Using Computational Fluid Dynamics of Wind Simulations Coupled With Weather Data to Calculate Dynamic Line Ratings

Dynamic line rating is a technology that allows for the rating of electrical conductors to be calculated based on local weather conditions rather than using “worst-case” assumptions of weather conditions. The static ratings are typically based on weather conditions that are conservative in nature, and thus dynamic line rating may provide room to increase the current capacity. The locally resolved weather conditions estimate conditions more accurately near the transmission lines, accounting for terrain such as nearby hills. One way to estimate the local weather conditions is through the use of computational fluid dynamics. The results of a wind field simulation can be coupled with sparsely located weather stations to provide an accurate assessment of the wind speeds along the path of the conductor. The wind field simulations are calculated using a steady-state Reynolds-averaged Navier-Stokes model. These results, along with local solar irradiance measurements, can be used to provide estimates of the steady-state ampacity with the standard IEEE equations. An advanced test case for this process involves performing these simulations in a complex terrain: Hells Canyon, the deepest river gorge in North America. The results show that by using weather-based sensors without considering localized wind conditions, the available ampacity may be over-predicted significantly.