Transmission Lines Availability Online Assessment During Power System Restoration Using the Information From Protection Systems

Power system restoration after outages caused by natural disasters is difficult owing to the damage caused to transmission lines. To formulate an effective power system restoration scheme and avoid damage to power equipment, it is necessary to obtain the availability of transmission lines in real time. Due to the complexity and variability of natural disasters, the availability assessment of transmission lines that depends on statistical data cannot give effective availability, which will lead to the failure of recovery. Two correlation models between transmission line availability and information of relay action are established and then applied to different relays in this paper. Combined with the real time record from the sequence of event (SOE), the online availability assessment method for transmission lines is proposed, which can obtain the damage probability of transmission lines in real time. The proposed method is verified by testing on the IEEE 39-bus model, and the simulation results show that it can assess the availability of transmission lines in real time without needing to consider the type of disaster, thus, helping to avoid the use of damaged transmission lines in the recovery process.