CN103401226A - Substation area differential protection method for intelligent substation - Google Patents

Substation area differential protection method for intelligent substation Download PDF

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Publication number
CN103401226A
CN103401226A CN2013103459448A CN201310345944A CN103401226A CN 103401226 A CN103401226 A CN 103401226A CN 2013103459448 A CN2013103459448 A CN 2013103459448A CN 201310345944 A CN201310345944 A CN 201310345944A CN 103401226 A CN103401226 A CN 103401226A
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differential
transformer
differential protection
voltage side
little
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CN103401226B (en
Inventor
栾国军
王思诚
姜光
王俊凯
晋飞
董兴欣
李江林
张道杰
邱俊宏
穆宗军
王广民
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State Grid Corp of China SGCC
Xuchang XJ Software Technology Co Ltd
Weifang Power Supply Co of State Grid Shandong Electric Power Co Ltd
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State Grid Corp of China SGCC
Xuchang XJ Software Technology Co Ltd
Weifang Power Supply Co of State Grid Shandong Electric Power Co Ltd
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Publication of CN103401226A publication Critical patent/CN103401226A/en
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Abstract

The invention discloses a substation area differential protection method for an intelligent substation, which comprises a big differential protection mode taking the substation as the principal thing, and more than two small differential protection modes taking the substations as the principal things; the big differential protection mode serves as a starting element, any one small differential protection mode serves as an action element; when the two conditions are satisfied simultaneously, the differential protection outputs action; the small differential protection modes are still failure selecting elements; the range of the big differential protection mode is delimitated by high voltage side current of each transformer and all outlet current on the medium voltage side generating line and the low voltage side generating line, of the substation, (not comprising buscouple and segment); the ranges of the small differential protection modes are delimitated by corresponding high voltage side current of the transformer, and all corresponding outlet current on the generating lines connected with main change medium voltage side and low voltage side, (not comprising buscouple and segment). The method not only can thoroughly protect the substation, but also can close the failure transformer in a targeted manner, is small in influence range for the electricity using user, and is particularly suitable for the substation provided with two or more than two transformers to use.

Description

Territory, intelligent substation station differential protecting method
Technical field
The invention belongs to the relaying protection automatic field of power engineering, be used for improving the security reliability of power system operation, particularly territory, a kind of intelligent substation station differential protecting method.
Background technology
Transformer station (Substation) combines some electric devices, in order to the electric power facility of voltage of transformation, acceptance and distribution electric energy, the flow direction of controlling electric power and adjustment voltage.In electric power system, transformer station is the assembly place of transmission and disttrbution.Transformer station's chief component is: feed line (inlet wire, outlet) and bus, isolating switch, earthed switch, circuit breaker, power transformer (main transformer), voltage transformer TV(PT), current transformer TA (CT), lightning rod.Transformer station mainly can be divided into: load-center substation, one-end substation; Primary substation, step-down substation; The transformer station of electric power system, industrial and mineral transformer station, railroad substation (27.5kV, 50Hz); The transformer station of the electric pressures such as 1000kV, 750kV, 500kV, 330kV, 220kV, 110kV, 66kV, 35kV, 10kV, 6.3kV; The 10kV switching station; Box-type substation.
At present; transformer station has generally adopted Fibre Optical Communication Technology; synchronization accuracy can meet the requirement of protection; the network technology of high speed development has met the demand to network capacity and safety, unfailing performance that day by day increases; the IEC61850 standard has also solved complexity and the technology realization of original system integration and share of information effectively; the information sharing that is applied as intelligent substation of these advanced technologies is laid a good foundation, and also research, the enforcement for territory, station differential protection provides possibility.The characteristics of utilizing the intelligent substation internal information to share flexibly; use transformer station's integral body as protected object; utilize the information centralized decision-makings such as the input of full station, voltage, current information and the device action of exporting each element, state; complete the information gathering of territory, station differential protection, realize the centralized differential backup protection function in full station.
At present, in Power System in China, on the intelligent substation differential protecting method, be all to adopt whole station protected mode.That is to say, when differential guard method judgement is broken down, can control the circuit breaker action of whole transformer station, thereby play the purpose of protection transformer station.For example; China Patent No. is the phasor differential protecting method that the disclosed a kind of value difference stream of sampling of 200910025578.1 patent of invention starts; this guard method combines sampling value difference and the differential advantage of phasor; have higher anti-interference and reliability, but remain the purpose that reaches protection transformer station by controlling mode that whole station inputs or outputs.This guard method,, although played the effect of protecting whole transformer station, also affected the power supply in whole transformer station coverage, can not control targetedly in transformer station certain or some break down operating states of transformer.
Summary of the invention
The technical problem to be solved in the present invention be for above-mentioned deficiency provide a kind of can general protection transformer station, closing fault transformer targetedly again, the intelligent substation station territory differential protecting method little to the customer impact scope.
For solving the problems of the technologies described above; territory, this intelligent substation station differential protecting method comprises take transformer station as main large differential protection pattern and take each transformer as main plural little differential protection pattern; large differential protection pattern is starting component; arbitrary little differential protection pattern is action element; when above-mentioned two conditions meet simultaneously; differential protection outlet action, little poor protected mode or fault selectors.
Territory, this intelligent substation station differential protecting method is that realize by the double differential protected mode can general protection transformer station, and closing fault transformer targetedly, little to the customer impact scope again.
The double differential protected mode mainly refers to include two cover differential protection pattern, i.e. large differential protection pattern and little differential protection patterns in the differential protecting method of territory, this intelligent substation station.For convenience of narration, large differential protection pattern is called large poor or large differential mode formula, little differential protection pattern is called little difference or little differential mode formula.The protection range of large differential mode formula, take transformer station as main, that is to say that whole transformer station is all the object of protection protection protection range of large differential mode formula, and the quantity of therefore large differential mode formula only has a cover.The object of protection of little differential mode formula or protection range are single transformer and the relevant devices thereof in transformer station.Have several transformers that the little differential mode formula of several covers is just arranged in transformer station, the little differential mode formula of every cover is only protected the transformer corresponding with it and relevant device thereof.In the differential protecting method of territory, this intelligent substation station, large differential mode formula is as starting component, in order to distinguish transformer station's internal fault external fault.And little differential mode formula is namely action element, is also the fault selectors.
The course of work of this double differential protected mode is: under normal operating mode; when large differential mode formula and a certain little differential mode formula all met criterion, high-pressure side circuit breaker, the medium voltage side of the corresponding transformer of the little differential mode formula of tripping were included branch breaker, medium voltage side bus bus, low-pressure side circuit breaker and the low-pressure side bus section breaker of this little differential mode formula in.If only large differential mode formula meets operating criterion, all elements of tripping medium voltage side after time delay.By said process as can be known, when transformer station broke down, entry condition met, and large differential mode formula starts.When arbitrary transformer breaks down, the little differential mode formula action corresponding with this transformer, this double differential protected mode outlet action.After this double differential protected mode outlet action; select the little differential mode formula of this action as the fault selectors, and high-pressure side circuit breaker, the medium voltage side of controlling its corresponding transformer are included branch breaker, medium voltage side bus bus, low-pressure side circuit breaker and the low-pressure side bus section breaker of this little differential mode formula in.Like this; when transformer station breaks down; territory, this intelligent substation station differential protecting method is the transformer that breaks down of criterion exactly; and only cut off the input and output circuit of this transformer; can not cut off the input and output circuit of whole transformer station; like this, in same transformer station, the operation of other transformers that do not break down, with unaffected, has guaranteed the functional reliability of transformer station and the stability of power supply.
As a kind of implementation; large differential protection model domain is defined in that on each high voltage side of transformer electric current of transformer station, medium voltage side and low-pressure side bus, all go out line current (not comprising mother, segmentation), and little differential protection model domain is defined in that on corresponding high voltage side of transformer electric current, corresponding main transformer medium voltage side and low-pressure side institute connection bus, all go out line current (comprising mother, segmentation).
The coverage of large differential protection pattern is defined in transformer station, on each high voltage side of transformer electric current, medium voltage side and low-pressure side bus, all go out line current (not comprising mother, segmentation); exactly the protection range of large differential protection pattern is set in each high voltage side of transformer, medium voltage side and low-pressure side in transformer station, the namely high-pressure side of bed rearrangement transformer station, medium voltage side and low-pressure side.Large differential protection pattern can be according to the criterion that is set in current signal that in transformer station, on each high voltage side of transformer, medium voltage side and low-pressure side, current transformer feeds back and carries out entry condition.Relative; the coverage of little differential protection pattern is defined on corresponding high voltage side of transformer electric current, corresponding main transformer medium voltage side and low-pressure side institute connection bus, all go out line current (comprising mother, segmentation); exactly the protection range of little differential protection pattern is set in transformer station centered by corresponding transformer; scope take high-pressure side, medium voltage side and the low-pressure side of corresponding transformer as border, namely carry out the criterion of operation condition by being arranged on current signal that corresponding high voltage side of transformer, medium voltage side and low-pressure side current transformer feed back.After the scope of poor greatly and little difference is set; while by large poor criterion transformer station, breaking down; can excise this little poor corresponding transformer that breaks down according to the criterion of little difference; solved the drawback of in the traditional protection mode, a whole set of transformer station being cut off; effectively avoided affecting the operation of other transformers in same transformer station because of a transformer fault, improved the power supply reliability of transformer station.
Described large differential protection pattern consists of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
Described little differential protection pattern consists of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
Percentage differential; claim again the ratio brake differential protection; can not consider the saturated and inconsistent situation of current transformer transient characterisitics of current transformer (CT) in when work, therefore versatility or the interference free performance that can strengthen territory, this intelligent substation station differential protecting method are set after percentage differential.The differential impact that is not subjected to the load current of normal operation of increment, can also solve the slight turn-to-turn fault of transformer and high resistance earthing fault, helps to improve operational reliability.The configuration fast differential over current protection, can instantaneous operation, and each side circuit breaker of tripping, be particularly suitable for excising fast the serious internal fault of transformer station.The Threshold Crossing Alert of poor stream arranges delay protection exactly, and current signal that like this can some instantaneous mutations of filtering helps to reduce the probability of misoperation, has improved operational reliability.
In sum; adopt territory, the intelligent substation station differential protecting method of this mode, can general protection transformer station, closing fault transformer targetedly again; little to electricity consumption customer impact scope, the transformer station that is particularly suitable for being provided with two and above transformer uses.
Description of drawings
By reference to the accompanying drawings the present invention is described in further detail:
Fig. 1 is the electrical schematic diagram of transformer station in the present invention;
Fig. 2 is large poor protection range schematic diagram in the present invention;
Fig. 3 is the protection range schematic diagram of first little difference in the present invention;
Fig. 4 is the protection range schematic diagram of second little difference in the present invention;
Fig. 5 is the performance chart of percentage differential;
Fig. 6 is the biased differential protection logic diagram;
Fig. 7 is increment differential protection performance chart;
Fig. 8 is increment differential protection logic diagram;
Fig. 9 is the fast differential over current protection logic diagram;
The out-of-limit protection logic diagram of the poor stream of Figure 10.
Embodiment
As shown in Figure 1; this territory, intelligent substation station differential protecting method comprises take transformer station as main large differential protection pattern and take each transformer as main plural little differential protection pattern; large differential protection pattern is starting component; arbitrary little differential protection pattern is action element; when above-mentioned two conditions meet simultaneously; differential protection outlet action, little poor protected mode or fault selectors.Include two cover differential protection pattern, i.e. large differential protection pattern and little differential protection patterns in the differential protecting method of territory, this intelligent substation station.For convenience of narration, large differential protection pattern is called large poor or large differential mode formula, little differential protection pattern is called little difference or little differential mode formula.The protection range of large differential mode formula, take transformer station as main, that is to say that whole transformer station is all the object of protection protection protection range of large differential mode formula, and the quantity of therefore large differential mode formula only has a cover.The object of protection of little differential mode formula or protection range are single transformer and the relevant devices thereof in transformer station.Have several transformers that the little differential mode formula of several covers is just arranged in transformer station, the little differential mode formula of every cover is only protected the transformer corresponding with it and relevant device thereof.In the differential protecting method of territory, this intelligent substation station, large differential mode formula is as starting component, in order to distinguish transformer station's internal fault external fault.And little differential mode formula is namely action element, is also the fault selectors.
The protection process of territory, this intelligent substation station differential protecting method is: under normal operating mode; when large differential mode formula and a certain little differential mode formula all met criterion, high-pressure side circuit breaker, the medium voltage side of the corresponding transformer of the little differential mode formula of tripping were included branch breaker, medium voltage side bus bus, low-pressure side circuit breaker and the low-pressure side bus section breaker of this little differential mode formula in.If only large differential mode formula meets operating criterion, all elements of tripping medium voltage side after time delay.By said process as can be known, when transformer station broke down, entry condition met, and large differential mode formula starts.When arbitrary transformer breaks down, the little differential mode formula action corresponding with this transformer, this double differential protected mode outlet action.After this double differential protected mode outlet action; select the little differential mode formula of this action as the fault selectors, and high-pressure side circuit breaker, the medium voltage side of controlling its corresponding transformer are included branch breaker, medium voltage side bus bus, low-pressure side circuit breaker and the low-pressure side bus section breaker of this little differential mode formula in.Like this; when transformer station breaks down; territory, this intelligent substation station differential protecting method is the transformer that breaks down of criterion exactly; and only cut off the input and output circuit of this transformer; can not cut off the input and output circuit of whole transformer station; like this, in same transformer station, the operation of other transformers that do not break down, with unaffected, has guaranteed the functional reliability of transformer station and the stability of power supply.
As a kind of implementation; large differential protection model domain is defined in that on each high voltage side of transformer electric current of transformer station, medium voltage side and low-pressure side bus, all go out line current (not comprising mother, segmentation), and little differential protection model domain is defined in that on corresponding high voltage side of transformer electric current, corresponding main transformer medium voltage side and low-pressure side institute connection bus, all go out line current (comprising mother, segmentation).
The coverage of large differential protection pattern is defined in transformer station, on each high voltage side of transformer electric current, medium voltage side and low-pressure side bus, all go out line current (not comprising mother, segmentation); exactly the protection range of large differential protection pattern is set in each high voltage side of transformer, medium voltage side and low-pressure side in transformer station, the namely high-pressure side of bed rearrangement transformer station, medium voltage side and low-pressure side.Large differential protection pattern can be according to the criterion that is set in current signal that in transformer station, on each high voltage side of transformer, medium voltage side and low-pressure side, current transformer feeds back and carries out entry condition.Relative; the coverage of little differential protection pattern is defined on corresponding high voltage side of transformer electric current, corresponding main transformer medium voltage side and low-pressure side institute connection bus, all go out line current (comprising mother, segmentation); exactly the protection range of little differential protection pattern is set in transformer station centered by corresponding transformer; scope take high-pressure side, medium voltage side and the low-pressure side of corresponding transformer as border, namely carry out the criterion of operation condition by being arranged on current signal that corresponding high voltage side of transformer, medium voltage side and low-pressure side current transformer feed back.After the scope of poor greatly and little difference is set; while by large poor criterion transformer station, breaking down; can excise this little poor corresponding transformer that breaks down according to the criterion of little difference; solved the drawback of in the traditional protection mode, a whole set of transformer station being cut off; effectively avoided affecting the operation of other transformers in same transformer station because of a transformer fault, improved the power supply reliability of transformer station.
For convenience of narration, territory, this intelligent substation station differential protecting method just, referred to as territory, station differential protecting method, or referred to as territory, station differential protection.The territory differential protection of standing all adopts electronic current mutual inductor to realize based on transformer station; centralized backup protection as whole transformer station; phase fault and the single-phase earthing fault that can reflect bus inside, also can reflect phase fault, high-pressure side and medium voltage side single-phase earthing fault and shorted-turn fault that transformer (abbreviation main transformer) is inner.Stand the territory differential protection take Differential Protection Principles of Transformer as basis, the large difference of transformer station and each transformer are set little poor.Large poor by on each main transformer high voltage side current of transformer station, medium voltage side and low-pressure side bus, all go out line current and form (not comprising mother, segmentation), little difference is by on this TV station main transformer high voltage side current, medium voltage side and low-pressure side this TV station main transformer institute connection bus, all go out line current and form (comprising mother, segmentation).Large poor as starting component, in order to distinguish transformer station's internal fault external fault, little difference is the fault selectors.The territory differential protection of standing is comprised of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
1, data selection and processing
As shown in Figure 1, identified Substation Bus Arrangement figure in figure, contained two main transformers, main transformer is high, medium voltage side is double bus scheme, and the main transformer low-pressure side is single mother partition wiring.Territory, definition station differential protection protection range is two main transformers+medium voltage side outlet+low-voltage side outlet.For realizing territory, station differential protection function, the ac analog data that protection need to get are as follows:
Current sampling data:
Main transformer high-pressure side CT(CT11, CT21), main transformer medium voltage side CT(CT12, CT22), medium voltage side bus outlet CT(CT202, ┄, CT20m), medium voltage side mother CT(CT201), low-pressure side bus outlet CT(CT302, ┄, CT30n) and low-pressure side segmentation CT(CT301) current sampling data; Above-mentioned current data is used for forming each difference element of territory, station differential protection.
The voltage sample data:
Two sections busbar voltages of main transformer medium voltage side, two sections busbar voltages of main transformer low-pressure side.Obtain voltage data and be mainly used in realizing defencive function in charging process.
The data selection of large poor element
Large poor element is as entry condition or fault initiating element, in order to distinguish territory, station protection internal fault external fault.As shown in Figure 2, large poor protection range is two main transformers+medium voltage side bus+low-pressure side bus.The data that form large poor differential protection are:
High voltage side current: adopt two main transformer high-pressure side CT(CT11, CT21) gather the vector of electric current;
Medium voltage side electric current: adopt medium voltage side each branch road of bus (not containing main transformer branch road, mother) CT to gather the vector of electric current;
Low-pressure side electric current: adopt each branch road of low-pressure side bus (not containing main transformer branch road, segmentation) CT to gather the vector of electric current.
The data selection of little poor element
Little poor element is as the fault selectors.As shown in Figure 3, Figure 4, the protection range of each little difference is part medium voltage side bus and the low-pressure side bus of every main transformer+correspondence.
Be medium voltage side " fuzzy protection range " in empty frame scope in figure; it is main because the double bus scheme mode is adopted in the outlet of main transformer medium voltage side; this mode of connection has determined that on bus, all connection branch roads can switch in running; this has just determined that each little poor element protection scope is also fixing, according to the change of actual operating, dynamically changes.The electric current that each little poor element is chosen also changes along with the change of bus running manner.
The data that form each little poor element differential protection are:
High voltage side current: adopt this main transformer high-pressure side CT(such as CT11) gather electric current;
Medium voltage side electric current: adopt a certain section each branch road of bus of medium voltage side (not containing this main transformer branch road) of this main transformer connection and the vector that mother CT gathers electric current;
Low-pressure side electric current: adopt a certain section each branch road of bus of low-pressure side (not containing this main transformer branch road) of this main transformer connection and the vector that segmentation CT gathers electric current;
, for choosing of medium voltage side current data, adopt special logic to realize: the connection status of real-time tracking main transformer branch road, connection bus concrete according to the main transformer branch road determines to include in the outlet CT of this little poor element; It should be noted, the mother branch road is fixedly included two little poor elements in.The polarity of device mother CT arranges the female branch road that connects of same I, and is when counting the female corresponding little poor element of II, fixing with the sampled data negate of correspondence;
The computing formula of the little spill current of medium voltage side is as follows:
(3-1)
(3-2)
Press each branch road of bus (contain the mother branch road, do not contain the main transformer branch road) little poor incidence coefficient of 1# (incidence coefficient of j element to the little difference of 1#), the little poor incidence coefficient of 2# (incidence coefficient of j element to the little difference of 2#) during in formula, the calculating of medium voltage side electric current is introduced.The calculating of electric current is all carried out according to the primary current value.
Low-pressure side bus adopts single mother partition main wiring mode, and on bus, all branch roads are fixedly connected with, and can preset the branch road CT that each little poor element need to count according to on-the-spot physical cabling, and wherein segmentation CT fixedly counts two little poor elements; The polarity of segmentation CT is with the female branch road that connects of I, and is when counting the female corresponding little poor element of II, fixing with the sampled data negate of correspondence;
The territory differential protection of standing is comprised of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
Due to the difference of transformer joint group difference and each side CT no-load voltage ratio, each side current amplitude phase place of transformer station is also different, and at first differential protection will eliminate these impacts.Need to utilize digital method to compensate no-load voltage ratio and phase place, each side sense of current of transformer station is all to point to transformer as positive direction, and each side CT secondary current phase place, by the software adjustment, adopts the conversion regime of Y → △, and namely the Y side is carried out the phase place adjustment.For the transformer of Y/Y/ △-12-11 or the transformer of Y/Y/Y-12-12, Y side conversion formula is as follows:
(3-2-1)
For the transformer of Y/Y/ △-12-1, Y side conversion formula is as follows:
(3-2-2)
For the Y side is not changed front electric current, For each phase current after proofreading and correct.△ side electric current is corner not.
Below explanation is all based on the basis of eliminating each side current amplitude phase difference of transformer station.
Ratio brake differential protection operation equation comprises low definite value and high-set setting two parts, and low definite value operation equation is subjected to magnetizing inrush current and the abnormal locking of CT, and the high-set setting operation equation is not subjected to magnetizing inrush current and the abnormal locking of CT.The ratio brake differential protection is not considered the saturated and inconsistent situation of CT transient characterisitics of CT.
In conjunction with Fig. 5, Fig. 6, percentage differential operation equation once is described
Low definite value:
(3-2-3)
High-set setting:
(3-2-4)
For differential current, For longitudinal difference protection starting current definite value, For stalling current, S is ratio brake coefficient, For the reference current (usually take the high-pressure side rated current as benchmark) of differential protection, each side sense of current is all to point to transformer as positive direction.
(1) differential for both sides
(3-2-5)
(3-2-6)
Be respectively the electric current of transformer high and low pressure side Current Transformer Secondary side.
(2) differential for three sides and above several sides
(3-2-7)
(3-2-8)
In formula: Be respectively the electric current of each side Current Transformer Secondary side of transformer station.
In the present embodiment, also be provided with the magnetizing inrush current criterion, mainly comprise second harmonic mode and waveform manner of comparison, and can select by control word.Adjust while being 1 when " secondary harmonic brake " control word, adopt the locking of second harmonic mode, adjusting is 0 o'clock, adopts the locking of waveform manner of comparison.
The second harmonic mode claims again second harmonic criterion mode, below second harmonic criterion mode is elaborated.During the transformer air-drop, during shoving, three phase excitation often have one to contain mutually a large amount of second harmonics.But each side electric current of territory differential protection of standing will carry out the phase place adjustment, and the electric current after the phase place adjustment is no longer real magnetizing inrush current, and the secondary harmonic component in electric current also can change.Can automatically select the Current calculation secondary harmonic component according to the different operating modes of transformer station, as adopting the Current calculation secondary harmonic component before phase place is adjusted when the transformer during no-load closing, therefore, the secondary harmonic component that calculates magnetizing inrush current is truer, and performance is more reliable.Transformer when normal operation, adopts the secondary harmonic component in differential current to identify magnetizing inrush current.Discriminant equation is as follows:
In formula: For the second harmonic in poor stream, For the first-harmonic in poor stream, For the second harmonic coefficient.
If differing stream, certain meets following formula, the three-phase of locking simultaneously differential protection.
When adopting the locking of second harmonic "or", the fault in air-drop main transformer process is identified; drop in short-term by comprehensively opening mutually criterion; can correctly identify magnetizing inrush current; can open differential protection in fast and reliable ground when the air-drop failure transformer again, improve the responsiveness of differential protection when dropping transformer in fault.
The waveform comparison criterion
Can automatically select differential current or phase current to calculate the degree of asymmetry of waveform according to the different operating modes of transformer station, the waveform degree of asymmetry that calculates magnetizing inrush current be truer, and protective value is more reliable.Discriminant equation is as follows:
In formula: For the degree of asymmetry value of differential current sampled point, For the symmetry value of corresponding differential current sampled point, K is a certain fixed coefficient.If differing stream, certain meets following formula, this phase of locking differential protection.
As shown in Figure 7, Figure 8; the differential impact that is not subjected to the load current of normal operation of increment; have than vertical poor differential higher sensitivity; because the choosing of stalling current of indulging poor differential protection comprises normal load current; in while, in transformer station, weak fault occurring; vertical poor differential protection is because stalling current is large, possible deferred action or be failure to actuate.The differential slight turn-to-turn fault of transformer and the high resistance earthing fault of mainly solving of increment.
Operation equation
(3-2-9)
(3-2-10)
Wherein:
Middle amplitude the maximum;
Need to identify the magnetizing inrush current running status of transformer due to territory, station differential protection; when transformer station is inner when catastrophe failure occurs, can not excise fast fault, electric power system stable brought serious harm; so the configuration fast differential over current protection, be used for excising fast the serious internal fault of transformer station.
As shown in Figure 9, when arbitrary stream electric current fast differential over current protection instantaneous operation during greater than differential quick-break current ration, each side circuit breaker of tripping of differing.
As shown in figure 10, when differential protection drops into and arbitrary phase differential current during greater than 0.5 times of differential protection starting current definite value, the out-of-limit signal of the poor stream of time delay 5s newspaper.
Because our station territory differential protection adopts poor greatly+little differential mode formula, so the tripping operation mode of this territory differential protection of standing is: under normal operating mode, when large poor and corresponding little difference all met criterion, high-pressure side circuit breaker, the medium voltage side of jumping the corresponding main transformer of element of deserting were included branch breaker, medium voltage side bus bus, low-pressure side circuit breaker and the low-pressure side bus section breaker of this little poor element in; If only large difference meets operating criterion, all elements of tripping medium voltage side after time delay.

Claims (5)

1. territory, intelligent substation station differential protecting method; it is characterized in that: comprise take transformer station as main large differential protection pattern and take each transformer as main plural little differential protection pattern; large differential protection pattern is starting component; arbitrary little differential protection pattern is action element; when above-mentioned two conditions meet simultaneously; differential protection outlet action, little poor protected mode or fault selectors.
2. territory, intelligent substation station as claimed in claim 1 differential protecting method; it is characterized in that: large differential protection model domain is defined in that on each high voltage side of transformer electric current of transformer station, medium voltage side and low-pressure side bus, all go out line current (not comprising mother, segmentation), and little differential protection model domain is defined in that on corresponding high voltage side of transformer electric current, corresponding main transformer medium voltage side and low-pressure side institute connection bus, all go out line current (comprising mother, segmentation).
3. territory, intelligent substation station as claimed in claim 1 or 2 differential protecting method is characterized in that: described large differential protection pattern consists of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
4. territory, intelligent substation station as claimed in claim 1 or 2 differential protecting method is characterized in that: described little differential protection pattern consists of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
5. territory, intelligent substation station as claimed in claim 4 differential protecting method is characterized in that: described little differential protection pattern consists of percentage differential, differential, the differential quick-break of increment, the Threshold Crossing Alert of poor stream.
CN201310345944.8A 2013-08-09 2013-08-09 Substation area differential protection method for intelligent substation Expired - Fee Related CN103401226B (en)

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103779843A (en) * 2014-03-01 2014-05-07 华北电力大学 Substation area protection system and substation area protection method based on differential flexible overlapping division
CN104319735A (en) * 2014-09-30 2015-01-28 许继集团有限公司 Excitation inrush identification method for longitudinal differential protection of auto transformer
CN104868451A (en) * 2015-04-10 2015-08-26 国网山东省电力公司潍坊供电公司 Bus protection algorithm for realizing GIS accurate fault removing and automatic power supply recovery
CN105510731A (en) * 2015-11-26 2016-04-20 国网辽宁省电力有限公司大连供电公司 Parallel resonance detection alarming method and system for medium-voltage side power grid of power transformer
CN106300262A (en) * 2016-08-26 2017-01-04 大唐黄岛发电有限责任公司 A kind of 220kV grade transformer protection method for transformer station's remote power-feeding
CN106300288A (en) * 2016-08-27 2017-01-04 许继集团有限公司 A kind of station territory differential protecting method and device
CN106549367A (en) * 2016-10-20 2017-03-29 许继集团有限公司 A kind of differential protection method for bus abnormal for mother CT and device
CN108173240A (en) * 2017-12-19 2018-06-15 华中科技大学 A kind of transformer excitation flow recognition method and system based on compound time difference method
CN108181528A (en) * 2017-12-31 2018-06-19 中国能源建设集团华东电力试验研究院有限公司 The high-tension cable differential protection check system of no load condition
CN111060739A (en) * 2020-02-14 2020-04-24 东方电子股份有限公司 Fault type identification method based on differential current and fault characteristic quantity

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CN202178610U (en) * 2011-09-02 2012-03-28 广东电网公司深圳供电局 Switching apparatus of bypass switch for operating TA secondary circuit in replace of main transformer
CN102629754A (en) * 2012-03-31 2012-08-08 积成电子股份有限公司 Substation area back-up protecting method based on current differential principle
CN103107603A (en) * 2013-03-12 2013-05-15 华北电力大学 Region intelligent protection system of transformer substation

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CN101609979A (en) * 2009-07-24 2009-12-23 南京南瑞继保电气有限公司 OO bus protection setting method
CN101958530A (en) * 2010-10-26 2011-01-26 湖北白莲河抽水蓄能有限公司 Main transformer differential protection CT polarity check method of pumped storage power station
CN202178610U (en) * 2011-09-02 2012-03-28 广东电网公司深圳供电局 Switching apparatus of bypass switch for operating TA secondary circuit in replace of main transformer
CN102629754A (en) * 2012-03-31 2012-08-08 积成电子股份有限公司 Substation area back-up protecting method based on current differential principle
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Cited By (18)

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Publication number Priority date Publication date Assignee Title
CN103779843B (en) * 2014-03-01 2016-04-20 华北电力大学 Based on territory, station protection system and the guard method thereof of differential flexible overlapping subregion
CN103779843A (en) * 2014-03-01 2014-05-07 华北电力大学 Substation area protection system and substation area protection method based on differential flexible overlapping division
CN104319735B (en) * 2014-09-30 2018-02-02 许继集团有限公司 A kind of excitation flow recognition method of auto-transformer longitudinal difference protection
CN104319735A (en) * 2014-09-30 2015-01-28 许继集团有限公司 Excitation inrush identification method for longitudinal differential protection of auto transformer
CN104868451A (en) * 2015-04-10 2015-08-26 国网山东省电力公司潍坊供电公司 Bus protection algorithm for realizing GIS accurate fault removing and automatic power supply recovery
CN105510731B (en) * 2015-11-26 2018-04-20 国网辽宁省电力有限公司大连供电公司 Power transformer medium voltage side power grid parallel resonance detects alarm method and system
CN105510731A (en) * 2015-11-26 2016-04-20 国网辽宁省电力有限公司大连供电公司 Parallel resonance detection alarming method and system for medium-voltage side power grid of power transformer
CN106300262A (en) * 2016-08-26 2017-01-04 大唐黄岛发电有限责任公司 A kind of 220kV grade transformer protection method for transformer station's remote power-feeding
CN106300262B (en) * 2016-08-26 2019-02-05 大唐黄岛发电有限责任公司 A kind of 220kV grade transformer protection method for substation's remote power-feeding
CN106300288A (en) * 2016-08-27 2017-01-04 许继集团有限公司 A kind of station territory differential protecting method and device
CN106300288B (en) * 2016-08-27 2018-12-04 许继集团有限公司 A kind of station domain differential protecting method and device
CN106549367A (en) * 2016-10-20 2017-03-29 许继集团有限公司 A kind of differential protection method for bus abnormal for mother CT and device
CN108173240A (en) * 2017-12-19 2018-06-15 华中科技大学 A kind of transformer excitation flow recognition method and system based on compound time difference method
CN108173240B (en) * 2017-12-19 2019-06-28 华中科技大学 A kind of transformer excitation flow recognition method and system based on compound time difference method
CN108181528A (en) * 2017-12-31 2018-06-19 中国能源建设集团华东电力试验研究院有限公司 The high-tension cable differential protection check system of no load condition
CN108181528B (en) * 2017-12-31 2020-07-31 中国能源建设集团华东电力试验研究院有限公司 High-voltage cable differential protection checking system in no-load state
CN111060739A (en) * 2020-02-14 2020-04-24 东方电子股份有限公司 Fault type identification method based on differential current and fault characteristic quantity
CN111060739B (en) * 2020-02-14 2021-10-12 东方电子股份有限公司 Fault type identification method based on differential current and fault characteristic quantity

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