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UNIVERSIT

ANALYZING TR

This report submitte Malaysia Melaka (UT

(M

FACUL

ERSITI TEKNIKAL MALAYSIA ME

G TRANSFORMER MANUFACTURIN

BY USING FMEA APPROACH

bmitted in accordance with requirement of the Univ ka (UTeM) for the Bachelor Degree of Manufactur

(Manufacturing Management) with Honours.

By

ZHARIF ANWAR BIN SULAIMAN

ACULTY OF MANUFACTURING ENGINEERIN 2011

IA MELAKA

URING FAILURE

e Universiti Teknikal facturing Engineering

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i

ABSTRACT

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ii

ABSTRAK

Laporan ini menjurus kepada analisa kegagalan terhadap kegagalan “Tangent Delta”

di dalam proses pembuatan transformer. “Failure Mode and Effect Analysis” atau

FMEA ialah salah satu kaedah kualiti yang mampu membimbing jurutera atau pereka

untuk mengatasi masalah kegagalan yang dihadapi pada sesetengah produk atau

proses pembuatan. FMEA membantu pengurusan untuk mengetahui kegagalan

dengan mengenal pasti mod potensi kegagalan, kesan setiap kegagalan, kehadiran

kegagalan dan proses kawalan melalui tahap “Severity (S)”, “Occurence (O)” dan

“Detection (D)”. Daripada kombinasi tahap tadi melalui teknik “Risk Production

Number” atau RPN, keutaamaan untuk megurangkan atau menghapuskan

(barangkali) kegagalan boleh dilaksanakan dengan mengenal tahap RPN yang

tertinggi. Untuk keberkesanan FMEA, kaedah yang lain turut digunakan seperti

“Pareto chart”, “Fishbone diagram” dan “Why-Why Analysis” bersama-sama analisa

ini. Ulasan terdahulu menyediakan teori dan fakta dimana telah didapati daripada

buku dan kertas kajian. Maklumat berkenaan akan menjadi rujukan penting dengan

harapan dapat membimbing projek ini mencapai objektif utamanya. Sebelum

melaksanakan projek ini, terdapat beberapa perkara perlu diambil kira. Carta alir

menunjukan cara kerja dan menjadi rujukan untuk keseluruhan projek ini. Kajian kes

telah dijalankan melalui kajian terhadap proses yang terlibat didalam barisan

pengeluaran. Ia juga untuk menguatkan maklumat awal dengan tujuan member

pengetahuan yang jelas. Eksperimen FMEA telah mendedahkan kebarangkalian

kegagalan daripada beberapa faktor. Dengan mencadangkan beberapa langkah

pembaikan berdasarkan analisa, kebarangkalian untuk mengurangkan kesan

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iii

ACKNOWLEDGEMENTS

First of all, thanks to Allah for HIS guidance and blessing, I am able to complete the

final year project. I wish to express my gratitude to all those people whose has given me

their support during this project.

I would like to express my token of appreciation to Tn Hj Abd Rahman Mahmood who

responsible to become my project supervisor for his guidance, advice, encouragement,

and support throughout the project.

Special thanks to every staff in ABC Company especially to all staff under Production

Department, Quality Assurance Department and Test Department because every one of

them was particularly helpful.

I would like to thanks to all my friends for all their support and help. I am not being able

to get through the entire difficult situation and face the pressure well without their help

and support. Thank you.

Finally to my family, thank you so much for all your tremendous support to ensure that I

complete my project.

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iv

TABLE OF CONTENT

Abstract i

Abstrak ii

Acknowledgement iii

Table of Content iv

List of Tables viii

List of Figures x

List Abbreviations xiii

1. INTRODUCTION 1

1.1 Problem Statement 3 1.2 Objective 4 1.3 Importance of the Study 4 1.4 Scope of the Study 4

2. LITERATURE REVIEW 6 2.1 Failure Mode and Effect Analysis (FMEA) 7

2.1.1 Purpose of FMEA 7 2.1.2 Benefits of FMEA 8

2.1.3 Part of a Comprehensive Quality System 9

2.1.4 FMEA Standards 10

2.1.5 FMEA Planning 10 2.1.6 The FMEA Team 12 2.1.7 Design FMEA vs. Process FMEA 13 2.1.8 FMEA Scope 14

2.1.9 Input, Outputs and Other Quality Tools Related 15

2.1.10 FMEA Process 16

2.1.11 FMEA Worksheet 25

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v

2.2. Transformer Manufacturing 36

2.2.1 Electrical Transformer 36

3. METHODOLOGY 39

3.1 Project Planning 40

3.2 Project Flowchart Activities 43

3.2.1 Conforming the PSM Title 43

3.2.2 Project Details Discussion 43

3.2.3 Literature Review 44

3.2.4 Methodology Construction 44

3.2.5 Gathering Input 44

3.2.6 Brainstorming Session 45

3.2.7 FMEA Process 46

3.2.8 Result 47

3.2.9 Recommend the Corrective Actions 47

3.2.10 Modification 47

3.2.11 FMEA Output 47

3.2.12 Completing Report & Submission 48

3.3 FMEA Process 48

3.4. Technique Used 50

4. CASE STUDY 52

4.1 Product 53

4.1.1 Product Specification 53

4.2 Process Flow 54

4.2.1 Power Transformer Manufacturing Process 54

4.2.2 Production Process Section 54

4.2.3 Production Workflow 56

4.2.4 Core Building Section 56

4.2.5 Winding Section 58

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vi

4.2.6 Finishing Section 72

4.2.7 Insulation Section 78

4.3. Input Material and Output Product 79

4.4. Equipment and Manufacturing Process 82

4.5. Case Study Findings 85

4.5.1 Using 4M Technique 86

5. RESULT AND ANALYSIS 95

5.1 Fish Bone Diagram 95

5.2 Possibilities Explanations 96

5.3. Why-Why Analysis 100

5.4 FMEA Procedure 103

5.4.1 Determining the potential, causes likelihood

and current control process 103

5.4.2 Determining the severity, occurrence and detection 107

5.4.3 Constructing FMEA Experiment 109

5.4.4 Pareto Charts 111

5.5 Result Analysis 114

5.6 Action Recommended 116

5.6.1 Improving Detection 116

5.6.2 Reducing Occurrence 119

5.6.3 Reducing Severity 122

5.6.4 Possible new severity, occurrence and detection rankings 125

5.7 Revised RPN 126

5.7.1 RPN Comparison 128

5.7.2 Percentage of Reduced RPN 130

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vii

6. CONCLUSION AND RECOMMENDATIONS 134

REFERENCES 136

APPENDICES

A Gantt chart for PSM 1

B Gantt chart for PSM 2

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viii

LIST OF TABLES

2.1 Severity Criteria for Design FMEA 18

2.2 Severity Criteria for Process FMEA 19

2.3 Occurrence Criteria for Design FMEA 20

2.4 Occurrence Criteria for Process FMEA 21

2.5 Detection Criteria for Design FMEA 22

2.6 Detection Criteria for Process FMEA 23

3.1 Technique and data required for each activity 50

4.1 Product specification 53

4.2 Manufacturing section involved in the

power transformer production line 55

4.3 Sub-process involved in Core Building Section 57

4.4 Sub-process involved in Winding Section 59

4.5 Sub-process involved in Mechanical and Electrical Assembly Section 61

4.6 Sub-process involved in Finishing Section 72

4.7 Input material and output product involved

in each manufacturing sections 79

4.8 Equipment and manufacturing process involved in

each manufacturing sections 82

4.9 Case study findings during core cutting process 86

4.10 Case study findings during core stacking process 87

4.11 Case study findings during paper lapping process 87

4.12 Case study findings during winding process 88

4.13 Case study findings during drying process 88

4.14 Case study findings during coil pressing process 89

4.15 Case study findings during coil fitting process 89

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ix

4.17 Case study findings during top-yoke assembly process 90

4.18 Case study findings during electrical jointing and wiring process 91

4.19 Case study findings during pre-heating process 91

4.20 Case study findings during tap changer assembly process 92

4.21 Case study findings during pre-tank preparation process 92

4.22 Case study findings during tanking process 93

4.23 Case study findings during oil filling and purifying process 93

4.24 Case study findings during In-house machining process 94

5.1 Material factors with further explanation 97

5.2 Machine factors with further explanation 98

5.3 Method factors with further explanation 99

5.4 Man factors with further explanation 99

5.5 Determining potential failure modes for each factors 104

5.6 Determining causes for each factors 105

5.7 Determining the current control process for each factors 106

5.8 Determining severity rankings at each factors 107

5.9 Determining Occurrence rankings at each factors 108

5.10 Determining Detection rankings at each factors 109

5.11 FMEA table 110

5.12 Detection improvement 117

5.13 Reducing Occurrence 120

5.14 Reducing Severity 123

5.15 The new RPN generated with new possible severity, occurrence

and detection rankings 125

5.16 Comparison between benchmarked RPN and revised RPN 128

5.17 Reduction percentage 130

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x

LIST OF FIGURES

1.1 Power Transformer 3

1.2 Power transformer 30 MVA (33/11 KV) in operation. 5

2.1 Example of Start-up worksheet 25

2.2 Example of Design FMEA scope worksheet 26

2.3 Example of Process FMEA scope worksheet 27

2.4 Example of Design FMEA worksheet 28 2.5 The simple illustration of electrical transformer 36

2.6 The completed windings and the copper wire without insulation 37 2.7 The transformer core 38

2.8 The tank preparation and the oil filling 38 3.1 The project flowchart 41

3.2 The FMEA Process 42

4.1 Transformer unit, 30MVA-203 (33/11KV) 53

4.2 Production process flow 56

4.3 Core plate 57 4.4 Core Structure 57 4.5 Core Building flow chart 58 4.6 Paper lapping process 59 4.7 Winding process 59 4.8 Winding flow chart 60 4.9 Mechanical and Electrical Assembly Section general flow chart 62

4.10 Drying process flow chart 63 4.11 Drying oven 63

4.12 Coil pressing process flow chart 64

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xi

4.14 Coil fitting process flow chart 65

4.15 Coil fitting process 65 4.16 Coil phasing process flow chart 66

4.17 Coil phasing process 66

4.18 Top-yoke Assembly process flow chart 67

4.19 Top-yoke Assembly process 67

4.20 Electrical wiring and jointing process workflow 68

4.21 Pre-heating process flow chart 69

4.22 Tap Changer Installation process flow chart 70

4.23 On Load Tap Changer (OLTC) 71 4.24 Finishing Section general flow chart 73

4.25 Pre-tank preparation process flow chart 74

4.26 Tanking process flow chart 75

4.27 Oil filling and Purification process flow chart 76

4.28 Accessories Installation process flow chart 77

4.29 Insulation Section flow chart 78

4.30 The scoped studied area 85 5.1 Fish Bone Diagram 96

5.2 Why-why analysis for failure possibility factor in machine element 100 5.3 Why-why analysis for failure possibility factor in material element 101 5.4 Why-why analysis for failure possibility factor in method element 102

5.5 Why-why analysis for failure possibility factor in men element 103 5.6 MINITAB spreadsheet 111 5.7 Pareto chart selected 112

5.8 Dialog box appeared 112

5.9 Filling the required information 113 5.10 Pareto charts 113

5.11 Insulation material not in proper stored and been exposed 115

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xii

5.13 Pareto chart for the revised RPN from each factor 127

5.14 Comparison between Benchmarked RPN and Revised RPN 129

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xiii

LIST OF ABBREVIATIONS

FMEA - Failure Mode and Effect Analysis

EMF - Electro Magnetic Field

PSM I - Projek Sarjana Muda I

PSM II - Projek Sarjana Muda II

DOE - Design Of Experiment

KV - Kilovolt

ONAN - Oil Natural Air Natural

ONAF - Oil Natural Air Forced

TNB - Tenaga Nasional Berhad

MVA - Megavolt Ampere

Hz - Hertz

LV - Low Voltage

HV - High Voltage

FMEA - Failure Mode Effect Analysis

RPN - Risk Production Number

WIP - Work In Progress

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1

CHAPTER 1

INTRODUCTION

During this section, this chapter will explain about the background, problem

statement, objective, scope and importance of study. Furthermore this chapter also

briefly explains about the Failure Mode and Effect Analysis (FMEA) that will be

applying at the manufacturing or assembly processes for this final year project.

The production output is the most vital elements in the manufacturing industries.

This is why, the output or product reflects about the assembly operation and the

design of the product itself. When talk about the quality and reliability, when a

product or system fails to achieve its final objective (functionality), it will trigger a

disaster to the manufacturer which produce it. Customer complaints, critics, and

turnovers will be a price that had to pay with costly recall and rework from the

manufacturer. Many manufacturers are empowered themselves to gain loyalty from

their customers. Absolutely the quality, functionality and reliability will be the key

for their core strategy. Ensuring to achieve the objective, the manufacturer needs to

concern about the product design and also the manufacturing process operations

which important to the output that will produce.

The defects or failure of the products or sometimes in the manufacturing operations

can contribute product or system fail to achieve its main objective, to perform

functionality exactly as the manufacturer expectation. The effects of the defects or

failure of the product can contribute a huge significant in terms of quality, reliability,

functionality and another important addition, safety. This is because, the failure,

defects, and errors where occurred to the product or manufacturing assemblies

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2

of losses, delays, increased manufacturing costs, or any drawbacks which can

jeopardize their business.

Failure Mode Effect and Analysis or FMEA was becoming the powerful answer about the problems of reliability and failure analysis. FMEA is defined as “a systematic group of activities to; (a) recognize and evaluate the potential failure of a product / process and the effects of that failure, (b) identify actions that could eliminate or reduce the chance of the occurrence of potential failure”. Failure modes can be described as the modes of failures of a part or sub-assembly while the effect indicates the effect of the

failure of a part in any of the modes, on a system. FMEA is popular tool or technique

to identify failures of parts or components, which have significant consequences on

the system when it will use. Any failures related with the modes may affect the

system performance and also the quality of the system itself.

FMEA is useful for studying the failure modes, failure causes and their effects on the

system as well as taking appropriate preventive actions. It is a reliability evaluation /

design technique where it provides basic information to reliability prediction and

product & process design. The information was come from the examination or

research of the potential failure mode and effects through a product or system.

FMEA helps the engineers and designers to detect any potential problems which

contributing to the failure in the product or system in the early stages such as design

stage or simulation stage. From this stage it will ensure them to avoid any changes or

reworks at later stage such like production / manufacturing stage or product warranty

stage where it claims the higher price when performing it (Teng and Ho, 1996)

FMEA is becoming the selected method for this final year project, Analyzing

transformer failure by using FMEA approach. This is because; the FMEA providing

the detailed failure analysis and also detailed information and those data can be used

as conclusion and solution for the particular failure. Another advantage is, the data

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1.1. Problem State

“Tangent Delta” (Tan

manufacturing. “Tange

transformer unit excee

20°C. Tan δ is also kn

for electrical propertie

diagnostic test to det

electrical machines and

customer due to inten

electrical failure of the

3 Statement

(Tan δ) failure is a very common problem in

“Tangent Delta” is a problem where the power

exceeded the maximum specification value of 0.5

lso known the “loss angle” or “dissipation factor”

operties especially in transformer technology. It

to determine the level of degradation in insula

es and power cables. This problem could delay th

intensive rework and also increasing the risk

[image:17.595.156.477.322.562.2]

of the transformer unit itself.

Figure 1.1: Power Transformer

lem in the transformer

ower factor value of a

of 0.5% at temperature

factor” which important

gy. It been used as a

insulation materials of

elay the shipment to the

risk of another major

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4

1.2. Objective

1. To determine the possible factors that lead “Tangent Delta” problem by

applying with Fish Bone Diagram method.

2. To analyze the problem by using FMEA technique.

3. To analyze the identified possible factors by using Pareto chart and revise

RPN technique.

4. To propose a countermeasure with a purpose solution.

1.3. Importance Of The Study

The importance of this study is to investigate and determine the possible factors of

the problems which contribute to the failure of the transformer and to analyze the

failure by using FMEA technique. From the data collected from the study can be use

to propose the new solution or answer to countermeasure the particular problem and

defects.

1.4. Scope Of The Study

The study and the observation will be conducted at the ABC Company plant at Ulu

Kelang, Kuala Lumpur. ABC Company is one of the transformer manufacturers in

the ASEAN region which been established in early 1980s. The scope of this final

year project will be focus only at the entire manufacturing process of the electrical

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The research of this f

analyzing it by using

method such as Caus

process flowchart and

technique.

The subject for this stu

information of this pow

the country. This tran

ABC Company and

[image:19.595.158.478.331.573.2]

manufacturing stage.

Figure 1

5

this final year project study is focus on the sta

using FMEA technique. To meet this propose

Cause-and-Effect diagram (fish bone diagrams),

rt and other necessary method will be use to su

his study is the power transformer unit (step down t

is power transformer unit is 30MVA (33/11 KV) a

transformer type is among the highest product

and also always obtaining “Tangent Delta”

gure 1.2: Power transformer 30 MVA (33/11 KV) in operati

the stated problem and

oposed research, other

rams), Pareto diagram,

to support the FMEA

down type). The general

KV) and widely used in

roduction output in the

Delta” failure during

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6

CHAPTER 2

LITERATURE REVIEW

This chapter provides a basic knowledge and information about the Failure Mode

and Effect Analysis (FMEA) where it been selected as a primary study for this final

year project. The FMEA will be described with the necessary element required,

benefit & limitation, and other relevant knowledge related to the FMEA and also to

the project. This chapter also will describe another relevant topic in order to provide

a deep understanding about the study in order to strengthen the purposed project.

Without the guidelines from it, it will impossible to conduct the particular study and

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7

2.1. Failure Mode and Effect Analysis (FMEA)

Failure Mode and Effects Analysis or FMEA is a common methodology used by

engineer or designer for analyzing the potential reliability problems in early

development stage where it were easier to take appropriate actions to overcome these

selective issues, thereby enhancing the reliability. FMEA is a proactive tool

developed to identify, evaluate and prevent product and/or process failures

(Bluvband and Grabov, 2009)

FMEA also is a decision making tool for prioritizing corrective action to enhance

product or system performance by eliminating or reducing failure rate (Chang and

Sun, 2009). Until now, FMEA has been recognized as a powerful tool used to

identify critical components / parts / functions whose failure will lead to undesirable

outcomes such as production loss, production rework, injury or even an accident

(Sharma et al. 2007). Previously, this tool was first proposed by NASA in 1963 for their obvious reliability requirements. Since then, it has been intensively used as a

powerful technique for system safety and reliability analysis of product and

processes in a wide range of industries such as aerospace, nuclear, automotive and

medical (Ebeling, 2001)

2.1.1. Purpose of FMEA

The main purposed of FMEA is to identify the possible failure modes that could

occur in the design or manufacturing of a product and determining the impact of

those failures. (Bluvband and Grabov, 2009). Thus the corrective action can be taken

in order to reduce or eliminate the potential for failures to occur. An effective FMEA

identifies corrective actions required to prevent failures from reaching the customer

and to assure the highest possible yield, quality and reliability.

There are several types of FMEA that has been implemented in the industries.

Although the process steps is relatively same but they are some differences regarding

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8

a) System - focus on global system functions

b) Design - focuses on components and subsystems

c) Process - focuses on manufacturing and assembly processes

d) Service - focuses on service functions

e) Software - focuses on software functions

FMEA also documents current knowledge and actions about the risks of failures, for

use in continuous improvement. FMEA is used during design to prevent failures.

Later it’s used for control, before and during ongoing operation of the process. The

information used in the FMEA process should come from the company’s own

production lines, the customers, and the field data of similar products (Teng and Ho,

1996). Ideally, FMEA begins during the earliest conceptual stages of design and

continues throughout the life of the product or service.

2.1.2. Benefits of FMEA

The FMEA programme offers a wide range of benefit for the organization which

implemented it. Main benefits of implementing FMEA are improving the product or

process quality and reliability and satisfying the customers (Teng and Ho, 1996). The

several benefits that can be described are:

a) Minimizes late changes and associated cost since FMEA is been carried out

during design stage.

b) Identifies failure modes which will have significant impact

c) Identifies the causes of failures and minimizes them

d) Helps in redesigning to reduce the effect of failures

e) Improve product reliability, maintainability and availability of the system

f) Increases customer satisfaction

g) Prioritize product / process deficiencies for improvement

h) Emphasizes problem prevention

i) Providing information of:

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9 ii. Safety analysis

iii. Survivability

iv. Vulnerability

v. Logistic support analysis

vi. Maintenance plan analysis

vii. Risk analysis

viii. Failure detection

ix. Failure isolation

2.1.3. Part of a Comprehensive Quality System

A formal FMEA process should be a part of comprehensive quality system. This is

why, a standalone FMEA process could be effective but the company will not get a

maximum benefit without other system to support conducting FMEAs and

implementing improvements that are result of the FMEAs. The example of from this

statement such as one element of comprehensive quality system is effective use of

data and information. Without reliable product or process data, the FMEA becomes a

guessing game based on opinions rather than actual facts. This factor could lead the

FMEA team focused on the wrong failure modes, thus missing significant

opportunities to improve the failure modes that are the biggest problems.

2.1.4. FMEA Standards

For the stand alone FMEAs, the primary standards were been used are the “military

standard” (Mil-Std 1629A) and the “Society of Automotive Engineers standard”

(SAE J1739). These standards are only limited for the design and process FMEAs.

These standards provide general FMEA forms and documents, identify criteria for

the quantification of risk associated with potential failures, and provide very general

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10

Since the FMEA can be used as a part of the comprehensive quality system, it is been

subjected under the quality standards of ISO/TS 16949. This standard is created for

the automotive industry and based on ISO 9000 and builds on QS 9000, which was

originally developed by the Chrysler, Ford, and General Motors (GM) Supplier

Quality Requirement Task Force. The objective was to develop a fundamental

quality system that provides for continuous improvement, emphasizing defect

prevention and the reduction of waste in the supply chain. Furthermore ISO/TS

16949 incorporates the process approach to the quality system requirements

originally presented in QS 9000

2.1.5. FMEA Planning

Before planning the FMEA steps on process, there are several series of

considerations that have to be view. The following statement below will be regards

as a minimum consideration.

2.1.5.1Selecting appropriate applications for the analysis

The FMEA may be authorized by individuals at various levels in the organization or

may be required by ISO 9000, QS 9000, Six Sigma methodologies, internal quality

programs or customer requirements. However, the FMEA is expensive to complete

and should be completed only in those instances where the benefit outweigh the cost.

2.1.5.2Identifying and allocating resources

The resources will includes FMEA team members and reporting structure, physical

space to conduct the analysis and store to documentation, time, and clerical or

Figure

Figure 1.1: Power Transformer
Figure 1gure 1.2: Power transformer 30 MVA (33/11 KV) in operatiperation.

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