Annual risk assessment for overload security

This paper presents an approach to assess the cumulative risk associated with overload security for the purposes of mid-term power system planning. The work is motivated by a need to refine bulk power system reliability assessment to meet the needs of the restructured industry. There are two main contributions to the work. First, the assessment is performed over a year-long trajectory of hourly operating conditions, resulting in reliability assessment of all expected conditions and not just a limited number of snapshots. Secondly, the assessment is quantified by a risk index comprised of summed products of probability and consequence. This index is a good indicator of the actual reliability level, it is decomposable, and it can be effectively integrated into economic decision making paradigms. The work is illustrated using the 1996 IEEE Reliability Test System.