9.

Hardware design, Testing and Validation(At AEPL)

CHAPTER 9: HARDWARE DESIGN, TESTING AND

VALIDATION (PRACTICAL APPLICATION OF THE TDO
TECHNIQUE TO THE MANUFACTURING PROCESS AT
ATLANTA ELECTRICALS PVT. LTD. (V. U. NAGAR), ANAND,
GUJARAT.)

9.1 AEPL Introduction:

Atlanta Electricals Pvt. Ltd is one of the leading transformer manufacturing
company in India established in year 1983. Having more than 3 decades
experience for transformer Design, Manufacturing and supply. Till date AEPL
has supplied more than 5500 transformers to both Indigenous and overseas
clients. AEPL has type tested hundreds of transformer including 100 MVA
220 kv class transformer from nationally reputed NABL transformer test
laboratories like ERDA,CPRI etc. AEPL manufactures all kinds of
transformers. The detailed product range is as following.

9.1.1 Oil Filled Transformers

• Power Transformers (Up to including 160MVA, 220 kV)
• Mobile Substation (Up to and including 60MVA, 132 kV)
• Distribution Transformers (Including Corrugated type-
Starting from 5KVA, 6.6 kV)
• Furnace Transformers (Up to and including 50MVA, 66 kV)
• Induction Furnace Duty
• Arc furnace Duty
• Motor Starting Transformers (For L T & H.T. Motors)
• Neutral Grounding Transformers
• Rectifier Duty Transformers
• Testing Transformer”

9.1.2 Encapsulated& VPI Transformers

• Air Cooled Transformers
• Cast Resin Transformers
• Boosters & Voltage

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 9.Hardware design, Testing and Validation(At AEPL)

• Regulators
• Unitized Substation”
9.1.3 Reactors
• Air core reactor
• Gapped core reactor
9.1.4 EPC Contract
• Substation design, erection and commissioning

9.2 Development of New Transformer:

10 MVA 66/11 kV Transformer is designed as per following specifications with

reference to AEPL code of practice. The design data are presented herewith
in Table 9.1. It also indicates the cost of raw material. The data sheet is
prepared as per conventional method of designing of transformer prevailing at
AEPL. The design data validated with previously executed same rating
transformer.

DESIGN
SPECIFICATIONS

kVA 10000 Guaranteed 8000 watts

N.L.Loss

HV Volts 66000 Guaranteed Load 50000Watts

Loss

LV Volts 11000 Guaranteed % Z 9.5

No of Phases 3 Tap +ve 5

Frequency 50 Hz Tap -ve 15

HV Connection delta Step 1.25

LV Connection star Type OLTC

Vector Group Dyn11 Variation HV

Cooling ONAN Oil Rise/Winding 35/45⁰C

Rise

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 9.Hardware design, Testing and Validation(At AEPL)

Table 9.1 Transformer Design Data Sheet by Conventional Method at AEPL

DESIGN SPECIFICATIONS COST WORKING

No of Phases 3 Tap +ve : 5 Material Quantity Rate Cost
Frequency 50 Tap -ve : 15 Lamination 6791 200 1358200
LV Copper 1538 400 615200
KVA 10000 Step : 1.25 HV Copper (M) 1866 400 746400
HV Volts 66000 Type : Oltc HV Copper (T) 391 400 156400
LV Volts 11000 Variation : LV Oil 6700 40 268000
HV
Connection Delta Tank 3100 70 217000
LV
Connection Star Frame Parts 950 68 64600
Vector Group Dyn11 N.L.Loss 8000 Radiators 10 36288 362880
Cooling ONAN Load Loss 50000 Pressboard 350 160 56000
Oil Rise 35 %Z 9.5 Permawood 200 160 32000
Wdg.Rise 45 HV Bushing 3 30000 90000
Tap Switch 1 220000 220000
Total A 4186680
Other
accessories+tax B 293067.6
Total RM cost A+B 4479747.6
DESIGNER'sCHOICE DESIRED TECHNICAL OUTPUT
Conductor Core
Size LV Material : MoH MoH k Factor 0.44
Axial 13 No Load 8000 7628 WH/Dia 2.78
Radial 2.5 Load Loss 50000 48593 Lx/Dia 2.34
Nos Axial 2 %Z 9.5 9.23 LV TURNS 144
Nos Radial 4 Bm 1.67 1.67 No of Discs 32
Covering 0.45 LVA/mm2 2.8 2.05 T/Disc 4.5
Conductor
Size HV HV A/mm2 2.8 2.15 HV Turns 1497
Axial 10 Core - LV 10 10 Tap Turns 18.71
Radial 2.4 LV - HV 31 27 Nomal Discs 52
T/Normal
Nos Axial 1 Bet.Phase 28 27 Disc 25.04
Nos Radial 1 Tap Discs 12
Covering 0.7 T / Tap Disc 22.83
Core Dia. : 410 Net Area : 1187.7 %R 0.49
WH : 1140 Et : 44.1 %X 9.22
CL : 795 Bm : 1.67 %Z 9.23
Material : MoH Weight : 6779

With reference to praposed optimization and analytical innovative techniques for

TDO a 10 MVA, 66/11 kV transformer designed and the same transformer was
manufactured(By NSGA-TDO (multi-objective) including FEM analysis). The

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 9.Hardware design, Testing and Validation(At AEPL)

design data, photographs of transformer and Nationalized test lab results is

presented herewith in Table 9.2, Fig 9.1, Fig.9.2 and Fig 9.3 respectively.

Table 9.2 Transformer Design Data Sheet After Implementation of Proposed

Technology to AEPL Design Process.

DESIGN SPECIFICATIONS Cost Working

No of 3 Tap +ve : 5 Material Quantity Rate Cost
Phases
Frequency 50 Tap -ve : 15 Lamination 6416 200 1283200
LV Copper 1416 400 566400
kVA 10000 Step : 1.25 HV Copper (M) 1705 400 682000
HV Volts 66000 Type : Oltc HV Copper (T) 358 400 143200
LV Volts 11000 Variation : HV Oil 6700 40 268000
HV Delta Tank 3100 70 217000
Connection
LV Star Frame Parts 950 68 64600
Connection
Vector Dyn11 N.L.L 8000 Radiators 10 36288 362880
Group
Cooling ONAN Load Loss 50000 Pressboard 350 160 56000
Oil Rise 35 %Z 9.5 Permawood 200 160 32000
Wdg.Rise 45 HV Bushing 3 30000 90000
Tap Switch 1 220000 220000
Total A 3985280
Other
accessories
+tax B 291161.
Total RM cost A+B 4276441
DESIGNER' CHOICE DESIRED TECHNICAL OUTPUT
Conductor : Core
Size : LV Mater : MoH MoH k Factor 0.432
Axial : 12.8 No Load : 8000 7749 WH/Dia 2.8
Radial : 2.3 Load Loss: 50000 49764 Lx/Dia 2.35
Nos Axil : 2 % Z: 9.5 8.82 LV TURNS 147
Nos Radial : 4 Bm 1.7 1.71 No of Discs 32
Covering : 0.4 LV A/mm2 2.8 2.27 T/Disc 4.5975
ConductorSi
ze: HV HV A/mm2 2.8 2.3 HV Turns 1528
Axial : 9.8 Core - LV 9 9 Tap Turns 19.1
Radial : 2.3 LV - HV 31 25 Nomal Discs 52
T/Normal
Nos Axial : 1 Bet.Phase 27 29 Disc 25.55
Nos Radial : 1 Tap Discs 12
Covering : 0.65 T / Tap Disc 23.25
Core Dia.: 402 Net Area : 1140.6 %R 0.5
WH : 1125 Et : 43.2 %X 9.16
CL : 765 Bm : 1.71 %Z 9.17
Material : MoH Weight : 6352

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 9.Hardware design, Testing and Validation(At AEPL)

Figure 9.1 Design Output of Proposed Optimization Methodology for

10 MVA 66/11 kV Power Transformer.

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 9.Hardware design, Testing and Validation(At AEPL)

TABLE 9.3 Comparisons Between Conventional &NSGA Design

Optimization Methodology For 10 MVA Transformer

Design Parameters TDO- Conventional NSGA-TDO

Design Methodology

K factor 0.44 0.432

Bm(Wb/m²) 1.67 1.71
Current 2.15 2.3
Density(HV)-A/mm²
Current 2.05 2.27
Density(LV) -A/mm²
Core Dia(mm) 410 409
Core Height(mm) 1140 1140
Core CL(mm) 795 795
Core Wt(Kg) 6779 6724
Copper Wt( HV)- 2227 2042
Kg
Copper Wt( LV)-Kg 1570 1402
Load Loss( kW) 48593 49764
No Load Loss( kW ) 7628 7749
%Impedance(%Z) 9.23 9.17

%η 99.44 99.44
GLV⁰C 12.14 11.2
GHV⁰C 16.5 17.2
Deflection (mm) 7.32 8.03
Cost (INR-Lacs) 44.80 42.76

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 9.Hardware design, Testing and Validation(At AEPL)

Winding

Core

Core & Coil Assembly

Figure 9.2 Stage Wise Photographs of 10 MVA Power Transformer

Developed with NSGA-TDO and Manufactured at AEPL

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 9.Hardware design, Testing and Validation(At AEPL)

Connection

Tanking and Fitting

Testing

Figure 9.3 Stage Wise Photographs of 10 MVA Power Transformer

Developed with NSGA-TDO and Manufactured at AEPL

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 9.Hardware design, Testing and Validation(At AEPL)

NABL laboratory test report ( ERDA)

Figure 9.4 NABL Laboratory Test Report of 10 MVA Transformer

Developed with NSGA-TDO

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 9.Hardware design, Testing and Validation(At AEPL)

TABLE 9.4 Result Comparisons Between Conventional Design-NSGA

Optimization, AEPL Laboratory (Hardware) Test Result, NABL
Laboratory(Hardware) Test Result For 10 MVA Transformer.

Variables and TDO- NSGA- AEPL NABL

Constraints Conventional TDO Laboratory Laboratory
Design Test Result Test Result
Methodology
No Load Loss( kW) 7628 7749 7825 7810
% I mag (Amp.) 0.162 0.149 0.152 0.154
HV Resistance(Ohm) 3.52 3.75 3.66 3.71
@ 75 ⁰C
LV Resistance(m.Ohm) 20.03 20.96 20.80 20.62
@ 75 ⁰C
LV I2R @ 75 ⁰C 16555 17314 17195 17048
HV I2R @ 75 ⁰C 26962 28673 28057 28399
Total I2R @ 75⁰ C 43014 45987 45253 45447
Stray Loss @ 75⁰ C 5578 3777 3885 3524
Load Loss( kW) 48593 49764 49139 48971
@ 75 ⁰C
%R 0.49 0.5 0.491 0.49
%X 9.23 9.17 8.825 8.75
%Impedance(%Z) 9.23 9.17 8.839 8.76
%η 99.44 99.43 99.44 99.44

9.3 Conclusion

A10 MVA 66/11 kV transformer is manufactured on the basis of the proposed

design optimization technique.At design stage , the output remained effective
concern to cost reduction, which is almost 5-6% compare to conventional
code of practice. While transformer manufactured and tested at various
laboratories, all the technical parameters are achieved as designed. So the
simulated design become more reliable as it is strongly validated by real
manufacturing at Industry. This approach will surely helpful to the
transformer designer.

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