US3670192A - Rotating electrical machine with means for preventing discharge from coil ends - Google Patents

Rotating electrical machine with means for preventing discharge from coil ends Download PDF

Info

Publication number
US3670192A
US3670192A US82955A US3670192DA US3670192A US 3670192 A US3670192 A US 3670192A US 82955 A US82955 A US 82955A US 3670192D A US3670192D A US 3670192DA US 3670192 A US3670192 A US 3670192A
Authority
US
United States
Prior art keywords
coil
voltage
layer
machine
conducting layer
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
US82955A
Other languages
English (en)
Inventor
Anders R Andersson
Lars-Goran Virsberg
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.)
ABB Norden Holding AB
Original Assignee
ASEA AB
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
Application filed by ASEA AB filed Critical ASEA AB
Application granted granted Critical
Publication of US3670192A publication Critical patent/US3670192A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K3/00—Details of windings
    • H02K3/32—Windings characterised by the shape, form or construction of the insulation
    • H02K3/40—Windings characterised by the shape, form or construction of the insulation for high voltage, e.g. affording protection against corona discharges
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S174/00—Electricity: conductors and insulators
    • Y10S174/13—High voltage cable, e.g. above 10kv, corona prevention
    • Y10S174/14—High voltage cable, e.g. above 10kv, corona prevention having a particular cable application, e.g. winding
    • Y10S174/19—High voltage cable, e.g. above 10kv, corona prevention having a particular cable application, e.g. winding in a dynamo-electric machine
    • Y10S174/20—Stator

Definitions

  • the present invention relates to a means of avoiding corona discharges between the coil ends of a rotating electrical machine with coils arranged in winding slots and neighboring grounded machine parts during high test voltage.
  • FIGS. 1, 2 and 3 show three different embodiments of the invention in tangential view in relation to the rotating machine and FIG. 4 gives a graphic picture of potential conditions in the embodiment shown in FIG. 3.
  • FIG. 1a shows a section through the free coil part along the line 8-8 in FIG. I. 1
  • FIG. 1 designates an end part of the stator core in a rotating electric machine and 2 an end part of a rotor surrounded by the stator core, the air gap between stator and rotor being designated 3.
  • the dotted line 4 indicates the bottom of a winding slot and the part lying outside the stator core.
  • a coil side arranged in the winding slot is designated 5.
  • 6 is an end connection for joining two coil sides.
  • the straight side of the coil provided with compressed insulation comprises between the slot part a short part running axially outside the stator core which, at the line AA, continues into the weakly insulated part of the coil ends.
  • a machine part in the vicinity of this latter coil part is designated 7.
  • a partof the coil side 5 in the vicinity of the machine part 7 is provided with a conducting surface layer 9.
  • this part is indicated by a small check pattern.
  • 5a designates the copper conductor of the coil side and 5b the surrounding coil insulation.
  • the conducting surface layer 9 is connected to ground by a resistive element 8, the resistance of which is voltage-dependent in such a way that the impedance decreases as the voltage increases.
  • the layer 9 does not necessarily mean that the layer must consist of a material having low resistivity. It may, for example, consist of a varnish having relatively slight additions of graphite powder.
  • the resistor 8 is chosen with such resistance/voltage characteristic that its resistance at a voltage corresponding to the maximum potential to ground of the winding at normal operation is several times greater than the impedance formed by the capacitance between the layer 9 and the conductor of the coil side, for example six times as great. This means that the potential of the conducting layer during normal operation deviates only negligibly from the conductor potential of the coil side.
  • the conductor of the coil is given a potential in relation to ground which is considerably greater than normal operating potential, for example 3.5 times as great, the resistance of the resistor 8 drops to, for example, 10 percent of its previous value.
  • the high test voltage does not cause any essential increase in the potential of the layer 9 in relation to ground and consequently the risk of glow during testing is eliminated.
  • the coil insu lation will be subjected to the greater part of the test voltage but, in view of the short testing time, this can certainly be permissible.
  • the conducting layer 9 has very high surface resistivity, certain potential difierences may occur within the layer. If desired, these differences can be reduced by connecting the resistor 8 to the conducting layer at one end at a number of suitably spaced contact points. If the transition between the ends of the conducting layer and the uncoated coil insulation is carried out without field equalizing means, it may be advantageous if the ends of the layer during testing have a somewhat higher potential than the central part of the coating. This is achieved with the device shown in FIG. 1 if the resistivity of the layer 9 is high. If the conducting layer is provided with some'field equalizing means (for example similar to that shown in British Pat. No. 842,039) only at one end, it may be an advantage to make the layer with a relatively high surface resistivity and connect the resistor 8 at the same end.
  • some'field equalizing means for example similar to that shown in British Pat. No. 842,039
  • 12 is a conducting layer which differs from the corresponding layer 9 in FIG. 1 in that it comprises coil end parts of two different coil sides and also intermediate coil ends parts.
  • a neighboring grounded machine part in FIG. 2 is designated 10.
  • an-impedance element arranged outside the coil surface, for example of the same type as the resistor 8 in FIG. 1.
  • conducting coating 13 is also arranged in known manner to surround the part of each coil side lying in the winding slot and also projects slightly outside the slot.
  • the coating 11 has the function of controlling the electric field, as described in British Pat. No. 842,039, and at the same time provides the effect intended according to the invention and achieved by the resistor 8 in FIG. I. If the outermost portion of the coil ends is constructed in accordance with FIG. 1, that is, with a means corresponding to 6 in FIG. ljintended to connect the conductors of the coil sides, this should also be surrounded by the conducting layer 12. It is of course also assumed that the device 6 is provided with insulation. If not, which is often the case, the layer 12 should not be drawn out in the vicinity of the uninsulated part.
  • the coating A corresponds to the conducting, grounded coating 13 in FIG. 2.
  • B designates a coating of the same voltage-dc pendent material as the coating 11 in FIG. 2
  • A is a well conducting layer and B, a coating of material having voltage-dependent resistivity.
  • FIG. 4 where the fully drawn curve shows the potential distribution of the part of a winding coil shown in FIG. 3 during normal operation of the machine, and the broken curve during testing with increased voltage.
  • the distance X from the end of the winding slot is indicated along the abscissa and the potential of the-coil surface in relation to ground along the ordinate.
  • the potential in relation to ground given to the coil conductors during testing is designated U whereas the potential of the conductors during normal operation is designated U
  • the well conducting layer A can, by suitable dimensioning (composition, length) of the coating B be made to assume an arbitrary potential U, between zero and test voltage during the testing, whereas at operating voltage it assumes approximately the potential of the copper conductor and thus does not cause any increase of the dielectric stress on the coil insulation.
  • the voltage-dependent impedance element characteristic of the invention is principally of resistivetype.
  • a device according to the invention can be constructed with many different types of voltagedependent resistive impedance elements and it is even feasible to use voltage-dependent impedance elements of capacitive or inductive type.
  • each coil side having a relatively strongly insulated first portion, substantially located adjacent to a winding slot and a second, relatively weakly insulated coil end portion spaced from the slot, said machine having a grounded part adjacent to said second portion and spaced from the slot end, means for avoiding glow between said second portion and said grounded machine part during high voltage testing comprising a conducting layer on the surface of said second portion, said layer being electrically spaced from the winding slot, and an impedance element connecting said conducting layer tosaid grounded machine part, the impedance element being voltage-dependent in a voltage range beyond normal machine voltage in such a way that the impedance decreases as the voltage increases.
  • said impedance element comprising a resistive member arranged on the outside of the coil surface.
  • At least a part of said impedance element comprising a coating having voltage-dependent surface resistivity andarranged on the coil surface between the conducting layer and the end of the winding slot.
  • said conducting layer being joined at its axially outer end to a layer of a resistive material arranged axially outside this layer and on the same coil, said material being voltage-dependent in such a manner that its surface resistivity decreases as the voltage increases.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Insulation, Fastening Of Motor, Generator Windings (AREA)
US82955A 1969-10-29 1970-10-22 Rotating electrical machine with means for preventing discharge from coil ends Expired - Lifetime US3670192A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE14763/69A SE326758B (zh) 1969-10-29 1969-10-29

Publications (1)

Publication Number Publication Date
US3670192A true US3670192A (en) 1972-06-13

Family

ID=20299622

Family Applications (1)

Application Number Title Priority Date Filing Date
US82955A Expired - Lifetime US3670192A (en) 1969-10-29 1970-10-22 Rotating electrical machine with means for preventing discharge from coil ends

Country Status (4)

Country Link
US (1) US3670192A (zh)
CH (1) CH516249A (zh)
GB (1) GB1319257A (zh)
SE (1) SE326758B (zh)

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3886387A (en) * 1973-07-31 1975-05-27 Gen Electric Flux shield for dynamoelectric machines
US4001616A (en) * 1974-02-18 1977-01-04 Canadian General Electric Company Limited Grounding of outer winding insulation to cores in dynamoelectric machines
US4207482A (en) * 1978-11-14 1980-06-10 Westinghouse Electric Corp. Multilayered high voltage grading system for electrical conductors
US4473765A (en) * 1982-09-30 1984-09-25 General Electric Company Electrostatic grading layer for the surface of an electrical insulation exposed to high electrical stress
US5821652A (en) * 1996-08-28 1998-10-13 Marathon Electric Manufacturing Corporation Dynamoelectric machines with shaft voltage prevention method and structure
WO1999017428A1 (en) * 1997-09-30 1999-04-08 Abb Ab Method and arrangement for earthing a rotating electric machine, and a rotating electric machine
US6261437B1 (en) 1996-11-04 2001-07-17 Asea Brown Boveri Ab Anode, process for anodizing, anodized wire and electric device comprising such anodized wire
US6279850B1 (en) 1996-11-04 2001-08-28 Abb Ab Cable forerunner
US6357688B1 (en) 1997-02-03 2002-03-19 Abb Ab Coiling device
US6369470B1 (en) 1996-11-04 2002-04-09 Abb Ab Axial cooling of a rotor
US6376775B1 (en) 1996-05-29 2002-04-23 Abb Ab Conductor for high-voltage windings and a rotating electric machine comprising a winding including the conductor
US6396187B1 (en) 1996-11-04 2002-05-28 Asea Brown Boveri Ab Laminated magnetic core for electric machines
US6417456B1 (en) 1996-05-29 2002-07-09 Abb Ab Insulated conductor for high-voltage windings and a method of manufacturing the same
US6429563B1 (en) 1997-02-03 2002-08-06 Abb Ab Mounting device for rotating electric machines
US6439497B1 (en) 1997-02-03 2002-08-27 Abb Ab Method and device for mounting a winding
US6465979B1 (en) 1997-02-03 2002-10-15 Abb Ab Series compensation of electric alternating current machines
US6498415B1 (en) * 2000-09-06 2002-12-24 Siemens Westinghouse Power Corporation High voltage stator coil having low loss insulator and electrode covering and method therefor
US6525504B1 (en) 1997-11-28 2003-02-25 Abb Ab Method and device for controlling the magnetic flux in a rotating high voltage electric alternating current machine
US6577487B2 (en) 1996-05-29 2003-06-10 Asea Brown Boveri Ab Reduction of harmonics in AC machines
US6624547B1 (en) 2000-09-27 2003-09-23 Siemens Westinghouse Power Corporation Power system having stator coils for grading voltage between inner vent tubes and coil strands and associated methods
US6646363B2 (en) 1997-02-03 2003-11-11 Abb Ab Rotating electric machine with coil supports
US6801421B1 (en) 1998-09-29 2004-10-05 Abb Ab Switchable flux control for high power static electromagnetic devices
US6822363B2 (en) 1996-05-29 2004-11-23 Abb Ab Electromagnetic device
US6825585B1 (en) 1997-02-03 2004-11-30 Abb Ab End plate
US6828701B1 (en) 1997-02-03 2004-12-07 Asea Brown Boveri Ab Synchronous machine with power and voltage control
US6831388B1 (en) 1996-05-29 2004-12-14 Abb Ab Synchronous compensator plant
US6867674B1 (en) 1997-11-28 2005-03-15 Asea Brown Boveri Ab Transformer
US6873080B1 (en) 1997-09-30 2005-03-29 Abb Ab Synchronous compensator plant
US6885273B2 (en) 2000-03-30 2005-04-26 Abb Ab Induction devices with distributed air gaps
US6891303B2 (en) 1996-05-29 2005-05-10 Abb Ab High voltage AC machine winding with grounded neutral circuit
US6970063B1 (en) 1997-02-03 2005-11-29 Abb Ab Power transformer/inductor
US6972505B1 (en) 1996-05-29 2005-12-06 Abb Rotating electrical machine having high-voltage stator winding and elongated support devices supporting the winding and method for manufacturing the same
US6995646B1 (en) 1997-02-03 2006-02-07 Abb Ab Transformer with voltage regulating means
US7019429B1 (en) 1997-11-27 2006-03-28 Asea Brown Boveri Ab Method of applying a tube member in a stator slot in a rotating electrical machine
US7046492B2 (en) 1997-02-03 2006-05-16 Abb Ab Power transformer/inductor
US7045704B2 (en) 2000-04-28 2006-05-16 Abb Ab Stationary induction machine and a cable therefor
US7061133B1 (en) 1997-11-28 2006-06-13 Abb Ab Wind power plant
US7141908B2 (en) 2000-03-01 2006-11-28 Abb Ab Rotating electrical machine
EP1903662A1 (en) * 2006-09-25 2008-03-26 Abb Research Ltd. A high voltage rotating machine and an electric installation provided therewith
US20110072641A1 (en) * 2006-01-24 2011-03-31 Thomas Baumann Method for the production of a stator winding
CN104937819A (zh) * 2013-01-15 2015-09-23 西门子公司 用于构成防电晕保护层的方法和设备

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH662454A5 (de) * 1980-12-18 1987-09-30 V Proektno Izyskatelskyi Nii G Anordnung zur verbindung zweier schichtkabel im stirnteil der staenderwicklung eines hochspannungsgenerators.
US4420701A (en) * 1980-12-30 1983-12-13 Nauchno-Issledovatelsky Sektor Vsesojuznogo Proektno-Izyskatelskogo I Nauchno-Issledovatelskogo Instituta "Gidroproekt" Imeni S.Ya. Zhuka Coupling unit for connection of generator high-voltage winding and inlet bar
GB2331867A (en) 1997-11-28 1999-06-02 Asea Brown Boveri Power cable termination

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2061503A (en) * 1934-04-12 1936-11-17 Westinghouse Electric & Mfg Co Method of diminishing corona and insulation heating at the ends of slots
US2061502A (en) * 1934-04-12 1936-11-17 Westinghouse Electric & Mfg Co Method of diminishing corona and insulation heating at the ends of slots
US2788456A (en) * 1954-09-28 1957-04-09 Westinghouse Electric Corp Conductor-ventilated generators
US2939976A (en) * 1956-08-31 1960-06-07 Westinghouse Electric Corp Corona suppression in high voltage coils
US3066180A (en) * 1957-04-06 1962-11-27 Asea Ab Coating for equalizing the potential gradient along the surface of an electric insulation
US3210461A (en) * 1962-10-12 1965-10-05 Westinghouse Electric Corp Electrical stress-grading coatings
US3354331A (en) * 1966-09-26 1967-11-21 Gen Electric High voltage grading for dynamoelectric machine
US3412200A (en) * 1966-12-08 1968-11-19 Asea Ab High voltage cable with potential gradient equalization means
US3487455A (en) * 1967-04-18 1969-12-30 Asea Ab Insulated high voltage conductor with potential gradient equalization means
US3508096A (en) * 1967-12-05 1970-04-21 Bbc Brown Boveri & Cie Arrangement for preventing glow discharges between insulated conductors in generator end turns

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2061503A (en) * 1934-04-12 1936-11-17 Westinghouse Electric & Mfg Co Method of diminishing corona and insulation heating at the ends of slots
US2061502A (en) * 1934-04-12 1936-11-17 Westinghouse Electric & Mfg Co Method of diminishing corona and insulation heating at the ends of slots
US2788456A (en) * 1954-09-28 1957-04-09 Westinghouse Electric Corp Conductor-ventilated generators
US2939976A (en) * 1956-08-31 1960-06-07 Westinghouse Electric Corp Corona suppression in high voltage coils
US3066180A (en) * 1957-04-06 1962-11-27 Asea Ab Coating for equalizing the potential gradient along the surface of an electric insulation
US3210461A (en) * 1962-10-12 1965-10-05 Westinghouse Electric Corp Electrical stress-grading coatings
US3354331A (en) * 1966-09-26 1967-11-21 Gen Electric High voltage grading for dynamoelectric machine
US3412200A (en) * 1966-12-08 1968-11-19 Asea Ab High voltage cable with potential gradient equalization means
US3487455A (en) * 1967-04-18 1969-12-30 Asea Ab Insulated high voltage conductor with potential gradient equalization means
US3508096A (en) * 1967-12-05 1970-04-21 Bbc Brown Boveri & Cie Arrangement for preventing glow discharges between insulated conductors in generator end turns

Cited By (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3886387A (en) * 1973-07-31 1975-05-27 Gen Electric Flux shield for dynamoelectric machines
US4001616A (en) * 1974-02-18 1977-01-04 Canadian General Electric Company Limited Grounding of outer winding insulation to cores in dynamoelectric machines
US4207482A (en) * 1978-11-14 1980-06-10 Westinghouse Electric Corp. Multilayered high voltage grading system for electrical conductors
US4473765A (en) * 1982-09-30 1984-09-25 General Electric Company Electrostatic grading layer for the surface of an electrical insulation exposed to high electrical stress
US6972505B1 (en) 1996-05-29 2005-12-06 Abb Rotating electrical machine having high-voltage stator winding and elongated support devices supporting the winding and method for manufacturing the same
US6894416B1 (en) 1996-05-29 2005-05-17 Abb Ab Hydro-generator plant
US6891303B2 (en) 1996-05-29 2005-05-10 Abb Ab High voltage AC machine winding with grounded neutral circuit
US6831388B1 (en) 1996-05-29 2004-12-14 Abb Ab Synchronous compensator plant
US6577487B2 (en) 1996-05-29 2003-06-10 Asea Brown Boveri Ab Reduction of harmonics in AC machines
US6822363B2 (en) 1996-05-29 2004-11-23 Abb Ab Electromagnetic device
US6376775B1 (en) 1996-05-29 2002-04-23 Abb Ab Conductor for high-voltage windings and a rotating electric machine comprising a winding including the conductor
US6906447B2 (en) 1996-05-29 2005-06-14 Abb Ab Rotating asynchronous converter and a generator device
US6417456B1 (en) 1996-05-29 2002-07-09 Abb Ab Insulated conductor for high-voltage windings and a method of manufacturing the same
US6940380B1 (en) 1996-05-29 2005-09-06 Abb Ab Transformer/reactor
US6936947B1 (en) 1996-05-29 2005-08-30 Abb Ab Turbo generator plant with a high voltage electric generator
US6919664B2 (en) 1996-05-29 2005-07-19 Abb Ab High voltage plants with electric motors
US5821652A (en) * 1996-08-28 1998-10-13 Marathon Electric Manufacturing Corporation Dynamoelectric machines with shaft voltage prevention method and structure
US6396187B1 (en) 1996-11-04 2002-05-28 Asea Brown Boveri Ab Laminated magnetic core for electric machines
US6369470B1 (en) 1996-11-04 2002-04-09 Abb Ab Axial cooling of a rotor
US6261437B1 (en) 1996-11-04 2001-07-17 Asea Brown Boveri Ab Anode, process for anodizing, anodized wire and electric device comprising such anodized wire
US6279850B1 (en) 1996-11-04 2001-08-28 Abb Ab Cable forerunner
US6465979B1 (en) 1997-02-03 2002-10-15 Abb Ab Series compensation of electric alternating current machines
US6429563B1 (en) 1997-02-03 2002-08-06 Abb Ab Mounting device for rotating electric machines
US6825585B1 (en) 1997-02-03 2004-11-30 Abb Ab End plate
US6439497B1 (en) 1997-02-03 2002-08-27 Abb Ab Method and device for mounting a winding
US6646363B2 (en) 1997-02-03 2003-11-11 Abb Ab Rotating electric machine with coil supports
US6995646B1 (en) 1997-02-03 2006-02-07 Abb Ab Transformer with voltage regulating means
US6357688B1 (en) 1997-02-03 2002-03-19 Abb Ab Coiling device
US7046492B2 (en) 1997-02-03 2006-05-16 Abb Ab Power transformer/inductor
US6970063B1 (en) 1997-02-03 2005-11-29 Abb Ab Power transformer/inductor
US6828701B1 (en) 1997-02-03 2004-12-07 Asea Brown Boveri Ab Synchronous machine with power and voltage control
US6873080B1 (en) 1997-09-30 2005-03-29 Abb Ab Synchronous compensator plant
WO1999017428A1 (en) * 1997-09-30 1999-04-08 Abb Ab Method and arrangement for earthing a rotating electric machine, and a rotating electric machine
US7019429B1 (en) 1997-11-27 2006-03-28 Asea Brown Boveri Ab Method of applying a tube member in a stator slot in a rotating electrical machine
US6525504B1 (en) 1997-11-28 2003-02-25 Abb Ab Method and device for controlling the magnetic flux in a rotating high voltage electric alternating current machine
US6867674B1 (en) 1997-11-28 2005-03-15 Asea Brown Boveri Ab Transformer
US7061133B1 (en) 1997-11-28 2006-06-13 Abb Ab Wind power plant
US6801421B1 (en) 1998-09-29 2004-10-05 Abb Ab Switchable flux control for high power static electromagnetic devices
US7141908B2 (en) 2000-03-01 2006-11-28 Abb Ab Rotating electrical machine
US6885273B2 (en) 2000-03-30 2005-04-26 Abb Ab Induction devices with distributed air gaps
US7045704B2 (en) 2000-04-28 2006-05-16 Abb Ab Stationary induction machine and a cable therefor
US6498415B1 (en) * 2000-09-06 2002-12-24 Siemens Westinghouse Power Corporation High voltage stator coil having low loss insulator and electrode covering and method therefor
US6624547B1 (en) 2000-09-27 2003-09-23 Siemens Westinghouse Power Corporation Power system having stator coils for grading voltage between inner vent tubes and coil strands and associated methods
US20110072641A1 (en) * 2006-01-24 2011-03-31 Thomas Baumann Method for the production of a stator winding
EP1903662A1 (en) * 2006-09-25 2008-03-26 Abb Research Ltd. A high voltage rotating machine and an electric installation provided therewith
CN104937819A (zh) * 2013-01-15 2015-09-23 西门子公司 用于构成防电晕保护层的方法和设备
US9843246B2 (en) 2013-01-15 2017-12-12 Siemens Aktiengesellschaft Method and apparatus for forming corona shielding
CN104937819B (zh) * 2013-01-15 2018-04-27 西门子公司 用于构成防电晕保护层的方法和设备

Also Published As

Publication number Publication date
GB1319257A (en) 1973-06-06
DE2050674B2 (de) 1972-11-23
SE326758B (zh) 1970-08-03
DE2050674A1 (de) 1971-05-19
CH516249A (de) 1971-11-30

Similar Documents

Publication Publication Date Title
US3670192A (en) Rotating electrical machine with means for preventing discharge from coil ends
US4634911A (en) High voltage dynamoelectric machine with selectively increased coil turn-to-turn insulation strength
JPH0213445B2 (zh)
KR20000016037A (ko) 고전압 ac 장치
US4604673A (en) Distribution transformer with surge protection device
US4153891A (en) Transient voltage distribution improving line shield for layer wound power transformer
US3699488A (en) Distribution transformer having static shield
US4484085A (en) Spiral line voltage pulse generator characterized by secondary winding
US4724600A (en) Method of making a high voltage dynamoelectric machine with selectively increased coil turn-to-turn insulation strength
HU200029B (en) High-voltage transformer
US3975653A (en) Creeping discharge and partial discharge prevention means for a coil end of a rotary electric machine
US5093598A (en) Semiconductor insulation layer for stator coil connections
US4042900A (en) Electrostatic shielding of disc windings
US1891716A (en) Winding for dynamo electric machines
US2316558A (en) Transformer
US3531653A (en) Multiphase generator and bus system
US1784989A (en) Elimination of corona in alternators
US3564470A (en) Electrical winding structures
US3387243A (en) Inductive disk winding with improved impulse voltage gradient
US3391365A (en) Interleaved winding having high series capacitance
JPH0365106B2 (zh)
JPS6259450B2 (zh)
US676105A (en) Protecting device for coils of electrical apparatus.
US3643196A (en) Electrical inductive apparatus
US4437083A (en) Current transformer for turbine generators