Dynamic line rating in the operating environment

The authors present power line data and dynamic line rating statistics obtained during a one-year study in new York State. Conclusions from the study apply specifically to the Porter/Rotterdam line #30. Dynamic line ratings, defined as the minimum dynamic rating for the power line, were 20% lower than the average or single-station ratings. The greatest gains to dynamic line rating come from the limited time or transient rating. Limited time dynamic ratings derive their added benefit from the use of actual preload conductor temperatures in the rating calculation rather than the 95°C conductor temperature assumed by many utilities. A forecast rating algorithm is proposed for calculating power line ratings intended to remain valid over a defined period of time in the future with minimal risk. Based on the algorithm, the 4-h forecast ratings were found to be 12% lower on the average than dynamic line ratings