TRANSFORMER DIAGNOSIS.pdf

8/9/2019 TRANSFORMER DIAGNOSIS.pdf

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© OMICRON 11/6/2014 Page: 1

TRANSFORMER DIAGNOSIS

Dipl.-Ing. Dr. Michael Krüger © 2006


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Sources of Faults

W i n d i n g

C o r e

B u s h i n g s

V e s s e l & O i l

A c c e s s o r i e s

T a p C h a n g e r

F r e q u e n c y

i n %

Source: Cigre_WG 12-05 „An international survey on failures in large power

transformers in service“, Electra No. 88, 1983


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Gas-in-Oil Analysis

Source: Möllmann, A. u.a. „IEC/VDE Standards für flüssige Isolierstoffe zur Diagnostik

von Transformatoren und Wandlern“, ETG Fachbericht 87: Diagnostik elektrischer

Betriebsmittel, Berlin 2002

Type of Fault

Partial Discharge

Discharge with lowEnergy

Discharge with high

Energy

Thermal Fault T


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Tests for Diagnosis

(Fault Location)

•Winding resistance and OLTC test•Practical examples for winding ratio,excitation current, leakage reactance

•FRSL

•Capacitance and dissipation factor

•FRA


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Universal Transformer

Test SystemPower Amplifier

15-400Hz

•Up to 2000A, 2kV AC / 400A DC

•Measurement of

•Ratio

•Complex Impedance•Resistances

• …...

C-Tanδδδδ-Prüfsystem


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Testing OLTC


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On-load tap changer principle (1)

Voltage Selector

Diverter

Switch

Commutating

Resistors


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Voltage Selector

Diverter

Switch

Commutating

Resistors


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Voltage Selector

Diverter

Switch

Commutating

Resistors


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Voltage Selector

Diverter

Switch

Commutating

Resistors


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Voltage Selector

Diverter

Switch

Commutating

Resistors


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Voltage Selector

Diverter

Switch

Commutating

Resistors


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On-load tap changer


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Measurement of the staticresistance values of:

1) all internal contacts (diverter

switch contacts + tapselector switch + connectionclamps) +

2) the winding resistance


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New voltage selector contact


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Voltage selector switch in a good

conditionWiderstand V-Mp

235.00

240.00

245.00

250.00

255.00

260.00

265.00

270.00

275.00

280.00

285.00

1 2 3 4 5 6 7 8 9 1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

2 0

2 1

Stufen

W i d e r s t a n

d [ m Ω ΩΩ Ω ] KEMA

OMICRON 1…21Ref. Temp.

OMICRON 21…1Ref. Temp.


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Influence of the Temperature

Maschinentransformator27kV/400kV 1100MVA

1. Measurement: 20°C

Last Meas.: 23°C


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Influence of the Temperature

R Winding (Tap)

0.14Ω

0.145Ω

0.15Ω

0.155Ω

0.16Ω

0.165Ω

000 005 010 015 020 025 030Taps

A UP

A DOWN

B UP

B DOWNC UP

C DOWN

012.1*)20()23(:235

235)()(

1

212 °=°

+

+= R R Beispiel

T

T T RT R

Delta =1.2%


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Faulty voltage selector contact


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Defective Voltage Selector


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Defective Tap Selector

Starke Verrußung durch Erwärmung und Ablagerungen


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Resistance U-Mp

R L1 (referred to 20°C)

450.0

500.0

550.0

600.0

650.0

700.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Taps

m O h m

R L1 1974

R L1 20.2.02 1...19

RL1 20.2.02 19…1


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100MVA 220/110 kV W

R L3 (referred to 20°)

450.0

470.0

490.0

510.0

530.0

550.0

570.0

590.0

610.0

630.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Taps

m O h m

R L3 1974

R L3 20.2.02 1…19

R L3K 20.2.02 19…1


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Winding Resistance U-Mp After RepairResistance L1

450.0

470.0

490.0

510.0

530.0

550.0570.0

590.0

610.0

630.0

650.0

1 2 3 4 5 6 7 8 9 1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

Taps

R e s i s t a n c e

[ m Ω ] Ω ] Ω ] Ω ]

Factory MeasurementOMICRON 1…19

OMICRON 19…1


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Delta R for U-Mp „UP“-„DOWN“

Resistance Differenz L1 Up-Down

-6.0

-4.0

-2.0

0.0

2.0

4.0

6.0

1 2 3 4 5 6 7 8 9 1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

Taps

R e s i s t a n c e

[ m Ω ] Ω ] Ω ] Ω ]

Resistance Differenz L1 Up-Down

-30.0

-20.0

-10.0

0.0

10.0

20.0

30.0

40.0

1 2 3 4 5 6 7 8 9 1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

Taps

R e s i s t a n c e [ m

Ω ] Ω ] Ω ] Ω ]

Before repair

After repair


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Cleaning effect of OLTC movement

R Winding (Tap)

0.14 Ohm

0.15 Ohm

0.16 Ohm

0.17 Ohm

0.18 Ohm

0.19 Ohm

0.2 Ohm

0 5 10 15 20Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN

R Winding (Tap)

0.14 Ohm

0.15 Ohm

0.16 Ohm

0.17 Ohm

0.18 Ohm

0.19 Ohm

0.2 Ohm

0 5 10 15 20Taps

A UP

A DOWN

B UP

B DOWNC UP

C DOWN


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Increased contact resistance on a

diverter switch in phase AR Winding (Tap)

0.13 Ohm

0.135 Ohm

0.14 Ohm

0.145 Ohm

0.15 Ohm0.155 Ohm

0.16 Ohm

0.165 Ohm

0.17 Ohm0.175 Ohm

0.18 Ohm

0 2 4 6 8 10 12Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN


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Measurement of „Low Ohmic“ Windings


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Analysis of the TransientSwitching Behavior of the

Diverter Switch

T i t i l f it hi


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Transient signal of one switching

procedure in detail

1 = Diverter switch commutates from the first tap to the first commutating resistor

2 = The second commutationg resistor is switched in parralel

3 = shorting of the second commutating resistor and commutating to the second tap

4 = Charging of the additional windings

Ripple

Slopeαααα


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Diagnosis of the diverter switch


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Ripple of a diverter switch in a

good condition (1100MVA)Ripple

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

000 005 010 015 020 025 030Taps

A UP

A DOWN

B UPB DOWN

C UP

C DOWN


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Slope of a diverter switch in a

good condition (1100MVA)Slope

-0.6A/s

-0.5A/s

-0.4A/s

-0.3A/s

-0.2A/s

-0.1A/s

0.0A/s

000 005 010 015 020 025 030

Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN


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Ripple on a Diverter Switch with

bouncing Contacts in Phase CRipple

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

40.0%

45.0%

50.0%

0 2 4 6 8 10 12Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN

Sl Di S i h i h


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Slope on a Diverter Switch with

bouncing Contacts in Phase CSlope

-1.8A/s

-1.6A/s-1.4A/s

-1.2A/s

-1.0A/s

-0.8A/s

-0.6A/s

-0.4A/s

-0.2A/s

0.0A/s

0 2 4 6 8 10 12

Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN

E I t ti f 500


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Even Interruptions of 500us can

be detected

530us

Ri l f (Ti f I t ti )


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Ripple = f (Time of Interruption)Dauer der

Unterbrechnung

[ms]

Ripple mitUnter-

brechung [%]

Ripple ohne

Unter-brechung

[%]

Slope mit

Unter-brechung

[mA/s]

Slope mit

Unter-brechung

[mA/s]

0.5 4.12 1.00 -42 -2

1 4.64 1.00 -49.17 -2

10 32.96 1.00 -405.6 -2

1000 100.00 1.00 -1192 -2

Ripple OS Wicklung mit 0.5A Prüfstrom

0.00

20.00

40.00

60.00

80.00

100.00

120.00

0.1 1 10 100 1000

Time of Interruption [ms]

R i p p

l e [ % ]

Ripple mitUnterbrechung

Ripple ohne

Unterbrechung


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Ripple of an aged diverter switch

Ripple

3.0%

3.5%

4.0%

4.5%

5.0%

5.5%

0 5 10 15 20Taps

A UP

A DOWN

B UPB DOWN

C UP

C DOWN


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Slope of an aged diverter switch

Slope

-1.1A/s

-1.05A/s-1.0A/s

-0.95A/s

-0.9A/s

-0.85A/s-0.8A/s

-0.75A/s

-0.7A/s

-0.65A/s

-0.6A/s

0 5 10 15 20

Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN

Aged diverter switch


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Aged diverter switch

Contact Problems (static)


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Ripple

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

000 005 010 015 020 025 030Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN

005 0.145044615Ω 0.061% 2.601% -1.75A/s 20.0A 2.9008923V

006 0.14168819Ω 0.046% 2.253% -1.65A/s 20.0A 2.8337638V007 0.142732395Ω 0.069% 2.701% -1.75A/s 20.0A 2.8546479V

008 0.139659045Ω 0.097% 2.903% -1.69A/s 20.0A 2.7931809V

009 0.13919992Ω 4.612% 16.975% -11.37A/s 20.01A 2.7853904V

009 0.1396798Ω 1.028% 14.25% -2.6A/s 20.0A 2.793596V

009 0.139666415Ω 0.204% 14.7% -1.75A/s 20.0A 2.7933283V

009 0.13958899Ω 0.174% 15.7% -0.56A/s 20.0A 2.7917798V

010 0.13754698Ω 0.059% 15.666% -1.91A/s 20.0A 2.7509396V

011 0.137932135Ω

0.055% 3.402% -1.75A/s 20.0A 2.7586427V012 0.13525902Ω 0.086% 2.703% -1.69A/s 20.0A 2.7051804V

013 0.12915814Ω 0.079% 3.4% -2.62A/s 20.0A 2.5831628V

Ripple



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Slope

-12.0A/s

-10.0A/s

-8.0A/s

-6.0A/s

-4.0A/s

-2.0A/s

0.0A/s

000 005 010 015 020 025 030Taps

A UP

A DOWN

B UP

B DOWN

C UP

C DOWN

005 0.145044615Ω 0.061% 2.601% -1.75A/s 20.0A 2.9008923V

006 0.14168819Ω 0.046% 2.253% -1.65A/s 20.0A 2.8337638V007 0.142732395Ω 0.069% 2.701% -1.75A/s 20.0A 2.8546479V

008 0.139659045Ω 0.097% 2.903% -1.69A/s 20.0A 2.7931809V

009 0.13919992Ω 4.612% 16.975% -11.37A/s 20.01A 2.7853904V

009 0.1396798Ω 1.028% 14.25% -2.6A/s 20.0A 2.793596V

009 0.139666415Ω 0.204% 14.7% -1.75A/s 20.0A 2.7933283V

009 0.13958899Ω 0.174% 15.7% -0.56A/s 20.0A 2.7917798V

010 0.13754698Ω 0.059% 15.666% -1.91A/s 20.0A 2.7509396V

011 0.137932135Ω

0.055% 3.402% -1.75A/s 20.0A 2.7586427V012 0.13525902Ω 0.086% 2.703% -1.69A/s 20.0A 2.7051804V

013 0.12915814Ω 0.079% 3.4% -2.62A/s 20.0A 2.5831628V

Slope


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Measurement of the shortcircuit impedance

a) Measurement of the leakage reactance


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Short circuit impedance

220kV Winding220kV

Forces

10kV Winding

220kV Winding

Leakage

Flux

Short circuit impedance - deviation limits


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p

400kVA transformer


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400kVA transformerTemplate: TR Short Circuit Imp.

Version: 1.40

3 Phase Measurement

Uk [V] Ik [A] P [W] f [Hz] Z [OHM] Phi [°] R [OHM] X [OHM] L [H]

1479.40 8.89 6270 50 288.2335 74.02338 79.33485 277.1002 0.882037449

Phase A

f [Hz] Z [OHM] Phi [°] R [OHM] X [OHM] L [H]

50 287.8106 74.21368 78.29901 276.9553 0.881576072

Difference to Factory Test [%] -0.14671 0.257084 -1.30566 -0.05231 -0.05230818

Phase B


50 287.9643 73.82169 80.23478 276.5607 0.880319891

Difference to Factory Test [%] -0.09342 -0.27247 1.134345 -0.19473 -0.19472629

Phase C


50 288.7539 74.01075 79.53928 277.583 0.883574133

Difference to Factory Test [%] 0.180545 -0.01706 0.257675 0.17422 0.174219805

Average Difference to Factory Test [%] -0.01986 -0.01082 0.028788 -0.02427 -0.02427155

Factory Test with W-Meter


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Measurement of the short circuitimpedance

b) Measurement of the AC-short circuit resistance(FRSL = Frequency response of stray losses)

Parallel strands without twisting


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g

BHV Winding

LV Winding

Lossesby inducedcurrents

Parallel strands with twisting


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g

Inducedcurrents arecompensated

BHV Winding

LV Winding

Parallel strands with short circuit


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BHV Winding

LV Winding

Additionallossesby induced

currents

Equivalent circuit diagram


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q g

R (f)


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Comparison of the 3 phases


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Comparison of the 3 phases

R(f)

0.0 Ohm

0.5 Ohm

1.0 Ohm

1.5 Ohm2.0 Ohm

2.5 Ohm

3.0 Ohm

3.5 Ohm4.0 Ohm

4.5 Ohm

0 100 200 300 400 500

Frequency (Hz)

A

B

C

Case study


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y

40-MVA, Y∆∆∆∆, 121 kV/12.85 kV transformerThe transformer was removed from service because it

produced gas, which, upon analysis, showed a hot spot

involving paper. In the laboratories, however, none of the

standard tests showed a fault in the windings. In fact, it was

found that:

• The turns ratio was correct;• The excitation current was normal;• The DC resistance was normal;•A comparative measurement of the impedance in the

three phases showed no significant difference (less

than 3%).

Case study


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y

40-MVA, Y∆∆∆∆, 121 kV/12.85 kV transformer

Case study


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y

40-MVA, Y∆∆∆∆, 121 kV/12.85 kV transformer

Phase A: eight of the 13 parallel strands of this winding had been short-circuited. In this condition, the section perpendicular to the lines of

flux was much higher and, hence, the eddy current losses

Phase B: two parallel strands were found to be in short-circuit but the fault

was not located in the winding after it had been dismantled

Phase C: No fault was detected in the windings


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Short circuit impedance - deviation limits


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Diagnosis of a damaged


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g g

transformer 220kV / 110kV / 10kV

• Short circuit of the 10kV

winding by a marten•Short circuit current Is = 52kA

•Switching “off” time about100ms

Result:

Short circuit of the 10kVwinding to the core (Phase A)

Ratio and excitation current


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at o a d e c tat o cu e t

Ratio Error= -21.5% !

Lk=f(f)


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k ( )

Faultywinding

Defective 10kV winding skin-


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effect in the coreLow Frequencies

High Frequencies


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FRA phases V und W


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p

Phase: V

Phase: W

FRA Phases U und W


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Phase: W

Phase: U

Opened Transformer


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p

DefectivePhase

Currentlimiting

coils

View from the Top


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p

10 kV

110 kV

220 kV

View from the Top


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View from the Top


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Broken wire


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CAPACITANCE AND TAN DELTAMEASUREMENTS ON

TRANSFORMERS

Definition of Tan DeltaEquivalent Parallel Circuit Diagram and Vector Diagram


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Equivalent Parallel Circuit Diagram and Vector Diagram

with

and Frequency

Mainly conductive losses

Equivalent Serial Circuit Diagram


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RSRS

CS

URs

UCs

S S

C

R

C RU

U

ω δ ==tan

Mainly polarization losses


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Transformer Winding Insulation


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b. Model for thebehaviour of adielectric withpolarisationcharacteristic andconductivity

d. Simplified geometrymodel for the maincomponents oil,barriers and spacers

a. Plate condenseras a model fordielectric insulation

c. Part of the crosssection of a powertransformer maininsulation systembetween HV and LVwindings

e: Dielectric modelfor the insulationsystem of powertransformers

Tan Delta (f) Pressboard Dependenton the Water Content


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Losses in Dielectric Material


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•Transport of electrons and ions

•Losses through polarisation effects

•Losses in dielectrics are dependent of

•Ageing

•Water content

•Conductive losses by particles

•Partial discharges

What can C-Tan Delta tell us?


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•Capacity:

• Bushings:

• Partial breakdowns between layers

• Incoming oil into cracks of solid insulation (RBP hard

paper)

•Transformer windings:

• Change of the geometry between windings

(deformation and displacement of windings due to

big fault currents trough the transformer)

What can C-Tan Delta tell us?


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•Dissipation factor:

• Bushings:

• Aging and decomposition of insulation

• Water content

• Bad contacted electrodes or capacitive layers

• Cracks in the insulation

• Partial discharges

• Transformers:

• Aging• Water content in the oil and in the paper

• Contamination by particles

Schering Bridge (1919)First application for insulation diagnosis 1924


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Has to be balancedfor each frequency


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Universal Transformer Test and


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Diagnosis SystemPower amplifier 15-400Hz•Outputs up to 2000A, 2kV AC / 400A DC

•Measurement of

•Ratio

•Complex Impedance

•Resistance

• …...

C-Tanδδδδ-Test System

Features and Advantages of

h D ib d T


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the Described Test system• One test system for complete transformer testing

• Excellent noise suppression (50/60 Hz)

• Variable frequency of output voltage 15…400Hz

enables frequency sweeps

• Most accurate instrument for field use (TD: 5*E-5 C: 0.05%)

• Automatic test procedures with voltage and

frequency sweeps -> saves testing time !

• Automatic reporting and easy export to Excel

--> saves time for post-processing !


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Screenshot UST-B Mode


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Measurement onPowerTransformers

High Voltage Winding

Tapped WindingCore

400kV Bushing

Measuring Tap

Low VoltageBushing

Low Voltage Winding


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Transformer Winding Test

No sepuedemostrar la imagen en estemomento.

Test Procedure for a3-Windings Transformer


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DF (f) H, HL, L

0.0 %

0.05 %

0.1 %

0.15 %

0.2 %

0.25 %

0.3 %

0.35 %

0.4 %

0.45 %

0 . 0

H z

5 0

. 0 H z

1 0 0

. 0 H z

1 5 0

. 0 H z

2 0 0

. 0 H z

2 5 0

. 0 H z

3 0 0

. 0 H z

3 5 0

. 0 H z

4 0 0

. 0 H z

4 5 0

. 0 H z

H(f)

HL(f)

L(f)

Tan Delta (f) with aged oil


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DF (f) H, HL, L

0.0 %

0.1 %

0.2 %

0.3 %

0.4 %

0.5 %

0.6 %

0 . 0

H z

5 0

. 0 H z

1 0 0

. 0 H z

1 5 0

. 0 H z

2 0 0

. 0 H z

2 5 0

. 0 H z

3 0 0

. 0 H z

3 5 0

. 0 H z

4 0 0

. 0 H z

4 5 0

. 0 H z

H(f)

HL(f)

L(f)

Tan Delta (f) of a 110kV transformer withhigh water content


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DF (f) H, HL

0.0 %

0.2 %

0.4 %

0.6 %

0.8 %

1.0 %

1.2 %

1.4 %

1.6 %

1.8 %

0 . 0 H z

5 0 . 0 H z

1 0 0 . 0 H z

1 5 0 . 0 H z

2 0 0 . 0 H z

2 5 0 . 0 H z

3 0 0 . 0 H z

3 5 0 . 0 H z

4 0 0 . 0 H z

4 5 0 . 0 H z

H(f)

HL(f)

Tan Delta 11kV-0.4kV 800KVA (1966)


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DF HV-LV (f)

0.0 %

0.5 %

1.0 %

1.5 %

2.0 %

2.5 %

0.0 Hz 50.0 Hz 100.0 Hz 150.0 Hz 200.0 Hz 250.0 Hz

Unexpected ferquency curves8.0 %


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-1.0 %

0.0 %

1.0 %

2.0 %

3.0 %

4.0 %

5.0 %

6.0 %

7.0 %

0.0 Hz 100.0 Hz 200.0 Hz 300.0 Hz 400.0 Hz 500.0 Hz

17.0 Hz

30.0 Hz

80.0 Hz

130.0 Hz230.0 Hz

400.0 Hz

220kV Gießharzdurchführungen

0.4 %

0.45 %

0.5 %

0.55 %

0.6 %

0.65 %

0.7 %

0.75 %

0.8 %

0.0Hz 50.0Hz 100.0H

z

150.0H

z

200.0H

z

250.0H

z

300.0H

z

350.0H

z

400.0H

z

450.0H

z

Phase A

Phase BPhase C

DF (f)

-1.5 %

-1.0 %

-0.5 %

0.0 %

0.5 %

1.0 %

0

. 0 H z

5 0

. 0 H z

1 0 0

. 0 H z

1 5 0

. 0 H z

2 0 0

. 0 H z

2 5 0

. 0 H z

3 0 0

. 0 H z

3 5 0

. 0 H z

4 0 0

. 0 H z

4 5 0

. 0 H z

Phases Not Connected or Bad Contacts


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DF (f)

0.1 %

0.3 %

0.5 %

0.7 %


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Bad contact ofshort circuit

-1.5 %

-1.3 %

-1.1 %

-0.9 %

-0.7 %

-0.5 %

-0.3 %

-0.1 %

0 . 0

H z

5 0 . 0

H z

1 0 0 . 0

H z

1 5 0 . 0

H z

2 0 0 . 0

H z

2 5 0 . 0

H z

3 0 0 . 0

H z

3 5 0 . 0

H z

4 0 0 . 0

H z

4 5 0 . 0

H z

DF (f)

0.0 %

0.1 %

0.2 %

0.3 %

0.4 %

0.5 %

0.6 %

0.7 %

0.8 %

0 . 0

H z

5 0

. 0 H z

1 0 0

. 0 H z

1 5 0

. 0 H z

2 0 0

. 0 H z

2 5 0

. 0 H z

3 0 0

. 0 H z

3 5 0

. 0 H z

4 0 0

. 0 H z

4 5 0

. 0 H z

Good contacts

of short circuit



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Emax= high

A

Emax=smaller

A

without

capacitivelayers

withcapacitivelayers

Earthing Cap

Capacitive Bushings (2)


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Bushing Fault


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220kV RIP Bushing stored outside


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66kV Oil Circuit Breaker (USA)


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Circuit Breaker Bushing C-PF Test

V TEST* [V] C meas. PF meas.[%]10032.20 2.836E-10 0.457

10031.81 2.815E-10 0.491

10031.55 2.853E-10 0.49310031.20 2.837E-10 0.486

10028.73 2.855E-10 0.504

10030.49 2.853E-10 0.449

DF (f) 69 kV OIP Bushings 60Hz

0.6 %


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0.0 %

0.1 %

0.2 %

0.3 %

0.4 %

0.5 %

*0.0 Hz *100.0 Hz *200.0 Hz *300.0 Hz *400.0 Hz *500.0 Hz

1

2

3

4

56

DF (f) 69 kV OIP Bushings 17-400Hz


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0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 100 200 300 400

Hz

%

U

V

W

360

365

370375

380

385

390

395

400

405

410

415

0 100 200 300 400

Hz

p F

U

V

W

+ 10%


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Defectice 110 kV RPB Bushing

Tan Delta (U)

0.75


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Tan Delta (V)

0.3

0.35

0.4

0.45

0.5

0.55

0.6

0.65

0.7

0 5 10 15

kV

%

2V

2N

Tan Delta (U)

Suspicious 400 kV OIP Bushings (1998)


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0.0%

0.05%

0.1%

0.15%

0.2%

0.25%

0.3%

0.35%

0.4%

0.45%

0.5%

0.0V 2000.0V 4000.0V 6000.0V 8000.0V 10000.0V 12000.0V 14000.0V

U TanDelta

V TanDelta

W TanDelta

Spannungsverläufe unauffällig

Suspicious 400 kV OIP Bushings (1998)Reason ?

Tan Delta (V)


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0.37%

0.39%

0.41%

0.43%

0.45%

0.47%

0.49%

0.0 Hz 50.0 Hz 100.0 Hz 150.0 Hz 200.0 Hz 250.0 Hz 300.0 Hz 350.0 Hz

U TanDelta

V TanDelta

W TanDelta

Frequenzververläufe auffällig

Suspicious 123 kV RIP BushingReason ?

0.8%


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© OMICRON Page: 12004.12.200411/6/2014

0.0%

0.1%

0.2%

0.3%

0.4%

0.5%

0.6%

0.7%

0.0 Hz 100.0 Hz 200.0 Hz 300.0 Hz 400.0 Hz 500.0 Hz

T a n D e l t a

73

80

Measurement with high interference


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Durchführung

Erdungsgarnitur

HS Anschluss

Measurement with high interference

Documents

TRANSFORMER DIAGNOSIS.pdf