ASSESSING THE RELIABILITY OF THE ELECTRICITY DISTRIBUTION SYSTEM IN GHANA
- 주제(키워드) Energy studies
- 발행기관 아주대학교
- 지도교수 Jaesung Jung, Ph.D
- 발행년도 2020
- 학위수여년월 2020. 2
- 학위명 석사
- 학과 국제대학원 융합에너지학과
- 실제URI http://www.dcollection.net/handler/ajou/000000029418
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Erratic power outages in Ghana have made reliability of electricity supply a top priority to regulators, utilities and consumers alike. The term “Dumsor” became common on the lips of Ghanaians from 2009 to 2016 during the peak of the power outages[1]. This term signified the frequent nature of the outages. Consumers in emerging countries are now very sensitive to power outages. This is due to the change in their taste resulting from the increase in industries and the standard of living. The impact of power outages are now very costly, making the access to high quality and reliable electricity a crucial agendum for governments in emerging countries [2]. This study sought to evaluate the performance of the electricity system in Ghana by identifying the reliability indices of the biggest utility for the last 10 years. It also identified factors that causes variation in the identified indices. Lastly it benchmarked the performance of Ghana to peer income countries that meet Ghana’s standards. The System Average Interruption Frequency and Duration Indices (SAIFI and SAIDI) values from 2009 to 2018 were identified from reports or computed using information from log books. The CAIDI and ASAI values for the same period were also computed from the SAIFI and SAIDI values. Independent variables on which variations in SAIFI and SAIDI potentially depended were requested from experts at the Energy Commission of Ghana. Two of the variables, namely Sales of ECG and tariff set by government were confirmed to be significant in explaining variations in the SAIDI values by using correlation and multiple regression analysis. All the independent variables tested for SAIFI were shown not to be significant variables. The researcher concluded that other factors such as ageing of the equipment and technology innovations in the distribution system which could not be tested due to lack of data were likely to be the significant independent variables for SAIFI. Using a DEA model with SAIFI and SAIDI as outputs and tariff and sales of the decision making units as inputs, Bhutan and Uzbekistan were selected as the benchmarking targets for Ghana.
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Contents
Acknowledgement ..................................................................................................
Abstract ................................................................................................................. i
List of figures ................................................................................................... vi
List of tables .................................................................................................... vii
List of Equations ............................................................................................ viii
List of Abbreviations ....................................................................................... ix
CHAPTER ONE ................................................................................................... 1
1.0 INTRODUCTION .......................................................................................... 1
1.1 Background ................................................................................................. 1
1.2 Global Electricity Perspective .................................................................... 2
1.2.1 Generation perspective ........................................................................ 2
1.2.2 Demand perspective ............................................................................. 3
1.3 Electricity Perspective – Ghana case .......................................................... 3
1.4 Motivation of Study .................................................................................... 4
1.5 Research Problem ....................................................................................... 5
1.6 Aim and Objectives of Study ...................................................................... 5
1.7 Research Questions ..................................................................................... 6
1.8 Scope of the Study ....................................................................................... 6
1.9 Significance of Study ................................................................................... 6
1.10 Methodology .............................................................................................. 7
1.11 Organization of Study ............................................................................... 7
CHAPTER TWO.................................................................................................. 8
2.0 LITERATURE REVIEW ............................................................................... 8
2.1 Introduction ................................................................................................ 8
2.2 Relevant Literature review ......................................................................... 8
2.3 An Overview of the Energy System in Ghana ............................................ 9
2.3.1 The Electricity Company of Ghana ................................................... 10
2.4 Reliability of Power Systems .................................................................... 11
2.5 Reliability Indices ..................................................................................... 12
iv
2.5.1 System Average Interruption Frequency Index ................................ 13
2.5.2 System Average Interruption Duration Index (SAIDI ...................... 13
2.5.3 Customer Average Interruption Duration Index .............................. 13
2.5.4 Average Service Availability Index.................................................... 14
2.6 Causes of distribution system reliability issues ........................................ 14
2.6.1 Equipment failure .............................................................................. 14
2.6.2 Transformers ...................................................................................... 14
2.6.3 Underground lines .............................................................................. 16
2.6.4 Overhead lines .................................................................................... 16
2.6.5 Poles .................................................................................................... 16
2.6.6 Circuit Breakers ................................................................................. 16
2.6.7 Surge Arresters .................................................................................. 17
2.7 Review of Methodologies .......................................................................... 17
2.7.1 Regression .......................................................................................... 17
2.7.2 Benchmarking .................................................................................... 18
2.7.3 Data Envelopment Analysis ............................................................... 20
2.8 Conceptual Framework ............................................................................ 22
CHAPTER THREE............................................................................................ 24
3.0 METHODOLOGY ....................................................................................... 24
3.1 Data Collection .......................................................................................... 24
3.1.1 Identification of Independent Variables ................................................ 24
3.2 Data Cleaning and Analysis ...................................................................... 25
3.2.1 Criteria for Correlation and multiple regression .............................. 25
3.2.2 Benchmarking .................................................................................... 26
3.3 Tools used in the Study ............................................................................. 28
CHAPTER FOUR .............................................................................................. 29
4.0 RESULTS FROM DATA ANALYSIS AND DISCUSSIONS ..................... 29
4.1 SYSTEM AVERAGE INTERRUPTION DURATION INDEX (SAIDI)29
4.2 SYSTEM AVERAGE INTERRUPTION FREQUENCY INDEX (SAIFI) ......................................................................................................................... 35
v
4.3 OTHER INDICES .................................................................................... 41
4.3.1 CAIDI ................................................................................................. 42
4.3.2 ASAI ................................................................................................... 43
4.4 Benchmarking best practices to achieve set targets ................................. 44
4.4.1 Results from the DEA analysis .......................................................... 45
4.5 Inference from results ............................................................................... 47
CHAPTER FIVE ................................................................................................ 48
5.0 SUMMARY OF FINDINGS, CONCLUSION AND RECOMMENDATIONS .................................................................................... 48
5.1 Summary of Findings................................................................................ 48
5.2 Conclusion ................................................................................................. 49
5.2.1 System Average Interruption Duration index ................................... 49
5.2.2 System Average Interruption Frequency Index ................................ 49
5.2.3 Customer Average Interruption Index .............................................. 50
5.2.4 Average System Availability Index .................................................... 50
5.2.5 Selection of target for ECG ................................................................ 50
5.3 Limitation of Study ................................................................................... 50
5.4 Future Works ............................................................................................ 51
Bibliography ....................................................................................................... 52
Appendix ............................................................................................................. 56
