Comparative Study of Power System Security Assessment using Deterministic and Probabilistic Methods

Escalating electricity demand has forced the power system to operate very close to its security margin. Any unpredictable occurrence of a contingency would exacerbate the condition and threaten power system security. Thus, it is of utmost importance for the system operator to evaluate the actual system health accurately to avoid voltage collapse incidents and to evade overly conservative protection. This paper presents a risk-based security assessment (RBSA) in power system operation that quantifies the degree of risk faced by the system in its proximity to voltage stability violations due to transmission line outages that occur in the system. The risk value is calculated by considering the closeness of the system condition to the point of instability, which is also regarded as severity, as well as the likelihood of the contingency to occur. In the research, the performance of RBSA is compared with the traditional deterministic method in assessing power system conditions. The IEEE 30 bus system is engaged as the test system, and the simulation is done using MATLAB software.