Impact assessment of transmission line switching on system reliability performance

Power system topology control through transmission line switching for economic gains has been recently considered for day to day operations. This paper investigates the impact of various DC and AC optimal switching solutions on the system-wide reliability indices. Probabilistic performance indices of the system reliability, e.g., expected energy not supplied (EENS), customer interruption costs (CIC), delivery point unreliability index (DPUI), and loss of load probability (LOLP), are utilized to assess the robustness of the new migrated system state after implementation of switching plans from the reliability viewpoint. The information of such studies will help the operator evaluate the economic benefits and system reliability requirements and decide whether to implement the optimal switching solutions at each hour. The approach is tested using a modified IEEE 118-Bus test system and the results revealed its applicability and efficiency.