Risk-Based Management of Transmission Lines Enhanced With the Dynamic Thermal Rating System

This paper presents a risk-based management framework for transmission lines equipped with a dynamic thermal rating system. In this framework, future wind speed values required for calculating conductor temperature are forecasted using the auto-regressive moving-average model. The dynamic thermal model used in this paper is based on the IEEE 738 standard. The forecasted conductor temperature is used to determine the associated conductor loss of tensile strength, i.e., the annealing degree of the conductor, on the basis of the Harvey model. A cost profile is also provided for tensile strength lost. Simultaneously, temperature and conductor age are used to predict the failure probability of the conductor using the Arrhenius-Weibull model. Finally, the product of the economics of conductor annealing and conductor failure probability provides the risk value, which can be compared with the admissible risk. The results show that risk can be mitigated by reducing either conductor temperature or the applied duration of the conductor. Moreover, a desirable forecast of wind speed values also poses less risk and vice versa. The sensitivity analyses show that the considerations taken during the formulation of the framework are reasonable and they only affect the numerical results, thereby indicating that the proposed framework is robust against various operating conditions of the parameters considered in the framework.