Impact of Transmission Line Overloads on Network Reliability and Conductor Ageing

摘要

Any disturbances may lead to a broad range of transmission line overloads, threating the reliability and security of the network. This paper introduces a network reliability evaluation methodology based on sequential Monte Carlo (SMC) simulation, which helps to assess the impact of transmission line overloads on network reliability and plant ageing. A fault chain search model is implemented via AC power flow to capture cascading failures as a result of severe line overloads. The methodology also integrates a detailed electrothermal modelling of overhead lines (OHLs) considering their key design and environmental properties to capture the risks of thermal ageing during emergency overload operations. A cost/worth analysis is performed to quantify the value of extensive emergency ratings on network performance against the risk of plant ageing and cascading failures. An application of the methodology is demonstrated on both IEEE 14-bus and RTS-96 network to test its scalability.