표제지
목차
List of Terms and Abbreviations 10
Abstract 12
I. 서론 14
II. 이론 및 연구배경 15
2-1. 전력기기의 자산관리 15
2-1-1. IEC White Paper 16
2-1-2. CIGRE TB 18
2-1-3. 국외 전력사 24
2-2. 국내 지중 전력케이블 설치 현황 31
2-2-1. 22kV 지중선로 32
2-2-2. 지중배전선로 33
2-2-3. KEPCO의 지중선로 설치 및 고장현황 35
2-3. 와이블 분포함수 36
2-3-1. 와이블 분포함수의 이론 42
2-4. 몬테카를로 시뮬레이션 44
III. 지중 OF 케이블 Health Index 46
3-1. Health Index의 수학적 모델링 46
3-2. KEPCO OF 케이블 Health Index 51
3-3. Health Index 기반 예상수명 추정 54
IV. 결과 및 고찰 57
4-1. OF 케이블 Health Index (2013) 모델 57
4-2. 몬테카를로 시뮬레이션을 이용한 Health Index 추정 65
4-3. OF Health Index (2021) 모델의 제안 74
4-4. OF Health Index (2021) 모델의 운용범위 추정 81
V. 결론 92
참고문헌 93
초록 98
Table 4-4-1. Estimation of health index apply to OFHI(2021) model including confidence interval at D%~N(10,4). 83
Table 4-4-2. Estimation of health index apply to OFHI(2021) model including confidence interval at D%~N(10,16). 84
Table 4-4-3. Estimation of operation period and confidence interval according to operation threshold at D%~N(10,4). 87
Fig. 2-1-1. Age distribution and life estimation of overhead lines. 19
Fig. 2-1-2. Age distribution and life estimates for underground OF cables. 19
Fig. 2-1-3. Organizational structure : asset owner - asset manager - service provider. 21
Fig. 2-1-4. Example of a risk assessment matrix. 21
Fig. 2-1-5. Example of replacement plan. 23
Fig. 2-1-6. Health Index concept using three types of assessment functions. 26
Fig. 2-1-7. Example of failure distribution using Bayesian statistics. 26
Fig. 2-1-8. Example of risk matrix for Health Index. 28
Fig. 2-1-9. Example of focused in risk analysis. 28
Fig. 2-2-1. Underground power cable specification in KEPCO. 34
Fig. 2-2-2. Underground circuit length and failure in KEPCO. 35
Fig. 2-3-1. Probability density function of Weibull distribution. 40
Fig. 2-3-2. Reliability function of Weibull distribution. 40
Fig. 2-3-3. Failure rate of Weibull distribution. 41
Fig. 3-1-1. Mathematical model of health index for estimation of operation period. 48
Fig. 3-1-2. Maximum of aging index according to weight factor. 48
Fig. 3-1-3. Difference of aging index according to point of degradation beginning. 50
Fig. 3-1-4. Difference of aging index according to degradation speed. 50
Fig. 4-1-1. Thermal Index of OF cable according to operation year. 58
Fig. 4-1-2. Electrical Index of OF cable according to operation year. 58
Fig. 4-1-3. Mechanical Index of OF cable according to operation year. 60
Fig. 4-1-4. Environmental Index of OF cable according to operation year. 60
Fig. 4-1-5. Aging Index of OF cable according to operation year. 62
Fig. 4-1-6. Health index of OF cable according to operation year. 62
Fig. 4-1-7. CDF of health index according to operation year using Weibull box chart. 64
Fig. 4-2-1. Process of Monte Carlo simulation of OF cable health index. 66
Fig. 4-2-2. Process of load rate simulation. 68
Fig. 4-2-3. Histogram of the frequency of load rate occurrence of level A. 68
Fig. 4-2-4. Histogram of the frequency of load rate occurrence of level B. 69
Fig. 4-2-5. Thermal index of according to operation year of OF cables using MCS. 72
Fig. 4-2-6. Aging index of according to operation year of OF cables using MCS. 72
Fig. 4-2-7. Health index of according to operation year of OF cables using MCS. 73
Fig. 4-3-1. Distribution of OFHI(2013) model using Weibull box chart. 76
Fig. 4-3-2. Distribution of OFHI(2021) model using Weibull box chart. 76
Fig. 4-3-3. Distribution of health index of each model of OF cable operated over 30 years. 79
Fig. 4-3-4. Distribution of health index of OFHI(2021) model and OF cable operated over 30 years using MCS. 79
Fig. 4-3-5. Compare distribution of health index of applied OFHI (2021) model to MCS data of OF cable operated over 30 years. 80
Fig. 4-4-1. Compare distribution of health index OFHI(2013) model to OFHI(2021) model including confidence interval at D%~N(10,4). 83
Fig. 4-4-2. Compare distribution of health index OFHI(2013) mode lto OFHI(2021) model including confidence interval at D%~N(10,16). 84
Fig. 4-4-3. Estimation of operation period of OFHI(2021) model according to D% at operation threshold 5 and 10. 87
Fig. 4-4-4. Cable replacement wave using TBM, OFHI(2013) and OFHI(2021) model at operation threshold 10. 88
Fig. 4-4-5. Apply to risk matrix of Monte Carlo simulation data at operation threshold 10. 91