CN105468858A - Structural transformer fault diagnosis method based on finite element simulation and field test - Google Patents

Structural transformer fault diagnosis method based on finite element simulation and field test Download PDF

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Publication number
CN105468858A
CN105468858A CN201510864608.3A CN201510864608A CN105468858A CN 105468858 A CN105468858 A CN 105468858A CN 201510864608 A CN201510864608 A CN 201510864608A CN 105468858 A CN105468858 A CN 105468858A
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China
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transformer
finite
simulation
circuit
electric
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CN201510864608.3A
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Chinese (zh)
Inventor
鲁非
史天如
周凯
金雷
刘思维
刘毅
李化
王珂
林福昌
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国家电网公司
国网湖北省电力公司电力科学研究院
华中科技大学
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Priority to CN201510864608.3A priority Critical patent/CN105468858A/en
Publication of CN105468858A publication Critical patent/CN105468858A/en

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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/30—Circuit design
    • G06F30/36—Circuit design at the analogue level
    • G06F30/367—Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods

Abstract

The invention provides a structural transformer fault diagnosis method based on finite element simulation and field test. The method comprises the following steps: a first step, establishing a transformer finite element model in finite element simulation software; a second step, simulating different structural faults in the transformer finite element model; a third step, resolving main electric parameters in a structural fault model, and establishing a relation of ''structural fault-electric parameter''; a fourth step, establishing a circuit model according to the resolved electric parameters to simulate a corresponding field test result, resolving frequency response curves and short circuit impedance of the transformer at different electric parameters by a simulation circuit model, and establishing a corresponding relationship of ''electric parameter-test result''; and a fifth step, establishing a corresponding relationship of the test result and the structural fault with the electric parameter as a middle variable. By adopting the structural transformer fault diagnosis method provided by the invention, the diagnosis reliability of the structural faults of the transformer is improved, and the problems that the cognition on the test result in inaccurate, and wrong judgment is present and the like in the field test are solved.

Description

Based on the transformer device structure method for diagnosing faults of finite element simulation and site test

Technical field

The present invention relates to transformer fault diagnosis technical field, specifically a kind of transformer device structure method for diagnosing faults based on finite element simulation and site test.

Background technology

Structural failure causes power transformer to be damaged the one of the main reasons of accident.The safe and stable operation that structural failure diagnosis can guarantee transformer is carried out to the transformer after transport or short-circuit impact.Transformer device structure fault off-line checking method conventional at present mainly contains frequency response method (FrequencyResponseAnalysis, FRA), short circuit impedance method (Short-CircuitImpedanceMethod, SCI) etc.Frequency response method can on wider frequency band Measurement and analysis circuit network frequency response characteristic thus judge winding state, there is higher sensitivity.Short circuit impedance method can reflect the radial deformation of coil, and have accumulated a large amount of field test datas.But, at present for the change of the site test results such as frequency response curve and short-circuit impedance basic reason and still require study with the corresponding relation of fault type, therefore there is the problem that test findings understanding is indefinite, there is erroneous judgement, causing trouble diagnostic reliability reduces.

Summary of the invention

Technical matters to be solved by this invention is to provide a kind of transformer device structure method for diagnosing faults combined with site test based on finite element simulation, to improve the reliability of transformer device structure fault diagnosis, solve indefinite to test findings understanding in site test, there is the problems such as erroneous judgement.

Based on a transformer device structure method for diagnosing faults for finite element simulation and site test, comprise the steps:

Step one, in finite element emulation software, set up transformer finite element model;

Step 2, in transformer finite element model, different structure fault to be simulated;

In step 3, the dissimilar and degree structural failure model that arranges in step 2, solve its main electrical parameters, set up the relation between " structural failure-electric parameter ";

Step 4, solve the electric parameter obtained according to transformer finite element model, set up the site test results that circuit-model simulation is corresponding, solved frequency response curve and the short-circuit impedance of transformer under different electric parameter by simulation circuit model, set up " electric parameter-test findings " corresponding relation;

Step 5, be intermediate variable with electric parameter, set up the corresponding relation of test findings and structural failure: by finite element model, dissimilar and degree structural failure are simulated, solve the change of its electric parameter, and then set up different circuit models, solved frequency response curve and the short-circuit impedance of transformer under different electric parameter by simulation circuit model, set up the corresponding relation of " structural failure-electric parameter-test findings ".

Further, the material behavior of main support is considered when setting up transformer finite element model in step one.

Further, by the structure of each parts in change transformer finite element model, relative position, connected mode, transformer common structure fault is simulated in step 2.

Further, described structural failure comprises short circuit between radial deformation, axial displacement, turn-to-turn short circuit, cake, imperfect earth.

Further, solve transformer electric parameter and mainly its capacitance matrix and inductance matrix carried out, in described finite element model transformer n line cake between electric capacity form the n rank capacitance matrix of transformer, wherein: C ijit is the coupling capacitance between i-th line cake and a jth line cake; C iibe the self-capacitance of i-th line cake, it mainly comprises the ground capacitance of line cake and the coupling capacitance sum with other line cakes, and the coupling capacitance between two line cakes is obtained by following formula:

C i j = 2 W i j V 2 = 1 2 ∫ Ω D i × E j d Ω

In formula, W ijfor electric field storage power, D ithe electric displacement density that i-th line cake is corresponding, E jfor the electric field intensity of jth line cake;

When foreign current is by means of only i-th line cake, its self-inductance L iiand resistance R iifollowing vector form can be described to:

U i ^ = I ^ i ( R i i + jωL i i )

In formula, ω is angular frequency, for induced voltage, the imaginary part of above formula is only associated with the self-inductance of i-th line cake, therefore obtains its self-inductance:

L i i = 1 ω Im ( U i ^ I ^ i )

In like manner, the coupling inductance between i-th line cake and a jth line cake is obtained by following formula:

M i j = 1 ω Im ( U j ^ I ^ i ) .

Further, the circuit model in step 4 comprises lumped parameter model, " field-Lu " coupling model, and lumped parameter model is used for simulation frequency response curve, and coupling magnetic field with electric circuit model is used for artificial short-circuits impedance.

The present invention proposes the fault diagnosis thinking based on " structural parameters-electric parameter-test findings ", by setting up transformer limit element artificial module, different structure fault type and different faults degree are emulated, solve the electric parameter under Different structural parameters, according to the electric parameter solved, set up the typical transformer field test of emulation (short-circuit impedance, frequency response) result, set up the corresponding relation of test findings and structural failure, realize transformer device structure fault diagnosis.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of the transformer device structure method for diagnosing faults that the present invention is based on finite element simulation and site test;

Fig. 2 is the transformer finite element model figure of the 110kV electric pressure of being built by AnsoftMaxwell software;

Fig. 3 is distortion winding wire cake schematic diagram;

Fig. 4 is axis of winding displacement diagram;

Fig. 5 is the capacitance matrix that finite element solving obtains;

Fig. 6 is frequency response method corresponding circuits illustraton of model;

Fig. 7 is short circuit impedance method corresponding circuits illustraton of model;

Frequency response curve corresponding when Fig. 8 is axial displacement fault 3%, 6% and 9%.

Embodiment

Below in conjunction with the accompanying drawing in the present invention, the technical scheme in the present invention is clearly and completely described.

Figure 1 shows that the schematic flow sheet of the transformer device structure method for diagnosing faults that the present invention is based on finite element simulation and site test, described method comprises the steps:

Step one, in finite element emulation software, set up transformer finite element model; Be different from general transformer realistic model, for Exact Solution is carried out in the electric parameter change caused transformer device structure Parameters variation, the present invention need set up the finite element model considering transformer real material characteristic.Except the structure such as transformer core, winding, this model also needs the material behavior considering main support (as stay, cushion block).

Fig. 2 is the transformer finite element model of the 110kV electric pressure of being built by AnsoftMaxwell software.This type transformer is 110/10.5kV, three-phase three-column oil immersed type core type transformer.Carry out support structure by stay between high and low pressure winding, each line cake is formed by the flat type copper wire surrounding empire paper, in simulation process, high-pressure side winding is set to 8 cakes, each cake 220 circle; Low pressure winding is set to 8 cakes, each cake 21 circle.

In Fig. 2, Corecrosssection is cross section of transformer core schematic diagram, and unshakable in one's determination by adopting DW360 type siliconized plate to consist of laminar, its BH curve is consistent with actual measurement with maintenance by outside input.In Fig. 2, Clamping is apparatus for fixing transformer, and Support is stay, and carry out support structure to each line cake of winding, Spacer is elastic cushion block, is evenly distributed between each line cake of transformer.

Step 2, in transformer finite element model, different structure fault to be simulated; By changing the structure of each parts in transformer finite element model, relative position, connected mode simulate transformer common structure fault, mainly comprises following fault simulation: short circuit, imperfect earth etc. between radial deformation, axial displacement, turn-to-turn short circuit, cake.Be described for the radial deformation of line cake and axis of winding displacement below.

(1) the radial deformation of line cake

Inside transformer winding is subject to inside electromagnetic force, and outside winding is subject to outside electromagnetic force.Therefore, under the effect of the radial component of electromagnetic force, may there is radial deformation in Transformer Winding.When the rigidity of winding conductor is much smaller than the rigidity of support member, internal low-voltage winding is fixedly secured by stay, and electromagnetic force makes conductor bend, and causes winding to cave at a place or have more, is forced to warpage.As shown in Figure 3, the line cake that the depression of line cake is R by two mean radiuss intersects and forms, and the mean radius of two line cakes is identical in the process, and the central angle intersecting section correspondence is consistent, and therefore circumference total length is constant.For weighing the distortion degree of annulus molded line cake, define following sign:

In formula, R is the mean radius of line cake, and R1 is the minimum average B configuration radius of line cake.

(2) axis of winding displacement

Fig. 4 is integral axial displacement schematic diagram, and figure mesolow winding moves Δ h in the axial direction.Axis of winding displacement is that integral is subject to the effect of axial electromagnetic force and creates axial movement due under the effect of short-circuit current and radial leakage flux.Simultaneously because winding two end clamp plate is not by the effect of short-circuit electromagnetic force, the winding conductor to one end movement can produce extruding to the end pressing plate of winding direction of motion, may bring out the damage of pressing plate.

In step 3, the dissimilar and degree structural failure model that arranges in step 2, solve its main electrical parameters (such as ground capacitance, turn-to-turn capacitance, coupling capacitance etc.), set up the relation between " structural failure-electric parameter ".

Solve transformer electric parameter mainly to solve its capacitance matrix and inductance matrix.

In finite element model transformer n line cake between electric capacity constitute the n rank capacitance matrix of transformer.Wherein: C ijit is the coupling capacitance between i-th line cake and a jth line cake; C iibe the self-capacitance of i-th line cake, it mainly comprises the ground capacitance of line cake and the coupling capacitance sum with other line cakes.Coupling capacitance between two line cakes obtains by following formula:

C i j = 2 W i j V 2 = 1 2 ∫ Ω D i × E j d Ω

In formula, W ijfor electric field storage power, D ithe electric displacement density that i-th line cake is corresponding, E jfor the electric field intensity of jth line cake.

When foreign current is by means of only i-th line cake, its self-inductance (L ii) and resistance (R ii) following vector form can be described to:

U i ^ = I ^ i ( R i i + jωL i i )

In formula, ω is angular frequency, for induced voltage.The imaginary part of above formula is only associated with the self-inductance of i-th line cake, therefore can obtain its self-inductance:

L i i = 1 ω Im ( U i ^ I ^ i )

In like manner, the coupling inductance between i-th line cake and a jth line cake obtains by following formula:

M i j = 1 ω Im ( U j ^ I ^ i )

Fig. 5 solves by finite element model the transformer capacitor matrix obtained.The self-capacitance of this matrix description high pressure winding 8 line cakes and low pressure winding 8 line cakes and mutual capacitance size between any two.

Table 1 ~ 3 are in axial displacement fault 1% ~ 9% situation, solve the transformer main electrical parameters obtained respectively.

Electric parameter during table 1 axial displacement 1% ~ 3%

Electric parameter during table 2 axial displacement 1% ~ 3%

Electric parameter during table 3 axial displacement 1% ~ 3%

Step 4, solve the electric parameter obtained according to transformer finite element model, set up the site test results that circuit-model simulation is corresponding, by simulation circuit model (as lumped parameter model, " field-Lu " coupling model), solve frequency response curve and the short-circuit impedance of transformer under different electric parameter, set up " electric parameter-test findings " corresponding relation.

For different site tests, different circuit models can be adopted to emulate.Adopt lumped parameter model simulation frequency response curve in the present invention, adopt coupling magnetic field with electric circuit model emulation short-circuit impedance.

Fig. 6 is frequency response method corresponding circuits illustraton of model.The electric parameter solved in employing table 1 ~ 3, can simulate frequency response test result, achieves the corresponding of structural failure and frequency response curve.

Fig. 7 is short circuit impedance method corresponding circuits illustraton of model.This lumped parameter coupling magnetic field with electric circuit model can be simulated short-circuit impedance test findings, achieves the corresponding of structural failure and short-circuit impedance.

Step 5, be intermediate variable with electric parameter, set up the corresponding relation of test findings and structural failure: by finite element model, dissimilar and degree structural failure are simulated, solve the change of its electric parameter, and then set up different circuit models, solved frequency response curve and the short-circuit impedance of transformer under different electric parameter by simulation circuit model, set up the corresponding relation of " structural failure-electric parameter-test findings ".

Frequency response curve corresponding when Fig. 8 is axial displacement fault 3%, 6% and 9%.Therefore, the corresponding relation of axial displacement fault and test findings is set up:

Corresponding relation 1: axial displacement fault---frequency response curve occurs amplitude deviation at 150kHz;

Corresponding relation 2: axial displacement fault---the entirety of frequency response curve harmonic peak moves to right;

Corresponding relation 3: axial displacement fault---frequency response curve first harmonic peak amplitude reduces;

Corresponding relation 4: axial displacement fault---frequency response curve first antiresonance peak amplitude increases;

Corresponding relation 5: axial displacement fault---short-circuit impedance does not change.

That is, the changing features trend from the direct deagnostic structure fault of test findings is established.

For axial displacement fault 3%, 6% and 9%, according to " structural failure-electric parameter-test findings " this diagnosis thinking proposed by the invention, solve the electric parameter (table 1 ~ 3) under fault in various degree respectively, and then obtain corresponding frequency response curve (Fig. 8).Finally draw from the changing features trend of the direct deagnostic structure fault of test findings and (that is, thought that axial displacement fault can cause frequency response curve to produce amplitude change at about 150kHz, cause the entirety of harmonic peak to move to right simultaneously.Along with the aggravation of axial displacement degree, the amplitude of its first resonance peaks will obviously reduce, and the amplitude at first antiresonance peak place will obviously increase).

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly belongs to those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.

Claims (6)

1., based on a transformer device structure method for diagnosing faults for finite element simulation and site test, it is characterized in that comprising the steps:
Step one, in finite element emulation software, set up transformer finite element model;
Step 2, in transformer finite element model, different structure fault to be simulated;
In step 3, the dissimilar and degree structural failure model that arranges in step 2, solve its main electrical parameters, set up the relation between " structural failure-electric parameter ";
Step 4, solve the electric parameter obtained according to transformer finite element model, set up the site test results that circuit-model simulation is corresponding, solved frequency response curve and the short-circuit impedance of transformer under different electric parameter by simulation circuit model, set up " electric parameter-test findings " corresponding relation;
Step 5, be intermediate variable with electric parameter, set up the corresponding relation of test findings and structural failure: by finite element model, dissimilar and degree structural failure are simulated, solve the change of its electric parameter, and then set up different circuit models, solved frequency response curve and the short-circuit impedance of transformer under different electric parameter by simulation circuit model, set up the corresponding relation of " structural failure-electric parameter-test findings ".
2. as claimed in claim 1 based on the transformer device structure method for diagnosing faults of finite element simulation with site test, the material behavior of consideration main support when it is characterized in that setting up transformer finite element model in step one.
3., as claimed in claim 1 based on the transformer device structure method for diagnosing faults of finite element simulation with site test, it is characterized in that being simulated transformer common structure fault by the structure of each parts in change transformer finite element model, relative position, connected mode in step 2.
4., as claimed in claim 1 based on the transformer device structure method for diagnosing faults of finite element simulation and site test, it is characterized in that described structural failure comprises short circuit between radial deformation, axial displacement, turn-to-turn short circuit, cake, imperfect earth.
5. as claimed in claim 1 based on the transformer device structure method for diagnosing faults of finite element simulation and site test, it is characterized in that: solve transformer electric parameter and mainly its capacitance matrix and inductance matrix are carried out, in described finite element model transformer n line cake between electric capacity form the n rank capacitance matrix of transformer, wherein: C ijit is the coupling capacitance between i-th line cake and a jth line cake; C iibe the self-capacitance of i-th line cake, it mainly comprises the ground capacitance of line cake and the coupling capacitance sum with other line cakes, and the coupling capacitance between two line cakes is obtained by following formula:
C i j = 2 W i j V 2 = 1 2 ∫ Ω D i × E j d Ω
In formula, W ijfor electric field storage power, D ithe electric displacement density that i-th line cake is corresponding, E jfor the electric field intensity of jth line cake;
When foreign current is by means of only i-th line cake, its self-inductance L iiand resistance R iifollowing vector form can be described to:
U i ^ = I i ^ ( R i i + jωL i i )
In formula, ω is angular frequency, for induced voltage, the imaginary part of above formula is only associated with the self-inductance of i-th line cake, therefore obtains its self-inductance:
L i i = 1 ω Im ( U i ^ I i ^ )
In like manner, the coupling inductance between i-th line cake and a jth line cake is obtained by following formula:
M i j = 1 ω Im ( U i ^ I i ^ ) .
6. as claimed in claim 1 based on the transformer device structure method for diagnosing faults of finite element simulation and site test, it is characterized in that the circuit model in step 4 comprises lumped parameter model, " field-Lu " coupling model, lumped parameter model is used for simulation frequency response curve, and coupling magnetic field with electric circuit model is used for artificial short-circuits impedance.
CN201510864608.3A 2015-12-01 2015-12-01 Structural transformer fault diagnosis method based on finite element simulation and field test CN105468858A (en)

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CN106485009A (en) * 2016-10-18 2017-03-08 三峡大学 The simulation method of transformer winding fault situation under a kind of lightning impulse voltage
CN107247208A (en) * 2017-07-20 2017-10-13 云南电网有限责任公司电力科学研究院 A kind of transformer shorted-turn fault location positioning method
CN107633114A (en) * 2017-08-21 2018-01-26 江苏省电力试验研究院有限公司 A kind of primary cut-out latency Mechanical Fault Vibration Signals emulation mode and device

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105956269A (en) * 2016-04-29 2016-09-21 国家电网公司 Method for acquiring relationship between transformer winding state and inter-pancake capacitance parameter
CN106485009A (en) * 2016-10-18 2017-03-08 三峡大学 The simulation method of transformer winding fault situation under a kind of lightning impulse voltage
CN106485009B (en) * 2016-10-18 2019-07-09 三峡大学 The simulation method of transformer winding fault situation under a kind of lightning impulse voltage
CN107247208A (en) * 2017-07-20 2017-10-13 云南电网有限责任公司电力科学研究院 A kind of transformer shorted-turn fault location positioning method
CN107633114A (en) * 2017-08-21 2018-01-26 江苏省电力试验研究院有限公司 A kind of primary cut-out latency Mechanical Fault Vibration Signals emulation mode and device
CN107633114B (en) * 2017-08-21 2018-08-14 江苏省电力试验研究院有限公司 A kind of high-voltage circuitbreaker latency Mechanical Fault Vibration Signals emulation mode and device

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Application publication date: 20160406