US20070252576A1 - Methods and apparatus for testing power generators - Google Patents
Methods and apparatus for testing power generators Download PDFInfo
- Publication number
- US20070252576A1 US20070252576A1 US11/779,361 US77936107A US2007252576A1 US 20070252576 A1 US20070252576 A1 US 20070252576A1 US 77936107 A US77936107 A US 77936107A US 2007252576 A1 US2007252576 A1 US 2007252576A1
- Authority
- US
- United States
- Prior art keywords
- group
- stator
- stator bars
- phase group
- coupled together
- 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.)
- Abandoned
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-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/40—Testing power supplies
- G01R31/42—AC power supplies
Abstract
Description
- This invention relates generally to electrical power generators and more particularly, to methods and systems for testing electrical components in electrical power generators.
- In at least some known generators, a stator yoke in the generator surrounds an armature core and partially encloses a plurality of armature windings, which are sometimes referred to as stator windings or stator bars. At least some known stator windings are formed with a plurality of copper conductors that are wound in the armature to form loops. More specifically, the armature windings are arranged in such a manner to enable a desired voltage and current characteristics to be generated during operation. A plurality of hollow individual conductors, or strands inside the stator bars enable cooling water to be channeled within the stator bars.
- Electrical insulation is wrapped around the stator bars electrically to isolate the stator bars from each other. The insulation facilitates preventing arcing between the windings, and also shields the bars from foreign objects that could electrically short the bars. However, the insulating properties of the insulation may degrade if the insulation becomes damp or is damaged. Voltage arcs may occur from the armature bars through degraded regions or wet regions of the insulation. Over time, continued operation with arcs may prematurely shorten the useful life of the generator.
- To facilitate extending the useful life of the generator, the stator bars may be periodically tested. Within at least some known tests, groups of stator bars are “tied together” electrically and tested as a set, while the remaining bars are electrically grounded. More specifically, insulation is used to isolate the groups under test from the groups that are grounded to prevent electrical discharge or arcing between these groups. During at least some known tests, high-voltage blankets fabricated from rubber are positioned between the groups to facilitate electrically isolating adjacent groups from one another. However, known blankets may be difficult to use because of their size, shape, and weight, and may frequently not prevent arcing. When arcing occurs, the test is considered a failure and is stopped to prevent damage to the generator. Additional insulation is then installed in the area of the arcing and the test is re-performed. The process may need to be repeated several times before a successful test for the group under test may be performed at the required voltage level.
- In one aspect, a method for testing a generator including a plurality of phase groups is provided. The method includes electrically isolating a first phase group from remaining phase groups by substantially encapsulating at least a portion of a plurality of stator bars electrically coupled together within the first phase group with an insulative member, electrically grounding at least a second phase group, and inducing a high voltage to the first phase group to facilitate proof testing the first phase group.
- In another aspect, a method for testing a generator during a rewind process is provided. The method includes electrically isolating a first phase group being rewound by substantially encapsulating at least a portion of a plurality of stator bars electrically coupled together within the first phase group with an insulative member, coupling at least a second phase group to an electrical ground, and supplying a high voltage to the first phase group to facilitate proof testing the first phase group.
- In a further aspect, a method for testing a plurality of stator bars of a generator is provided. The method includes coupling an insulative tubular member around at least a portion of each stator bar coupled together within the first group of stator bars, coupling a second group of stator bars to an electrical ground, and coupling the first phase group to a voltage source.
-
FIG. 1 is a perspective end view of an exemplary generator; and -
FIG. 2 is a perspective end view of the generator shown inFIG. 1 during a testing procedure. -
FIG. 1 is a perspective end view of anexemplary generator 100. Arotor 102 is transparently represented by dashed lines.FIG. 2 is a perspective end view ofgenerator 100 during a testing procedure. A plurality ofstator bar windings 104 are positioned inslots 106 defined around an inner circumference of astator core 108. More specifically, eachstator bar winding 104 includes at least onecircumferential bend 110 defined between aturbine end 112 and a generator end (not shown) of eachwinding 104.Bends 110 are the portion of each stator bar winding 104 that may be most susceptible to insulation wetting. In the exemplary embodiment,stator bars windings 104 are formed from a plurality of flat bar conductors orstator bars 305 that are coupled together prior to form to a pre-determined winding path through winding 104. In one embodiment,stator bars 305 are fabricated from copper.Conductor ends 310 are electrically connected together to form each winding ofgenerator 100.Stator bar windings 104 are covered withelectrical insulation 308, except for aconductor end 310 which remains exposed. - An insulative
tubular member 320 is coupled over the exposedconductor ends 310 ofstator bar windings 104 being tested.Tubular member 320 includes aninner surface 322, anouter surface 324, and acavity 326 defined therein. In the exemplary embodiment,tubular member 320 is high-voltage shrink tubing fabricated from a polyolefin-based material. More specifically,tubular member 320 is slidably coupled over statorbar winding ends 310 such thatmember 320 remains in an “un-shrunk” condition. - At various stages during a full or a partial rewind of
generator 100, high voltage testing is performed to facilitate ensuringstator bar insulation 308 has not sustained damage that may compromise its dielectric strength. More specifically, the testing is conducted on individualstator bar windings 104, or in phase groups ofstator bar windings 104, such that thewindings 104 being tested are electrically isolated bytubular members 320 from thosewindings 104 not being tested. As one group is coupled to a voltage source and tested, the remaining groups are electrically connected to ground for safety reasons. This process continues until all phase groups have been tested. - During testing,
tubular member 320 facilitates electrically isolating each stator bar winding 104 being tested from those not currently being tested. More specifically, eachtubular member 320 is slidably coupled around each winding 104 such that the plurality ofstator bars 305 within thatparticular winding 104 are substantially encapsulated withintubular member cavity 326. Accordingly,tubular member 320 substantially circumscribeswinding conductor end 310 and is coupled to eachrespective windings 104 without the use of any mechanical fasteners. Once coupled in position,tubular member 320 substantially electrically isolates each respective statorwinding conductor end 310 from otherwinding conductor ends 310. In the exemplary embodiment,end 328 of eachmember 320 is folded over to substantially encapsulate the respective stator windingconductive end 310. In an alternative embodiment,tubular member 320 includes a sealed or closed end. - During testing, at least one stator bar winding 104, or a phase group of
stator bar windings 104, are identified for testing. Accordingly, a first stator bar winding 330, which will be coupled to a voltage source (not shown) and tested, is adjacent or proximate to a second stator bar winding 340, which will not be tested. At least onetubular member 320 is then coupled to that respective statorbar conductor end 310 to substantially electricallyinsulate stator bars 305 within first stator bar winding 330 fromstator bars 305 coupled within adjacentstator bar windings 340. In the exemplary embodiment, at least one stator bar winding 350 that is being tested is electrically coupled to ground.Tubular member 320 substantially prevents arcing between first stator bar winding 330 and adjacentstator bar windings - The above-described tubular member allows for temporary insulation for high voltage testing conducted on electrical generators. More specifically, the shape of the tubular member allows tubular member to be slipped over stator bar easily and conveniently. As a result, a tubular member is provided which substantially electrically isolates windings being tested from those not being tested in a cost-effective and reliable means.
- Exemplary embodiments of methods for testing generators are described above in detail. The systems are not limited to the specific embodiments described herein, but rather, components of each assembly may be utilized independently and separately from other components described herein. Each generator component can also be used in combination with other rotor and stator bar components.
- While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
Claims (13)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/779,361 US20070252576A1 (en) | 2004-07-23 | 2007-07-18 | Methods and apparatus for testing power generators |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/897,691 US7259583B2 (en) | 2004-07-23 | 2004-07-23 | Methods and apparatus for testing power generators |
US11/779,361 US20070252576A1 (en) | 2004-07-23 | 2007-07-18 | Methods and apparatus for testing power generators |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/897,691 Division US7259583B2 (en) | 2004-07-23 | 2004-07-23 | Methods and apparatus for testing power generators |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070252576A1 true US20070252576A1 (en) | 2007-11-01 |
Family
ID=35756803
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/897,691 Expired - Fee Related US7259583B2 (en) | 2004-07-23 | 2004-07-23 | Methods and apparatus for testing power generators |
US11/779,361 Abandoned US20070252576A1 (en) | 2004-07-23 | 2007-07-18 | Methods and apparatus for testing power generators |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/897,691 Expired - Fee Related US7259583B2 (en) | 2004-07-23 | 2004-07-23 | Methods and apparatus for testing power generators |
Country Status (1)
Country | Link |
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US (2) | US7259583B2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1821389A1 (en) * | 2006-01-24 | 2007-08-22 | ALSTOM Technology Ltd | Insulating cover for a bar to bar connection of a stator winding |
US9697488B1 (en) | 2009-03-05 | 2017-07-04 | Amazon Technologies, Inc. | System and method for generating predictions for unit allocation in a materials processing network |
US8235369B2 (en) * | 2010-02-17 | 2012-08-07 | General Electric Company | Cart support system for dynamoelectric machine coils |
US8666848B1 (en) | 2011-10-04 | 2014-03-04 | Amazon Technologies, Inc. | Continuous planning review system |
Citations (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2525413A (en) * | 1946-11-07 | 1950-10-10 | Westinghouse Electric Corp | Testing apparatus for generator winding insulation |
US2558091A (en) * | 1947-09-27 | 1951-06-26 | Westinghouse Electric Corp | Method and means for detecting discharges on high-voltage windings |
US2815481A (en) * | 1954-02-16 | 1957-12-03 | Gen Electric | Automatic rejection circuit for electrical testing apparatus |
US4152640A (en) * | 1977-09-23 | 1979-05-01 | Westinghouse Electric Corp. | Two phase high voltage insulation testing of multiphase windings |
US4156846A (en) * | 1977-01-10 | 1979-05-29 | Westinghouse Electric Corp. | Detection of arcing faults in generator windings |
US4356443A (en) * | 1980-08-26 | 1982-10-26 | Westinghouse Electric Corp. | Detection of arcing faults in polyphase electric machines |
US4385254A (en) * | 1981-05-27 | 1983-05-24 | Vakser Boris D | Electric-machine stator bar winding |
US4758171A (en) * | 1985-11-29 | 1988-07-19 | Raychem Gmbh | Cable connection |
US5006769A (en) * | 1989-04-05 | 1991-04-09 | Asea Brown Boveri Ltd. | Arrangement for detecting winding shorts in the rotor winding of electrical machines |
US5379632A (en) * | 1992-10-29 | 1995-01-10 | Westinghouse Electric Corporation | Method of testing a gas cooled electrical generator |
US5384429A (en) * | 1993-06-24 | 1995-01-24 | Emerson Electric Co. | Low impedance surge protective device cables for power line usage |
US5913243A (en) * | 1997-09-30 | 1999-06-15 | General Electric Co. | Ultrasonic transducer for nondestructive testing of generator field coils of dynamoelectric machines |
US5949247A (en) * | 1996-05-23 | 1999-09-07 | Fremont/Dynamics Coporation Of America | Method and apparatus for automatically testing and evaluating electric generator sets |
US6225813B1 (en) * | 1997-06-09 | 2001-05-01 | General Electric Co. | Portable apparatus for in situ field stator bar insulation capacitance mapping |
US6452416B1 (en) * | 1999-05-24 | 2002-09-17 | Mitsubishi Denki Kabushiki Kaisha | Abnormality detecting apparatus for a rotating electric machine |
US6787704B2 (en) * | 2000-05-09 | 2004-09-07 | Donald W. Owen | Method and apparatus for increasing the rating of a transformer |
US6911838B2 (en) * | 2003-03-31 | 2005-06-28 | General Electric Company | Online detection of shorted turns in a generator field winding |
US7064454B2 (en) * | 2002-04-22 | 2006-06-20 | Yamaha Hatsudoki Kabushiki Kaisha | Power generator system |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3551784A (en) * | 1967-07-24 | 1970-12-29 | Rotax Ltd | Alternating current generators having plural output windings |
DE2606401A1 (en) * | 1975-02-19 | 1976-09-02 | Matsushita Electric Ind Co Ltd | STATOR FOR AN ELECTRIC MACHINE AND THE PROCESS FOR ITS MANUFACTURING |
US4543503A (en) * | 1983-12-20 | 1985-09-24 | General Electric Company | Ventilated end turns for rotor windings of a dynamoelectric machine |
US4584497A (en) * | 1984-09-28 | 1986-04-22 | General Electric Company | Beam support for bar windings of large electric generator |
US4580325A (en) * | 1985-02-13 | 1986-04-08 | Westinghouse Electric Corp. | Winding temporary positioning apparatus for a dynamoelectric generator |
US4621850A (en) * | 1985-06-26 | 1986-11-11 | Westinghouse Electric Corp. | Coil removal apparatus for a dynamoelectric generator |
US4678931A (en) * | 1985-10-18 | 1987-07-07 | General Electric Company | Armature winding for large turbine generator |
US5155441A (en) * | 1986-12-17 | 1992-10-13 | Zelm Richard J | Automatic insulation tester for grounded and ungrounded electrical equipment |
US5432391A (en) * | 1994-03-21 | 1995-07-11 | General Electric Company | Conformable dynamoelectric machine field distance blocks and methods of installation |
US5421077A (en) * | 1994-05-18 | 1995-06-06 | General Electric Company | Method for the substitution of copper windings in generator rotor fields originally having aluminum windings |
US5581869A (en) * | 1995-08-15 | 1996-12-10 | General Electric Co. | Repair method for sealing liquid-cooled stator bar end fittings for a generator |
US6191510B1 (en) * | 1997-12-19 | 2001-02-20 | 3M Innovative Properties Company | Internally damped stator, rotor, and transformer and a method of making |
US6553665B2 (en) * | 2000-03-08 | 2003-04-29 | General Electric Company | Stator vane assembly for a turbine and method for forming the assembly |
US6603227B2 (en) * | 2001-04-16 | 2003-08-05 | Briggs & Stratton Corporation | Small engine vehicle including a generator |
-
2004
- 2004-07-23 US US10/897,691 patent/US7259583B2/en not_active Expired - Fee Related
-
2007
- 2007-07-18 US US11/779,361 patent/US20070252576A1/en not_active Abandoned
Patent Citations (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2525413A (en) * | 1946-11-07 | 1950-10-10 | Westinghouse Electric Corp | Testing apparatus for generator winding insulation |
US2558091A (en) * | 1947-09-27 | 1951-06-26 | Westinghouse Electric Corp | Method and means for detecting discharges on high-voltage windings |
US2815481A (en) * | 1954-02-16 | 1957-12-03 | Gen Electric | Automatic rejection circuit for electrical testing apparatus |
US4156846A (en) * | 1977-01-10 | 1979-05-29 | Westinghouse Electric Corp. | Detection of arcing faults in generator windings |
US4152640A (en) * | 1977-09-23 | 1979-05-01 | Westinghouse Electric Corp. | Two phase high voltage insulation testing of multiphase windings |
US4356443A (en) * | 1980-08-26 | 1982-10-26 | Westinghouse Electric Corp. | Detection of arcing faults in polyphase electric machines |
US4385254A (en) * | 1981-05-27 | 1983-05-24 | Vakser Boris D | Electric-machine stator bar winding |
US4758171A (en) * | 1985-11-29 | 1988-07-19 | Raychem Gmbh | Cable connection |
US5006769A (en) * | 1989-04-05 | 1991-04-09 | Asea Brown Boveri Ltd. | Arrangement for detecting winding shorts in the rotor winding of electrical machines |
US5379632A (en) * | 1992-10-29 | 1995-01-10 | Westinghouse Electric Corporation | Method of testing a gas cooled electrical generator |
US5384429A (en) * | 1993-06-24 | 1995-01-24 | Emerson Electric Co. | Low impedance surge protective device cables for power line usage |
US5949247A (en) * | 1996-05-23 | 1999-09-07 | Fremont/Dynamics Coporation Of America | Method and apparatus for automatically testing and evaluating electric generator sets |
US6225813B1 (en) * | 1997-06-09 | 2001-05-01 | General Electric Co. | Portable apparatus for in situ field stator bar insulation capacitance mapping |
US5913243A (en) * | 1997-09-30 | 1999-06-15 | General Electric Co. | Ultrasonic transducer for nondestructive testing of generator field coils of dynamoelectric machines |
US6452416B1 (en) * | 1999-05-24 | 2002-09-17 | Mitsubishi Denki Kabushiki Kaisha | Abnormality detecting apparatus for a rotating electric machine |
US6787704B2 (en) * | 2000-05-09 | 2004-09-07 | Donald W. Owen | Method and apparatus for increasing the rating of a transformer |
US7064454B2 (en) * | 2002-04-22 | 2006-06-20 | Yamaha Hatsudoki Kabushiki Kaisha | Power generator system |
US6911838B2 (en) * | 2003-03-31 | 2005-06-28 | General Electric Company | Online detection of shorted turns in a generator field winding |
Also Published As
Publication number | Publication date |
---|---|
US20060028234A1 (en) | 2006-02-09 |
US7259583B2 (en) | 2007-08-21 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: GENERAL ELECTRIC COMPANY, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MARINO, CHARLES JAMES;BURROUGHS, STEPHEN LAWRENCE;TRAVER, BERNARD WILLIAM;AND OTHERS;REEL/FRAME:019569/0674;SIGNING DATES FROM 20040709 TO 20070709 |
|
AS | Assignment |
Owner name: GENERAL ELECTRIC COMPANY, NEW YORK Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE EXECUTION DATE OF CHARLES JAMES MARINO PREVIOUSLY RECORDED ON REEL 019569 FRAME 0674;ASSIGNORS:MARINO, CHARLES JAMES;BURROUGHS, STEPHEN LAWRENECE;TRAVER, BERNARD WILLIAM;AND OTHERS;REEL/FRAME:019595/0175 Effective date: 20040709 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |