AC GENERATOR WORKSHOP EXPERTISE REPORT - · PDF fileAC GENERATOR WORKSHOP EXPERTISE REPORT...

24.03.2016

GEN-MOT / PSS Tüm hakları saklıdır. 1/10

AC GENERATOR WORKSHOP EXPERTISE REPORT

Report Code: XXXXX.XX.XX.XX

GENERAL INFO

Company Name: XXXXXXX

Company Address: XXXXXXX

Equipment Location: XXXXXXX

Equipment Name: ME Shaft Generator

ALTERNATOR INFO

Brand: AvK

Type: DSG 74 l2-4

S/N: 67 27219 A101

Power: 1750 kVA

Voltage: 450 V

Current: 2245 A

Speed: 1800 rpm

Frequency: 60 Hz

Cos φ: 0,80

Rot. Direction: CCW (W-V-U)

Insulation Class: H

Protection Class: IP23

Mechanic Conn: Coupling

Excit. Stator Volt: 23,7 V

Excit. Stator Curr: 3,2 A

Excit. Rotor Volt: 85,3 V

Excit. Rotor Freq: 60 Hz

Coolant Temp: 45°C

Weight: 4,16 t

Manufactured: 2005

Grease: Unirex N3

Heater Power: 350 W

Heater Voltage: 230 V

Heater Current: 1,52 A

TEST OPERATOR

Onur SOLMAZ (+90 532 783 83 38) - GEN-MOT / PSS

CONTENT

Electrical Expertise

Mechanic Expertise

Appendix – Thermal Imaging Report

24.03.2016


ELECTRICAL EXPERTISE

MAIN STATOR INSPECTION

Insulation Measurement of Stator Windings

Tests Results (Ru-v-w to Ground)

Function Fixed Voltage

Date 19.03.2016

Voltage 473,8 V

R(t°amb) 15°C

Resistance (t°amb) 3,758 MΩ

R(t°ref) 40°C

Resistance (t°ref) 2,621 MΩ

PI 1,003

PI1 3,745 MΩ

PI2 3,758 MΩ

DD 2,203

Capacitance 64,24 nF

DD Current -67,06 nA

DC Resistences of Stator Windings

Y-connected

U – V 1,873 mΩ

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,40°C

R (t°amb) 1,873 mΩ

t°ref 20,00°C

R (t°ref) 1,912 mΩ

U – W 1,887 mΩ

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,50°C

R (t°amb) 1,887 mΩ

t°ref 20,00°C

R (t°ref) 1,926 mΩ

V – W 1,883 mΩ

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,60°C

R (t°amb) 1,883 mΩ

t°ref 20,00°C

R (t°ref) 1,921 mΩ

Maximum rate of resistence unbalance: %0,7

3,20

3,30

3,40

3,50

3,60

3,70

3,80

3,90

4,00

4,10

MΩ

19:39:29.000

19.03.2016

19:49:28.000

19.03.2016

1 min/Div

9:59,000 (min:s)

24.03.2016


Stator Visual Check

Stator windings and iron core are dirty and all surfaces covered by oil-grease mixture.

Some of energy output cables have insulation wears. Bares of phases in terminal box are so dirty and

need to be cleaned and painted.

After taking the rotor out of the stator, it has been seen that the rotor had rubbed to the stator during

operation. Stator has some deep scratches and short-circuits between some group of laminations. This

parts of the iron core has been specified by painting it with white colour.

The rotor iron core has also scratches on the pole surfaces. However, rotor poles are in better condition

than the stator iron core.

Loop Test for Stator Core

Iron core has been tested as described below:

(8 turn) x (60 A) = (480 A*turn) which means that iron core saturated approximately up to %20 of full

magnetic field. Test has been applied for 30 mins.

24.03.2016


Thermal Imaging

For thermal images, please refer to Appendix-Thermal Report at the end of this report.

Assessment:

• According to standard IEEE43-2000; the insulation resistence of the stator windings is too low.

• According to standard IEEE43-2000; the polarisation index is too low.

• As a result of loop test, stator core has many hot spots which can be seen on the thermal report.

• So, stator windings should be removed from the stator. After that, stator core needs to be

repaired, then cleaned and painted. After stator core work, stator needs to be rewinded.

MAIN ROTOR INSPECTION

Insulation Measurement of Rotor Windings

Tests Results (R2-3 to Ground)


Date 19.03.2016

Voltage 500,0 V

R(t°amb) 15°C

Resistance (t°amb) 3,305 GΩ

R(t°ref) 40°C

Resistance (t°ref) 2,811 GΩ

PI 1,985

PI1 1,665 GΩ

PI2 3,305 GΩ

DD 12,30



0,00

500M

1000M

1,50G

2,00G

2,50G

3,00G

3,50G

Ω

19:52:57.000

19.03.2016

20:02:56.000

19.03.2016

1 min/Div

9:59,000 (min:s)

24.03.2016


DC Resistence of Rotor Winding

4 poles serial connected

2 – 3 0,540 Ohm

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,60°C

R (t°amb) 0,540 mΩ

t°ref 20,00°C

R (t°ref) 0,550 mΩ

Rotor Visual Check

Rotor windings and iron core are dirty and all surfaces covered by oil-grease mixture.

The rotor iron core has also scratches on the pole surfaces due to the rubbing. However, rotor poles are in

better condition than the stator iron core.

Rotor pole cable leads are in good condition.

Assessment:

• According to standard IEEE43-2000; the insulation resistence of the rotor winding is sufficient.

• According to standard IEEE43-2000; the polarisation index is at good value.

• Rotor pole windings need to be cleaned, varnished and painted for protection.

24.03.2016


EXCITER ROTOR INSPECTION

Insulation Measurement of Exciter Rotor Windings

Tests Results (RU-V-W to Ground)


Date 19.03.2016

Voltage 500,4 V

R(t°amb) 15°C


R(t°ref) 40°C


PI 2,166

PI1 1,994 GΩ

PI2 4,320 GΩ

DD 36,33



DC Resistences of Exciter Rotor Windings

Y-connected

U – V 45,65 mΩ

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,60°C

R (t°amb) 45,65 mΩ

t°ref 20,00°C

R (t°ref) 46,57 mΩ

U – W 46,03 mΩ

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,70°C

R (t°amb) 46,03 mΩ

t°ref 20,00°C

R (t°ref) 46,94 mΩ

V – W 45,67 mΩ

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 14,60°C

R (t°amb) 45,67 mΩ

t°ref 20,00°C

R (t°ref) 46,57 mΩ

Maximum rate of resistence unbalance: %0,8

Exciter Rotor Visual Check

Exciter rotor windings and iron core are dirty and all surfaces covered by oil-grease mixture.

0,00

500M

1000M

1,50G

2,00G

2,50G

3,00G

3,50G

4,00G

4,50G

Ω

20:05:35.000

19.03.2016

20:15:35.000

19.03.2016

2 min/Div

10:00,000 (min:s)

24.03.2016


The exciter rotor iron core has some partial scratches on the core surface due to the rubbing to the

exciter stator. However, general condition is good. Exciter rotor leads are in good condition.

Assessment:

• According to standard IEEE43-2000; the insulation resistence of the exciter rotor windings are

sufficient.


• Exciter rotor windings need to be cleaned, varnished and painted for protection.

EXCITER STATOR INSPECTION

Insulation Measurement of Exciter Stator Windings

Tests Results (RU-V-W to Ground)


Date 19.03.2016

Voltage 500,4 V

R(t°amb) 15°C


R(t°ref) 40°C


PI 1,891

PI1 22,53 GΩ

PI2 42,60 GΩ

DD 10,37



0,00

5,00

10,0

15,0

20,0

25,0

30,0

35,0

40,0

45,0

GΩ

20:20:09.000

19.03.2016

20:30:08.000

19.03.2016

1 min/Div

9:59,000 (min:s)

24.03.2016


DC Resistence of Exciter Stator Winding

12 poles serial connected

I1 – K1 7,660 Ohm

Measurement Auto

Date 19.03.2016

Metal Copper

t°amb 13,90°C

R (t°amb) 7,660 mΩ

t°ref 20,00°C

R (t°ref) 7,830 mΩ

Exciter Stator Visual Check

Exciter stator windings and iron core are dirty and all surfaces covered by oil-grease mixture.

The exciter stator iron core has some partial scratches at the bottom side poles due to the rubbing to the

exciter rotor. However, general condition is very good.

Assessment:

• According to standard IEEE43-2000; the insulation resistence of the exciter stator windings are

sufficient.


• Exciter stator windings need to be cleaned, varnished and painted for protection.

CONTROL CIRCUITS INSPECTION

PT100 Sensors Rotating Diodes AVR

1 pc. at DE Bearing Housing - OK 3 pcs. DD89N14K Infineon - OK Cosimat N+

1 pc. at NDE Bearing Housing - OK

2 pcs. at U Phase Winding - OK Thrystor

2 pcs. at V Phase Winding - OK

2 pcs. at W Phase Winding - OK 1 pc. SKVC20A460C Semikron - OK

24.03.2016


MECHANIC EXPERTISE

DRIVE-END MEASUREMENTS

DE Shaft Excentricity N/A – Cannot be measured due to bearing fault

DE Bearing Shaft Diameter 150,03 mm – Needs to be grinded due to fused burres

DE Shield Bearing Housing 270,03 - 270,09 mm – Bearing housing needs to be fixed

DE Outer Grease Flange Has 3 cracked place – Needs to be renewed

DE Shaft Place of Outer Flange Scratched – Shaft needs to be spinned

DE Outer Scraper Ring Fused – Needs to be renewed

DE Shaft Place of Scraper Ring Scratched – Shaft needs to be spinned

DE Inner Grease Flange Cracked – Needs to be renewed

DE Shaft Place of Inner Flange Scratched – Shaft needs to be spinned

DE Bearing 6230 C3

DE Gressor OK

Cooler Fan OK

Outer Grease Flange Crack Dispersed DE Bearing Fused Outer Scraper Ring

Shaft Place of Outer Ring-Flange Shaft Place of Inner Flange Inner Grease Flange Crack

24.03.2016


NON-DRIVE-END MEASUREMENTS

NDE Shaft Excentricity N/A – Cannot be measured due to bearing fault

NDE Bearing Shaft Diameter 150,03 mm – OK

NDE Shield Bearing Housing 270,05 - 270,85 mm – Bearing housing needs to be fixed

NDE Outer Grease Flange OK

NDE Shaft Place of Outer Flange OK

NDE Outer Scraper Ring OK

NDE Shaft Place of Scraper Ring OK

NDE Inner Grease Flange Deformed – Needs to be repaired

NDE Shaft Place of Inner Flange Scratched – Shaft needs to be spinned

NDE Bearing 6230 C3

NDE Gressor OK

Shaft Place of Outer Ring-Flange Shaft Place of Inner Flange Shaft Place of Inner Flange

Appendix - Thermal Imaging Report

1/5

19.03.2016 18:51:28 UNIT_CELSİUS

Bx1

Sp1

Li1

18,5

10,2FLIR0007.jpg FLIR E4 63964217

19.03.2016 18:51:28

FLIR0007.jpg FLIR E4 63964217

Initial condition of the stator before test started.

Ölçümler UNIT_CELSİUSBx1 Max 16,2

Min 15,6

Average 16,0

Sp1 15,9

Li1 Max 16,2

Min 14,9

Average 16,0

ParametrelerEmisyon 0.95

Yans. sıc. 20 UNIT_CELSİU


2/5

19.03.2016 18:52:27 UNIT_CELSİUS

Bx1

Sp1Sp2

Sp3

Sp4

Li1

22,2

13,6FLIR0009.jpg FLIR E4 63964217

19.03.2016 18:52:27


Some points at the stator get thermally visible by the end of 1 minute.


Min 14,9

Average 16,9

Sp1 32,3

Sp2 25,9

Sp3 24,1

Sp4 25,9

Li1 Max 33,4

Min 15,8

Average 18,5


Yans. sıc. 20 UNIT_CELSİ


3/5

19.03.2016 19:02:28 UNIT_CELSİUS

Sp1

Sp2 Sp3

Sp4

Sp5

Sp6

Sp7

Sp8Sp9

Li1

Li2

46,2

18,6FLIR0013.jpg FLIR E4 63964217

19.03.2016 19:02:28


10 minutes later, the difference between the hottest point and the coldest area is more than 25°C which means the iron core sings a problem.

Ölçümler UNIT_CELSİUSSp1 57,5

Sp2 44,8

Sp3 44,7

Sp4 51,6

Sp5 49,2

Sp6 43,1

Sp7 46,2

Sp8 45,2

Sp9 42,0

Li1 Max 58,9

Min 20,4

Average 30,7

Li2 Max 46,0

Min 24,2

Average 30,2




4/5

19.03.2016 19:12:18 UNIT_CELSİUS

Bx1

Sp1

Sp2 Sp3

Sp4

Sp5

Li1

Li2

51,7

21,6FLIR0016.jpg FLIR E4 63964217

19.03.2016 19:12:18


20 minutes later, temperature difference got higher, more than 40°C.


Min 24,2

Average 33,1

Sp1 65,1

Sp2 50,0

Sp3 51,3

Sp4 57,4

Sp5 54,8

Li1 Max 64,3

Min 22,2

Average 31,3

Li2 Max 49,6

Min 23,2

Average 31,0

Dt1 Sp1 - Ref. sıc. 65,1




5/5

19.03.2016 19:23:43 UNIT_CELSİUS

Bx1

Sp1Sp2

Sp3

Sp4

Sp5

Sp6

Li1

Li2

Li356,6

23,5FLIR0025.jpg FLIR E4 63964217

19.03.2016 19:23:43


30 minutes later, at the end of the test the temperature difference reached to 45°C.

This iron core needs to be repaired.


Min 25,8

Average 32,3

Sp1 70,5

Sp2 63,9

Sp3 55,6

Sp4 27,2

Sp5 56,0

Sp6 55,1

Li1 Max 55,9

Min 32,0

Average 39,5

Li2 Max 69,1

Min 28,4

Average 38,6

Li3 Max 70,9

Min 26,3

Average 36,2



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