US3649875A - Lightning arrester - Google Patents

Lightning arrester Download PDF

Info

Publication number
US3649875A
US3649875A US58874A US3649875DA US3649875A US 3649875 A US3649875 A US 3649875A US 58874 A US58874 A US 58874A US 3649875D A US3649875D A US 3649875DA US 3649875 A US3649875 A US 3649875A
Authority
US
United States
Prior art keywords
lightning arrester
gap
shielding
rings
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US58874A
Other languages
English (en)
Inventor
Nobuo Nagai
Shoji Tada
Katsu Ujita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP6086669A external-priority patent/JPS4827104B1/ja
Priority claimed from JP5328170A external-priority patent/JPS4948093B1/ja
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Application granted granted Critical
Publication of US3649875A publication Critical patent/US3649875A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T4/00—Overvoltage arresters using spark gaps
    • H01T4/16—Overvoltage arresters using spark gaps having a plurality of gaps arranged in series
    • H01T4/20—Arrangements for improving potential distribution

Definitions

  • This invention relates to improvements in a lightning arrester including an arrester element disposed within a grounded housing.
  • lightning arresters of the. type including an arrester element disposed within a grounded housing filled with an electrically negative gas such as sulfur hexafluoride (SF for the purpose of safely effecting the maintenance and inspection thereof.
  • Such lightning arresters have included voltage dividing elements consisting of resistors and capacitors in order to uniformly distribute any electric surge across discharging gaps involved.
  • the surface of the voltage-dividing element is affected by a potential due to the grounded housing to cause the equipotential lines to obliquely penetrated into the surface of the element. This causes a decrease in voltage with which a corona discharge is initiated and also a decrease in withstand-test voltage required between the voltage-dividing element and the grounded housing.
  • the voltage-dividing element can increase in longitudinal dimension to increase the withstand-test voltage required between the same and the grounded housing this measure is undesirable in that the resulting lightning arrester increases in overall dimension.
  • the invention accomplishes these objects by the provision of a lightning arrester comprising a grounded housing and an arrester element disposed in the grounded housing characterized by a plurality of shielding rings for encircling the arrester element.
  • the adjacent shielding rings may be preferably different from each other in dimension of an electrical conductor forming the ring.
  • At least one of a diameter of the electrical conductor forming the shielding ring and the outside diameter of the shielding ring may progressively decrease from the side of the application of voltage toward the grounded side.
  • FIG. 1 is a schematic longitudinal sectional view of a lightning arrester constructed in accordance with the principles of the invention.
  • FIGS. 2, 3 and 4 are views similar to FIG. 1 but illustrating different modifications of the invention.
  • an arrangement disclosed herein comprises a grounded housing filled with any suitable electrically negative gas high in electrically insulating property, for example, sulfer hexafluoride (SP a characteristic element 12 disposed on the bottom of the housing 10, and a discharging gap unit 14 disposed on the characteristic element 12.
  • the characteristic element 12 comprises a nonlinear resistor formed essentially of silicon carbide (SiC).
  • the discharging gap unit includes a plurality of discharging gaps interconnected in series circuit relationship. Each gap has connected thereacross a resistor 16 and a capacitor 18 forming a voltage-dividing element for the discharging gap unit. Both end gaps of the unit 14 are connected respectively to the characteristic element 12 and a line terminal 20 extending through the surface of the grounded housing 10 and hermetically surrounded by an electric insulation 22 sealed through that top surface.
  • the voltage-dividing element formed of the resistors and capacitors 16 and 18 respectively is effective for uniformly distributing electric surges resulting, for example, from lightning strokes across the discharging gaps but the surface thereof are affected by a potential due to the grounded housing 10 so that equipotential lines are obliquely penetrated into the surface of the voltage-dividing element.
  • the voltagedividing element should increase in longitudinal dimension. This results in a disadvantageous increase in the overall dimension of the lightning arrester.
  • a plurality of shielding rings disposed outside the voltage-dividing element and around the discharging gap unit and therefore around an arrester element formed of the voltage-dividing element and the discharging gap unit. More specifically, as shown in FIG. 1, a plurality of shielding rings 24 are disposed in axially aligned, spaced relationship outside and slightly spaced away from the voltage-dividing element 16-18 while they encircle the discharging gap unit 14.
  • the shielding rings 24 are of the same construction and the same dimension.
  • Each of the shielding rings 24 comprises a length of circular, electrically conductive pipe bent into a closed circle and an electrically conductive disc 26 connected at the outer periphery to the inner periphery thereof in the central plane.
  • the disc 26 is sandwiched on the central portion between each pair of adjacent electrodes forming the discharge gaps except for both end discs 26 having the central portions sandwiched between the line terminal 20 and the adjacent electrode and between the characteristic element 12 and the adjacent electrode respectively.
  • the disc 26 and therefore the shielding ring 24 is maintained at the same potential as the gap electrode connected thereto.
  • FIG. 1 the four discharging gaps and the five shielding rings 24 are shown so that each discharge gap is operatively coupled to at least one shielding ring.
  • the shielding ring and disc 24 and 26 respectively permit the equipotential lines to be penerated substantially perpendicularly into the surface of the voltage-dividing element 16-18 to establish a desirable electric field around that element. This makes it difficult to cause a corona discharge along the surface of the voltage-dividing element 16-18 while much increasing a withstand-test voltage required between the voltage-dividing element and the grounded housing. This results in a small-sized lightning arrester.
  • the withstand-test voltage required between the shielding rings and the grounded housing is one of the important factors for determining the capability of the arrester. It has been found that the larger the diameter a (see FIG. 1) of the circular conductor or the metallic pipe forming the ring 24 the more the established electric field will be alleviated and therefore the higher the withstand-test voltage.
  • the diameter a of the rings pipe can not sufficiently increase because the rings 24 are axially close to one another.
  • FIG. 2 This increase in lateral dimension of the arrester can be avoided by an arrangement as shown in FIG. 2.
  • a plurality of larger shielding rings 24A formed of an electrically conductive pipe of larger diameter a alternate smaller shielding rings 248 formed of a conductive pipe of smaller diameter.
  • the rings 24A and B have the outside diameters of d and d respectively while they are substantially equal in inside diameter. In other respects the arrangement is identical to that shown in FIG. 1.
  • the withstand-test voltage required between the rings 24 and the grounded housing 10 can be sufficiently high even for the housing small in lateral dimension. Further a voltage applied across each of the discharging gaps can be controlled by varying the diameters of the pipes forming the rings with the magnitudes of the voltage-dividing resistors and capacitors remaining unchanged. Therefore the resulting arrester is possible to be improved in discharge characteristics.
  • FIG. 3 shows a modification of the arrangement illustrated in FIG. 2.
  • the arrangement of FIG. 3 is different from that illustrated in FIG. 2 only in that, in FIG. 3, the shielding rings 24A and B are embedded in any suitable electrically insulating material 28 such as an expoxide resin into a unitary structure.
  • This measure causes an increase in withstand voltage required between each pair of adjacent rings to permit a further increase in diameter of the pipe for the larger ring 24A and therefore a further increase in withstand-test voltage required between the rings 24 and the housing 10.
  • FIG. 4 illustrates another modification of the invention.
  • the discharging gaps l4 alternate the characteristic elements 12 and have operative coupled thereto the respective shielding rings 24 one for each gap.
  • the rings 24 are formed of electrically conductive pipes progressively decreased in diameter from the upper side as viewed in FIG. 4 or the side of the application of voltage toward the lower side or the grounded side. It is seen that the rings 24 have respec tive outside progressively decreased from the upper side to the lower side while the inside diameters thereof remain substantially unchanged.
  • the shielding rings 24 each have the conductive disc 26 connected at the outer periphery to the upper end thereof and sandwiched on the central portion between the associated electrode for gap and the adjacent characteristic element.
  • the shielding rings 24 as shown in FIG. 4 serve to progressively decrease the stray capacitances between the same and the grounded housing 10 as the rings is near to the grounded side with the result that any electric surge isallowed to be more uniformly distributed across the discharging gaps 14. Therefore the arrangement of FIG. 4 is advantageous in that the discharge characteristics can be controlled without the necessity of increasing the number of the voltage-dividing elements.
  • only one of the pipe's diameter and the outside diameter of the ring may changed in the manner as above described.
  • a lightning arrester comprising a grounded housing, a plurality of gap units serially disposed within said grounded housing and defining gaps between successive gap units, voltage-dividing means interconnecting said gap units and a shielding ring encircling and disposed radially outwardly of each said gap unit, and means electrically connecting each said shielding ring with the respective ga unit.
  • a lightning arrester as claimed in claim 1 wherein at least one of a diameter of an electrical conductor forming said shielding ring and the outside diameter of the said shielding ring progressively decreases from the side of the application of voltage toward the grounded side.
  • each said shielding ring comprises a toroidal member and said connecting means comprises a disc extending out from said gap unit and united at its periphery with said toroidal member.

Landscapes

  • Thermistors And Varistors (AREA)
US58874A 1969-08-01 1970-07-28 Lightning arrester Expired - Lifetime US3649875A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP6086669A JPS4827104B1 (enrdf_load_stackoverflow) 1969-08-01 1969-08-01
JP5328170A JPS4948093B1 (enrdf_load_stackoverflow) 1970-06-19 1970-06-19

Publications (1)

Publication Number Publication Date
US3649875A true US3649875A (en) 1972-03-14

Family

ID=26393998

Family Applications (1)

Application Number Title Priority Date Filing Date
US58874A Expired - Lifetime US3649875A (en) 1969-08-01 1970-07-28 Lightning arrester

Country Status (4)

Country Link
US (1) US3649875A (enrdf_load_stackoverflow)
CH (1) CH523615A (enrdf_load_stackoverflow)
DE (1) DE2037921C3 (enrdf_load_stackoverflow)
FR (1) FR2056942B1 (enrdf_load_stackoverflow)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753045A (en) * 1972-10-11 1973-08-14 Westinghouse Electric Corp Shielded metal enclosed lightning arrester
US3767973A (en) * 1972-10-11 1973-10-23 Westinghouse Electric Corp Shielded metal enclosed lightning arrester
US3842318A (en) * 1972-10-11 1974-10-15 Westinghouse Electric Corp Shielded metal enclosed electrical equipment
US4011485A (en) * 1975-05-30 1977-03-08 Joslyn Mfg. And Supply Co. Valve type surge arrester
US4136299A (en) * 1976-04-26 1979-01-23 Mitsubishi Denki Kabushiki Kaisha Lightning arrester device
US4203143A (en) * 1977-05-07 1980-05-13 Mitsubishi Denki Kabushiki Kaisha Protective device
US4219862A (en) * 1977-06-22 1980-08-26 Mitsubishi Denki Kabushiki Kaisha Lightning arrester device
US4227229A (en) * 1978-03-20 1980-10-07 Mitsubishi Denki Kabushiki Kaisha Lightning arrester device
US4234902A (en) * 1977-10-07 1980-11-18 Mitsubishi Denki Kabushiki Kaisha Enclosed lightning arrester
US4340924A (en) * 1980-10-27 1982-07-20 General Electric Company Grading means for high voltage metal enclosed gas insulated surge arresters
US4369480A (en) * 1980-03-28 1983-01-18 Siemens Aktiengesellschaft Overvoltage arrester including a column of arrester elements and shielding therefor
US4463404A (en) * 1981-03-26 1984-07-31 Siemens Aktiengesellschaft Surge voltage arrester with shielding bodies enclosing a column of arrester elements
DE3411735A1 (de) * 1984-03-30 1985-10-03 Karl Pfisterer Elektrotechnische Spezialartikel Gmbh & Co Kg, 7000 Stuttgart Ueberspannungsableiter

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE369803B (enrdf_load_stackoverflow) * 1972-03-17 1974-09-16 Asea Ab
DE2619317C2 (de) * 1976-04-30 1985-07-11 Mitsubishi Denki K.K., Tokio/Tokyo Blitzschutzvorrichtung
JPS53143952A (en) * 1977-05-21 1978-12-14 Mitsubishi Electric Corp Protective device for anomalous voltage
JPS5421556A (en) * 1977-07-19 1979-02-17 Toshiba Corp Protective gap
JPS55105989A (en) * 1979-02-09 1980-08-14 Hitachi Ltd Tank type arrester
JPS6126449B2 (enrdf_load_stackoverflow) * 1980-03-19 1986-06-20 Sandvik Ab
JP3283104B2 (ja) * 1993-06-18 2002-05-20 株式会社東芝 タンク形避雷器

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2002042A (en) * 1934-01-11 1935-05-21 Ralph R Pittman Excess-voltage protective structure
US3087094A (en) * 1956-07-13 1963-04-23 Mc Graw Edison Co Lightning arrester
US3259781A (en) * 1961-07-25 1966-07-05 Dale Electronics Method of and means for distributing the electrical field around the bushing of lightning arrestors

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2002042A (en) * 1934-01-11 1935-05-21 Ralph R Pittman Excess-voltage protective structure
US3087094A (en) * 1956-07-13 1963-04-23 Mc Graw Edison Co Lightning arrester
US3259781A (en) * 1961-07-25 1966-07-05 Dale Electronics Method of and means for distributing the electrical field around the bushing of lightning arrestors

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753045A (en) * 1972-10-11 1973-08-14 Westinghouse Electric Corp Shielded metal enclosed lightning arrester
US3767973A (en) * 1972-10-11 1973-10-23 Westinghouse Electric Corp Shielded metal enclosed lightning arrester
US3842318A (en) * 1972-10-11 1974-10-15 Westinghouse Electric Corp Shielded metal enclosed electrical equipment
US4011485A (en) * 1975-05-30 1977-03-08 Joslyn Mfg. And Supply Co. Valve type surge arrester
US4136299A (en) * 1976-04-26 1979-01-23 Mitsubishi Denki Kabushiki Kaisha Lightning arrester device
US4203143A (en) * 1977-05-07 1980-05-13 Mitsubishi Denki Kabushiki Kaisha Protective device
US4219862A (en) * 1977-06-22 1980-08-26 Mitsubishi Denki Kabushiki Kaisha Lightning arrester device
US4234902A (en) * 1977-10-07 1980-11-18 Mitsubishi Denki Kabushiki Kaisha Enclosed lightning arrester
US4227229A (en) * 1978-03-20 1980-10-07 Mitsubishi Denki Kabushiki Kaisha Lightning arrester device
US4369480A (en) * 1980-03-28 1983-01-18 Siemens Aktiengesellschaft Overvoltage arrester including a column of arrester elements and shielding therefor
US4340924A (en) * 1980-10-27 1982-07-20 General Electric Company Grading means for high voltage metal enclosed gas insulated surge arresters
US4463404A (en) * 1981-03-26 1984-07-31 Siemens Aktiengesellschaft Surge voltage arrester with shielding bodies enclosing a column of arrester elements
DE3411735A1 (de) * 1984-03-30 1985-10-03 Karl Pfisterer Elektrotechnische Spezialartikel Gmbh & Co Kg, 7000 Stuttgart Ueberspannungsableiter

Also Published As

Publication number Publication date
DE2037921B2 (de) 1972-08-17
DE2037921A1 (de) 1971-02-18
FR2056942A1 (enrdf_load_stackoverflow) 1971-05-07
FR2056942B1 (enrdf_load_stackoverflow) 1973-01-12
DE2037921C3 (de) 1978-11-02
CH523615A (de) 1972-05-31

Similar Documents

Publication Publication Date Title
US3649875A (en) Lightning arrester
US3305694A (en) Electrical resistor with a parallel high voltage protective gap
US2135085A (en) Lightning arrester
US4340924A (en) Grading means for high voltage metal enclosed gas insulated surge arresters
US2703852A (en) Overvoltage protected induction apparatus
US1561249A (en) Spark-gap lighting arrester
US4234902A (en) Enclosed lightning arrester
US3733521A (en) Lightning arrester
CN105529617B (zh) 一种线路避雷器
US2618765A (en) Excess voltage grounding device
US3629660A (en) Lightning arrest assembly
US2608600A (en) Arrangement at surge diverters for increasing the discharging ability
US2611107A (en) Electric lightning arrester
US4056753A (en) Overvoltage protecting element
SE447041B (sv) Blixtskyddsanordning
US3328631A (en) Lightning arrester with semiconductor electrodes
US4219862A (en) Lightning arrester device
US1683590A (en) Impulse lightning arrester
GB1314597A (en) Lightning arrester
US3091721A (en) Lightning arrester and gap unit with capacitive grading
JP2562045B2 (ja) サージ吸収装置
US1783052A (en) Electric discharge device
US4204239A (en) Abnormal voltage protection device
US2503912A (en) Electric capacitor
US3106661A (en) Lightning arrester