EP0078985A1 - Spannungsverteilung über der Wicklung und Schutz von Leistungstransformatorwicklung gegen transiente Spannungen - Google Patents

Spannungsverteilung über der Wicklung und Schutz von Leistungstransformatorwicklung gegen transiente Spannungen Download PDF

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Publication number
EP0078985A1
EP0078985A1 EP82109918A EP82109918A EP0078985A1 EP 0078985 A1 EP0078985 A1 EP 0078985A1 EP 82109918 A EP82109918 A EP 82109918A EP 82109918 A EP82109918 A EP 82109918A EP 0078985 A1 EP0078985 A1 EP 0078985A1
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EP
European Patent Office
Prior art keywords
winding
voltage
taps
varistor elements
varistor
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.)
Withdrawn
Application number
EP82109918A
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English (en)
French (fr)
Inventor
William James Mcnutt
Eugene Clemens Sakshaug
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General Electric Co
Original Assignee
General Electric Co
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Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Publication of EP0078985A1 publication Critical patent/EP0078985A1/de
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27/343—Preventing or reducing surge voltages; oscillations

Definitions

  • Power transformer windings are subjected to a variety of potentially damaging dielectric stresses in the 'field. The most catastrophic, variety is the extreme transient voltage surges induced by lightning strikes on power lines.
  • externally mounted surge arresters are utilized to shunt the currents associated with these-surges to ground and thus suppress the surge voltage peaks to an arrester protective level which the insulation system of the power transformer can safely handle.
  • this protective level is greater than the normal operating voltage.
  • An additional object is to provide a protection system of the above character wherein transformer winding voltage stress is relieved on an incremental basis along the entire winding length.
  • Yet another object is to provide a protection system of the above character wherein voltage surge arrestment is achieved internally of a power transformer tank, thus eliminating the need for externally installed lightning arresters.
  • Still another object is to provide a protection system of the above character wherein effective voltage surge arrestment and improved voltage grading is afforded throughout each power transformer winding while, at the same time, voltage oscillations occurring within the windings are suppressed by safely absorbing the energy of any extreme oscillating voltage which could unduly stress the insulation of adjacent turns located anywhere along the transformer winding length.
  • Another object is to provide a protection system of the above character which is eminently effective and reliable in operation, is capable of long service life, and affords significant reductions in the dimensions of power transformer parts and thus a more compact power transformer unit.
  • the protection system of the present invention comprises the utilization of a series connected string of discrete metal oxide varistor elements, such as zinc oxide varistors, electrically connected from termination to termination across the.entire multiturn winding of electromagnetic inductive-devices, such as power transformers and shunt reactors.
  • a particularly significant application of the present invention is to power transformers, in which case a separate varistor string is connected across one or more windings on the high and low voltage sides, as well as each phase winding if a multiphase power transformer is involved.
  • the varistor strings are located within the transformer tank and since they perform the same effective voltage surge suppression as traditional externally installed lightning arresters, need for the latter is eliminated.
  • the varistor string provides surge protection for the entire winding across which it is connected in the manner of an external lightning arrester, while the individual varistor elements of the string provide surge protection for those portions or turns of the windings across which they are respectively connected.
  • the individual varistor elements act both in concert and on an individual basis to improve the voltage grading of the associated winding and to suppress transient oscillations within the associated winding itself. All of these benefits are achieved without resort to electrostatic shielding and exotic winding patterns to modify the winding capacitance.
  • FIGURE 1 The surge protection system of the present invention is illustrated in FIGURE 1 in its application to a power transformer, generally indicated at 10, comprising at least one multiturn high voltage winding 11, and at least one multiturn low voltage winding 12 arranged about a magnetic core 14.
  • a power transformer generally indicated at 10
  • These windings may be of various configurations, e.g., layer windings, disc windings, etc.
  • the line and ground or neutral terminals of the high and low voltage windings are indicated at Hl, H2, Ll, and L2, respectively.
  • Located within the transformer tank (not shown) and electrically connected between the high voltage winding terminals H1, H2 is a series connected string, generally indicated at 17, of individual varistor elements 17A - 17N.
  • a series string; generally indicated at 18, of individual varistor elements 18A - 18N is connected between the low voltage winding terminals Ll, L2.
  • winding taps 20 are brought out for respective electrical connection to the junctions between varistor elements 17A - 17N.
  • varistor element 17A is individually connected across a portion or section 11A of the high voltage winding between its line end and the first tap 20 thereon.
  • Varistor element 17B is individually electrically connected with the first and second taps across the next high voltage winding section 11 B , and so on.
  • the low voltage winding is provided with spaced taps 22 which are respectively connected to the junctions between the varistor elements 18A - 18N, and thus these varistor elements are seen to be individually connected across respective low voltage winding sections 12A - 12N.
  • the varistors 17A - 17N, 18A- 18N are zinc oxide varistors having a highly nonlinear resistance characteristic and proven voltage surge suppression capabilities.
  • a suitable zinc oxide varistor composition is disclosed in U.S. Patent No. 3,928,245. If transformer 10 utilizes an oil or gas dielectric coolant, the internally mounted zinc oxide varistor elements should include protective coatings, such as disclosed in commonly assigned U.S. patent application Serial No. 161,935, filed June 23, 1980.
  • the varistor strings 17 and 18 serve to shunt to ground the excessive currents associated with lightning- induced, high-magnitude voltage surges arriving at winding terminals H1, Ll. Consequently, externally installed lightning arresters to protect power transformer windings equipped with the internal varistor strings of the present invention become redundant and therefore can be eliminated.
  • the additional benefits derived from the present invention can be appreciated from the fact that the varistor elements provide individualized surge suppression for the specific winding portions or sections across which they are respectively electrically connected.
  • Yet another benefit achieved by the present invention is the ability of the individual,varistor elements to suppress any extreme transient voltage oscillations that are excited in the transformer windings by aperiodic voltage surges or by high frequency oscillatory electrical disturbance on the transmission lines. Regardless of which winding section 11A - llN, 12A - 12N happens to be subjected to an extreme voltage peak, there is a discrete varistor element standing by to instantly suppress the voltage oscillation to a safe level.
  • FIGURE 2 plot the initial voltage distribution along a power transformer winding 11 or 12 of a voltage surge arriving at the line terminals thereof.
  • Curve 26 depicts a typical voltage gradient for a transformer winding lacking any voltage grading improvement means. It is seen that fifty per cent of a typical voltage surge is dropped across only the first fifteen per cent of the total winding measured from the line end.
  • Curve 28 is a straight line representing an idealized linear surge voltage distribution, i.e., perfect voltage grading.
  • Curve 30 represents a typical surge voltage distribution achieved by the resistive grading approach of the present invention, which, although not perfect, is a vast improvement over the voltage distribution represented by curve 26.
  • FIGURE 3 depicts a series of profile curves depicting the maximum voltage differential, in terms of percentage of winding terminal voltage which can typically appear across consecutive winding section pairs progressing along the winding length starting from the line end for a worst-case transient voltage oscillation excited within the winding.
  • the data for plotting these curves was obtained from a 500 kV transformer high voltage winding of a plain disc configuration depicted schematically in FIGURE 4, having sixty disc winding sections indicated at 11 - 1 through 11 - 60.
  • Curve 32 is a profile of the consecutive section pair voltages of the disc winding without transient suppression, while curve 34 is a-section pair voltage profile of the same winding equipped with internal shielding. The humps in these curves occurring adjacent the ground end of the winding are produced by voltage reflections.
  • Curve 36 of FIGURE 3 is a profile of the section pair voltage differential achieved.with the individual zinc oxide varistor elements 17 of the string tapped across every six disc winding sections, i.e., shunting sections 11 - 1 through 11 - 6, 11 - 7 through 11 - 12, etc. as indicated in solid line.
  • the jaggedness of this curve indicates that oscillations in the shunted winding sections do occur to some extent; however, the magnitudes of the voltage differentials all along the winding are consistently suppressed to significantly lower levels than those illustrated by curves 32 and 34.
  • each varistor element of the string need not be uniform.
  • the inherent capacitive grading of a transformer winding causes a disproportionately large percentage of a voltage surge to be dropped across those winding sections nearest the line end, it would be appropriate-to connect the varistor element at the line end of the string across smaller increments of winding than the varistor elements further down in the string.
  • the present invention provides such complete voltage surge and transient suppression along the full winding length, the amount of winding insulation, particularly for the turns adjacent the line end can be significantly reduced from that necessary heretofore. Moreover, the spacings between winding turns of adjacent sections and between the windings and other parts of the transformer can be reduced, thus providing for a more compact power transformer than has heretofore been possible.
  • the present invention contemplates that the single varistor string herein shown shunting a transformer winding may be paralleled with additional varistor strings for increased energy absorbing capacity.
  • the various winding taps are jointly connected to corresponding junctions in each string.
  • the various winding portions or sections may be shunted by plural, series-connected varistor elements, again for increased energy absorbing capacity.
EP82109918A 1981-11-09 1982-10-27 Spannungsverteilung über der Wicklung und Schutz von Leistungstransformatorwicklung gegen transiente Spannungen Withdrawn EP0078985A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US31916881A 1981-11-09 1981-11-09
US319168 1981-11-09

Publications (1)

Publication Number Publication Date
EP0078985A1 true EP0078985A1 (de) 1983-05-18

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EP82109918A Withdrawn EP0078985A1 (de) 1981-11-09 1982-10-27 Spannungsverteilung über der Wicklung und Schutz von Leistungstransformatorwicklung gegen transiente Spannungen

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EP (1) EP0078985A1 (de)
JP (1) JPS5895932A (de)
ES (1) ES516519A1 (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0163907A1 (de) * 1984-05-04 1985-12-11 Siemens Aktiengesellschaft Hochspannungswicklung mit gesteuerter Spannungsverteilung für Transformatoren
EP0190930A2 (de) * 1985-02-06 1986-08-13 Kuhlman Corporation Schutz von Ringkerntransformatoren gegen transiente Spannungen
DE3533882A1 (de) * 1985-09-23 1987-03-26 Transformatoren Union Ag Hochstromlagenwicklung fuer transformatoren und drosseln grosser leistung aus elektrisch parallel geschalteten leitern
EP2747098A1 (de) * 2012-12-19 2014-06-25 ABB Research Ltd. Transformatoranordnung zur Abschwächung von Einschwingspannungsschwankungen
WO2016079224A1 (en) * 2014-11-21 2016-05-26 Abb Technology Ltd System for protetion of dry type transformers
EP3282458A1 (de) 2016-08-09 2018-02-14 ABB Schweiz AG Überspannungsableiter für einen leistungstransformator
CN107851534A (zh) * 2015-07-28 2018-03-27 Abb瑞士股份有限公司 电力配电开关柜和电力电流切断方法
CN110783081A (zh) * 2019-11-14 2020-02-11 中车大连机车车辆有限公司 一种机车、牵引变压器及其过电压保护方法
DE102018213661A1 (de) * 2018-08-14 2020-02-20 Siemens Aktiengesellschaft Wicklungsanordnung mit Feldglättung und Armierung
CN112151239A (zh) * 2020-09-29 2020-12-29 新昌灵思变压器科技有限公司 一种安装于电杆上的变压器保护装置
EP3747100B1 (de) * 2018-01-30 2022-03-16 Hitachi Energy Switzerland AG Dimensionierung eines überspannungsschutzes in einem gleichstromübertragungssystem

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1763599A1 (de) * 1965-08-16 1972-01-05 Licentia Gmbh Axial fortschreitende Roehrenwicklung fuer Transformatoren,Drosselspulen u.dgl.fuer hohe Nennspannungen
DE2421728A1 (de) * 1974-05-04 1975-11-13 Transformatoren Union Ag Transformator mit einer ueberspannungsschutzeinrichtung
DE2609548A1 (de) * 1975-06-06 1976-12-16 Nat Ind As Wicklung fuer transformatoren oder drosselspulen
FR2386175A1 (fr) * 1977-04-01 1978-10-27 Alsthom Cgee Dispositif de protection des installations contre les surtensions, notamment dues a la foudre
FR2389987A1 (en) * 1977-05-06 1978-12-01 Reinhausen Kg Maschf Transformer with tappings switched by stepping switch - has voltage dependent resistors in series with ohmic resistors in groups limiting surge currents
JPS55138214A (en) * 1979-04-11 1980-10-28 Toshiba Corp Lightning-proof transformer
JPS5680109A (en) * 1979-12-05 1981-07-01 Toshiba Corp Transformer

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1763599A1 (de) * 1965-08-16 1972-01-05 Licentia Gmbh Axial fortschreitende Roehrenwicklung fuer Transformatoren,Drosselspulen u.dgl.fuer hohe Nennspannungen
DE2421728A1 (de) * 1974-05-04 1975-11-13 Transformatoren Union Ag Transformator mit einer ueberspannungsschutzeinrichtung
DE2609548A1 (de) * 1975-06-06 1976-12-16 Nat Ind As Wicklung fuer transformatoren oder drosselspulen
FR2386175A1 (fr) * 1977-04-01 1978-10-27 Alsthom Cgee Dispositif de protection des installations contre les surtensions, notamment dues a la foudre
FR2389987A1 (en) * 1977-05-06 1978-12-01 Reinhausen Kg Maschf Transformer with tappings switched by stepping switch - has voltage dependent resistors in series with ohmic resistors in groups limiting surge currents
JPS55138214A (en) * 1979-04-11 1980-10-28 Toshiba Corp Lightning-proof transformer
JPS5680109A (en) * 1979-12-05 1981-07-01 Toshiba Corp Transformer

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENTS ABSTRACTS OF JAPAN, vol. 5, no. 145, 12th September 1981, page 817 E74; & JP - A - 56 80 109 (TOKYO SHIBAURA K.K.) (01-07-1981) *
PATENTS ABSTRACTS OF JAPAN, vol. 5, no. 7, 17th January 1981, page 679 E41; & JP - A - 55 138 214 (TOKYO SHIBAURA DENKI K.K.) (28-10-1980) *

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0163907A1 (de) * 1984-05-04 1985-12-11 Siemens Aktiengesellschaft Hochspannungswicklung mit gesteuerter Spannungsverteilung für Transformatoren
EP0190930A2 (de) * 1985-02-06 1986-08-13 Kuhlman Corporation Schutz von Ringkerntransformatoren gegen transiente Spannungen
EP0190930A3 (de) * 1985-02-06 1987-07-29 Kuhlman Corporation Schutz von Ringkerntransformatoren gegen transiente Spannungen
DE3533882A1 (de) * 1985-09-23 1987-03-26 Transformatoren Union Ag Hochstromlagenwicklung fuer transformatoren und drosseln grosser leistung aus elektrisch parallel geschalteten leitern
KR101591235B1 (ko) 2012-12-19 2016-02-02 에이비비 리써치 리미티드 과도 전압 발진들을 경감시키는 변압기 장치
WO2014095206A1 (en) * 2012-12-19 2014-06-26 Abb Research Ltd Transformer arrangement for mitigating transient voltage oscillations
EP2747098A1 (de) * 2012-12-19 2014-06-25 ABB Research Ltd. Transformatoranordnung zur Abschwächung von Einschwingspannungsschwankungen
US9953760B2 (en) 2012-12-19 2018-04-24 Abb Research Ltd. Transformer arrangement for mitigating transient voltage oscillations
CN107210122B (zh) * 2014-11-21 2019-09-06 Abb瑞士股份有限公司 用于干式变压器的保护的系统
WO2016079224A1 (en) * 2014-11-21 2016-05-26 Abb Technology Ltd System for protetion of dry type transformers
CN107210122A (zh) * 2014-11-21 2017-09-26 Abb瑞士股份有限公司 用于干式变压器的保护的系统
EP4290539A3 (de) * 2014-11-21 2024-03-06 Hitachi Energy Ltd System zum schutz von trockentransformatoren
CN107851534A (zh) * 2015-07-28 2018-03-27 Abb瑞士股份有限公司 电力配电开关柜和电力电流切断方法
CN107851534B (zh) * 2015-07-28 2019-06-07 Abb瑞士股份有限公司 电力配电开关柜和电力电流切断方法
WO2018028875A1 (en) 2016-08-09 2018-02-15 Abb Schweiz Ag Surge arresters for power transformer
EP3282458A1 (de) 2016-08-09 2018-02-14 ABB Schweiz AG Überspannungsableiter für einen leistungstransformator
EP3747100B1 (de) * 2018-01-30 2022-03-16 Hitachi Energy Switzerland AG Dimensionierung eines überspannungsschutzes in einem gleichstromübertragungssystem
DE102018213661A1 (de) * 2018-08-14 2020-02-20 Siemens Aktiengesellschaft Wicklungsanordnung mit Feldglättung und Armierung
CN110783081A (zh) * 2019-11-14 2020-02-11 中车大连机车车辆有限公司 一种机车、牵引变压器及其过电压保护方法
CN112151239A (zh) * 2020-09-29 2020-12-29 新昌灵思变压器科技有限公司 一种安装于电杆上的变压器保护装置

Also Published As

Publication number Publication date
JPS5895932A (ja) 1983-06-07
ES516519A1 (es) 1983-08-01

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Inventor name: SAKSHAUG, EUGENE CLEMENS