CN102393494A - Online measurement method and system for capacity of transformer - Google Patents

Online measurement method and system for capacity of transformer Download PDF

Info

Publication number
CN102393494A
CN102393494A CN2011102734171A CN201110273417A CN102393494A CN 102393494 A CN102393494 A CN 102393494A CN 2011102734171 A CN2011102734171 A CN 2011102734171A CN 201110273417 A CN201110273417 A CN 201110273417A CN 102393494 A CN102393494 A CN 102393494A
Authority
CN
China
Prior art keywords
transformer
voltage
short
impedance
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN2011102734171A
Other languages
Chinese (zh)
Inventor
何为
陈民铀
李霞
叶君
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
QUZHOU POWER SUPPLY BUREAU
Chongqing University
Original Assignee
Chongqing University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chongqing University filed Critical Chongqing University
Priority to CN2011102734171A priority Critical patent/CN102393494A/en
Publication of CN102393494A publication Critical patent/CN102393494A/en
Pending legal-status Critical Current

Links

Images

Abstract

The invention belongs to the technical field of power systems and particularly relates to an online measurement method for the true capacity of a transformer. The measurement method is disclosed by aiming at the conditions that the nameplate of the transformer can possibly lose in practical operation, the capacity of the nameplate does not coincide with the true capacity and the like. The online measurement method for the true capacity of the transformer has the measurement principle that the relation between the short-circuit impedance and the primary and secondary voltage current of the transformer is deduced through analyzing the equivalent circuit model of the transformer. In order to avoid performing online measurement on the high-voltage side signal of the transformer, an ideal alternating current power supply signal is utilized by the online measurement method for the true capacity of the transformer to replace the high-voltage side voltage of the transformer according to the characteristic that the high-voltage side voltage hardly changes along with load when the transformer normally runs; then, acquired secondary voltage and current signals and ideal power supply signals are simply calculated, and obtained signals are further calculated in the manner of linear fit, thus, the short-circuit impedance of the transformer to be measured can be obtained, and finally, the true capacity of the transformer is calculated by utilizing a short-circuit impedance method. By adopting the measurement method, the disadvantage of measuring the capacity of the transformer when a power supply is interrupted is overcome, and the safety of the online measurement technology is greatly improved.

Description

Transformer capacity On-line Measuring Method and system
Technical field
The present invention relates to technical field of power systems, be specifically related to a kind of transformer capacity On-line Measuring Method, also relate to a kind of transformer capacity on-line measurement system simultaneously.
Background technology
The transformer rated capacity is characterizing the size of transformer electric energy transmitting.The selection of transformer capacity is that power supply department is taken all factors into consideration according to the ability to bear of position resolver, load and Normal Overload Capability of Oil, accident overload and the requirement of Transformer Economic operation.But have two kinds of phenomenons in the market: 1) some change high capacity into low capacity so that hand over basic charge as per installed capacity less with electric unit change transformer famous brand capacity; 2) minority transformer production enterprise pretends to be high capacity, low-loss transformer to reach the purpose of profit with the transformer of low capacity, high loss in producing bid.Above-mentioned situation brings some illegal profits for indivedual enterprises, seriously influences but power supply department and electrical network caused.
Need a kind of efficient pressure swing device capacity test method to the problems referred to above.The method of testing of transformer capacity mainly contains loss relative method, impedance voltage method and element method at present, but these methods are all measured under off-line state.When existing, the distribution transformer capacity for networking operation queries; In the time of need testing it; Adopt power-off method that transformer capacity is measured the very big drawback of existence, not only waste lot of manpower and material resources, and do not meet the requirement of power grid security, reliable, economy, uninterrupted power supply.
Summary of the invention
In view of this; One of the object of the invention provides a kind of transformer capacity On-line Measuring Method; Can be under the situation that does not reduce measuring accuracy; Only utilize step down side voltage, current signal to realize the on-line measurement of its capacity, and the measurement of need not cutting off the power supply, thereby the dirigibility that this method is utilized strengthened greatly; Two of the object of the invention provides a kind of transformer capacity on-line measurement system.
One of the object of the invention is realized through following technical scheme:
This transformer capacity On-line Measuring Method comprises the following steps:
Step 1: set up the transformer equivalent circuit model, obtain short-circuit impedance and the former and deputy polygonal voltage of transformer of transformer, the relational model between the electric current according to circuit model;
Relational model between the former and deputy polygonal voltage of said short-circuit impedance and transformer, the electric current is based on following relational expression:
Figure 395002DEST_PATH_IMAGE001
；
In the formula, z 1It is the impedance of a winding;
Figure 764804DEST_PATH_IMAGE002
,
Figure 717716DEST_PATH_IMAGE003
Be primary side voltage, current value;
Figure 514771DEST_PATH_IMAGE004
, Be secondary side voltage, current value;
Figure 107219DEST_PATH_IMAGE006
, For secondary side voltage, electric current in primary side reduction value;
Figure 148173DEST_PATH_IMAGE008
Be exciting current; kBe no-load voltage ratio; z kBe short-circuit impedance;
Step 2: through online acquisition transformer primary side voltage and secondary side voltage, current signal; Obtain can be used for the voltage and current signal of mathematical operation through conversion; Utilize desirable AC constant voltage source signal to replace the primary side voltage signal of transformer to be measured; Then the voltage that collects, current signal and desirable constant pressure source signal are carried out calculation process; Signal after handling is carried out linear fit,, obtain the value of the short-circuit impedance of transformer in real time in conjunction with the relation between the short-circuit impedance of transformer and the former and deputy polygonal voltage of transformer, the electric current;
Step 3: utilize short circuit impedance method to calculate the true capacity of transformer to be measured, realize the on-line measurement of transformer capacity.
Further, in step 1, the relational expression of said short-circuit impedance polygonal voltage former and deputy with it, electric current obtains through following steps:
1) can obtain following relational expression according to transformer T type equivalent-circuit model:
Figure 244305DEST_PATH_IMAGE009
，
Wherein: z 1It is the impedance of a winding; z 21Be the reduction value of Secondary Winding impedance at primary side;
Figure 768958DEST_PATH_IMAGE002
,
Figure 634146DEST_PATH_IMAGE003
Be primary side voltage, current value; ,
Figure 418748DEST_PATH_IMAGE005
Be secondary side voltage, current value; ,
Figure 466787DEST_PATH_IMAGE007
For secondary side voltage, electric current in primary side reduction value; z mBe excitation impedance;
Figure 776546DEST_PATH_IMAGE008
Be exciting current; kBe no-load voltage ratio; z 1+ z 2Be short-circuit impedance;
2) order z k= z 1+ z 2, can make up following relational expression according to step 1):
Figure 909587DEST_PATH_IMAGE010
；
3) according to step 2) relational expression and
Figure 962993DEST_PATH_IMAGE011
that obtain;
Figure 615823DEST_PATH_IMAGE012
can get:
，
Be in the formula
Figure 451241DEST_PATH_IMAGE013
Value with
Figure 308338DEST_PATH_IMAGE014
Value linear, and no-load voltage ratio is z k
Further, said step 2 specifically may further comprise the steps:
21) with an ideal voltage source that equates with transformer high-voltage side signal U s Replace transformer high-voltage side voltage signal;
22) gather the Circuit Fault on Secondary Transformer voltage signal U 2With the secondary side current signal I 2
23) with step 22) in the secondary side signal that obtains and the desirable constant pressure source of substituting disposable side voltage signal U s Carry out mathematic(al) manipulation, obtain signal: U s- KU 2With I 2/ k, wherein kBe no-load voltage ratio;
24) according to step 23) the middle AC signal that obtains U s- KU 2With I 2/ k, can get through linear fit:
Figure 812744DEST_PATH_IMAGE015
；
25) combine following two formulas, the value that can get the transformer short-circuit impedance is z k= a,
Figure 464306DEST_PATH_IMAGE016
，
Figure 509622DEST_PATH_IMAGE001
；
Further, step 3 comprises following concrete steps:
31) obtain the impedance voltage
Figure 967148DEST_PATH_IMAGE017
of transformer through following formula:
Figure 515941DEST_PATH_IMAGE018
Wherein, S n ---the transformer rated capacity;
z k ---the transformer short-circuit impedance;
U n ---the transformer rated voltage;
I n ---the transformer rated current.
32) according to step 31) relational expression that obtains can make up following relational expression:
Figure 417032DEST_PATH_IMAGE019
，
Following formula middle impedance voltage is the value under the reference temperature;
33) according to step 32) in the requirement actual measurement short-circuit impedance z of relational expression kValue also reduction to reference to the temperature under value, the reduction formula is following:
Figure 684065DEST_PATH_IMAGE020
，
Wherein:
Figure 945282DEST_PATH_IMAGE021
,
Figure 348582DEST_PATH_IMAGE022
Be the short-circuit impedance under the observed temperature, short-circuit resistance; K t Be temperature coefficient, computing formula is following:
Figure 420574DEST_PATH_IMAGE023
；
34) according to step 32) relational expression that obtains, the impedance voltage of given transformer U k (%), transformer rated voltage U n , the short-circuit impedance that combines abovementioned steps to try to achieve then z k , according to step 33) and reduction is the value under the reference temperature, according to step 32) calculate the rated capacity that can obtain transformer.
Two of the object of the invention is realized through following technical scheme:
This transformer capacity on-line measurement system comprises
The Modeling Calculation unit; Set up the transformer equivalent circuit model; Obtain short-circuit impedance and the former and deputy polygonal voltage of transformer of transformer, the relational model between the electric current according to circuit model, and the relational model between transformer short-circuit impedance and short circuit loss and the open circuit loss;
The online acquisition unit is used to gather transformer primary side voltage and secondary side voltage, current signal;
Short-circuit impedance value computing unit; With the transformer primary side voltage of online acquisition and secondary side voltage, current signal; Obtain can be used for the voltage and current signal of mathematical operation through conversion; With the voltage and current signal through linear fit, the relational model between the short-circuit impedance that combines transformer and the former and deputy polygonal voltage of transformer, the electric current, the value that obtains the short-circuit impedance of substation transformer is also exported;
The transformer capacity computing unit according to the value of short-circuit impedance, utilizes short circuit impedance method to calculate the true capacity of transformer to be measured.
Further, the relational model of said short-circuit impedance and the true rated capacity of transformer is based on following relational expression:
Figure 174904DEST_PATH_IMAGE024
;
In the formula, U n Be the transformer load voltage value; U k (%) be transformer impedance drop; z k The transformer short-circuit resistance value that calculates for online fitting.
The invention has the beneficial effects as follows:
1) the present invention utilizes the ideal signal source to replace transformer high-voltage side voltage signal; Under the situation that does not reduce measuring accuracy; Overcome the shortcoming of utilizing high-side signal to carry out on-line measurement; The present invention only utilizes step down side voltage, current signal to realize the on-line measurement of its capacity, has improved the safe reliability of online measuring technique greatly, has further reduced the financial cost of online measuring technique;
2) the present invention can accomplish the online capacity measurement to transformer in service under the situation of not cutting off the power supply, thereby has increased the dirigibility that method is utilized greatly, and has reduced the human cost of measuring, and has higher popularization and application values.
Other advantages of the present invention, target and characteristic will be set forth in instructions subsequently to a certain extent; And to a certain extent; Based on being conspicuous to those skilled in the art, perhaps can from practice of the present invention, obtain instruction to investigating of hereinafter.Target of the present invention and other advantages can realize and obtain through following instructions and claims.
Description of drawings
In order to make the object of the invention, technical scheme and advantage clearer, will combine accompanying drawing that the present invention is made further detailed description below, wherein:
Fig. 1 transformer equivalent circuit model;
Fig. 2 Y, yn0 connects the Transformer Winding wiring diagram;
Fig. 3 Y, d11 connects the Transformer Winding wiring diagram;
Fig. 4 is the three-phase voltage current fitting curve synoptic diagram of three-phase transformer.
Embodiment
Below will carry out detailed description to the preferred embodiments of the present invention with reference to accompanying drawing.Should be appreciated that preferred embodiment has been merely explanation the present invention, rather than in order to limit protection scope of the present invention.
Transformer capacity On-line Measuring Method of the present invention comprises the following steps:
Step 1:Set up the transformer equivalent circuit model, obtain short-circuit impedance and the former and deputy polygonal voltage of transformer of transformer, the relational model between the electric current according to circuit model;
Relational model between the former and deputy polygonal voltage of said short-circuit impedance and transformer, the electric current is based on following relational expression:
Figure 974232DEST_PATH_IMAGE001
；
In the formula, z 1It is the impedance of a winding; ,
Figure 740511DEST_PATH_IMAGE003
Be primary side voltage, current value;
Figure 716558DEST_PATH_IMAGE004
,
Figure 257260DEST_PATH_IMAGE005
Be secondary side voltage, current value;
Figure 963048DEST_PATH_IMAGE006
,
Figure 298215DEST_PATH_IMAGE007
For secondary side voltage, electric current in primary side reduction value;
Figure 837256DEST_PATH_IMAGE008
Be exciting current; kBe no-load voltage ratio; z k Short-circuit impedance;
Step 2:Through online acquisition transformer primary side voltage and secondary side voltage, current signal; Obtain can be used for the voltage and current signal of mathematical operation through conversion; Utilize desirable AC constant voltage source signal to replace the primary side voltage signal of transformer to be measured; Then the voltage that collects, current signal and desirable constant pressure source signal are carried out calculation process; Signal after handling is carried out linear fit,, obtain the value of the short-circuit impedance of transformer in real time in conjunction with the relation between the short-circuit impedance of transformer and the former and deputy polygonal voltage of transformer, the electric current;
Particularly, said step 2 specifically may further comprise the steps:
21) with an ideal voltage source that equates with transformer high-voltage side signal U s Replace transformer high-voltage side voltage signal;
22) gather the Circuit Fault on Secondary Transformer voltage signal U 2With the secondary side current signal I 2Promptly change the load of single transformer within the specific limits, ideal voltage source voltage under the record different loads situation
Figure 916070DEST_PATH_IMAGE025
And the secondary side voltage of transformer
Figure 476365DEST_PATH_IMAGE026
, secondary side current
Figure 982432DEST_PATH_IMAGE027
, wherein i=1,2,3 ... N, n is for measuring number of times;
23) with step 22) in the secondary side signal that obtains and the desirable constant pressure source of substituting disposable side voltage signal U s Carry out mathematic(al) manipulation, obtain signal: can get
Figure 198650DEST_PATH_IMAGE028
With
Figure 894205DEST_PATH_IMAGE029
, wherein kBe no-load voltage ratio;
24) according to step 23) middle AC signal
Figure 246689DEST_PATH_IMAGE030
and
Figure 251554DEST_PATH_IMAGE029
that obtains; With
Figure 689488DEST_PATH_IMAGE029
is dependent variable, and
Figure 110105DEST_PATH_IMAGE030
can get for carrying out linear fit from variable:
Figure 395724DEST_PATH_IMAGE016
；
25) combine following two formulas, the value that can get the transformer short-circuit impedance does z k = a,
Figure 243595DEST_PATH_IMAGE016
，
Figure 231142DEST_PATH_IMAGE001
。
Step 3:Utilize short circuit impedance method to calculate the true capacity of transformer to be measured, realize the on-line measurement of transformer capacity.
Particularly, step 3 may further comprise the steps:
31) obtain the impedance voltage
Figure 455450DEST_PATH_IMAGE017
of transformer through following formula:
Wherein,
Figure 879926DEST_PATH_IMAGE032
---transformer rated capacity;
---transformer short-circuit impedance;
Figure 950747DEST_PATH_IMAGE034
---transformer rated voltage;
Figure 132329DEST_PATH_IMAGE035
---transformer rated current.
32) according to step 31) relational expression that obtains can make up following relational expression:
Figure 649898DEST_PATH_IMAGE019
，
Following formula middle impedance voltage is the value under the reference temperature;
33) according to step 32) in the requirement actual measurement short-circuit impedance of relational expression z k Value also reduction to reference to the temperature under value, the reduction formula is following:
，
Wherein:
Figure 115832DEST_PATH_IMAGE021
, Be the short-circuit impedance under the observed temperature, short-circuit resistance; K t Be temperature coefficient, computing formula is following:
Figure 591124DEST_PATH_IMAGE037
；
34) according to step 32) relational expression that obtains, the impedance voltage of given transformer U k (%), transformer rated voltage U n , the short-circuit impedance that combines abovementioned steps to try to achieve then z k , according to step 33) and reduction is the value under the reference temperature, according to step 32) calculate the rated capacity that can obtain transformer.
About further specifying of step 1:
A. in step 1), the relational expression of said short-circuit impedance polygonal voltage former and deputy with it, electric current obtains through following steps:
1) accompanying drawing 1 is single transformer T type equivalent-circuit model figure, can obtain following relational expression according to transformer T type equivalent-circuit model:
，
Wherein: z 1It is the impedance of a winding; z 21Be the reduction value of Secondary Winding impedance at primary side;
Figure 144782DEST_PATH_IMAGE002
,
Figure 114006DEST_PATH_IMAGE003
Be primary side voltage, current value;
Figure 911061DEST_PATH_IMAGE004
,
Figure 519897DEST_PATH_IMAGE005
Be secondary side voltage, current value;
Figure 755706DEST_PATH_IMAGE006
,
Figure 766387DEST_PATH_IMAGE007
For secondary side voltage, electric current in primary side reduction value; z mBe excitation impedance; Be exciting current; kBe no-load voltage ratio; z 1+ z 2Be short-circuit impedance;
2) order z k = z 1+ z 2, can make up following relational expression according to step 1):
Figure 643524DEST_PATH_IMAGE039
；
3) according to step 2) relational expression and
Figure 89549DEST_PATH_IMAGE011
that obtain;
Figure 282633DEST_PATH_IMAGE012
can get:
，
When transformer is operated in the range of linearity of magnetization curve, can think that excitation impedance is constant, and since the primary side impedance much smaller than excitation impedance, so exciting current is proportional to
Figure 815038DEST_PATH_IMAGE041
, approximate being proportional to
Figure 64754DEST_PATH_IMAGE042
So, exciting current
Figure 112344DEST_PATH_IMAGE043
Can think approximate constant, because the impedance of transformer first side winding z 1Be a constant value, so in following formula
Figure 422103DEST_PATH_IMAGE044
Can be considered an approximate constant amount.Be in the formula
Figure 492827DEST_PATH_IMAGE045
Value with
Figure 359283DEST_PATH_IMAGE046
Value linear, and no-load voltage ratio is z k
About further specifying of step 2:
A. particularly, Y, the three-phase transformer short-circuit impedance that yn0 connects can obtain through following steps:
1) accompanying drawing 2 is Y; The three-phase transformer winding connection figure that yn0 connects; Replace single transformer high side voltage signal with a three-phase ideal voltage source that equates with three-phase transformer high side voltage signal : ,
Figure 34481DEST_PATH_IMAGE049
,
Figure 704628DEST_PATH_IMAGE050
; Measure three-phase transformer low-pressure side voltage under the different loads situation then:
Figure 398915DEST_PATH_IMAGE051
, , ; Low-pressure side electric current:
Figure 553318DEST_PATH_IMAGE054
, ,
Figure 3202DEST_PATH_IMAGE056
; I=1 wherein; 2; 3, n.
2) according to 22 in the step 2), 23), 24) can get:
Figure 332552DEST_PATH_IMAGE057
,
Figure 265873DEST_PATH_IMAGE058
,
Figure 934752DEST_PATH_IMAGE059
; With it is from variable, is that dependent variable is carried out linear fit and can be obtained following three relational expressions with
Figure 3815DEST_PATH_IMAGE060
,
Figure 492565DEST_PATH_IMAGE061
,
Figure 557473DEST_PATH_IMAGE062
:
Figure 58173DEST_PATH_IMAGE064
Wherein, kBe the no-load voltage ratio of transformer, can obtain by above three relational expressions a 1, a 2, a 3Three values, calculating three's mean value, this is worth promptly the short-circuit impedance value of three-phase distribution transformer for this reason, that is:
Figure 840501DEST_PATH_IMAGE066
B.Y, the three-phase transformer short-circuit impedance that d connects can obtain through following steps:
1) accompanying drawing 3 is Y, and the three-phase transformer winding connection figure that d11 connects is converted into phase current to the secondary side line current of the three-phase transformer that records, among the figure, i La, i Lb, i LcBe line current, can be expressed as:
Figure 280709DEST_PATH_IMAGE067
;
2), can obtain following relational expression according to Kirchhoff's law by accompanying drawing 3:
Figure 881455DEST_PATH_IMAGE068
，
3) according to above-mentioned steps 1) and step 2) relational expression that obtains can obtain following relational expression:
;
4) according to Y, the step 2 of the three-phase transformer short-circuit impedance computing method that yn0 connects) can obtain the three-phase transformer short-circuit impedance value that Yd or Ydn connect.
Based on the thought of said method, a kind of transformer capacity on-line measurement system that the present invention proposes comprises
The Modeling Calculation unit; Set up the transformer equivalent circuit model; Obtain short-circuit impedance and the former and deputy polygonal voltage of transformer of transformer, the relational model between the electric current according to circuit model, and the relational model between transformer short-circuit impedance and short circuit loss and the open circuit loss;
The online acquisition unit is used to gather Circuit Fault on Secondary Transformer voltage, current signal;
Short-circuit impedance value computing unit; Desired voltage source signal with Circuit Fault on Secondary Transformer voltage, current signal and the substituting disposable side of online acquisition; Obtain can be used for the voltage and current signal of mathematical operation through conversion; The voltage and current signal that will pass through mathematical operation in conjunction with the relational model between the former and deputy polygonal voltage of transformer, the electric current, obtains the value of the short-circuit impedance of substation transformer through linear fit;
The transformer capacity computing unit according to the value of short-circuit impedance, utilizes short circuit impedance method to calculate the true capacity of transformer to be measured.
Wherein, the relational model between said short-circuit impedance and transformer secondary voltage, the electric current is based on following relational expression:
Figure 564557DEST_PATH_IMAGE070
；
In the formula, z 1It is the impedance of a winding;
Figure DEST_PATH_IMAGE071
For replacing ideal voltage source magnitude of voltage, the current value of transformer primary side voltage; ,
Figure 381652DEST_PATH_IMAGE005
Be secondary side voltage, current value;
Figure 660186DEST_PATH_IMAGE006
, For secondary side voltage, electric current in primary side reduction value;
Figure 705295DEST_PATH_IMAGE008
Be exciting current; kBe no-load voltage ratio; z k Be short-circuit impedance.
AsShown in Figure 4, this figure is the electric current and voltage matched curve figure (each point wherein begins from top for the measured value of each phase among the figure, and B phase, C arrange with A fit line mutually mutually from top to bottom) of the three-phase transformer of 10kV level S9 series 30kvA, this diagram be with
Figure 382264DEST_PATH_IMAGE072
Be dependent variable,
Figure 820199DEST_PATH_IMAGE046
For carry out each phase fit line that linear fit obtains from variable, by knowing that the slope of fit line is the short-circuit impedance value of the transformer of being asked to be measured among the figure.
 
Explanation is at last; Above embodiment is only unrestricted in order to technical scheme of the present invention to be described; Although with reference to preferred embodiment the present invention is specified, those of ordinary skill in the art should be appreciated that and can make amendment or be equal to replacement technical scheme of the present invention; And not breaking away from the aim and the scope of present technique scheme, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (6)

1. the transformer capacity On-line Measuring Method is characterized in that: comprise the following steps:
Step 1: set up the transformer equivalent circuit model, obtain short-circuit impedance and the former and deputy polygonal voltage of transformer of transformer, the relational model between the electric current according to circuit model;
Relational model between the former and deputy polygonal voltage of said short-circuit impedance and transformer, the electric current is based on following relational expression:
Figure 456494DEST_PATH_IMAGE001
；
In the formula, z 1It is the impedance of a winding;
Figure 373634DEST_PATH_IMAGE002
,
Figure 966420DEST_PATH_IMAGE003
Be primary side voltage, current value;
Figure 361630DEST_PATH_IMAGE004
,
Figure 176002DEST_PATH_IMAGE005
Be secondary side voltage, current value; ,
Figure 327815DEST_PATH_IMAGE007
For secondary side voltage, electric current in primary side reduction value;
Figure 339764DEST_PATH_IMAGE008
Be exciting current; kBe no-load voltage ratio; z k Be short-circuit impedance;
Step 2: through online acquisition transformer primary side voltage and secondary side voltage, current signal; Obtain can be used for the voltage and current signal of mathematical operation through conversion; Utilize desirable AC constant voltage source signal to replace the primary side voltage signal of transformer to be measured; Then the voltage that collects, current signal and desirable constant pressure source signal are carried out calculation process; Signal after handling is carried out linear fit,, obtain the value of the short-circuit impedance of transformer in real time in conjunction with the relation between the short-circuit impedance of transformer and the former and deputy polygonal voltage of transformer, the electric current;
Step 3: utilize short circuit impedance method to calculate the true capacity of transformer to be measured, realize the on-line measurement of transformer capacity.
2. transformer capacity On-line Measuring Method according to claim 1 is characterized in that:
In step 1, the relational expression of said short-circuit impedance polygonal voltage former and deputy with it, electric current obtains through following steps:
1) can obtain following relational expression according to transformer T type equivalent-circuit model:
，
Wherein: z 1It is the impedance of a winding; z 21Be the reduction value of Secondary Winding impedance at primary side;
Figure 64324DEST_PATH_IMAGE002
,
Figure 818653DEST_PATH_IMAGE003
Be primary side voltage, current value;
Figure 365784DEST_PATH_IMAGE004
,
Figure 889170DEST_PATH_IMAGE005
Be secondary side voltage, current value;
Figure 319014DEST_PATH_IMAGE006
,
Figure 622956DEST_PATH_IMAGE007
For secondary side voltage, electric current in primary side reduction value; z m Be excitation impedance;
Figure 898080DEST_PATH_IMAGE008
Be exciting current; kBe no-load voltage ratio; z 1+ z 2Be short-circuit impedance;
2) order z k = z 1+ z 2Can make up following relational expression according to step 1):
Figure 354600DEST_PATH_IMAGE010
；
3) according to step 2) relational expression and
Figure 689767DEST_PATH_IMAGE011
that obtain;
Figure 418688DEST_PATH_IMAGE012
can get:
Figure 559819DEST_PATH_IMAGE013
，
Be in the formula
Figure 57797DEST_PATH_IMAGE014
Value with
Figure 829444DEST_PATH_IMAGE015
Value linear, and no-load voltage ratio does z k
3. transformer capacity On-line Measuring Method according to claim 2 is characterized in that: said step 2 specifically may further comprise the steps:
21) with an ideal voltage source that equates with transformer high-voltage side signal U s Replace transformer high-voltage side voltage signal;
22) gather the Circuit Fault on Secondary Transformer voltage signal U 2With the secondary side current signal I 2
23) with step 22) in the secondary side signal that obtains and the desirable constant pressure source of substituting disposable side voltage signal U s Carry out mathematic(al) manipulation, obtain signal: U s- KU 2With I 2/ k, wherein kBe no-load voltage ratio;
24) according to step 23) the middle AC signal that obtains U s- KU 2With I 2/ k, can get through linear fit:
；
25) combine following two formulas, the value that can get the transformer short-circuit impedance is z k= a,
Figure 475637DEST_PATH_IMAGE016
，
Figure 890438DEST_PATH_IMAGE013
。
4. according to claim 1 or 2 or 3 described transformer capacity On-line Measuring Method, it is characterized in that: step 3 comprises following concrete steps:
31) obtain the impedance voltage
Figure 832986DEST_PATH_IMAGE017
of transformer through following formula:
Figure 270921DEST_PATH_IMAGE018
Wherein, S n ---the transformer rated capacity;
z k ---the transformer short-circuit impedance;
U n ---the transformer rated voltage;
I n ---the transformer rated current;
32) according to step 31) relational expression that obtains can make up following relational expression:
Figure 504587DEST_PATH_IMAGE019
，
Following formula middle impedance voltage is the value under the reference temperature;
33) according to step 32) in the requirement actual measurement short-circuit impedance z of relational expression kThe value reduction to reference to the temperature under value, the reduction formula is following:
Figure 977157DEST_PATH_IMAGE020
，
Wherein:
Figure 152923DEST_PATH_IMAGE021
,
Figure 78154DEST_PATH_IMAGE022
Be the short-circuit impedance under the observed temperature, short-circuit resistance; K t Be temperature coefficient, computing formula is following:
Figure 112581DEST_PATH_IMAGE023
；
34) according to step 32) relational expression that obtains, the impedance voltage of given transformer U k (%), transformer rated voltage U n , the short-circuit impedance z that combines abovementioned steps to try to achieve then k, according to step 33) and reduction is the value under the reference temperature, according to step 32) calculate the rated capacity that can obtain transformer.
5. transformer capacity on-line measurement system, it is characterized in that: said system comprises
The Modeling Calculation unit; Set up the transformer equivalent circuit model; Obtain short-circuit impedance and the former and deputy polygonal voltage of transformer of transformer, the relational model between the electric current according to circuit model, and the relational model between transformer short-circuit impedance and short circuit loss and the open circuit loss;
The online acquisition unit is used to gather Circuit Fault on Secondary Transformer voltage, current signal;
Short-circuit impedance value computing unit; Desired voltage source signal with Circuit Fault on Secondary Transformer voltage, current signal and the substituting disposable side voltage signal of online acquisition; Obtain can be used for the voltage and current signal of mathematical operation through conversion; The voltage and current signal of mathematical operation gained through linear fit, in conjunction with the relational model between the short-circuit impedance of transformer and the former and deputy polygonal voltage of transformer, the electric current, is obtained the value of the short-circuit impedance of substation transformer;
The transformer capacity computing unit according to the value of short-circuit impedance, utilizes short circuit impedance method to calculate the true capacity of transformer to be measured.
6. transformer capacity on-line measurement system according to claim 5 is characterized in that: the relational model of said short-circuit impedance and the true rated capacity of transformer is based on following relational expression:
Figure 174078DEST_PATH_IMAGE019
;
In the formula, U n Be the transformer load voltage value; U k (%) be transformer impedance drop; z k The transformer short-circuit resistance value that calculates for online fitting.
CN2011102734171A 2011-09-15 2011-09-15 Online measurement method and system for capacity of transformer Pending CN102393494A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2011102734171A CN102393494A (en) 2011-09-15 2011-09-15 Online measurement method and system for capacity of transformer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2011102734171A CN102393494A (en) 2011-09-15 2011-09-15 Online measurement method and system for capacity of transformer

Publications (1)

Publication Number Publication Date
CN102393494A true CN102393494A (en) 2012-03-28

Family

ID=45860853

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2011102734171A Pending CN102393494A (en) 2011-09-15 2011-09-15 Online measurement method and system for capacity of transformer

Country Status (1)

Country Link
CN (1) CN102393494A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102721898A (en) * 2012-02-27 2012-10-10 衢州电力局 On-line measurement method and on-line measurement system for deformation of transformer winding
CN103063963A (en) * 2012-12-30 2013-04-24 保定市汇邦电气有限公司 Testing method of transformer capacity
CN103779059A (en) * 2013-12-17 2014-05-07 国网上海市电力公司 Dynamic capacity increasing method for oil-immersed transformer
CN105717387A (en) * 2015-11-27 2016-06-29 国网河南宜阳县供电公司 Test apparatus and method for online measurement of transformer loss
CN106093642A (en) * 2016-06-08 2016-11-09 福州大学 Capacitance characteristic measuring circuit under a kind of any AC carrier and method thereof
CN106291195A (en) * 2016-08-31 2017-01-04 昆明耀龙置信变压器制造有限公司 A kind of Intellectualized starting functional transformer comprehensive test device
WO2017041572A1 (en) * 2015-09-08 2017-03-16 中国电力科学研究院 Improved distribution transformer energy efficiency measurement testing method, device and storage medium
CN108303606A (en) * 2018-01-02 2018-07-20 国网江西省电力有限公司电力科学研究院 A kind of distribution transformer capacity online evaluation method
CN109975607A (en) * 2019-02-19 2019-07-05 国网江西省电力有限公司电力科学研究院 Power distribution station capacity recognition methods, device, storage medium and electronic equipment
CN110196370A (en) * 2019-06-26 2019-09-03 山东电工电气集团智能电气有限公司 The monitoring method and device of transformer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5532961A (en) * 1978-08-29 1980-03-07 Toyota Central Res & Dev Lab Inc Leak detection method and apparatus for high-voltage circuit of internal combustion engine ignition system
JPS60114775A (en) * 1983-11-28 1985-06-21 Toshiba Corp Apparatus for detecting deterioration of non-linear resistance element
CN102053203A (en) * 2010-11-04 2011-05-11 武汉国测恒通智能仪器有限公司 Detection method and device for high-voltage power quality

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5532961A (en) * 1978-08-29 1980-03-07 Toyota Central Res & Dev Lab Inc Leak detection method and apparatus for high-voltage circuit of internal combustion engine ignition system
JPS60114775A (en) * 1983-11-28 1985-06-21 Toshiba Corp Apparatus for detecting deterioration of non-linear resistance element
CN102053203A (en) * 2010-11-04 2011-05-11 武汉国测恒通智能仪器有限公司 Detection method and device for high-voltage power quality

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
XIA LI: "a novel method for online measuring the short-circuit impedance of distribution transformers", 《ADVANCED MATERIALS RESEARCH》 *
吴喜红: "配电变压器损耗和容量在线检测方法研究", 《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》 *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102721898A (en) * 2012-02-27 2012-10-10 衢州电力局 On-line measurement method and on-line measurement system for deformation of transformer winding
CN103063963A (en) * 2012-12-30 2013-04-24 保定市汇邦电气有限公司 Testing method of transformer capacity
CN103063963B (en) * 2012-12-30 2015-11-18 保定市汇邦电气有限公司 A kind of transformer capacity method of testing
CN103779059A (en) * 2013-12-17 2014-05-07 国网上海市电力公司 Dynamic capacity increasing method for oil-immersed transformer
CN103779059B (en) * 2013-12-17 2015-12-30 国网上海市电力公司 A kind of dynamic compatibilization method of oil-filled transformer
WO2017041572A1 (en) * 2015-09-08 2017-03-16 中国电力科学研究院 Improved distribution transformer energy efficiency measurement testing method, device and storage medium
GB2556308A (en) * 2015-09-08 2018-05-23 China Electric Power Res Institute Company Limited Improved distribution transformer energy efficiency measurement testing method, device and storage medium
GB2556308B (en) * 2015-09-08 2021-09-15 China Electric Power Res Institute Company Limited Improved distribution transformer energy efficiency measurement testing method, device and storage medium
CN105717387A (en) * 2015-11-27 2016-06-29 国网河南宜阳县供电公司 Test apparatus and method for online measurement of transformer loss
CN106093642A (en) * 2016-06-08 2016-11-09 福州大学 Capacitance characteristic measuring circuit under a kind of any AC carrier and method thereof
CN106093642B (en) * 2016-06-08 2019-02-01 福州大学 Capacitance characteristic measuring circuit and its method under a kind of any AC carrier
CN106291195A (en) * 2016-08-31 2017-01-04 昆明耀龙置信变压器制造有限公司 A kind of Intellectualized starting functional transformer comprehensive test device
CN108303606A (en) * 2018-01-02 2018-07-20 国网江西省电力有限公司电力科学研究院 A kind of distribution transformer capacity online evaluation method
CN108303606B (en) * 2018-01-02 2020-05-22 国网江西省电力有限公司电力科学研究院 Online capacity evaluation method for distribution transformer
CN109975607A (en) * 2019-02-19 2019-07-05 国网江西省电力有限公司电力科学研究院 Power distribution station capacity recognition methods, device, storage medium and electronic equipment
CN110196370A (en) * 2019-06-26 2019-09-03 山东电工电气集团智能电气有限公司 The monitoring method and device of transformer
CN110196370B (en) * 2019-06-26 2021-05-04 山东电工电气集团智能电气有限公司 Transformer monitoring method and device

Similar Documents

Publication Publication Date Title
CN102393494A (en) Online measurement method and system for capacity of transformer
CN102721898A (en) On-line measurement method and on-line measurement system for deformation of transformer winding
CN102435858A (en) Method and system for online measurement of short-circuit loss and open-circuit loss of transformer
CN102680798B (en) Online measurement method and device for grounding resistor of rod tower
CN103995962A (en) Online real-time calculation and analysis method of equipped wire loss
CN102208807A (en) Medium and low voltage distribution network energy efficiency evaluation method based on accurate load measurement data
CN103364692B (en) A kind of power distribution network single-phase grounded malfunction in grounded system selection method
CN102497021A (en) Real-time monitoring and analysis system for distribution circuit
CN103713210A (en) Dry power transformer monitoring and diagnosis system
CN108988367A (en) A kind of H-type wiring capacitance device group degree of unbalancedness leveling method
CN104297616A (en) 10kV distribution line breaking detection method based on multi-system information interaction
CN104466972B (en) Voltage reactive distribution type control method making substation and power distribution network being harmonious
CN107248736A (en) A kind of on-line identification method of the positive order parameter of distribution network line
CN204575811U (en) A kind of test macro of high-voltage switch contact
CN102901868A (en) Method for electric energy acquisition system data checking
Priya et al. Design and development of distance protection scheme for wind power distributed generation
CN103679551B (en) Method for on-line calculation of power flow of power distribution network
CN105223470B (en) A kind of Distribution Network Failure localization method based on failure high-frequency information
CN110333409A (en) The online test method of distribution transformer rated capacity
CN103972889B (en) A kind of distribution line impedance on-line identification method
CN107292759A (en) Distribution network planning based on power supply reliability calculates analysis system
CN105606897A (en) Branch insulating impedance monitoring and PV power generation method, inverter and PV power generation system
CN104459247A (en) Split-phase line loss management method of intelligent ammeter without automatic split-phase function
CN102420426B (en) Power grid partial loss reduction method based on injection power sensitivity
CN203870165U (en) Double-transformation-ratio access type electric energy meter

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
ASS Succession or assignment of patent right

Owner name: QUZHOU POWER SUPPLY BUREAU

Free format text: FORMER OWNER: CHONGQING UNIVERSITY

Effective date: 20130327

Owner name: CHONGQING UNIVERSITY

Effective date: 20130327

C41 Transfer of patent application or patent right or utility model
C53 Correction of patent of invention or patent application
CB03 Change of inventor or designer information

Inventor after: Wang Yuezhong

Inventor after: Lou Fengdan

Inventor after: He Wei

Inventor after: Chen Minyou

Inventor after: Li Xia

Inventor after: Ye Jun

Inventor before: He Wei

Inventor before: Chen Minyou

Inventor before: Li Xia

Inventor before: Ye Jun

COR Change of bibliographic data

Free format text: CORRECT: INVENTOR; FROM: HE WEI CHEN MINYOU LI XIA YE JUN TO: WANG YUEZHONG LOU FENGDAN HE WEI CHEN MINYOU LI XIA YE JUN

Free format text: CORRECT: ADDRESS; FROM: 400044 SHAPINGBA, CHONGQING TO: 324000 QUZHOU, ZHEJIANG PROVINCE

TA01 Transfer of patent application right

Effective date of registration: 20130327

Address after: 324000 No. 6, New River, Quzhou, Zhejiang

Applicant after: Quzhou Power Supply Bureau

Applicant after: Chongqing University

Address before: 400044 Shapingba street, Shapingba District, Chongqing, No. 174

Applicant before: Chongqing University

WD01 Invention patent application deemed withdrawn after publication
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20120328