CN106443302A - Large-scale hydro-generator stator earth fault safe finding method - Google Patents
Large-scale hydro-generator stator earth fault safe finding method Download PDFInfo
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- CN106443302A CN106443302A CN201610940461.6A CN201610940461A CN106443302A CN 106443302 A CN106443302 A CN 106443302A CN 201610940461 A CN201610940461 A CN 201610940461A CN 106443302 A CN106443302 A CN 106443302A
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- 238000000034 method Methods 0.000 title claims abstract description 17
- 238000009413 insulation Methods 0.000 claims abstract description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 230000008878 coupling Effects 0.000 claims description 6
- 238000010168 coupling process Methods 0.000 claims description 6
- 238000005859 coupling reaction Methods 0.000 claims description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 238000001514 detection method Methods 0.000 claims description 4
- 231100000768 Toxicity label Toxicity 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 230000007935 neutral effect Effects 0.000 claims description 3
- 238000003466 welding Methods 0.000 abstract description 5
- 238000004804 winding Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 3
- 240000007594 Oryza sativa Species 0.000 description 1
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Classifications
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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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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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
- G01R31/34—Testing dynamo-electric machines
- G01R31/346—Testing of armature or field windings
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Control Of Eletrric Generators (AREA)
- Protection Of Generators And Motors (AREA)
Abstract
The invention discloses a large-scale hydro-generator stator earth fault safe finding method. The method comprises connecting a DC power circuit, correcting connection direction of open-type CTs and ammeters, determining the ground fault phase according to insulation resistance, determining ground fault branches in sequence according to current direction, and determining a ground fault point. The method is simple and practical, and can find the generator stator earth fault point safely, accurately and quickly through a safe current smaller than 1 A; and in the whole fault finding process, the tail end of each branch winding bar does not needed to be sawed off, thereby reducing a lot of workload of sawing off and welding, and preventing risk caused by welding heat.
Description
Technical field
The present invention relates to a kind of safe lookup method of large-sized water turbine generator Stator ground fault.
Background technology
In electric power enterprise production, generator stator ground is a typical fault of electromotor.
The big wiring complexity of large-sized water turbine generator stator volume（As certain 700MW electromotor machine stator diameter 16m, high 3.3m,
Bar 1248, every 8 branch of phase）, grain of rice size earth point will be accurately found, traditional method is the ground connection electricity for being applied more than 5A
Stream, allows earth point to produce big smog to find earth point.
《Generator transformer relay protection application》Show etc. data, the safety that 1A electric current is grounded for Generator Stator
Electric current, stator grounding electric current is more than the safety that may threaten generator iron-core after 1A.
Conventional electric generators stator grounding searches method 5A electric current, it is possible to scaling loss stator core.The country is connect due to searching stator
Earth fault and scaling loss stator core event occasionally has generation, cause bigger loss.Particularly large-sized water turbine generator, repairs ferrum
The direct and consequential damage of core and electric quantity loss can exceed that hundred million yuan.Therefore, large-sized water turbine generator Stator ground fault is searched must
Must perfectly safe, be perfectly safe.
In addition, the lookup method having at present needs sawed-off each branch's tail end to reduce fault coverage, high-rating generator is typically every
8 branches of phase or so, after branch's tail end is sawed-off, welding job amount is big, time-consuming many again, while also having that welded when recovering acutely to send out
Heat may destroy the risk of bar insulation.
Content of the invention
Present invention aims to problems of the prior art and defect, there is provided a kind of simple and practical, logical
Cross the safe current less than 1A and just can safely, accurately and fast find the large-sized water turbine of generator stator ground trouble point and send out
The safe lookup method of motor stator earth fault.
To achieve these goals, technical scheme below present invention employs：
A kind of safe lookup method of large-sized water turbine generator Stator ground fault, sets large-sized water turbine generator per 3 branches of phase,
10 bars of each branch, and number consecutively 1,2 ..., 9,10（Every general 8 or so, the phase branch of large-sized water turbine generator,
Per branch's about 52 bars of bar, it is assumed herein that being for clear narration technical solution of the present invention, the restriction of protection domain is not done,
In actual implementation process, can be numbered according to practical situation）；Comprise the following steps：
（1）Prepare 50V DC source, 200 Ω current-limiting resistances, three 0.25A ammeters, a switch and two with
Open C T that electromotor bar size matches（Current transformer）；Described open C T is provided with 25 layers of iron core, secondary side coiling
15 circles；
（2）Untie generator outlet A, B, C three-phase head end to be flexible coupling, pull open neutral point isolating switch, untie electromotor A, B, C three-phase tail
End is flexible coupling；Using each phase insulation resistance of 2500V megameter measurement electromotor, earth fault phase is determined；
（3）Connect DC power supply circuit in the head end of earth fault phase, specially：The positive terminal of 50V DC source is connect
The head end of earth fault phase, the negative pole end of 50V DC source, switch, current-limiting resistance, the negative terminal of a 0.25A ammeter are gone here and there successively
Connection；The positive ending grounding of 0.25A ammeter（Ground connection can be treated as being connected with fault ground herein）；
（4）The secondary side line of two open C T is connected with two other 0.25A ammeter respectively, then the two is open
CT is placed into the upper end of branch's Line 1 rod of earth fault phase, closes the switch of DC power supply circuit, observes the two
Whether the pointer deflection of 0.25A ammeter is consistent, if inconsistent, by secondary side line and the 0.25A of one of open C T
The wiring of ammeter is exchanged, and is partial to the pointer of the two 0.25A ammeters consistent, is then glued on the top of the two open C T
Patch red-label；
（5）Using step（4）Open C T that adjusts mutually carries out detection and searches at earth fault, specially to earth fault：
First, the two open C T are individually positioned at Line 1 rod and No. 10 line rod of one of branch, observe and opening
The pointer deflection of the 0.25A ammeter that CT is connected, determines earth fault branch；
Between the odd number bar of the non-faulting branch in earth fault phase, the sense of current is consistent, the sense of current one between even number bar
Cause, the sense of current between odevity bar conversely, thus can determine that, when the sense of current of Line 1 rod and No. 10 line rod is contrary, should
Ungrounded fault branch is branched into, conversely, this branches into earth fault branch；
Then, it is determined that after earth fault branch, one of open C T is placed in other bars, observation is with open C T-phase even
The pointer deflection of the 0.25A ammeter for connecing, determines earth point according to following logic：
1. in earth fault branch, the odd number bar in branch and the inconsistent person of the Line 1 rod sense of current, then earth point is at this
Before individual bar；Odd number bar in branch person identical with the Line 1 rod sense of current, then earth point is after this bar
Face；
2. in earth fault branch, the even number bar in branch and the inconsistent person of the Line 1 rod sense of current, then earth point is at this
After individual bar；Even number bar in branch person identical with the Line 1 rod sense of current, then earth point is before this bar
Face；
3., in earth fault branch, certain bar upper end is with the bottom sense of current conversely, then bar ground connection；
4., in earth fault branch, while downwards, then their bottom is grounded certain 2 adjacent bar upper and lower end parts electric currents；
5., in earth fault branch, while upwards, then their upper end is grounded certain 2 adjacent bar upper and lower end parts electric currents.
Advantages of the present invention：
1. employing 50V DC source and detection electric current is provided, the electric current of stator bar is flowed through less than 1A, it is possible to safe, smart
Really, generator stator ground trouble point is quickly found.
2. search in failure process whole, it is not necessary to sawed-off each branch's bar tail end, reduce sawed-off, welding extensive work
Amount, can also avoid welding the risk that heating brings.
Description of the drawings
Fig. 1 is the structural representation of one embodiment of the invention split shed CT.
Fig. 2 is the circuit diagram being grounded in the middle part of bar in one embodiment of the invention.
Fig. 3 is the circuit diagram of bar bottom ground connection in one embodiment of the invention.
Fig. 4 is the circuit diagram of bar upper end ground connection in one embodiment of the invention.
In figure arrow is the sense of current.
Specific embodiment
The present invention is further described with reference to the accompanying drawings and examples.
Embodiment：
A kind of safe lookup method of large-sized water turbine generator Stator ground fault, as illustrated, set large-sized water turbine generator per
3 branches of phase, 10 bars of each branch, and number consecutively 1,2 ..., 9,10（Large-sized water turbine generator is per phase branch one
As 8 or so, per branch about 52 bars of bar, it is assumed herein that being for clear narration technical solution of the present invention, do not protect
The restriction of scope, in actual implementation process, can be numbered according to practical situation）；Comprise the following steps：
（1）Prepare 50V DC source, 200 Ω current-limiting resistances, three 0.25A ammeters, a switch and two with
Open C T that electromotor bar size matches（Current transformer）；Described open C T is provided with 25 layers of iron core, secondary side coiling
15 circles；
（2）Untie generator outlet A, B, C three-phase head end to be flexible coupling, pull open neutral point isolating switch, untie electromotor A, B, C three-phase tail
End is flexible coupling；Using each phase insulation resistance of 2500V megameter measurement electromotor, earth fault phase is determined；
（3）Connect DC power supply circuit in the head end of earth fault phase, specially（As shown in Figure 2, Figure 3, Figure 4）：By 50V direct current
The head end of the positive terminal connection earth fault phase of power supply, the negative pole end of 50V DC source, switch, current-limiting resistance, a 0.25A
The negative terminal of ammeter is sequentially connected in series；The positive ending grounding of 0.25A ammeter（Ground connection can be treated as being connected with fault ground herein）；
（4）The secondary side line of two open C T is connected with two other 0.25A ammeter respectively, then the two is open
CT is placed into the upper end of branch's Line 1 rod of earth fault phase（At A in Fig. 2）, the switch of DC power supply circuit is closed,
Whether the pointer deflection for observing the two 0.25A ammeters is consistent, if inconsistent, by the secondary side of one of open C T
Line is exchanged with the wiring of 0.25A ammeter, is partial to the pointer of the two 0.25A ammeters consistent, is then open at the two
Red-label is pasted on the top of CT；
（5）Using step（4）Open C T that adjusts mutually carries out detection and searches at earth fault, specially to earth fault：
First, the two open C T are individually positioned at Line 1 rod and No. 10 line rod of one of branch, observe and opening
The pointer deflection of the 0.25A ammeter that CT is connected, determines earth fault branch；
Between the odd number bar of the non-faulting branch in earth fault phase, the sense of current is consistent, the sense of current one between even number bar
Cause, the sense of current between odevity bar conversely, thus can determine that, when the sense of current of Line 1 rod and No. 10 line rod is contrary, should
Ungrounded fault branch is branched into, conversely, this branches into earth fault branch；
Then, it is determined that after earth fault branch, one of open C T is placed in other bars, observation is with open C T-phase even
The pointer deflection of the 0.25A ammeter for connecing, determines earth point according to following logic：
1. in earth fault branch, the odd number bar in branch and the inconsistent person of the Line 1 rod sense of current, then earth point is at this
Before individual bar；Odd number bar in branch person identical with the Line 1 rod sense of current, then earth point is after this bar
Face；
2. in earth fault branch, the even number bar in branch and the inconsistent person of the Line 1 rod sense of current, then earth point is at this
After individual bar；Even number bar in branch person identical with the Line 1 rod sense of current, then earth point is before this bar
Face；
3., in earth fault branch, certain bar upper end is with the bottom sense of current conversely, then bar ground connection, such as Fig. 2
Shown；
4., in earth fault branch, while downwards, then their bottom is grounded certain 2 adjacent bar upper and lower end parts electric currents,
As shown in Figure 3；
5., in earth fault branch, while upwards, then their upper end is grounded certain 2 adjacent bar upper and lower end parts electric currents,
As shown in Figure 4.
Claims (1)
1. a kind of safe lookup method of large-sized water turbine generator Stator ground fault, sets large-sized water turbine generator per 3 points of phase
, 10 bars of each branch, and number consecutively 1,2 ..., 9,10；Characterized in that, comprising the following steps：
（1）Prepare 50V DC source, 200 Ω current-limiting resistances, three 0.25A ammeters, a switch and two with
Open C T that electromotor bar size matches；Described open C T is provided with 25 layers of iron core, 15 circle of secondary side coiling；
（2）Untie generator outlet A, B, C three-phase head end to be flexible coupling, pull open neutral point isolating switch, untie electromotor A, B, C three-phase tail
End is flexible coupling；Using each phase insulation resistance of 2500V megameter measurement electromotor, earth fault phase is determined；
（3）Connect DC power supply circuit in the head end of earth fault phase, specially：The positive terminal of 50V DC source is connect
The head end of earth fault phase, the negative pole end of 50V DC source, switch, current-limiting resistance, the negative terminal of a 0.25A ammeter are gone here and there successively
Connection；The positive ending grounding of 0.25A ammeter；
（4）The secondary side line of two open C T is connected with two other 0.25A ammeter respectively, then the two is open
CT is placed into the upper end of branch's Line 1 rod of earth fault phase, closes the switch of DC power supply circuit, observes the two
Whether the pointer deflection of 0.25A ammeter is consistent, if inconsistent, by secondary side line and the 0.25A of one of open C T
The wiring of ammeter is exchanged, and is partial to the pointer of the two 0.25A ammeters consistent, is then glued on the top of the two open C T
Patch red-label；
（5）Using step（4）Open C T that adjusts mutually carries out detection and searches at earth fault, specially to earth fault：
First, the two open C T are individually positioned at Line 1 rod and No. 10 line rod of one of branch, observe and opening
The pointer deflection of the 0.25A ammeter that CT is connected, determines earth fault branch；
Between the odd number bar of the non-faulting branch in earth fault phase, the sense of current is consistent, the sense of current one between even number bar
Cause, the sense of current between odevity bar conversely, thus can determine that, when the sense of current of Line 1 rod and No. 10 line rod is contrary, should
Ungrounded fault branch is branched into, conversely, this branches into earth fault branch；
Then, it is determined that after earth fault branch, one of open C T is placed in other bars, observation is with open C T-phase even
The pointer deflection of the 0.25A ammeter for connecing, determines earth point according to following logic：
1. in earth fault branch, the odd number bar in branch and the inconsistent person of the Line 1 rod sense of current, then earth point is at this
Before individual bar；Odd number bar in branch person identical with the Line 1 rod sense of current, then earth point is after this bar
Face；
2. in earth fault branch, the even number bar in branch and the inconsistent person of the Line 1 rod sense of current, then earth point is at this
After individual bar；Even number bar in branch person identical with the Line 1 rod sense of current, then earth point is before this bar
Face；
3., in earth fault branch, certain bar upper end is with the bottom sense of current conversely, then bar ground connection；
4., in earth fault branch, while downwards, then their bottom is grounded certain 2 adjacent bar upper and lower end parts electric currents；
5., in earth fault branch, while upwards, then their upper end is grounded certain 2 adjacent bar upper and lower end parts electric currents.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610940461.6A CN106443302B (en) | 2016-11-02 | 2016-11-02 | A kind of safe lookup method of large-sized water turbine generator Stator ground fault |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610940461.6A CN106443302B (en) | 2016-11-02 | 2016-11-02 | A kind of safe lookup method of large-sized water turbine generator Stator ground fault |
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| CN106443302B CN106443302B (en) | 2019-09-06 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110618343A (en) * | 2019-09-30 | 2019-12-27 | 广西桂冠电力股份有限公司 | Device and method for searching generator stator bar ground fault point |
| CN111650533A (en) * | 2020-06-15 | 2020-09-11 | 国家电网有限公司 | Searching method of rotor magnetic pole grounding point searching instrument |
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| US7253634B1 (en) * | 2006-03-31 | 2007-08-07 | General Electric Company | Generator protection methods and systems self-tuning to a plurality of characteristics of a machine |
| CN101295004A (en) * | 2007-04-24 | 2008-10-29 | 许继集团有限公司 | Method for judging single-phase grounding fault point position of generator stator winding |
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| CN102508119A (en) * | 2011-12-09 | 2012-06-20 | 江苏镇安电力设备有限公司 | Method for positioning earth faults of parallel loop of IT (Isolation-Terre) power system |
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| US9236726B2 (en) * | 2012-08-21 | 2016-01-12 | Alliant Energy Corporate Services, Inc. | Methods for providing generator stator winding ground fault protection |
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2016
- 2016-11-02 CN CN201610940461.6A patent/CN106443302B/en not_active Expired - Fee Related
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| US7253634B1 (en) * | 2006-03-31 | 2007-08-07 | General Electric Company | Generator protection methods and systems self-tuning to a plurality of characteristics of a machine |
| CN101295004A (en) * | 2007-04-24 | 2008-10-29 | 许继集团有限公司 | Method for judging single-phase grounding fault point position of generator stator winding |
| CN101719657A (en) * | 2009-12-24 | 2010-06-02 | 中国电力科学研究院 | System and method for simulating internal fault of electric generator |
| CN102508119A (en) * | 2011-12-09 | 2012-06-20 | 江苏镇安电力设备有限公司 | Method for positioning earth faults of parallel loop of IT (Isolation-Terre) power system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110618343A (en) * | 2019-09-30 | 2019-12-27 | 广西桂冠电力股份有限公司 | Device and method for searching generator stator bar ground fault point |
| CN111650533A (en) * | 2020-06-15 | 2020-09-11 | 国家电网有限公司 | Searching method of rotor magnetic pole grounding point searching instrument |
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| Publication number | Publication date |
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| CN106443302B (en) | 2019-09-06 |
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