CN107591784B - A kind of distribution statements based on collusion adaptive incomplete differential protection method of route - Google Patents
A kind of distribution statements based on collusion adaptive incomplete differential protection method of route Download PDFInfo
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- CN107591784B CN107591784B CN201710727617.7A CN201710727617A CN107591784B CN 107591784 B CN107591784 B CN 107591784B CN 201710727617 A CN201710727617 A CN 201710727617A CN 107591784 B CN107591784 B CN 107591784B
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Abstract
A kind of distribution statements based on collusion adaptive incomplete differential protection method of route.The protection scope of line related differential protection is identified according to DTU communications status: the corresponding magnitude of current being selected to participate in the calculating of line differential protection; it chooses whether using the breaker to be tripped when not exclusively expanding Differential Protection Theory, and selecting corresponding breaker as differential protection movement.Basis presets principle simultaneously; select the setting method of difference current definite value, differential action time definite value; to realize the failure differential positioning entirely of entire distribution area protection system; fast power restoration provides strong guarantee after accessing the quick and precisely fault location and failure of distribution network systems for clean energy resource distribution.
Description
Technical field
The invention belongs to relay protection of power system and automatic field, and in particular to be applied to distribution area protection system
In, a kind of adaptive incomplete differential protection method of statements based on collusion route.
Background technique
With the continuous continuous variation increased with urban power distribution network rack of new energy access power distribution network demand, lead to looped network
Even the case where multi-ring network power supply, is more and more.Under especially more power conditions, the uncertainty of current direction, so that traditional
Power distribution automation means are no longer satisfied the requirement of the selectivity of distribution network protection, the lance between the quick-action and selectivity of protection
Shield seems more prominent in this case.For matching problem present in troubleshooting mode in part in distribution, match barrier
Domain protection can more easily realize unified matching management as a protection and control system, and main protection and back-up protection are assisted
Allotment is closed, and has very big advantage compared with master station-centralized feeder automation at real-time aspect.When solving line failure
In terms of the problem of cooperating difficult overstepping between breaker, locality protection greatly improves the selectivity of protection and quick-action is wanted
It asks.Area protection system is furnished with differential function, can identify fault point rapidly, then after tripping higher level breaker, then tripping failure
Route bilateral on-load switch, then closes breaker by spare power, with fast recovery of power supply.
For Line Current Differential Protection, it is necessary to which the current information for obtaining each side of protected circuit just can guarantee base
The application of your Hough theorem.Centralized distribution region differential protection depends on the network communication of distribution network terminal (DTU), when some
For DTU there is a situation where communication disruption, line related differential protection cannot obtain the side current information, and differential protection will have to move back
It runs out, brings hidden danger to the safe operation of distribution line.
Summary of the invention
In distribution area protection system, by interconnector Differential Protection Theory between adjacent ring network cabinet, realize that failure is fixed
Position and isolation, once some DTU failure or communication abnormality, then cause the DTU line related differential protection to exit.The present invention provides
A kind of distribution is acted in collusion to make each other's confessions the adaptive incomplete differential protection method of route, to overcome existing distribution region wire differential protection
It is insufficient.
The present invention specifically uses following technical scheme.
A kind of distribution statements based on collusion adaptive incomplete differential protection method of route, in power distribution network, ring network cabinet passes through hand in hand
Mode is connected between two substations, and distribution network terminal device DTU is mounted in each ring network cabinet, and DTU is logical in each ring network cabinet
Cross data communication network interactive simulation amount sampled data；The distribution statements based on collusion route includes the interconnection between adjacent ring network cabinet
Interconnector between road and substation and ring network cabinet；It is characterized in that, the guard method the following steps are included:
(1) this side three-phase current of interconnection between local mounted DTU acquisition ring network cabinet in each ring network cabinet, while each DTU
The electric current and adjacent interconnection opposite side three-phase current of interconnection opposite side are obtained from data communication network；
(2) communications status for judging DTU in each ring network cabinet enters step (3) when DTU communication is normal in each ring network cabinet, when
A certain ring network cabinet DTU communication disruption then enters step (4)；
(3) each route protection unit takes this section of route two sides electric current to carry out differential protection calculating on distribution statements based on collusion route,
If differential protection acts, this route of tripping two sides breaker；
(4) in there are a certain ring network cabinet when DTU communication disruption, the ring network cabinet two sides line differential protection unit across this
The ring network cabinet of DTU communication disruption selects adjacent lines opposite side electric current to input as the differential protection of opposite end, using not exclusively differential
Protection philosophy carries out fault location differentiation, this side of tripping switch and adjacent lines opposite side switch when movement, by Fault Isolation range
It is extended to adjacent lines.
The present invention further comprises following preferred embodiment:
In step (4), when using difference stream definite value self-adaptive sites, difference current definite value need to escape logical across the DTU
Believe the ring network cabinet route poor memory stream interrupted, i.e., its affiliated ring network cabinet two sides route opposite end calculates difference stream before the DTU communication disruption
Value, the setting mode are suitable for the steady situation of ring network cabinet load fluctuation；
When not using difference stream definite value self-adaptive sites, difference current definite value needs to escape the looped network of the DTU communication disruption
The maximum load current of cabinet, the setting mode are suitable for the larger situation of ring network cabinet load fluctuation.
When differential time definite value use quick-action principle when, the not exclusively differential time setting of route be 0s, when occur route or
When bus-bar fault, protection all can quick acting；When differential time definite value is using bus differential protecting actuation time principle is escaped,
The route not exclusively differential time can adjust as 0.2s, if bus-bar fault occurs, bus differential protection action cuts off failure, and route is incomplete
Differential protection is failure to actuate, and second of setting mode needs to consider that 10kV protection for feed line actuation time leaves differential fault location time for
Whether nargin is had.
The invention has the following beneficial technical effects:
Not exclusively expanding differential protection function cannot identify in the interconnector failure occurred in area, bus-bar fault or station
Load line failure, therefore differential action time definite value adjusts and is applicable in two kinds of principles, first, preferential quickly excision and restoration principles,
Above 3 kinds of fault types, short delay quick acting are not distinguished at this time；Second, expand differential protection function and comes as back-up protection
The principle used escapes bus differential protection action time and charge circuit operating time of protection.
The present invention can identify DTU plant failure state and DTU communications status in distribution district system, solve because individual
Plant failure or communication disruption can not application circuit differential protection the problem of, mentioned for the safety and reliable location failure of distribution line
Perfect measure is supplied.
Detailed description of the invention
Fig. 1 is the current differential protection schematic diagram of distribution line；
Fig. 2 is the flow diagram of the application distribution statements based on collusion adaptive incomplete differential protection method of route.
Specific embodiment
The present invention is described in further detail with example with reference to the accompanying drawing.
It is as shown in Figure 1 the current differential protection schematic diagram of the 10kV distribution statements based on collusion route method of operation.The first and second two power transformations
There are multiple ring network cabinets between standing, is respectively provided with the DTU equipment for supporting distribution regional function, the defencive function of configuration includes that interconnection is poor
Dynamic defencive function, bus differential protecting function, charge circuit overcurrent protection function, and adaptive not exclusively expansion differential protection
Function；DTU equipment is interconnected by private data communication network and constitutes " distribution area protection system ", is as shown in the figure the system institute
The minimum wiring scale covered.
Wherein, the interconnector between first ring network cabinet and second ring network cabinet is protected circuit, is line differential protection principle
Protection scope, i.e., " poor 1 " of line in figure；It is got in touch between first ring network cabinet and the third ring network cabinet by second ring network cabinet, is not exclusively poor
The protection scope of dynamic protection philosophy, i.e., " the interconnection L1 between poor the first and second ring network cabinet of 2 " of line, the contact between the third ring network cabinet of second in figure
Line L2 adjacent lines each other.
It is illustrated in figure 2 the process signal of the distribution statements based on collusion adaptive incomplete differential protection method of route disclosed in the present application
Figure, the automatic adaptation not exclusively expand line differential protection method specifically includes the following steps:
By taking the first and second the third 3 ring network cabinets as an example, second ring network cabinet DTU is because communication disruption occurs for failure, with distribution locality protection system
System loses data exchange capability.
Step 1: by the DTU equipment of distribution area protection system, the magnitude of current needed for acquiring differential protection, DTU1 acquires first
Route three-phase current, the DTU3 of route three-phase current, the DTU2 acquisition switch of second ring network cabinet 201 that ring network cabinet 102 switchs acquire third
The route three-phase current that ring network cabinet 301 switchs, and it is sent to private data communication network.Install L1, L2 line differential protection
DTU equipment subscribes to the magnitude of current for obtaining the above acquisition from private data communication network；
Step 2: communications status of the acquisition second ring network cabinet DTU in distribution district system, according to second ring network cabinet DTU in distribution
Communications status in district system chooses whether the adaptive not exclusively expansion differential protection function of investment.DTU device is normal and net
When network communication is normal, the route three-phase current that DTU2 acquisition second ring network cabinet 201 switchs can be obtained, it is believed that second ring network cabinet communicates just
Often, otherwise it is assumed that second ring network cabinet communication abnormality；
Not exclusively expand the difference current definite value and difference of differential protection function according to preset principle self-adaptive sites
Dynamic operating time of protection.
Step 3: when second ring network cabinet DTU communication is normal, as shown in Figure 1, when f1 failure occurs, by first ring network cabinet 102
The differential protection movement for the line current composition that the line current of switch, second ring network cabinet 201 switch, i.e. line in figure poor 1, are protected
Shield and isolation range are route L1；When f2 failure occurs, acted by the bus differential protecting of second ring network cabinet DTU；As generation f3
When failure, acted by the charge circuit overcurrent protection of second ring network cabinet DTU.
Step 4: when second ring network cabinet DTU communication abnormality, which cannot send out our station current information to Local Area Network, line
Poor 1 functional unit is exited because lacking side current data.At this point, investment is adaptive not exclusively to expand differential protection function, first
The line current of line current, the third ring network cabinet 301 switch that ring network cabinet 102 switchs is as differential protection input current, when movement
The switch of tripping 102 and 301 switches, are extended to adjacent lines L2 for protection and isolation range.
Adjusting for difference current definite value, when using difference stream definite value self-adaptive sites, difference current definite value need to be escaped
Across the ring network cabinet route poor memory stream of the DTU communication disruption, i.e., its affiliated ring network cabinet two sides route pair before the DTU communication disruption
End calculates poor flow valuve, as shown in figure 1 calculating difference flow valuve of 102 switches with 301 switches before second ring network cabinet DTU interruption, the adjusting side
Formula is suitable for the steady situation of ring network cabinet load fluctuation；When not using difference stream definite value self-adaptive sites, difference current definite value is needed
The maximum load current of the ring network cabinet of the DTU communication disruption is escaped, as shown in figure 1 the maximum load current of second ring network cabinet, this is whole
Determine the mode situation larger suitable for ring network cabinet load fluctuation.
Adjusting for differential time definite value, when differential time definite value uses quick-action principle, when route is not exclusively differential
Between adjusting be 0s, when route occurring or when bus-bar fault, protection all can quick acting；Bus is escaped when differential time definite value uses
When differential protection actuation time principle, the route not exclusively differential time can be adjusted as 0.2s, if bus-bar fault, bus differential protection occurs
Movement excision failure, route incomplete differential protection are failure to actuate, and second of setting mode needs to consider that 10kV protection for feed line acts
Time leaves whether differential fault location time has nargin for.
Hereafter reclosing is executed by region self-healing logic and turn power supply, to restore fault-free block supply.
Example given above not makees in any form the present invention to illustrate the present invention and its practical application
Limitation, any one professional and technical personnel in the range of without departing from technical solution of the present invention, according to the above technology and
Method makees certain modification and change when the equivalent embodiment for being considered as equivalent variations.
Claims (3)
- A kind of adaptive incomplete differential protection method of route 1. distribution is acted in collusion to make each other's confessions, in power distribution network, ring network cabinet passes through side hand in hand Formula is connected between two substations, distribution network terminal device DTU is mounted in each ring network cabinet, DTU passes through in each ring network cabinet Data communication network interactive simulation amount sampled data；The distribution statements based on collusion route includes the interconnector between adjacent ring network cabinet, And the interconnector between substation and ring network cabinet；It is characterized in that, the guard method the following steps are included:(1) this side three-phase current of interconnection between local mounted DTU acquisition ring network cabinet in each ring network cabinet, while each DTU is from number The electric current and adjacent interconnection opposite side three-phase current of interconnection opposite side are obtained according to communication network；(2) communications status for judging DTU in each ring network cabinet, when DTU communication normally, enters step (3), when a certain in each ring network cabinet Ring network cabinet DTU communication disruption then enters step (4)；(3) each route protection unit takes this section of route two sides electric current to carry out differential protection calculating on distribution statements based on collusion route, if poor Dynamic protection act, this route of tripping two sides breaker；(4) in there are a certain ring network cabinet when DTU communication disruption, the ring network cabinet two sides line differential protection unit is across the DTU The ring network cabinet of communication disruption selects adjacent lines opposite side electric current to input as the differential protection of opposite end, using incomplete differential guarantor It protects principle and carries out fault location differentiation, this side of tripping switch and adjacent lines opposite side switch, Fault Isolation range is expanded when movement Greatly to adjacent lines.
- The adaptive incomplete differential protection method of route 2. distribution according to claim 1 is acted in collusion to make each other's confessions, it is characterised in that:In step (4), when using difference stream definite value self-adaptive sites, difference current definite value need to be escaped across in DTU communication Disconnected ring network cabinet route poor memory stream, i.e., its affiliated ring network cabinet two sides route opposite end calculates poor flow valuve before the DTU communication disruption, should Setting mode is suitable for the steady situation of ring network cabinet load fluctuation；When not using difference stream definite value self-adaptive sites, difference current definite value needs to escape the ring network cabinet of the DTU communication disruption Maximum load current, the setting mode are suitable for the larger situation of ring network cabinet load fluctuation.
- The adaptive incomplete differential protection method of route 3. distribution according to claim 2 is acted in collusion to make each other's confessions, it is characterised in that:When differential time definite value uses quick-action principle, the not exclusively differential time setting of route is 0s, when generation route or bus When failure, protection all can quick acting；When differential time definite value is using bus differential protecting actuation time principle is escaped, route The incomplete differential time can adjust as 0.2s, if bus-bar fault occurs, bus differential protection action cuts off failure, and route is not exclusively differential Protection is failure to actuate, and when differential time definite value is using bus differential protecting actuation time principle is escaped, needs to consider 10kV feeder line Operating time of protection leaves whether differential fault location time has nargin for.
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Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109687415B (en) * | 2018-12-27 | 2020-08-04 | 长园深瑞继保自动化有限公司 | Fault diagnosis isolation recovery method and system for distributed data transmission unit |
| CN110854839A (en) * | 2019-10-12 | 2020-02-28 | 江苏远望仪器集团有限公司 | Power supply system for monitoring system and asymmetric load fault diagnosis method |
| CN113036727B (en) * | 2021-03-12 | 2022-08-30 | 国网江苏省电力有限公司常州供电分公司 | Distributed current differential protection system and method |
| CN114520493A (en) * | 2022-03-10 | 2022-05-20 | 南京智汇电力技术有限公司 | Self-adaptive incomplete differential protection method for series supply line of distribution network |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103078303A (en) * | 2012-07-20 | 2013-05-01 | 南京南瑞继保电气有限公司 | Differential protection method capable of automatically switching protection domains |
| CN103354353A (en) * | 2013-06-24 | 2013-10-16 | 国家电网公司 | Intelligent power-distribution-network whole-line quick-reacting main protection and determination system and method |
| CN103545799A (en) * | 2013-11-01 | 2014-01-29 | 北京四方继保自动化股份有限公司 | Circuit differential protection method automatically adapting to external bridge circuit |
| CN204425041U (en) * | 2014-12-15 | 2015-06-24 | 广东电网有限责任公司珠海供电局 | Distribution terminal system |
| CN104810809A (en) * | 2015-04-21 | 2015-07-29 | 国家电网公司 | Micro-grid current selective tripping protection method applicable to photovoltaic multipoint access |
| CN105048418A (en) * | 2015-07-06 | 2015-11-11 | 四川艾德瑞电气有限公司 | Digital incompletion bus differential protection method based on current state quantity |
| CN105186472A (en) * | 2015-10-14 | 2015-12-23 | 南京国电南自电网自动化有限公司 | Line longitudinal differential protection method for transformer station area information collection |
| CN106684836A (en) * | 2016-11-15 | 2017-05-17 | 南方电网科学研究院有限责任公司 | Valve bank differential protection method performing synthesis judgment based on difference stream waveforms |
| CN106711975A (en) * | 2017-03-20 | 2017-05-24 | 中国南方电网有限责任公司 | Method for positioning, isolating and quickly recovering fault on basis of distributed differential protection |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8634175B2 (en) * | 2011-04-13 | 2014-01-21 | Siemens Industry, Inc. | Method and system for programming and implementing automated fault isolation and restoration using sequential logic |
| US8942108B2 (en) * | 2012-12-14 | 2015-01-27 | General Electric Company | Method and system for current differential protection |
-
2017
- 2017-08-23 CN CN201710727617.7A patent/CN107591784B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103078303A (en) * | 2012-07-20 | 2013-05-01 | 南京南瑞继保电气有限公司 | Differential protection method capable of automatically switching protection domains |
| CN103354353A (en) * | 2013-06-24 | 2013-10-16 | 国家电网公司 | Intelligent power-distribution-network whole-line quick-reacting main protection and determination system and method |
| CN103545799A (en) * | 2013-11-01 | 2014-01-29 | 北京四方继保自动化股份有限公司 | Circuit differential protection method automatically adapting to external bridge circuit |
| CN204425041U (en) * | 2014-12-15 | 2015-06-24 | 广东电网有限责任公司珠海供电局 | Distribution terminal system |
| CN104810809A (en) * | 2015-04-21 | 2015-07-29 | 国家电网公司 | Micro-grid current selective tripping protection method applicable to photovoltaic multipoint access |
| CN105048418A (en) * | 2015-07-06 | 2015-11-11 | 四川艾德瑞电气有限公司 | Digital incompletion bus differential protection method based on current state quantity |
| CN105186472A (en) * | 2015-10-14 | 2015-12-23 | 南京国电南自电网自动化有限公司 | Line longitudinal differential protection method for transformer station area information collection |
| CN106684836A (en) * | 2016-11-15 | 2017-05-17 | 南方电网科学研究院有限责任公司 | Valve bank differential protection method performing synthesis judgment based on difference stream waveforms |
| CN106711975A (en) * | 2017-03-20 | 2017-05-24 | 中国南方电网有限责任公司 | Method for positioning, isolating and quickly recovering fault on basis of distributed differential protection |
Non-Patent Citations (1)
| Title |
|---|
| 适用主动配电网的差动保护方案研究;李瑞生;《电力***保护与控制》;20150616;第43卷(第12期);第104-109页 |
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