UNIVERSITI PUTRA MALAYSIA

AMI NURUL NAZIFAH BINTI ABDULLAH

FK 2011 55

DEVELOPMENT OF MULTI-TYPE INTERIOR PERMANENT MAGNET MOTOR

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DEVELOPMENT OF MULTI-TYPE INTERIOR PERMANENT MAGNET

MOTOR

By

AMI NURUL NAZIFAH BINTI ABDULLAH

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia

in Fulfillment of the Requirements for the Degree of Master of Science

MAY 2011

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Dedication

TO MY BELOVED ~ HUSBAND MOHD KHAIRUL CHE KAMKAH, MY

BELOVED PARENTS ~ MUHANIZAH MUSTAPHA, LATE FATHER CHE

ABDULLAH CHE MAT AND MY FAMILY.

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfillment

of the requirements for the degree of Master of Science

DEVELOPMENT OF MULTI-TYPE INTERIOR PERMANENT MAGNET

MOTOR

By

AMI NURUL NAZIFAH BINTI ABDULLAH

MAY 2011

Chairman: Assoc. Prof. Norhisam Misron, PhD

Faculty: Engineering

A new three-phase Multi-type Interior Permanent Magnet Motor (MT-IPM) is

proposed in this research. The type of motor is designed for high torque performance

with diameter of 200mm and thickness of 30mm. The main advantage of this motor

is to act as two types of motor as a Permanent Magnet Stepper Motor (PMST) and as

a Permanent Magnet Brushless DC Motor (BLDC).

BLDC operates in bi-directional variable speed operation in full torque mode. In

BLDC, the speed is simply controlled by DC supply voltage. However the BLDC

motor requires essentially an input feedback from rotor position sensor unlike PMST

that controls commutation sequences by using a frequency controller technique.

PMST is usually run at high torque at low speed. Unfortunately, PMST is suitable

only for large step angles applications as it is stepped by pulse frequency technique.

Also missing or over stepping in the sequence of commutation occurs during the

rotor rotation in a PMST for smaller step angles.

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With this aim, the development of a three-phase multifunctional motor that act as

brushless and stepper motor is proposed. This research also proposes new pitch

arrangement of three-phase motor. The coils were arranged in a group according to

their respective phases. Analyzing torque characteristic and motor performance of

MT-IPM on various sizes of magnet and rotor are essential. The optimum model is

derived and fabricated for various experimental testing to validate the performance of

the proposed motor.

At the early stage, simulation analysis using finite element method (FEM) is

performed to analyze the magnetic circuit on various sizes of rotor and magnet. The

analysis parameters include the magnetic field flux, the cogging force and the

developed torque. Further study on the research is then done to analyze the

performance of the MT-IPM by using related mathematical model. The parameters

considered are no load speed, no load current, stall torque and efficiency of the

motor. Heat increment in coil is also taken into account during the observations.

Overall analyses are done based on volume of magnet. Thus, the MT-IPM proposed

is based on optimum result for testing in a laboratory environment.

As the result, optimized model are identified for the motors with volume of magnet

between 2000mm3 to 4000mm

3. The permanent magnet volume chosen for this MT-

IPM is 3600mm3 with the selected size of rotor as 50mm. Based on the measurement

results, the optimum output torque with low cogging force of 6.5 Nm is achieved at

phase current of 5A. Also the coil current when run as PMST motor is higher than

BLDC motor.

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Abstrak thesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai

memenuhi keperluan untuk ijazah Master Sains

MEMBANGUNKAN MOTOR PELBAGAI-JENIS MAGNET KEKAL

DALAMAN

Oleh

AMI NURUL NAZIFAH BINTI ABDULLAH

MEI 2011

Pengerusi: Prof. Madya Norhisam Misron, PhD

Fakulti: Kejuruteraan

Motor baru Tiga-Fasa Magnet Kekal Pelbagai Jenis (MT-IPM) telah dicadangkan

dalam penyelidikan ini. Motor jenis ini direka untuk mendapatkan prestasi daya kilas

yang tinggi dengan ukuran diameter 200mm dan ketebalan 30mm. Kelebihan utama

motor ini adalah boleh berfungsi sebagai dua motor iaitu Motor Magnet Kekal

Berlangkah (PMST) dan sebagai Motor Arus Terus Magnet Kekal Tanpa Berus

(BLDC).

BLDC beroperasi dalam keadaan kelajuan dua-arah boleh ubah iaitu dalam keadaan

daya kilas penuh. Bagaimanapun, BLDC pada asasnya memerlukan maklum balas

input dari alat pengesan posisi rotor yang mana tidak seperti PMST yang mana

mengawal jujukan-jujukan penukaran dengan menggunakan teknik kawalan

frekuensi. PMST biasanya beroperasi pada daya kilas tinggi dan pada kelajuan

perlahan. Malangnya, PMST hanya bersesuaian untuk aplikasi sudut langkah besar

memandangkan ianya berlangkah dengan teknik denyutan frekuensi. Malah, untuk

sudut-sudut langkah yang lebih kecil, PMST akan kehilangan atau terlebih langkah

dalam jujujan penukaran semasa rotor PMST berputar.

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Dengan tujuan ini, pembangunan satu motor tiga-fasa pelbagai fungsi yang dapat

berfungsi sebagai motor pelangkah dan motor tanpa berus adalah dicadangkan.

Penyelidikan ini juga mencadangkan susunan jarak larasan baru bagi motor tiga fasa.

Kumparan pada motor telah diatur dalam secara berkumpulan mengikut fasa masing-

masing. Menganalisis ciri-ciri daya kilas dan prestasi MT-IPM pada berbagai saiz

magnet dan rotor adalah sangat penting. Model optimum diterbitkan dan dihasilkan

untuk pelbagai ujian eksperimen bagi mengesahkan prestasi motor yang

dicadangkan.

Pada peringkat awal, simulasi analisis menggunakan kaedah unsur terhingga (FEM)

dilakukan untuk menganalisis litar magnet pada pelbagai saiz rotor dan magnet.

Parameter analisis adalah meliputi fluks medan magnet, daya ‘cogging’ dan daya

kilas yang telah dibangunkan. Kajian yang lebih lanjut tentang kajian ini kemudian

dilakukan untuk menganalisis prestasi MT-IPM dengan menggunakan kaedah

mathematik yang berkaitan. Parameter ini adalah kelajuan tanpa beban, arus tanpa

beban, daya kilas terhenti dan kecekapan motor. Pemerhatian terhadap peningkatan

haba dalam gegelung juga diambil kira dalam analisis matematik. Keseluruhan

analisis dinilai berdasarkan isipadu magnet. Kemudian, MT-IPM yang dicadangkan

berdasarkan keputusan optimum tersebut akan diuji dalam persekitaran makmal.

Sebagai keputusannya, model yang optimum dikenalpasti sebagai motor yang

mempunyai isipadu magnet antara 2000mm3 untuk 4000mm

3. Isipadu magnet kekal

yang dipilih untuk MT-IPM ini adalah 3600mm3 dengan saiz rotor yang dipilih

adalah 50mm. Berdasarkan keputusan ekperimen, hasil daya kilas optimum dengan

daya ‘cogging’ rendah iaitu 6.5 Nm dicapai pada arus fasa 5A. Arus pada belitan atau

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gegelung berfungsi sebagai Motor Magnet Kekal Berlangkah (PMST) adalah lebih

tinggi dari Motor Arus Terus Magnet Kekal Tanpa Berus (BLDC).

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ACKNOWLEDGEMENTS

All praise to supreme Almighty Allah swt, the only creator, cherisher, sustainer, and

efficient assembler of the world and galaxies whose blessings and kindness have

enabled the author to accomplish this project successfully.

The author also would like to take this opportunity to gratefully acknowledge the

guidance, advice, support and encouragement she received from her supervisor,

Assoc. Prof. Dr. Norhisam Misron who keeps advising and commenting throughout

this project until it turns to real success.

A great appreciation is expressed to Assoc. Prof. Dr. Ishak Aris for his valuable

remarks, help, advice, and encouragement. Furthermore, the author would like to

thanks to colleagues Norafiza, Raja Nor Firdaus, Suhairi Rizuan, Siti Khodijah and

Mohd Syahril for their kind assistance and guidance. Appreciation also to the Faculty

of Engineering for providing the facilities and the components required for

undertaking this project.

Finally, words alone cannot express the thanks she owes to her beloved mother,

Muhanizah Mustapha and also her husband, Mohd Khairul Che Kamkah for helping

her in so many ways.

The author understands that the intellectual property of this research belongs to Dr.

Eng. Norhisam Misron and Universiti Putra Malaysia. Both of them have rights at

any aspect of design and finding throughout this research.

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I certify that a Thesis Examination Committee has met on May, 23 2011 to conduct

the final examination of Ami Nurul Nazifah binti Abdullah on her thesis entitled

“Development of Multi-type Interior Permanent Magnet Motor (MT-IPM)” in

accordance with the Universities and University Colleges Act 1971 and the

Constitution of the Universiti Putra Malaysia [P.U.(A) 106] 15 march 1998. The

committee recommends that the student be awarded the degree of Master of Science.

Members of the Thesis Examination Committee were as follows:

Mohd Zainal Abidin Ab. Kadir, PhD

Associate Professor

Department of Electrical & Electronics Engineering

Faculty of Engineering

Universiti Putra Malaysia

(Chairman)

Hashim Hizam, PhD

Associate Professor

Department of Electrical & Electronics Engineering

Faculty of Engineering

Universiti Putra Malaysia

(Internal Examiner)

Norman Mariun, PhD

Professor Ir.

Department of Electrical & Electronics Engineering

Faculty of Engineering

Universiti Putra Malaysia

(Internal Examiner)

Nasrudin Abd Rahim, PhD

Professor

Department of Electrical Engineering

Faculty of Engineering

Universiti Malaysia

(External Examiner)

________________________________

BUJANG KIM HUAT, Ph.D

Professor and Deputy Dean

School of Graduate Studies

Universiti Putra Malaysia

Date:

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This thesis was submitted to the Senate of Universiti Putra Malaysia and has been

accepted as fulfilment of the requirement for the degree of Master of Science. The

members of the Supervisory Committee were as follows:

Norhisam Misron, PhD Eng.

Associate Professor

Faculty of Engineering

Universiti Putra Malaysia

(Chairman)

Ishak Aris, PhD

Associate Professor

Faculty of Engineering

Universiti Putra Malaysia

(Member)

___________________________________ HASANAH MOHD GHAZALI, PhD

Professor and Dean

School of Graduate Studies

Universiti Putra Malaysia

Date:

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DECLARATION

I declare that the thesis is my original work except for quotations and citations which

have been duly acknowledged. I also declare that it has not been previously and is

not concurrently, submitted for any other degree at Universiti Putra Malaysia or other

institutions.

____________________________________

AMI NURUL NAZIFAH BINTI

ABDULLAH

Date: 23 May 2011

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TABLE OF CONTENTS

Page

DEDICATION ii

ABSTRACT iii

ABSTRAK v

ACKNOWLEDGEMENTS viii

APPROVAL ix

DECLARATION xi

LIST OF TABLES xv

LIST OF FIGURES xvi

LIST OF ABBREVIATIONS xix

CHAPTER

I INTRODUCTION 1

1.1 Background 1

1.2 Problem Statement 3

1.3 Scope of Work 4

1.4 Objectives 5

1.5 Thesis layout 5

II LITERATURE REVIEW 7

2.1 Permanent Magnet 7

2.1.1 Applications of Permanent Magnet 8

2.1.2 Permanent Magnet Machines 10

2.2 Overview on Other Published Result of BLDC

and PMST 11

2.3 Finite Element Method as Simulation Package

Software 15

2.3.1 Finite Element Method on Other

Research 16

2.4 Summary 17

III METHODOLOGY 19

3.1 Research Methodology 19

3.2 Introduction of MT-IPM 21

3.2.1 Basic Operation of MT-IPM 22

3.2.2 Basic Principle of BLDC Configuration 24

3.2.3 Basic Principle of PMST Configuration 26

3.2.4 Structural Features of MT-IPM 27

3.3 Modeling of MT-IPM 31

3.3.1 Structure Modeling 33

3.3.2 Simulation Parameter 35

3.3.3 Magnetic Circuit Analysis 37

3.4 Cogging and Torque Analysis 40

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3.4.1 Cogging Torque Characteristic 42

3.4.2 Torque Characteristic 43

3.4.3 Cogging Percentage over Torque

Characteristic 44

3.5 Performance Analysis 45

3.5.1 Stall Torque Characteristic 52

3.5.2 No Load Current Characteristic 53

3.5.3 No Load Speed Characteristic 54

3.5.4 Motor Efficiency Analysis 55

3.6 Coil Heat Increment Analysis 56

3.6.1 Heat Characteristic on Difference Size

of Rotor Outer Radius 59

Heat Characteristic on Increment Valu

of Coil Current 60

3.7 Analysis Evaluation 61

3.7.1 Torque and Performance Analysis on

Various Sizes of Magnet for Rotor Outer

Radius 50mm. 62

3.7.2 Analysis Evaluation on Various

Volumes of Magnet. 63

3.8 Summary 65

IV RESULTS AND DISCUSSION 66

4.1 Design and Evaluation of MT-IPM 66

4.2 Prototype of MT-IPM 68

4.2.1 Structure of optimum MT-IPM 68

4.3 Frequency Characteristic 71

4.4 Static Torque Characteristic 74

4.4.1 Measurement Setup 74

4.4.2 Torque Characteristic on Commutation

Sequence 82

4.4.3 Torque versus Rotor Positioning

Characteristics 82

4.4.4 Torque versus Phase Current

Characteristic 84

4.5 Coil Current Characteristic 85

4.5.1 Measurement Setup 85

4.5.2 BLDC Characteristic 86

4.5.3 PMST Characteristic 87

4.6 Torque Speed Characteristic 88

4.6.1 Measurement Setup for BLDC 88

4.6.2 Torque Speed Characteristic for BLDC 89

4.7 Comparison to Other Published Results 91

4.8 Summary 92

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V CONCLUSION AND RECOMMENDATION 93

5.1 Conclusion 93

5.2 Future Recommendation 95

REFERENCES 97

APPENDICES 102

A Multi-type Interior Permanent Magnet Motor

Technical Drawing 103

PUBLICATIONS 113

BIODATA OF STUDENT 114