Overload strategy of transmission and transformation equipment for safety operation

Due to the continuing need for power demand, it´s necessary to increase the utilization of existing transmission and transformation equipment. To achieve that point, overload strategies under safe operation are discussed in this paper. Since dynamic line rating (DLR) is considered, the capacity and resistance of the overhead line, as well as risk of the power grid are all calculated under real-time environment and actual line situation. Overhead lines´ overload strategy is proposed with the precondition of risk not exceeding the risk value calculated in the traditional method. In addition, transformers´ overload operation needs to be applied in some scenarios. Overload strategy of transformers is also discussed under the limits of winding hot spot temperature and failure rate in our study, to ensure the reliability and safety. Finally, the validity of our overload strategy is illustrated by a series of simulations.