Transient stability risk assessment framework incorporating circuit breaker failure and severe weather

Due to the rising uncertainties in the power system and the need to develop a competitive electricity market, the risk of transient stability is an important issue to address. The traditional deterministic methods of transient stability assessment fail to consider the uncertain nature of input variables. Moreover, there is a dire requirement to incorporate the impact of circuit breaker failure and severe weather in the transient stability risk assessment procedure. Majority of transient stability risk research assumes that the circuit breaker will always trip upon fault detection; however, in practice, the circuit breaker may not operate due to internal fault. Thus, this paper proposes a transient stability risk assessment framework,incorporating circuit breaker failure and severe weather. It considers the impact of severe weather, in the form of wind storms. The concept of fragility curves is used to model this impact. The IEEE 14-bus and the IEEE 39-bus test systems were used to test and validate the effectiveness of the proposed approach. DIgSILENT PowerFactory was utilised for time-domain simulations for transient stability risk evaluation. The results show that it is vital to consider the circuit breaker failure and severe weather in the transient stability risk assessment procedure.