표제지
목차
List of Terms and Abbreviations 8
Abstract 9
I. 서론 11
II. 전력용 변압기 14
2-1. 구조 14
2-2. 고장 유형 20
2-3. 상태 진단 28
2-3-1. IEEE C57.104 29
2-3-2. IEC 60599 32
2-3-3. 일본전기협동연구 제65권 1호 35
III. 연구 방법 37
3-1. 절연유 특성 37
3-2. 시각화 특성 40
IV. 결과 및 고찰 41
4-1. 상태 판정 41
4-1-1. 유형 평가 41
4-1-2. 시각화 판별법 56
4-2. 사각 판별법 77
4-2-1. 정규화 77
4-2-2. 결함유형 및 조치방안 85
4-2-3. 사각 판별법 제안 90
4-3. 사각 판별법의 적합성 94
4-1. 변압기 사례 분석 94
4-2. 결함판별 정확도 109
V. 결론 111
참고문헌 112
초록 122
Table 2-1. Failures of core. 21
Table 2-2. Failures of winding. 23
Table 2-3. Failures of oil. 23
Table 2-4. Failures of OLTC. 24
Table 2-5. Failures of bushing. 25
Table 2-6. Failures of tank. 26
Table 2-7. Failures of cooler. 27
Table 2-8. Failures of oil preservation system. 27
Table 2-9. Ranges of 90[%] typical gas concentration values by... 30
Table 2-10. Doernenburg ration method. 31
Table 2-11. Rogers ratio method. 31
Table 2-12. Ranges of 90[%] typical gas concentration values. 33
Table 2-13. Criteria of dissolved gas concentration. 36
Table 3-1. Specification of oil analyzer. 39
Table 4-1. Fault locations. 42
Table 4-2. Winding. 43
Table 4-3. Core. 44
Table 4-4. Clamp. 45
Table 4-5. Bushing. 46
Table 4-6. OLTC. 47
Table 4-7. Oil. 48
Table 4-8. Dissolved gas characteristic. 49
Table 4-9. Failure locations. 51
Table 4-10. Winding. 52
Table 4-11. OLTC. 53
Table 4-12. Bushing. 54
Table 4-13. Dissolved gas characteristic. 55
Table 4-14. Normalization level by KEPCO dissolved gas criteria. 77
Table 4-15. Key gases by fault and failure types. 86
Table 4-16. Recommended actions according to fault types. 89
Table 4-17. Dissolved gas analysis history of case 1. 95
Table 4-18. Dissolved gas analysis history of case 2. 99
Table 4-19. Dissolved gas analysis history of case 3. 102
Table 4-20. Dissolved gas analysis history of case 4. 105
Table 4-21. Dissolved gas analysis history of case 5. 108
Table 4-22. Fault type and action results by rectangular method. 110
Figure 2-1. Structure of Power Transformer 14
Figure 2-2. Core 15
Figure 2-3. Winding 16
Figure 2-4. Mineral oil 16
Figure 2-5. OLTC 17
Figure 2-6. Bushing 18
Figure 2-7. Tank 18
Figure 2-8. Key gas method 31
Figure 2-9. IEC Interpretation method 33
Figure 2-10. Duval triangle method 34
Figure 2-11. Graphical abnormal diagnosis method 36
Figure 3-1. Sampling of oil 38
Figure 3-2. Oil analyzer 38
Figure 4-1. Result of IEC Interpretation by winding faults 58
Figure 4-2. Result of IEC Interpretation by core faults 60
Figure 4-3. Result of IEC Interpretation by clamp faults 62
Figure 4-4. Result of IEC Interpretation by bushing faults 64
Figure 4-5. Result of IEC Interpretation by OLTC faults 66
Figure 4-6. Result of IEC Interpretation by oil faults 68
Figure 4-7. Result of Duval triangle by winding faults 70
Figure 4-8. Result of Duval triangle by core faults 71
Figure 4-9. Result of Duval triangle by clamp faults 72
Figure 4-10. Result of Duval triangle by bushing faults 73
Figure 4-11. Result of Duval triangle by OLTC faults 74
Figure 4-12. Result of Duval triangle by oil faults 75
Figure 4-13. H₂ key gas patterns 79
Figure 4-14. C₂H₂ key gas patterns 80
Figure 4-15. C₂H₄ key gas patterns 81
Figure 4-16. CH₄ key gas patterns 82
Figure 4-17. C2H6 key gas patterns[이미지참조] 83
Figure 4-18. Key gas patterns of types of failure 84
Figure 4-19. Rectangular diagnostic method 91
Figure 4-20. Result of rectangular method by faults 92
Figure 4-21. 1st internal inspection of case 1(OLTC tap selector) 96
Figure 4-22. Factory disassemble of case 1 96
Figure 4-23. Result of rectangular method by case 1 97
Figure 4-24. 1st internal inspection of case 2 99
Figure 4-25. Factory disassemble of case 2(winding) 100
Figure 4-26. Result of rectangular method by case 2 100
Figure 4-27. Internal inspection of case 3(OLTC tap selector) 102
Figure 4-28. Result of rectangular method by case 3 103
Figure 4-29. Internal inspection of case 4(bottom of tank) 105
Figure 4-30. Factory disassemble of case 4(winding) 105
Figure 4-31. Result of rectangular method by case 4 106
Figure 4-32. Result of rectangular method by case 5 108