A Report on Transformer(Part-1)

Internship Report A study on Transformer design and manufacturing At General Electrical manufacturing company limited (GEMCO). By Murshedur Rahman ID # 0731084

Has been approved Summer 2011

-------------------------Prof. M. Nuruzzaman School of Engineering and Computer Science Independent University, Bangladesh

Letter of Transmittal Date: 27th September, 2011 To Prof. M. Nuruzzaman School of Engineering and Computer Science Independent University Bangladesh, Chittagong Subject: Submission of Internship Report Dear Sir, I, Mr. Murshedur Rahman bearing the ID # 0731084, am submitting my internship report to you with immense pleasure and humble obedience. My report is all about "A study on Transformer T ransformer design and manufacturing at GEMCO ltd”. I have undergone the internship program for three months and in this duration, I have learned the manufacturing process and design of o f transformer. This report is the documentation of most of the practical knowledge I have gathered during internship. If you have further enquiry concerning any additional information I would be very  pleased to clarify. Thanking You,

------------------------------Murshedur Rahman. ID: #0731084.

ii

Acknowledgement  All the praises are for the almighty, Allah who bestowed me with the ability and potential to complete this Internship. I also pay my gratitude to the Almighty for enabling enab ling me to complete this  Internship Report within due course of time. Words are very few to express enormous humble obligations to my affectionate Parents for their  prayers and strong determination to enabling me to achieve this job.  I take this opportunity to record my deep sense of o f gratitude and appreciation to the honorable  faculties of School of Engineering & Computer Science at IUB. Thanks to Prof. Nuruzzaman,  Mr. Swomitra Palit, Mr. Amran Haroon, Mr. Atiqur Rahman, and lastly MR. Rubell Sen Goopta,  for their constant encouragement and inspiring guidance with their the ir Wisdom. Special thanks to my respected supervisor MR. Sumsuddinn M. Elias without whom this report could not been  produced.  I also appreciate the cordial co-operation from all my Internship Supervisors in the different departments of GEMCO ltd for providing me requisite information and knowledge for compilation of my complete Internship, all the employers of GEMCO ltd, especially Engineer  Abdul Malek, who helped me a lot in performing all the activities and in gaining the practical knowledge of industry. They gave me best environment and knowledge to enhance my skills.

iii

E x ecuti ve Summar um mar y General Electric Manufacturing Company Ltd. (GEM CO), an enterprise of Bangladesh Steel &  Engineering Corporation under Ministry of Industries (GOB), was established in 1978 for  production of different capacities of Distribution and Power Transformer along with other  Electrical Equipments to cater the full demand of the country. M/s. Prommashexport of the then USSR was engaged for Construction, Supervision and Technical Know-how of the Project. The enterprise is situated at Patenga Industrial Area at port city of Chittagong, Bangladesh.

The enterprise is manufacturing quality Transformers and other Electrical Equipments for national agencies like Bangladesh Power Development Board(BPDB), Rural Electrification  Board(REB), Dhaka Electric Supply Authority (DESA), Dhaka Electric Supply Company (DESCO) etc. and other private organizations in order to proper electrification in the country and also for exporting its products duly participating in the Local/International Tenders  financed by ADB, World Bank etc. The company is looking forward to implement a Project for f or  producing single phase wound core Transformer to cater the demand of Rural Electrification.  I recently have done my m y internship in GEMCO LTD, LT D, in which I got training from f rom its Distribution Transformer unit. The internship basically revolved around the transformer design, manufacturing, inspection and quality control and maintenance. The system, the style of working & the commitment of the employees in GEMCO LTD is really exemplary.  In this report I have given a very brief review of what I have seen and learnt during my internship. I have mentioned all these as I have made an internship as according to the schedule. This report will give its reader knowledge about the GEMCO LTD and about transformer unit.  I have made it possible to write each and every thing that I have learnt here. I have all my  practical efforts in the form of this manuscript manuscript that  s the asset for my future career. ’  ’ 

iv

Table of content Chapterr & Po Chapte Poin in t

Parr ticul ars Pa

CHAPTER 1

Introduction

1.1 1.2 1.3 1.4

Internship Origin of the Report Methodology Limitations

CHAPTER 2

GEmco ltd

2.1 2.2 2.3 2.4 2.5 2.6 2.7

Company profile Products / Services Installed & Attainable Capacity of the Unit Quality / Standard of the Products Location Major Raw Material used by the Unit Technical Data

CHAPTER 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8

CAPTER 4 4.1 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.2 4.3

Page Pa ge 1 1 1 1

2 3 3 3 3 4 4

 Transformer  Defining Transformer Types of Transformers About Distrib Distribution ution Transformers Oil Filled Distribution Transformer Defined Transformer Construction Type 3.6 Transf Transformer ormer Outlook 3.7 Primary Transformer Accessories 3.8 Working Transformer parts

5 6 6 7 8 10 11 14

 Manufacturing & Design Technology for Manufacturing Oil-immersed Distribution Transformers 4.11: COIL WINDING 4.12: CORE ASSEMBLY 4.13: CORE-COIL ASSEMBLY 4.14: FINAL ASSEMBLY (TANK-UP) 4.15: TRANSFORMER TANK 4.16: PAINTING 4.17: FINISHING 4.18: QUALITY 4.19: TESTING 4.2: New Oil Oil-immersed -immersed Transformer Warranty Design of a 150KVA Transformer 11/.415KV, 3 phase, 50Hz,Dyn-11

16 18 19 19 20 20 20 21 21 22 22 23

v

CHAPTER 5

 Transformer Testing

5.1 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.2

5.1 Testing Station 5.11 Winding insulation testing 5.12 Power frequency test 5.13 Induce test 5.14 Ratio test 5.15 Vector Group test 5.16 No load loss test 5.17 Full Load test 5.18 DC Resistance test 5.19 Lightning Arrestor Test 5.2 An GEMCO-Transformer Inspection Report

29 30 30 31 31 32 33 33 34 34 35

CHAPTER 6

CPL-Central plant laboratory

6.1 6.11 6.12 6.13 6.14

6.1 Purpose of CPL 6.11 Wire Resistivi Resistivity ty test 6.12 Oil breakdown voltage test 6.13 Flash point and igniti ignition on point test 6.14 Viscosity test

CHAPTER 7

Conclusion

7.1

Concluded with Gratitude

40

Reference & Bibliography

41

37 37 38 39 39

vi

List of Figures Figure No.

Figure 2.1 Figure 3.1 Figure 3.2 Figure 3.3(a) Figure 3.3(b) Figure 3.4 Figure 3.5: (a) Figure 3.5: (b) Figure 3.5: (c) Figure 3.5: (d) Figure 3.5: (e) Figure 3.5: (f) Figure 2.5: (g) Figure 3.5: (h) Figure 3.6: Figure 3.7: (a) Figure 3.7: (b) Figure 4.1 Figure 4.2 Figure 4.3 Figure 4.4 Figure 4.5 Figure 4.6 Figure 4.7 Figure 5.1 Figure 5.2 Figure 5.3 Figure 5.4 Figure 5.5 Figure 5.6 Figure 6.1 Figure 6.2

Figure Detail

Logo & Motto of GEMCO ltd Working principle of Transformer Transformer oil barrel Core type Transformer Shell type transformer Typical Transformer parts labeling Conservator tank Silica gel Radiator Bushing Surge arrester Rating plate Tapping Transformer Tank A typical transformer winding over the core(transformer leg) Transformer core-type(transformer leg) -Angular cut Transformer core-type(transformer leg) -Straight cut Process fl flow ow diagram of GEMCO ltd HT winding LT winding Core assembling Core coil assembling Transformer after fini finishing shing Transformer at testing station Connection for Megger test Power frequency test Connection for DYN 11 Vector group triangle Double wattmeter connection for Y Lightning arrestor Wire resistivi resistivity ty test measuring device. Oil break down voltage test machine

Page

2 5 7 9 9 10 11 11 11 12 12 12 13 13 14 15 15 17 18 18 19 19 21 22 30 30 32 32 33 34 37 38

vii