Risk assessment of line overload in a practical power system considering different types of severity functions

Abstract

Power system security assessment based on the concept of risk is required in the current power environment. In risk based security assessment, the likelihood and severity of security violation are the two main factors that determine the security level of a power system. This paper presents the assessment of risk of line overload on a practical interconnected power system at various loading condition using a risk index. Two types of severity functions, namely the continuous and percentage of violation severity functions are considered in this study. A risk classification technique is also proposed so as to provide a qualitative interpretation of the risk index value by classifying the risk as low, medium and high degree of risk. Results are presented in terms of risk index curves.