A Risk-Based Probabilistic Transient Stability Approach for Ranking of Circuit Breakers in a Power System

Abstract: Power systems are getting more complex than ever and are consequently operating close to their limit of stability. Moreover, with the increasing demand of renewable wind generation, and the requirement to maintain a secure power system, the importance of transient stability cannot be overestimated. Current deterministic industry practices of transient stability assessment ignore the probability of variables involved. With increasing system uncertainties and widespread electricity market deregulation, there is a strong inevitability to incorporate probabilistic transient stability analysis. Circuit breakers play a critical role in fault clearing and consequently in determining the system transient stability. It is important that they undergo timely and appropriate maintenance procedures based on some criterion. Considering the need of incorporating risk in modern power systems, this paper proposes a risk-based probabilistic transient stability approach for ranking of circuit breakers in a power system. A novel priority index was proposed to rank the circuit breakers based on the system transient stability risk. DIgSILENT PowerFactory software was used to conduct the required simulations on IEEE 14 bus system. The proposed risk-based framework was deemed to be efficient in identification of the circuit breakers based on their priority rank index which can aid in power system planning process.