Analysis ofHigb Frequency Transformer Design in Converter Application
by
F athiah Zakaria
FINAL REPORT
Dissertation submitted in partial fulfilment of the requirements for the
Bachelor of Engineering (Hons) (Electrical & Electronic Engineering)
JUNE2008
Universiti Teknologi PETRONAS Bandar Seri Iskandar
31750 Tronoh Perak Darul Ridzuan
© Copyright 2008 by
Fathiah Zakaria, 2008
CERTIFICATION OF APPROVAL
Analysis of High Frequency Transformer Design in Converter Application
Approved:
Project Supervisor
by
Fathiah ZakariaA project dissertation submitted to the Electrical & Electronics Engineering Programme
Universiti Teknologi PETRONAS in partial fulfilment of the requirement for the
Bachelor of Engineering (Hons) (Electrical & Electronics Engineering)
UNIVERSITI TEKNOLOGI PETRONAS TRONOH, PERAK
June 2008
CERTIFICATION OF ORIGINALITY
This is to certify that I am responsible for the work submitted in this project, that the original work is my own except as specified in the references and acknowledgements, and that the original work contained herein have not been undertaken or done by unspecified sources or persons.
Fatll ah Zakaria
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ABSTRACT
The project is about analysis of the transformer behaviour when operating at a high frequency such as at MHz range. This is to ensure that the design can operate well in the region. There are many issues involved in designing transformer.
However, this project only focuses on minimization of the losses in the transformer.
A low-power-losses transformer is designed by employing the interleaved technique. When interleaved technique was applied to the winding, the primary and secondary winding AC resistances show a reduction of 43.89 % and 46.88 % respectively. This shows an agreement where AC resistances are proportional to losses. Thus, an improved transformer design with low losses has been successfully achieved.
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ACKNOWLEDGMENT
First and foremost, I would like to thank God forgiving on the completion of the Final Year Project (FYP). Not forgotten to Electrical and Electronics Engineering Department of Universiti Teknologi PETRONAS (UTP) for the guidance to carry out this project. Also, thanks a lot to my family who gives a lot of support to me.
A special thank you is extended to my supervisor, Ms Khairul Nisak Md Hassan for the suggestion and interesting topic and selecting me as her FYP student. Also special thank to Mr Nor Zaihar Yahaya, (Co-Supervisor) on the guidance, support and time spent throughout the duration of this project. Thanks also to the Ms Salina Mohmad (FYP Coordinator) and Ms Siti Hawa Tahir (FYP technician) for the assistance.
The appreciation also goes to the lecturers, technicians and colleagues who involved directly or indirectly towards completion of this project. All ideas, advices and compassions to me are greatly appreciated.
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TABLE OF CONTENTS
CERTIFICATION OF APPROVAL ... .i
CERTIFICATION OF ORIGINALITY ... .ii
ABSTRACT ... .iii
ACKNOWLEDGMENT ... .iv
LIST OF FIGURES ... x
LIST OF TABLES ... xii
LIST OF APPENDICES ... xiii
CHAPTER I: CHAPTER2: INTRODUCTION ... ! 1.1 Background of Study ... .! 1.2 Problem Statement. ... 2
1.3 Objectives and Scope of Study 1.3.1 Objectives ... 4
1.3.2 Scope of study ... 4
LITERATURE REVIEW ... .S 2.1 Isolation Transformer ... 5
2.2 Planar Magnetic Components ... ,6
2.2.1 Advantages and Disadvantages of Planar Magnetic Components ... 7
2.3 Losses ... 8
2.3.1 Eddy Current ... 8
2.3.2 Skin Effect ... 9
2.3.3 Proximity Effect ... .11 2.3.4 Copper and Core Losses Calculations
2.3.4.1 Copper Losses Calculation ... .l2 2.3.4.2 Core Losses Calculation ... l2 2.4 Interleaved Technique ... l3
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2.5 Design Approach ... 15
2.5.1 Analytical Method ... .15
2.5.2 CAD Simulation ... I6 2,6 Modelling Technique for Transformer Design ... .l6 CHAPTER3:
METHODOLOGY
3.I General Project Work Flow ... 183.1.I Understanding the Objectives ... I9 3.1.2 Problem Identification ... l9 3 .1.3 Research ... I9 3.1.4 Designing and Optimizing ... I9 3.2 General Design Work Flow ... 20
3.2.1 Creating a PExprt Project... ... 21
3.2.2 Assessing PExprt ... 22
3.2.3 Selecting Design Library ... .24
3.2.4 Selecting Waveform Input data ... 24
3.2.5 Specifying Design Input... ... 25
3.2,6 Selecting Model Input ... 26
3.2.7 Starting Design Process ... 26
3.2.8 Exploring and Analyzing Results ... 26
3.3 Determination of Suitable Core Material for Transformer Design ... 27
3.3.I Determination of Frequencies ... 28
3.3.2 Application of Determined Frequencies to All Libraries that Are Available ... 28
3.3.2 Application of the Three Frequencies to the Selected Core ... 28
3.3.4 Making a Group of IOO kHz Data Tabuiation ... 28
3.3.5 Core Type for I 00 kHz With Respect to the Lowest Winding Loss ... 28
3.3.6 Making a Group of I MHz Data Tabulation ... 28
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CHAPTER4:
3.3.7 Core Type for 1 MHz with Respect to the
Lowest Winding Loss ... 29
3.3.8 Making a Group of SO MHzData Tabulation ... 29
3.3.9 Core Type for SO MHz With Respect to the Lowest Winding Loss ... 29
3.3.10 Verification for the Chosen Core With Respect to High Frequency ... 29
3.4 Application oflnterleaved Technique and Optimizing 3.4.1 Inputting the Core Data ... .30
3.4.2 Starting the Design Process ... .31
3.4.3 Generate Analytical Mode1... ... .31
3.4.4 Invoke PEmag Modeler ... .31
3.4.5 Generating Analytical Model Calculation in PEmag ... .32
3.4.6 Viewing the Analytical Based Calculation Result. ... .33
3.4.7 Applying Interleaved Technique ... .33
3.4.8 Generating Analytical Model Calculation in PEmag ... .33
3.4.9 Viewing the Analytical Based Calculation Result.. ... 33
3.4.1 0 Comparing the Analytical Model Calculation Before And After the Application of Interleaved Technique ... .33
RESULTS AND DISCUSSION ... .34
4.1 The Suitable core for 100 kHz, I MHz and 50 MHz ... .36
4.1.1 Frequency Variation for Every Library ... 36
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4.1.2 Frequency Variation For Every
Selected Core Types ... .38
4.1.3 Core Types and Characteristics for 100 kHz ... 40
4.1.3.1 EE 25.4/32.4 Core Properties ... .41
4.1.3.2 Copper _70um _ 6mm Conductor Properties ... .42
4.1.3.3 PC40 Material Properties ... .43
4.1.3.4 Summary of the Core Types and Characteristics for 100 kHz ... 44
4.1.4 Core Types and Characteristics for 1 MHz ..•... .45
4.1.4.1 EE 25/16/16 Core Properties ... .46
4.1.4.2 Copper _70um _ 6mm Conductor Properties ... .47
4.1.4.3 3C81 Material Properties ... 48
4.1.4.4 Summary of the Core Types and Characteristics for I MHz ... 49
4.1.5 Core Types and Characteristics for 50 MHz ... 50
4.1.5.1 EE 25/16/16 Core Properties ... .51
4.1.5.2 Copper_70um_6mm Conductor Properties ... .52
4.1.5.3 3C81 Material Properties ... .53
4.1.5.4 Summary of the Core Types and Characteristics for 50 MHz ... 54
4.1.6 Summary ofthe suitable core for 100kHz, 1 MHz and 50 MHz ... .55
4.2 Interleaved Technique (Optimization of the design) 4.2.1 Before Interleaved ... 58
4.2.1.1 AC Resistance ... .58
4.2.1.2 Leakage lnductance ... 60
4.2.2 Application oflnterleaved Techniques ... 62
4.2.2.1 AC Resistance ... 62
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