CN105870892A - Line protection method capable of avoiding closing inrush current - Google Patents
Line protection method capable of avoiding closing inrush current Download PDFInfo
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- CN105870892A CN105870892A CN201610285998.3A CN201610285998A CN105870892A CN 105870892 A CN105870892 A CN 105870892A CN 201610285998 A CN201610285998 A CN 201610285998A CN 105870892 A CN105870892 A CN 105870892A
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- current
- inrush
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
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- Emergency Protection Circuit Devices (AREA)
Abstract
The invention relates to a line protection method capable of avoiding closing inrush current. Identification of second harmonics is adopted as the main criterion, and the opening time of inrush identification of the characteristics of closing inrush current of a 10 kV line is set as 1 s. The method has the advantages that the magnitude and main characteristics of closing inrush current are analyzed with test data; it is proposed that the inrush identification criterion is added in I-stage overcurrent protection or instantaneous overcurrent protection according to the reason for false action of a microprocessor protection device on closing inrush current, so that false action generated in line protection in initial operation of the line is greatly reduced, impact of false action on primary equipment and secondary equipment is avoided, and the method has an obvious effect in production field application.
Description
Technical field
The invention belongs to relay protection circuit protection field, particularly relate to a kind of line protection method that can escape inrush phenomenon.
Background technology
By repeatedly there is instantaneous over-current protection misoperation, line tripping situation, and by after line sectionalizing power transmission, power transmission is successful
Analysis without exception；By carrying out switching current test to allotting circuit at the scene, find in making process, there is the biggest conjunction
Lock shoves.It is complicated that 10kV allots line construction, is connected to small capacity transformer quantity many, produces when closing a floodgate and shoves, and
Exceed and crossed stream I section or instantaneous over-current definite value.Owing to microcomputer protecting device measurement sensitivity is the highest, common method is in quick-break
Add time delay in protection to arrange.But this kind of method is likely to malfunction at the circuit crossing stream I section definite value less, loses quickly simultaneously
The ability of excision fault, impacts equipment.By carrying out switching current test to allotting circuit at the scene, find closing
The biggest inrush phenomenon is there is during lock.The size of inrush phenomenon and key property, analyze by test data analysis
The microcomputer protecting device reason to inrush phenomenon malfunction.Propose the way that route protection is improved, and apply in production scene,
Effect is obvious.
Summary of the invention
For overcoming the deficiencies in the prior art, it is an object of the invention to provide a kind of line protection method that can escape inrush phenomenon,
Use and identify that second harmonic, as main criterion, can automatically engage the fast tripping protection of inrush current distinguishing criterion and cross the protection of stream I section.
For achieving the above object, the present invention is achieved through the following technical solutions:
A kind of line protection method that can escape inrush phenomenon, uses and identifies that second harmonic is as main criterion, inrush current distinguishing
The open hour of 10kV circuit inrush phenomenon characteristic are set as 1s, and concrete operations are:
Receive combined floodgate order time, protection device automatically engages the fast tripping protection with inrush current distinguishing, it is to avoid route protection because
The circuit overcurrent excessive misoperation caused when combined floodgate；Inrush current distinguishing criterion uses second harmonic and waveform symmetry principle locking；
Concrete employing overcurrent protection I section or fast tripping protection.
Second harmonic lock-out scheme in the inrush current distinguishing criterion used: use the secondary harmonic component in electric current to identify excitation
Shove, it determines equation is as follows:
IOP·2>K2*IOP·1 (1)
In formula: IOP·2For the second harmonic in electric current, IOP·1For the first-harmonic in electric current, K2For the second harmonic coefficient adjusted；
If certain phase current meets above formula, then locking fast tripping protection, three-phase split-phase locking；
Waveform symmetry principle differentiation scheme in the inrush current distinguishing criterion used:
Front half cycle and the second half of differential after current waveform are carried out symmetry and compare；If certain point on the front half cycle of differential current
Value be I 'i, the value of second half corresponding point isDefinition waveform symmetry criterion formula is:
In formula, K is degree of asymmetry；
If I 'iWithIn opposite direction, the most referred to as direction is symmetrical；Identical then referred to as direction is asymmetric；The asymmetric ripple in direction
Shape is unsatisfactory for formula (2)；Comparing the sampled point of half period continuously, to fault current, formula (2) perseverance is false；Excitation is gushed
Stream waveform, point more than 1/4 cycle meets formula (2)；
Determine excitation surge current then locking fast tripping protection, three-phase split-phase locking.
Described K value 0.4.
Compared with prior art, the invention has the beneficial effects as follows:
By size and the key property of test data analysis inrush phenomenon.For microcomputer protecting device to inrush phenomenon malfunction
Reason, proposes adding inrush current distinguishing criterion in overcurrent protection I section or fast tripping protection, when circuit is greatly reduced because initially putting into operation,
Misoperation produced by route protection, it is to avoid misoperation to once and secondary device produce impact, production scene apply,
Effect is obvious.
Detailed description of the invention
Below the present invention is described in detail, it should be noted that the enforcement of the present invention is not limited to following embodiment.
In the inrush phenomenon of 10kV circuit, second harmonic current accounts for leading part, therefore uses and identifies that second harmonic is as master
Wanting criterion, 10kV circuit overcurrent characteristic is basically identical with single transformer excitation surge current characteristic, but the rate of decay of shoving is faster than
The single transformer excitation surge current rate of decay, typically returns to normal value at about 1s.So, inrush current distinguishing 10kV circuit
The open hour of inrush phenomenon characteristic are set as 1s.But owing to there is line mutual-ground capacitor impact, it is the least that electric current raises multiple
In the excitation surge current multiple of single transformer, inrush phenomenon is typically not over 10 times of normal duty electric current, so the short time
Inrush phenomenon is the least on the impact of equipment, not over the class of insulation of equipment.
By size and the key property of test data analysis inrush phenomenon.For the protection device reason to inrush phenomenon malfunction,
Propose overcurrent protection I section or fast tripping protection add inrush current distinguishing criterion.
Concrete operations are: when receiving combined floodgate order, protection device automatically engages the fast tripping protection with inrush current distinguishing, it is to avoid
Route protection is because of the circuit overcurrent excessive misoperation caused when closing a floodgate；Inrush current distinguishing criterion uses second harmonic and waveform pair
Claim principle locking；Concrete employing overcurrent protection I section or fast tripping protection.
Second harmonic lock-out scheme in the inrush current distinguishing criterion used: use the secondary harmonic component in electric current to identify that excitation is gushed
Stream, it determines equation is as follows:
IOP·2>K2*IOP·1 (1)
In formula: IOP·2For the second harmonic in electric current, IOP·1For the first-harmonic in electric current, K2For the second harmonic coefficient adjusted；
If certain phase current meets above formula, then locking fast tripping protection, three-phase split-phase locking；
Waveform symmetry principle differentiation scheme in the inrush current distinguishing criterion used:
Front half cycle and the second half of differential after current waveform are carried out symmetry and compare；If certain point on the front half cycle of differential current
Value be I 'i, the value of second half corresponding point isDefinition waveform symmetry criterion formula is:
In formula, K is degree of asymmetry, K value 0.4.
If I 'iWithIn opposite direction, the most referred to as direction is symmetrical；Identical then referred to as direction is asymmetric；The asymmetric ripple in direction
Shape is unsatisfactory for formula (2)；Comparing the sampled point of half period continuously, to fault current, formula (2) perseverance is false；Excitation is gushed
Stream waveform, point more than 1/4 cycle meets formula (2)；
Determine excitation surge current then locking fast tripping protection, three-phase split-phase locking.
The present invention passes through size and the key property of test data analysis inrush phenomenon.For microcomputer protecting device to inrush phenomenon
The reason of malfunction, proposes, to adding inrush current distinguishing criterion in overcurrent protection I section or fast tripping protection, circuit to be greatly reduced because of initial
When putting into operation, misoperation produced by route protection, it is to avoid misoperation is to once and the impact that produces of secondary device, existing producing
Field application, effect is obvious.
Claims (4)
1. the line protection method that can escape inrush phenomenon, it is characterised in that using and identify that second harmonic is set as 1s as main criterion, the open hour of inrush current distinguishing 10kV circuit inrush phenomenon characteristic, concrete operations are:
When receiving combined floodgate order, protection device automatically engages the fast tripping protection with inrush current distinguishing, it is to avoid route protection is because of the circuit overcurrent excessive misoperation caused when closing a floodgate；Inrush current distinguishing criterion uses second harmonic and waveform symmetry principle locking；Concrete employing overcurrent protection I section or fast tripping protection.
A kind of line protection method that can escape inrush phenomenon the most according to claim 1; it is characterized in that; second harmonic lock-out scheme in the inrush current distinguishing criterion used: use the secondary harmonic component in electric current to identify excitation surge current, it determines equation is as follows:
IOp · 2>K2*IOP · 1 (1)
In formula: IOP · 2For the second harmonic in electric current, IOP · 1For the first-harmonic in electric current, K2For the second harmonic coefficient adjusted；
If certain phase current meets above formula, then locking fast tripping protection, three-phase split-phase locking.
A kind of line protection method that can escape inrush phenomenon the most according to claim 1, it is characterised in that waveform symmetry principle differentiation scheme in the inrush current distinguishing criterion used:
Front half cycle and the second half of differential after current waveform are carried out symmetry and compare；If the value of certain point is I ' on the front half cycle of differential currenti, the value of second half corresponding point isDefinition waveform symmetry criterion formula is:
In formula, K is degree of asymmetry；
If I 'iWithIn opposite direction, the most referred to as direction is symmetrical；Identical then referred to as direction is asymmetric；The asymmetric waveform in direction is unsatisfactory for formula (2)；Comparing the sampled point of half period continuously, to fault current, formula (2) perseverance is false；Excitation surge current waveform, point more than 1/4 cycle meets formula (2)；
Determine excitation surge current then locking fast tripping protection, three-phase split-phase locking.
A kind of line protection method that can escape inrush phenomenon the most according to claim 3, it is characterised in that described K value 0.4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610285998.3A CN105870892A (en) | 2016-04-29 | 2016-04-29 | Line protection method capable of avoiding closing inrush current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610285998.3A CN105870892A (en) | 2016-04-29 | 2016-04-29 | Line protection method capable of avoiding closing inrush current |
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| Publication Number | Publication Date |
|---|---|
| CN105870892A true CN105870892A (en) | 2016-08-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610285998.3A Pending CN105870892A (en) | 2016-04-29 | 2016-04-29 | Line protection method capable of avoiding closing inrush current |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113964785A (en) * | 2021-11-23 | 2022-01-21 | 贵州电网有限责任公司 | Method for solving reclosing of switch influenced by inrush current of transformer |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1929229A (en) * | 2006-08-17 | 2007-03-14 | 江苏省电力试验研究院有限公司 | New magneting inrush current recognition method adapted for large-scale power transformer additional with phase discrimination |
| CN101764391A (en) * | 2009-08-20 | 2010-06-30 | 北京四方继保自动化股份有限公司 | Method and system for braking magnetizing inrush current in differential protection of ultra-high voltage transformer |
| CN104319736A (en) * | 2014-10-17 | 2015-01-28 | 许继集团有限公司 | Differential protection method for extra-high voltage transformer |
| US20150204918A1 (en) * | 2012-08-31 | 2015-07-23 | Siemens Aktiengesellschaft | Magnetizing inrush current detection method, magnetizing inrush current restraint method and device |
-
2016
- 2016-04-29 CN CN201610285998.3A patent/CN105870892A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1929229A (en) * | 2006-08-17 | 2007-03-14 | 江苏省电力试验研究院有限公司 | New magneting inrush current recognition method adapted for large-scale power transformer additional with phase discrimination |
| CN101764391A (en) * | 2009-08-20 | 2010-06-30 | 北京四方继保自动化股份有限公司 | Method and system for braking magnetizing inrush current in differential protection of ultra-high voltage transformer |
| US20150204918A1 (en) * | 2012-08-31 | 2015-07-23 | Siemens Aktiengesellschaft | Magnetizing inrush current detection method, magnetizing inrush current restraint method and device |
| CN104319736A (en) * | 2014-10-17 | 2015-01-28 | 许继集团有限公司 | Differential protection method for extra-high voltage transformer |
Non-Patent Citations (1)
| Title |
|---|
| 秦俊敏: "10kV配网中变压器励磁涌流分析控制", 《中国高新技术企业》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113964785A (en) * | 2021-11-23 | 2022-01-21 | 贵州电网有限责任公司 | Method for solving reclosing of switch influenced by inrush current of transformer |
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Application publication date: 20160817 |
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