I= AGING INVESTIGATION OF POLYMERIC INSULATORS
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Title of Thesis
AGING INVESTIGATION OF POLYMERIC INSULATORS

Author(s)
Muhammad Amin
Institute/University/Department Details
University of Engineering and Technology, Taxila
Session
2007
Subject
Electrical Engineering
Number of Pages
145
Keywords (Extracted from title, table of contents and abstract of thesis)
polymeric insulators, traditional insulators, ceramic insulators, aging of polymeric insulators

Abstract
Traditional insulators made of glass and porcelain (ceramic insulators) used in power transmission and distribution systems ruled the market till the introduction of polymeric insulators which have potential to replace the ceramic insulators because of lightweight, aesthetic, hydrophobic properties, and superior anti-contamination performance. However, the field experience of polymeric insulators is relatively short which demands that further studies on the performance of these insulators under actual and simulated environmental conditions be carried out before their full scale application on real power systems.

This study contains the pioneer work carried out on polymeric insulators in Pakistan. The prime objective of this investigation is to determine how feasible polymeric insulators are for use in Pakistani environment so as to offer suitable recommendation to the national electric utility company (WAPDA) about the possible use of polymeric insulators on real system. Towards that end, polymeric insulators were exposed to lab and field aging representing Pakistani environmental conditions.

The laboratory study addressed aging under environmental parameters individually as well as collectively. Moreover, weather cycles, simulating Pakistani conditions were designed and corresponding aging performance was investigated. The environmental stresses used in the study included UV radiation, temperature, electric stress, low pressure and humidity. For field aging the samples were installed at two typical locations representing a clean environment as well as a heavily polluted industrial area of Hatta Industrial Estate. The aged samples were periodically analyzed using advance techniques such as FTIR and SEM. Hydrophobicity characteristics were also studied and samples were critically checked for any obvious surface degradation. The investigation revealed that the polymeric insulators follow a periodic degradation and self-restoration cycle and no irreversible degradation such as tracking or erosion was observed. In multi-stress aging, the samples were exposed to accelerated aging to represent an actual exposure of 12.67 years in the field. The insulators retained their characteristics throughout this period.

Based on very promising I results of this pioneering investigation which simulated environmental conditions prevalent in Pakistan, it appears that polymeric insulators made of silicone rubber have 1 bright future for application on real transmission and distribution systems of Pakistan W APDA. The matter will accordingly be taken up with decision makers to build some new distribution lines equipped with polymeric insulators to convert the benefits of polymeric insulators into a practical reality.

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8054.32 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
390.62 KB
2 1 Introduction 1
452.08 KB
  1.1 Climate Of Pakistan 2
  1.2 Environment Of Special Concern 4
  1.3 Objectives Of The Thesis 5
  1.4 Thesis Organization 5
  1.5 References 6
3 2 An Overview Of Aging Of Polymeric Insulators 8
1706.1 KB
  2.1 Introduction 8
  2.2 Aging Of Polymeric Insulators 10
  2.3 Determination Of Life Expectancy 17
  2.4 Aging Effects 21
  2.5 Measurement Techniques 26
  2.6 References 34
4 3 Effects Of Individual Environmental Parameters On Polymeric Insulators 37
951.72 KB
  3.1 Introduction 37
  3.2 Experiment 38
  3.3 Results And Discussion 41
  3.4 State Estimation 49
  3.5 Conclusion 51
  3.6 References 52
5 4 Effect Of Acidic Rain Along With Other Environment Parameters On Aging Of Polymeric Insulators 54
951.72 KB
  4.1 Introduction 54
  4.2 Laboratory Aging 55
  4.3 Test Specimens (Material And Sizes ) 56
  4.4 Applied Stresses 57
  4.5 Results And Discussion 58
  4.6 Conclusion 69
  4.7 References 69
6 5 Effect Of UV Radiations And Pressure On Heavily Polluted / Unpolluted Htv Sir Used As Outdoor Insulation 71
1310.18 KB
  5.1 Introduction 71
  5.2 Experimental Arrangement 72
  5.3 Results And Discussion 75
  5.4 Hydrophobicity 82
  5.5 Sem 88
  5.6 Conclusion 89
  5.7 References 90
7 6 Aging Of Polymeric Insulators In Simulated Environment Of Pakistan 92
1041.88 KB
  6.1 Introduction 92
  6.2 Need Of Multi €“ Stress Accelerated Aging 93
  6.3 Experimental Setup 93
  6.4 Test Specimens 95
  6.5 Test Procedure 95
  6.6 Acceleration Factor 95
  6.7 Results And Discussion 97
  6.8 Hydrophobicity 101
  6.9 SEM 103
  6.10 Leakage Current Monitoring 105
  6.11 General Discussion 105
  6.12 Conclusion 106
  6.13 References 107
8 7 Field Aging Of Polymeric Insulators In Clean Environment Of Pakistan 109
1408.31 KB
  7.1 Introduction 109
  7.2 Experiment 110
  7.3 Results And Discussion (Rod And Plate ) 113
  7.4 Scanning Electron Microscopy (Rod And Plate ) 119
  7.5 Hydrophobicity (Rod And Plate ) 122
  7.6 Conclusion 126
  7.7 References 127
9 8 Aging Of Polymeric Insulators In Industrial Pollution Environment 129
909.18 KB
  8.1 Introduction 129
  8.2 Experimental Setup 129
  8.3 Specimen Samples 132
  8.4 Results 132
  8.5 Summary Of Results 138
  8.6 Discussion 139
  8.7 Conclusion 141
  8.8 References 142
10 9 Overall Conclusion 143
33.59 KB
  9.1 Future Work 144