Reliability-Based Assessment and Cost Analysis of Power Distribution Systems at Risk of Tornado Hazard

Power distribution systems are susceptible to significant damage when hit by a tornado. This damage can cause huge economic losses resulting from the cost of repairing failed distribution lines, the loss of electricity service, and the indirect impact on other infrastructure systems that depend on the power system. Hence, it is important to study the reliability of power networks when hit by tornadoes, especially in tornado-active regions. However, there is still a lack of risk-based methods to study the behavior of power distribution systems when subjected to tornadoes. In this paper, scenario-based reliability and cost analyses of power distribution systems subjected to tornadoes are performed. In addition, the cost-effectiveness of targeted hardening of the power distribution lines is investigated. A notional power distribution system assumed to be located in Norman, OK, is used to demonstrate the proposed framework. The results of the case study show that targeted hardening can considerably increase the reliability of the power distribution system and reduce the total direct cost when hit by a tornado. (C) 2020 American Society of Civil Engineers.