315 MVA Trafo.pdf

7/21/2019 315 MVA Trafo.pdf

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CGL W.O.T09935, Rev.1, Dt.05.05.11

Prepared by:SS, Approved by:AVD

Page no. 1 of 12

1.0 Transformer application / designation Auto Transformer

2.0 Applicable standards IS 2026

3.0 Quantity required 4 nos

4.0 Full load rating MVA 315

5.0 3 Phase unit / bank of three (3) 1 phase units 3phase unit

6.0Auto wound / two winding transformers / threewinding transformers

Auto Wound

7.0 Rated no-load voltages :

7.1 HV kV 400

7.2 IV kV 220

7.3 LV kV 33

8.0Cooling (ONAN / ONAF / OFAN / OFAF /

OFWF)ONAN/ONAF/OFAF

9.0 Ratings 189/252/315MVA

9.1 Ratings of windings

9.1.1 HV MVA 315MVA

9.1.2 IV MVA 315MVA

9.1.3 LV MVA 105MVA

9.2 Ratings corresponding to cooling methods

9.2.1 ONAN MVA 189

9.2.2 ONAF MVA 252

9.2.3 OFAF MVA 315

10.0

Guaranteed impedance voltage at rated current

for the principal tapping (indicate tolerance) at315 MVA

10.1 HV LV % 60%(+15% Tol)

10.2 HV IV %12.5%(+/-10% Tol) at principal

tap

10.3%(+/-15% Tol) at max. tap

15.4%(+/-15% Tol) at min. tap

10.3 IV LV % 45%(+15% Tol)


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CGL W.O.T09935, Rev.1, Dt.05.05.11


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10.4Zero Sequence impedance at principle tap

between HV & IV%

0.9-1.0 times of Positive seq.

impedance

11.0 Efficiency at 750C at unity p.f.

11.1 At full load % 99.84%

11.2 At full load % 99.86%

11.3 At full load. % 99.88%

Maximum efficiency will beachieved at a load of 140.87

MVA

12.0Regulation at full load, 0.8 P.F at 75

0C

winding temperature% 8.1%

12.1Regulation at full load, Unity P.F at 75

0C

winding temperature% 0.92%

13.0 Rated frequency Hz. 50

14.0 External short circuit withstand capacity MVAFault MVA :29000 ie3x420kVx40kA

for 3secs

15.0 Core :

15.1 Material of core laminationCold rolled grain oriented

silicon steel Grade M5

15.2 Thickness of core plates. 0.3mm (approx)

15.3 Insulation of core lamination. Karlite

15.4 Insulation of core bolts Fibre glass

15.5 Insulation of core bolt washers Fibre glass

15.6 Insulation of core clamping plates. Fibre glass

16.0 Winding connections :

16.1 HV Auto Star

16.2 IV Auto Star


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CGL W.O.T09935, Rev.1, Dt.05.05.11


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16.3 LV Delta

16.4 Vector group YNa0d11

17.0 Tappings on winding Taps on HV for HV variation

17.1 On-load / off taps On Load Tap changer

17.2 On HV / IV / LV winding HV

17.3 Full power tapping range + % +10% to -10%

18.0 If ON load taps, specify details of OLTC gear. Easun MR, India

18.1 Manual / automatic control Manual / automatic

18.2 Remote / local control Remote

18.3If remote control, whether the remote controlcubicle included in Bidders scope of supply

Yes

18.4 Voltage class of the OLTC 220 kV

18.5 Current rating of the OLTC A 802

19.0Terminals of tertiary (stabilising) winding

brought out to bushings

Yes /

NoYes

20.0 Winding insulation category : Class A

20.1 HV uniform / non-uniform Non-uniform

20.2 IV uniform / non-uniform Non-uniform

20.3 LV uniform / non-uniform Uniform

21.0 Type of axial coil supports

21.1 HVPermawood , Pressboardcylinders

21.2 IVPermawood , Pressboardcylinders

21.3 LVPermawood , Pressboard

cylinders

22.0 Type of radial coil supports


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CGL W.O.T09935, Rev.1, Dt.05.05.11


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22.1 HVPermawood , Pressboard

cylinders

22.2 IV Permawood , Pressboardcylinders

22.3 LVPermawood , Pressboardcylinders

23.0 Impulse voltage withstand 1.2 / 50 s wave

23.1 HV kV/Peak 1300kVp

23.2 IV kV/Peak 950kVp

23.3 LV kV/Peak 250kVp

24.0Power frequency withstand voltage (dry andwet)

24.1 HV; HV neutral kV(rms)

P.D measurement shall be

carried out with u=364 kV at200 Hz / 70 kVrms

24.2 IV kV(rms)Shall be carried out with PD

measurement

24.3 LV kV(rms) 95kVrms

25.0 Guaranteed maximum temperature rise

25.1 Oil by thermometers0C 50

25.2 Winding by resistance for :

25.2.1 ONAN cooling0C 55

25.2.2 ONAFCooling0C 55

25.2.3 OFAF Cooling0C 55

26.0

Switching impulse withstand voltage for

highest equipment voltage >145 kV. HV(400kV) 1050kVp

27.0 Tank cover conventional / bell shaped Bell shaped

28.0Minimum clearance height for lifting core and

windings from tankmm 8650


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CGL W.O.T09935, Rev.1, Dt.05.05.11


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29.0 Bushings HV/IV/LV/HVn

29.1 Rated voltage class kV 420 / 245 / 52 / 36

29.2 Rated current A 800 / 1250 / 3150 / 3150

29.3 1.2 / 50 s impulse withstand kV(p) 1425 / 1050 /250/170

29.4One minute power frequency withstand dry

and wetkV(rms) 630 /460/ 95/75

29.5 Minimum clearance in air(ph-ph/ph-gnd) mm

HV mm 4000/3500

IV mm 2350/2150

LV mm530/480 .. (Outdoor Air

clearances)

HV & IV neutral mm 320 . (Line to Earth)

29.6 Minimum creepage distance

29.6.1 Total mm

HV mm 13020

IV mm 7595

LV mm 1612

HV & IV neutral mm 1116

29.6.2 Protected mmApprox 50% of the total

protected creepage

29.7 Quantity of oil in oil filled bushings Litres HV Line : 200 ltr

IV Line : 50 ltr

LV Line : 5ltr;

LVN: Not Applicable

29.6.8Free space required at top for removal of HVBushing

mm 12500

30.0

Load loss at rated current and 315MVA at75

0C winding temperature between IV & HV

(guaranteed subject to tolerance as per

applicable standard and excluding coolerlosses)

430kW(Max) at 75deg C on

principal tap.

467kW(Max) at 75deg C onMaximum tap.

578kW(Max) at 75deg C on

Minimum tap.

31.0 Maximum cooler losses at full load kW 14kW(Max)


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Page no. 6 of 12

32.0No load losses (core loss and di-electric loss) at100% rated voltage and frequency, guaranteedsubject to tolerance as per applicable standard

86kW(Max)

33.0 Guaranteed no-load current :

33.1When excited from LV side at 100% rated

voltageA

Approx 0.5% of the Full load

current

33.2When excited from LV side at 110% ratedvoltage

AApprox 1.5% of the Full loadcurrent

34.0 Maximum flux density

At 100% rated voltage Wb/m2 1.725





34.1 Overfluxing capability.

At 110% rated voltage Seconds Continuous

At 120% rated voltage Seconds 50





34.2 Voltage withstand time

At 110% rated voltage Seconds Continuous






35.0 Current density


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CGL W.O.T09935, Rev.1, Dt.05.05.11


Page no. 7 of 12

35.1 HV A/cm2 350(approx)

35.2 IV A/cm2 350(approx)

35.3 LV A/cm2 350(approx)

36.0 Wheels

36.1 Plain / flanged Flanged

36.2 Unidirectional / bi-directional Bi-directional

36.3 Quantity 8

36.4 Gauge (s) 1676

37.0 Vacuum withstand capability :

37.1 Main tankmm of

Hg.Full Vacuum

37.2 Radiators and accessoriesmm of

HgFull Vacuum

37.3 Pressure withstand capability :

37.4 Main tank torr Normal Head+5 PSI (35 kPa)

37.5 Radiators and accessories torr As per CBIP

38.0 All accessories supplied as specifiedYes /No

Yes

39.0Cooler control scheme conforms to

specification

Yes /

NoYes

40.0OLTC control scheme conforms tospecification

Yes

41.0 Weights

41.1 Net weight of the core kg 70500 approx.

41.2 Net weight of copper

41.2.1 HV kg24700 approx. (Series + Tapwinding)

41.2.2 LV kg12500 approx. (Common

winding)


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41.2.3 Tertiary kg 3600 approx.

41.2.4 Total kg 40800 approx.

41.3 Oil kg 77000 approx

41.4 Tank, coolers and fittings kg 77000 approx

41.5 Total Weight of transformer kg 314000 approx

41.6 Untanking weight kg 157000 approx

42.0 Sheet metal thickness

42.1 Outdoor cooler control cabinet mm 2.5 mm (approx)

42.2 Indoor OLTC control cabinet mm 2.5 mm (approx)

43.0Cooling fans : (State separately for ONAF &OFAF)

43.1 Type Propeller type

43.2 Quantity No.8 nos. working + 2 nos.Standby = 10 nos. total

43.3 Rating kW 0.7 kW per fan

44.0 Cooling oil pumps44.1 Type Axial flow

44.2 Quantity No. 2 running + 2 standby

44.3 Rating kW 4.1 kW per pump

45.0 Cooling water pumps NA

45.1 Type NA

45.2 Quantity No. NA

45.3 Rating kW NA

46.0

Capability of transformer to remain in

operation from hot condition after failure of

forced cooling

46.1 Full load Minutes 10 minutes (approx)


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CGL W.O.T09935, Rev.1, Dt.05.05.11


Page no. 9 of 12

47.0 On-load tap changer

47.1 Make Easun MR ,India

47.2 Type designation 3 x MI

47.3 Suitable for auto / manual operation Auto /manual

47.4 Rated voltage kV 245kV

47.5 Rated current Amp 800A

47.6 Number of steps 16

47.7 Step voltage Volts 1.25%

47.8 Rated voltage of drive motor V 400

47.9 Rated voltage of control circuit V 400

47.10Time to complete tap changing operation fromany one step to next higher or lower step

47.10.1 On auto operation Sec. 5secs (approx)

47.10.2On Manual operation i.e., through pushbutton

Sec. 5secs (approx)

48.0 List of routine tests to be carried out As per IS2026/ CBIP

49.0 Winding resistance, per phase at 75 deg.C

49.1 HV (from HV Line to Neutral) ohm 0.6867 approx.

49.2 IV (from IV Line to Neutral) ohm 0.4095approx.

49.3 LV ohm 0.12 approx.

50.0 Conductor area

50.1 Series winding sq.mm 250 approx.

50.2 Common winding sq.mm 150 approx.

50.3 Tap winding sq.mm 145 approx.

50.4 LV winding sq.mm 303 approx.

50.5Inter turn insulation for LV,TAP, Common &

Series windingInsulating Kraft Paper

50.6 Inter winding insulation Pre-compressed press boards


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50.7 LV winding to Core insulation Pre-compressed press boards

51.0 Shipping section

51.1 Size of largest package (LxBxH) mm16300 x 10450 x 10500

approx.

51.2 Weight of the largest package Tonnes 236 approx

52.0Manufacturers maintenance procedure andschedule for spare uncharged transformer

After final testing

53.0 Overload capacity of transformer for with allfans working simultaneously.

As per IS 2026

54.0 Bushings CTs, if offered

54.1 Quantity

54.2 Ratio

54.3 VA burden

54.4 Accuracy class Refer Table below

54.5 Knee point voltage Volts

54.6 Magnetising current at knee-point voltage Amps

54.7 Secondary resistance Ohms

55.0Values of transfer surge voltage withstand on

LV :

55.1 Lightning surges

55.1.1 Amplitude kVp


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CGL W.O.T09935, Rev.1, Dt.05.05.11


Page no. 11 of 12

arrangement is used.

58.0Whether neutral end surge diverter

recommended by the BidderNot required.

59.0 If yes, details of surge diverter NA

59.1 Make NA

59.2 Type NA

59.3 kV class NA

59.4 kV rating NA

60.0If unit cooler arrangement offered for cooling,advise ?

Pressed Steel sheet Radiators of

Unpainted Hot dippedGalvanised are used

(520 Wide x 1.2 mm thk)

60.1 Total no. of unit coolers provided.Radiators are arranged in 2

Banks of 50% capacity each.

60.2No. of unit coolers which would be in servicefor full load operation of transformer.

2 x 9 nos. per bank = 18 nos.total

60.3 No. of spare unit coolers NA

60.4 No. of fans in each unit cooler nos2 x (4 nos. working + 1 no.standby) per bankTotal 10 Nos.

60.5 No. of pumps in each unit cooler

2 x (1no. working + 1nos.

standby) per bankTotal 4 nos.

60.6 Rating of each fan motor3-Phase, 400V, 50Hz, 0.5A,

700Watts

60.7 Rating of each oil pump motor4500LPM, 3-Phase, 415V

10%, 50Hz, 8A, 4.1kW

61.0 Quantity of paper used for insulation kg 1700 approx.

62.0 Quantity of copper used for each winding kg Specified in Cl. 41.2 above


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CGL W.O.T09935, Rev.1, Dt.05.05.11


Page no. 12 of 12

Rev.01- Customer comments dated 4/05/11 are incorporated T1D/AVD-SS 05/05/11

315 MVA Trafo.pdf

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