Reliability Impacts of the Dynamic Thermal Rating System on Smart Grids Considering Wireless Communications

The dynamic thermal rating (DTR) system is one of most widely used state-of-the-art of smart grids owing to its proven ability to improve the existing line ratings at a fraction of the cost of most extant methods without infringing line safety requirements. However, the successful implementation of this system depends on the reliability of communication networks, especially wireless communication systems, in transmitting line rating information back to the utility company so that an appropriate line flow control can be executed. Therefore, the efficient, continuous, and secure operations of smart grids are equally affected by the reliability of the DTR and wireless communication systems. Despite this evidence, the reliability impacts of these systems on power grids are yet to be examined in a single framework. In this paper, a new model for investigating the reliability impacts of the DTR system on power grids considering the wireless communication network is proposed. The inability of the DTR system to perform, either due to its unavailability or communication failure, is taken as a function of line ratings that affect the transmission capacity and reliability of power grids. When the DTR system service is unavailable, the line rating is either reverted to the static thermal rating or estimated via the multi-linear regression (MLR) model based on information from neighboring regions. The comparison of these two models on the IEEE 24-bus reliability test system reveals that the MLR model is more beneficial in mitigating DTR and communication systems failures. This paper also explores various communication system failure scenarios and the reliability impacts of redundancy designs. The findings reveal that the communication system with moderate reliability levels yield the most benefits when the redundancy number increases from 1 to 4. Overall, the communication system significantly affects the availability of the DTR system.