DocumentCode :
2569461
Title :
Risk, reliability, cascading, and restructuring
Author :
Makarov, Y.V. ; Hardiman, R.C.
Author_Institution :
California Independent Syst. Oper. Corp., Folsom, CA, USA
Volume :
3
fYear :
2003
fDate :
13-17 July 2003
Firstpage :
1417
Abstract :
Restructuring of the electric utility sector introduces unprecedented uncertainty in transmission planning and operations practices. To cover the uncertainty and to provide robust solutions, it is necessary to consider a significant number of different situations and scenarios, and to base the decision-making on characteristics reflecting all this variety. The crisis caused by inadequacy of the old methodology to the new environment becomes increasingly evident, especially in transmission planning. Adequately handling the uncertainty should be based on risk assessment, multi-scenario analysis, and probabilistic methods. The stress posed on transmission systems due to the power flow diversity is also enormous and results in shrinking reliability margins. The lack of investments and fully adequate strategies to the development of open-access transmission systems also contributes to this problem. New incentives, methodologies, indices, and standards need to be developed. This paper introduces the new risk assessment indices and comprehensive reliability assessment technology developed by Southern Company. The indices include the risk and sharpness of transmission problems and the expected energy not produced (EENP). The risk and sharpness indices allow estimating the likelihood of thermal and voltage problems and the degree of locality of these problems in different parts of the grid. The EENP reflects the annual expected energy that cannot be injected into the grid due to transmission constraints. Reliability metrics are computed for all sources of unreliability including protection group outages, islanding, and network problems. The Southern Company/EPRI TRELSS software is used as the main tool. Studies include forecasting reliability trends and goal performance, identification of "weak elements", in-depth analysis of reasons and mechanisms of unreliability events, impacts of hotter-than-expected weather, reliability effects of across-system power transfers, reliability impacts of budgeted transmission projects, probabilistic risk analysis of thermal and voltage problem. Southern Company has developed a unique methodology to analyze hundreds of cascading failure scenarios, determine their expected consequences, and rank the scenarios according to their severit- y and likelihood of occurrence. Cascading studies are also conducted to analyze vulnerability of the system to acts of sabotage. The paper contains examples of real-life studies and their discussions.
Keywords :
decision making; load flow; power engineering computing; power markets; power transmission economics; power transmission planning; power transmission reliability; probability; risk analysis; uncertainty handling; electric utility sector; multiple analysis; open-access transmission system; power flow diversity; power industry restructuring; power system reliability; probabilistic method; reliability assessment technology; risk assessment; risk indices; sharpness indices; thermal problems; transmission operations; transmission planning; uncertainty handling; voltage problem; Decision making; Power industry; Power system planning; Power system reliability; Risk analysis; Risk management; Robustness; Uncertainty; Voltage; Weather forecasting;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Power Engineering Society General Meeting, 2003, IEEE
Print_ISBN :
0-7803-7989-6
Type :
conf
DOI :
10.1109/PES.2003.1267362
Filename :
1267362
Link To Document :
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