but may be cut off at one point. Further, any other planar shape may be used as long as it is a planar shape surrounding the building 2 such as a trapezoid or a circle. Furthermore, in this embodiment, the surrounding ground electrode 4 and the conducting wire 5 are only one round, but they may be wired twice. Further, in the case of FIGS. 4 and 5, the peripheral grounding electrode 4 and the grounding electrode 23 a of the utility pole 14 are connected by a single connection line 16, but they are separated from the grounding poles or overhead ground wires of a plurality of utility poles. You may make it connect by a connection line.
[Brief description of the drawings]
FIG. 1 is a plan view of an essential part showing an embodiment of a reduction device of the present invention.
FIG. 2 is an elevational view of the reduction device.
FIG. 3 is a plan view of an essential part showing still another embodiment of the reduction device of the present invention.
Is a plan view showing the overall implementation form of reduction apparatus of the present invention; FIG.
FIG. 5 is an elevational view of the reduction device of FIG. 4;
FIG. 6 is a graph schematically showing the operation of the reducing device.
FIG. 7 is an elevational view showing still another embodiment of the reduction device of the present invention.
FIGS. 8a to 8c are graphs schematically showing the operation of the reducing device.
FIG. 9 is a schematic perspective view showing the operation of a conventional reduction device during a lightning strike to an overhead ground wire needle.
FIG. 10 is a schematic perspective view showing the operation of the reduction device of the present invention during a lightning strike to an overhead ground wire needle.
FIG. 11 is a schematic perspective view showing the operation of a conventional reduction device during a lightning strike on a building.
FIG. 12 is a schematic perspective view showing the operation of the reduction device of the present invention during a lightning strike on a building.
FIG. 13 is a perspective view showing an example of a conventional lightning protection method.
FIG. 14 is an electric circuit diagram showing an example of a lightning-resistant transformer used in a conventional lightning-proof method.
FIG. 15 is an electric circuit diagram showing an example of a lightning protection method using the lightning protection transformer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reduction device 2 Building 3 Site 4, 4a Ambient earthing pole 5, 5a Lead wire 6, 6a Connection line 7, 7a Remote earthing pole 10 Reduction device 14 Electric pole 14a Nearest electric pole 15 Overhead ground wire 18 Lightning rod 19 First lead 20 Grounding Pole 21 Second conducting wire 22 Conducting wire 23 Grounding electrode 23a Grounding pole 24 of the nearest utility pole Construction wire 25 Branch line I _DT induced surge wave V _DT potential rise I _G induced surge wave V _G potential rise V Actual potential rise 27 Ground 28 Thundercloud 29 Receiving equipment 30 Electrical equipment grounding V _G1 Ground potential around the building V _G2 Potential of overhead ground wire

Claims

A plurality of surrounding ground poles grounded to surround the building;
Conductive wires that connect the surrounding grounding electrodes,
A remote earthing pole provided at a position away from the building;
A connection line connecting the surrounding grounding electrode or the conductive wire and the remote grounding electrode ;
An apparatus for reducing lightning damage in a building , wherein the remote grounding electrode is grounded in the vicinity of a plurality of utility poles arranged away from the building and connected to an aerial ground wire constructed along the upper end of the utility pole .

Said peripheral ground electrode surrounds the building in a rectangular shape, the remote ground electrode is different from other remote ground electrode, provided its dependent claim 1, wherein the spaced radially from the corner portion of the surrounding earth electrode pieces plant Lightning damage reduction device.

The building lightning rod is provided, the reduction apparatus according to claim 1 or 2, wherein its lightning rod and the surrounding earth electrode is connected.

The reduction device according to claim 1, 2 or 3, wherein an erected electric wire installed on the power pole is drawn into a building and connected to an electrical facility in the building.