CN201774233U - Novel protection device special for low voltage generator - Google Patents
Novel protection device special for low voltage generator Download PDFInfo
- Publication number
- CN201774233U CN201774233U CN2010205039965U CN201020503996U CN201774233U CN 201774233 U CN201774233 U CN 201774233U CN 2010205039965 U CN2010205039965 U CN 2010205039965U CN 201020503996 U CN201020503996 U CN 201020503996U CN 201774233 U CN201774233 U CN 201774233U
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- generator
- neutral point
- zero sequence
- sequence current
- low voltage
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Abstract
The utility model discloses a novel protection device special for a low voltage generator. The device comprises a neutral point lead, wherein the neutral point lead is connected with a neutral point of a three-phase winding of the generator and an impeder; the impeder is connected with a neutral line zero sequence current transformer; the neutral line zero sequence current transformer is connected with a generator metal shell; a low voltage bus which is connected with the three-phase winding of the generator is connected with an outgoing line breaker; the outgoing line breaker is connected with an outgoing line zero sequence current transformer; and the outgoing line zero sequence current transformer is connected with a line. The device has a rational structure, obvious using effect and reliable performance and is easy to maintain, so the device has great practical value and popularization value.
Description
Technical field:
It is main low compression engine protective device for the three-phase power set that the utility model relates to a kind of.
Background technology:
At present, also there is the situation of damaging generator because of thunderbolt in lightning arrester as protection though special-purpose low voltage generator is in operation; Single-phase earthing taking place can detect ground signalling, but can not locate, more can not search the fault point, can not adopt preferred protected mode; For the long system of cable, because of earthing capacitance current is bigger, electric arc is difficult to extinguish automatically, brings harm to operation; Single-phase earthing relies on and manually draws the road to check that not only time-consuming, particularly winding discharges to iron core, and the time one is long, the safety of its people of entail dangers to and equipment.So be necessary to adopt a kind of novel earthing mode and protective device, the background of the utility model generation that Here it is.
Summary of the invention:
It is a kind of rational in infrastructure that the purpose of this utility model is to provide, the novel protector of intelligentized special-purpose low voltage generator.
Technical solution of the present utility model is:
A kind of novel protector of special-purpose low voltage generator; it is characterized in that: comprise the neutral point lead-in wire; the neutral point lead-in wire is connected with the neutral point of three phase windings of generator; the neutral point lead-in wire is connected with impedor; impedor is connected with neutral line zero sequence current mutual inductor; neutral line zero sequence current mutual inductor is connected with the generator metal shell; the low-voltage bus bar that is connected with generator three phase windings is connected with the outlet circuit breaker; the outlet circuit breaker is connected with the outlet zero sequence current mutual inductor, and the outlet zero sequence current mutual inductor is connected with circuit.
Described impedor is the low pressure impedor.The resistance of impedor is 55～690 Ω.
Described neutral point lead-in wire is connected with the neutral point of three phase windings of generator and is meant that the neutral point that neutral point goes between with generator three phase windings are connected into the Y wiring is connected.
The utility model is rational in infrastructure, and result of use is remarkable, dependable performance, and easy care is so there is very big practical and popularizing value.Three phase windings of generator are connected into the Y type, and its neutral point inserts impedor, when taking place to bring into play its speciality behind the circuit single-phase earthing, promptly increase earth current, can correctly select faulty line, the zero-sequenceprotection of the locking neutral line, and can press the safety requirements grade employing priority protection that circuit moves, guarantee the visual plant safe operation; Use neutral line zero-sequenceprotection action can prevent that the iron core of generator is because of the damage of winding earth to iron core; It is that wherein the high resistance arc light during to ground connection plays inhibitory action that high resistance grounding also has characteristics; Another characteristics of high resistance grounding are that the neutral point current potential of winding is just often keeping equipotential with the generator metal shell, and generator casing can not produce counterattack to winding because of the following high potential of letting out generation of lightning current during thunderbolt.
The utility model links to each other with impedor owing to generator windings three-phase neutral point, the neutral point current potential is equated with the generator metal shell, when thunderbolt occurring, when generator metal shell current potential raises, the neutral point current potential of generator windings also raises simultaneously, potential difference between generator windings and its metal shell is the voltage to earth of generator windings only, thereby has avoided the damage of generator windings; At low pressure isolated neutral system generation single-phase earthing, less because of earthing capacitance current, detection of ground faults is difficulty comparatively, adopts neutral point behind impedance earth, flows through the electric current I=I of impedor
R+ I
L, its I
LCan compensate the capacitance current I of a part of low-pressure system
COutward, I wherein
RWith I
CSynthetic electric current is greater than former I
CElectric current is easy to be detected by outlet F0CT, if single-phase earthing takes place; then outlet F0CT sends ground signalling, and the N0CT to generator neutral point protects locking simultaneously, but outlet ground connection long-play; be convenient to fix a breakdown, also can carry out timing protection tripping operation by the importance of circuit.If single-phase earthing takes place between generator windings-bus, then the N0CT of the generator neutral line takes to select the protection tripping operation, has protected generator windings that iron core is discharged like this, avoids long-time ground connection to form damage to iron core; Owing to adopt the generator neutral point impedance earth,, also can reduce the electric arc flashover fault because of bigger resistance value is arranged; Adopt portable zero sequence current mutual inductor to search, easily find the fault point according to the variation of its electric current by the fault outlet.Therefore, the utility model earthing mode has been strengthened the reliability and stability of power transmitting device.
Description of drawings:
The utility model is described in further detail below in conjunction with drawings and Examples.
Fig. 1 is the configuration diagram of an embodiment of the utility model.
Embodiment:
A kind of novel protector of special-purpose low voltage generator; comprise neutral point lead-in wire (L) 1; the neutral point lead-in wire is connected with the neutral point of three phase windings of generator (M); the neutral point lead-in wire is connected with impedor (Z) 2; impedor is connected with neutral line zero sequence current mutual inductor (N0CT) 3; neutral line zero sequence current mutual inductor is connected with generator metal shell 5; the low-voltage bus bar 6 that is connected with generator three phase windings 9 is connected with outlet circuit breaker (B) 7; the outlet circuit breaker is connected with outlet zero sequence current mutual inductor (F0CT) 4, and outlet zero sequence current mutual inductor 4 is connected with circuit (F) 8.
Described impedor is the low pressure impedor, and the resistance of impedor is 55～690 Ω.
Described neutral point lead-in wire is connected with the neutral point of three phase windings of generator and is meant that the neutral point that neutral point goes between with generator three phase windings are connected into the Y wiring is connected.
Also has generator master switch 10 among the figure.
In service, when single-phase earthing took place, as in the outlet side fault being arranged, then outlet zero sequence current mutual inductor (F0CT) detected the zero-sequence current increase, can send ground signalling, and the zero-sequenceprotection of the locking neutral line, the generating function is normally moved, and the operations staff can hold portable zero sequence current mutual inductor trouble-shooting point, and eliminate it, or by the automatic trip automatically then of protection definite value, owing to contain bigger resistance value in the impedor, the automatic blow-out of single-phase earthing electric arc meeting; As earth fault between winding is to iron core or winding between low-voltage bus bar, take speed to cut protection usually, to guarantee the safety of generator core.During thunderbolt, the generator metal shell can produce higher current potential, easily generator windings is produced counterattack, and generator windings is behind high resistance grounding, because of winding neutral point and metal shell are idiostatic, just avoided of the counterattack of generator metal shell high potential to winding.
Claims (4)
1. the novel protector of a special-purpose low voltage generator; it is characterized in that: comprise the neutral point lead-in wire; the neutral point lead-in wire is connected with the neutral point of three phase windings of generator; the neutral point lead-in wire is connected with impedor; impedor is connected with neutral line zero sequence current mutual inductor; neutral line zero sequence current mutual inductor is connected with the generator metal shell; the low-voltage bus bar that is connected with generator three phase windings is connected with the outlet circuit breaker; the outlet circuit breaker is connected with the outlet zero sequence current mutual inductor, and the outlet zero sequence current mutual inductor is connected with circuit.
2. the novel protector of special-purpose low voltage generator according to claim 1, it is characterized in that: described impedor is the low pressure impedor.
3. the novel protector of special-purpose low voltage generator according to claim 2, it is characterized in that: the resistance of impedor is 55～690 Ω.
4. according to the novel protector of claim 1,2 or 3 described special-purpose low voltage generators, it is characterized in that: described neutral point lead-in wire is connected with the neutral point of three phase windings of generator and is meant that the neutral point that neutral point goes between with generator three phase windings are connected into the Y wiring is connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205039965U CN201774233U (en) | 2010-08-25 | 2010-08-25 | Novel protection device special for low voltage generator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205039965U CN201774233U (en) | 2010-08-25 | 2010-08-25 | Novel protection device special for low voltage generator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201774233U true CN201774233U (en) | 2011-03-23 |
Family
ID=43754070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010205039965U Expired - Fee Related CN201774233U (en) | 2010-08-25 | 2010-08-25 | Novel protection device special for low voltage generator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201774233U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107947493A (en) * | 2017-11-23 | 2018-04-20 | 中国电建集团华东勘测设计研究院有限公司 | A kind of generator neutral point earthing or grounding means and parameter selection method |
| CN108832745A (en) * | 2018-06-20 | 2018-11-16 | 安徽美芝精密制造有限公司 | The electric machine assembly and compressor of compressor |
| CN111127987A (en) * | 2020-01-15 | 2020-05-08 | 西安热工研究院有限公司 | Simulation model for calculating transmission overvoltage of generator-transformer set in PSCAD (power system computer aided design) |
-
2010
- 2010-08-25 CN CN2010205039965U patent/CN201774233U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107947493A (en) * | 2017-11-23 | 2018-04-20 | 中国电建集团华东勘测设计研究院有限公司 | A kind of generator neutral point earthing or grounding means and parameter selection method |
| CN107947493B (en) * | 2017-11-23 | 2023-06-23 | 中国电建集团华东勘测设计研究院有限公司 | Neutral point grounding device of generator and parameter selection method |
| CN108832745A (en) * | 2018-06-20 | 2018-11-16 | 安徽美芝精密制造有限公司 | The electric machine assembly and compressor of compressor |
| CN111127987A (en) * | 2020-01-15 | 2020-05-08 | 西安热工研究院有限公司 | Simulation model for calculating transmission overvoltage of generator-transformer set in PSCAD (power system computer aided design) |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110323 Termination date: 20120825 |