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UNIVERSITI PUTRA MALAYSIA
GHASEM NOURIRAD
FK 2014 56
INFLUENCE OF FLOATING ELECTRODE IN GAP BREAKDOWN WITH SPECIAL ATTENTION TO LIGHTNING SIDE FLASHES
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INFLUENCE OF FLOATING ELECTRODE IN GAP BREAKDOWN WITH
SPECIAL ATTENTION TO LIGHTNING SIDE FLASHES
By
GHASEM NOURIRAD
Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia,
in Fulfilment of the Requirement for the Degree of Master of Science
January 2014
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Dedicated to my parents, beloved brothers and sisters
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Abstract of thesis presented to the Senate of Universiti Putra Malaysia
in fulfilment of the requirement for the degree of Master of Science
INFLUENCE OF FLOATING ELECTRODE IN GAP BREAKDOWN WITH
SPECIAL ATTENTION TO LIGHTNING SIDE FLASHES
By
GHASEM NOURIRAD
January 2014
Chairman: Chandima Gomes, Professor
Faculty: Engineering
The influence of the presence of metallic parts on the body on the probability of
lightning strikes to a human being is a long debated phenomenon without any
concrete conclusions. There are many reported lightning incidents in publications
and news in which victim stood nearby a place that has been struck by lightning. The
two schools of thoughts that argue on both sides of the phenomenon mostly
concentrate on direct lightning strikes. The percentage of side flashing injuries is four
times more than that of direct strike. Some real events of lightning incidents have
been reported in the dissertation in which there was a metallic object in vicinity that
acted as a floating object. Consequently, the minimum separation between a human
without having a floating electrode and an object which has been struck by lightning
has been simulated and compared with the previous values. Then, the influence of
the floating electrode carrying on the body or nearby is studied. An experimental set-
up has been done in UPM, UTM and TNBR to conduct the study. A rod-rod gap of
30 cm length has been implemented. Some different floating electrodes have been
located between the two rods. Positive impulse is applied to one rod and the other
rod is grounded. The test has been done for some specific positions of the floating
electrodes to find out the influence of the floating electrode position. In each test, 25
shots have been attempted in the up and down procedure.Statistical analysis has been
done using SPSS software to find the statistical significant differences of comparing
two or more groups of obtained experimental data. Several modules have been used
due to different tasks. The modules that have been used are Paired t-test, Independent
t-test and Non-parametric test. The experimental results that are presented in this
thesis show that there is a statistically significant influence of floating electrodes on
rod-rod air gap breakdown when the floating electrode is close to either of the
electrodes. The results may be extrapolated to explain the influence of electrical
floating metal parts in lightning side flashes, where the arcing distances are a matter
of only few meters. The theoretical results of calculation of minimum separation
between a human and different objects stuck by lightning show that, the minimum
separation depends on several parameters such as object impedance and lightning
current parameters. In addition, the experimental outcomes are still inconclusive with
regard to direct lightning strikes where the final jump may be few hundreds of
meters. Based on our results we recommend the removal of metal parts from the
body, if such action is possible, in the event of thunderstorms, especially when the
person is within the proximity of potential objects for lightning strikes.
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Abstak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia
sebagai memenuhi keperluan untuk ijazah Master Sains
PENGARUH ELEKTROD TERAPUNG KE ATAS FENOMENA PECAHAN
ELEKTRIK CELAH UDARA DENGAN PERHATIAN KHUSUS PADA ISU
KILAT TIDAK LANGSUNG
Oleh
GHASEM NOURIRAD
Januari 2014
Pengerusi: Chandima Gomes, Professor
Fakulti: Kejuruteraan
Pengaruh kewujudan objek-objek logam pada badan manusia ke atas kebarangkalian
sambaran kilat adalah suatu isu yang telah lama diperdebatkan tetapi masih tidak
berkesudahan secara jelasnya. Berdasarkan kajian literatur, terdapat banyak insiden
manusia yang berdiri berhampiran objek atau kawasan yang disambar kilat turut
disambar kilat. Terdapat dua sudut pandangan pada fenomena tersebut dan ianya
tertumpu pada sambaran kilat langsung. Walaubagaimanapun, risiko kecederaan
sambaran kilat tidak langsung adalah empat kali ganda risiko sambaran kilat
langsung. Turut dilaporkan di tesis terdahulu bahawa terdapat logam yang bertindak
sebagai objek terapung dalam sesetengah insiden kilat. Dalam tesis ini, impak
kewujudan konduktor terapung pada risiko sambaran kilat pada objek berhampiran
objek yang disambar langsung akan dikaji.
Beberapa eksperimen telah dilakukan di UPM, UTM dan TNBR. Celah 30cm bagi
konfigurasi rod ke rod telah diaplikasikan. Konduktor terapung dalam beberapa
bentuk yang berlainan telah digantungkan di antara dua rod. Impuls positif telah
dihantar ke satu rod manakala rod yang kedua dibumikan. Ujikaji tersebut dilakukan
dengan menggantung setiap konduktor terapung pada beberapa posisi yang spesifik
untuk mengkaji kesan kedudukan atau lokasi konduktor terapung. 25 tembakan telah
di lepaskan dalam setiap ujikaji tersebut mengikut prosedur ―up and down‖. Analisis
statistic dengan perisian SPSS telah diimplementasikan untuk mengenalpasti samada
terdapat perbezaan signifikan antara dua atau lebih kumpulan data eksperimen.
Beberapa modul telah digunakan iaitu Paired t-test, Independent t-test dan Non-
parametric test. Keputusan eksperimen yang akan dibentangkan di tesis ini
menunjukkan bahawa wujudnya kesan yang signifikan apabila konduktor terapung
berada berhampiran kedua-dua rod. Keputusan tersebut boleh dilanjutkan untuk
menjelaskan kesan kewujudan konduktor logam terapung dalam insiden kilat tidak
langsung di mana jarak pengarkaan adalah tidak begitu panjang.
Keputusan eksperimen masih tidak mampu memberi konklusi yang ketara berhubung
insiden kilat langsung di mana lonjatan terakhir kilat adalah ratusan meter.
Berdasarkan keputusan kajian, kami menyarankan supaya dalam kejadian kilat petir,
manusia perlu menyingkirkan objek-objek bersifat logam terutamanya apabila berada
berhampiran objek yang berpotensi disambar kilat.
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ACKNOWLEDGEMENTS
All praise and gratitude will be to God the almighty for his mercy and support during
course of our life and moments of truth.
First and foremost, I would like to acknowledge my deep gratitude and appreciation
to my dear supervisor Prof. Dr. Chandima Gomes for his continual support and
endless encouragement and patience, without all nothing would have been
accomplished.
My special thanks go to Prof. Dr. Mohd Zainal Abidin Ab Kadir and Dr. Mahdi Izadi
for their guidance and working with all of you was a very good experience that could
never be forgotten.
I hereby would like to thank Bahareh Zarei Mohammadzadeh, Siow Chun Lim and
all people who somehow helped me to achieve these results.
I am deeply grateful to my parents‘ support, without which I could have never been
where I am today. Their unconditional love has always shown me the right path.
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I certify that a Thesis Examination Committee has met on 28.01.2014 to conduct the
final examination of Ghasem Nourirad on his thesis entitled "Influence of Floating
Electrode in Gap Breakdown with Special Attention to Lightning Side Flashes" 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 Master of Science.
Members of the Thesis Examination Committee were as follows:
Mohd Amran Mohd Radzi, PhD
Doctor
Faculty of Engineering
Universiti Putra Malaysia
(Chairman)
Hashim Hizam, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(Internal Examiner)
Noor Izzri Abdul Wahab, PhD
Doctor
Faculty of Engineering
Universiti Putra Malaysia
(Internal Examiner)
Zulkurnain Abdul Malek, PhD
Associate Professor
Universiti Teknologi Malaysia
Malaysia
(External Examiner)
NORITAH OMAR, PhD
Associate Professor and Deputy Dean
School of Graduate Studies
Universiti Putra Malaysia
Date: 17 February 2014
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This thesis was submitted to senate of Universiti Putra Malaysia and has been accepted as fulfilment of requirement for degree of Master of Science. Members of the Supervisory Committee were follows: Chandima Gomes, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Chairman) Mohd Zainal Abidin Ab Kadir, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Member)
BUJANG BIN KIM HUAT, PhD
Professor and Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
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DECLARATION
Declaration by graduate student
I hereby confirm that:
this thesis is my original work;
quotations, illustrations and citations have been duly referenced;
this thesis has not been submitted previously or concurrently for any
other degree at any other institutions;
intellectual property from the thesis and copyright of thesis are fully-
owned by Universiti Putra Malaysia, as according to the Universiti Putra
Malaysia (Research) Rules 2012;
written permission must be obtained from supervisor and the office of
Deputy Vice-Chancellor (Research and Innovation) before thesis is
published (in the form of written, printed or in electronic form) including
books, journals, modules, proceedings, popular writings, seminar papers,
manuscripts, posters, reports, lecture notes, learning modules or any other
materials as stated in the Universiti Putra Malaysia (Research) Rules
2012;
there is no plagiarism or data falsification/fabrication in the thesis, and
scholarly integrity is upheld as according to the Universiti Putra Malaysia
(Graduate Studies) Rules 2003 (Revision 2012-2013) and the Universiti
Putra Malaysia (Research) Rules 2012. The thesis has undergone
plagiarism detection software.
Signature: ________________________ Date: ____________________
Name and Matric No.: ___________________________________________
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Declaration by Members of Supervisory Committee
This is to confirm that:
The research conducted and the writing of this thesis was under our
supervision;
Supervision responsibilities as stated in the Universiti Putra Malaysia
(Graduate Studies) Rules 2003 (Revision 2012-2013) are adhered to.
Signature: Signature:
Name of
Chairman of
Supervisory
Committee:
Name of
Member of
Supervisory
Committee:
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TABLE OF CONTENTS
Page
DEDICATION ii
ABSTRACT iii
ABSTRAK iv
ACKNOWLEDGEMENTS v
APPROVAL vi
DECLARATION xiii
LIST OF TABLES xiii
LIST OF FIGURES xv
LIST OF ABBREVIATIONS xvii
CHAPTER
I INTRODUCTION 1
1.1 Background 1
1.2 Problems Statement 2
1.3 Need of the study 2
1.4 Objective 2
1.5 Contribution of Study 3
1.6 Scope and Limitations 3
1.7 Thesis organization 3
II LITERATURE REVIEW 5
2.1 Overview on breakdown voltage 5
2.1.1 Electrical breakdown under impulse conditions 5
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2.1.2 Parameters affected by breakdown 6
2.1.3 Concept of floating electrodes and the effects on BD
voltage
6
2.2 Lightning accident 8
2.2.1 Basic characteristics of lightning 8
2.2.2 Basic injury mechanisms 13
2.2.3 Side flashes 14
2.2.4 Lightning attachment process 15
2.3 The influence of floating particle on the side flashing 16
2.3.1 Breakdown process 16
2.3.2 Floating electrode effects on side flashing 17
2.3.3 Breakdown characteristics of air gap 17
2.4 SPSS software 17
2.4.1 Paired t-test 18
2.4.2 Independent t-test 18
2.5 Summary 18
III METHODOLOGY 19
3.1 Introduction 19
3.2 Probability of getting strike by side flashing 19
3.3 Experimental work 24
3.3.1 Procedure 32
3.4 SPSS software 33
3.5 Summary 34
IV RESULTS AND DISCUSSION 35
4.1 Introduction 35
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4.2 Breakdown parameters 35
4.3 Experimental Results 39
4.3.1 Results of A-1, A-4 and A-7 42
4.3.2 Results of B-1, B-4 and B-7 46
4.3.3 Results of C-1, C-4 and C-7 50
4.4 SPSS Results 54
4.4.1 Paired t-test results 56
4.4.2 Independent t-test results 58
4.5 Discussion 61
4.5.1 Comparison of the study with similar articles 65
4.6 Summary 68
V CONCLUSION AND FUTURE WORK 69
5.1 Conclusion 69
5.2 Recommendations 69
5.2.1 Guidelines recommendation 69
5.2.2 Future work recommendation 70
REFERENCES 71
APPENDICES 77
Appendix A 77
Appendix B 86
Appendix C 96
Appendix D 120
BIODATA OF STUDENT 143
LIST OF PUBLICATIONS 144
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