Lightning-Protection Software is Grounded in Reality

New research on the grounding properties of various soil types promises to result in more effective modeling of potential lightning-related transmission-line damage, as well as produce guidelines for better transmission-line design. The study was intended to improve the TFlash software—developed by the Electric Power Research Institute (EPRI)—by providing more accurate algorithms fo...

By Staff December 1, 2002

New research on the grounding properties of various soil types promises to result in more effective modeling of potential lightning-related transmission-line damage, as well as produce guidelines for better transmission-line design.

The study was intended to improve the TFlash software—developed by the Electric Power Research Institute (EPRI)—by providing more accurate algorithms for its calculations of transmission-line lightning performance. The soil surrounding grounding rods and transmission-tower footings plays an important role in protecting the lines from lightning-related damage. However, the EPRI researchers say, ionization during a lightning strike diminishes the soil’s grounding capabilities. As current increases, the soil’s protective capability decreases. Additionally, different soil types offer varying degrees of protection.

Researchers used full-scale transmission structures and high-voltage equipment at EPRI’s T&D Engineering Center in Lenox, Mass. to inject voltage into a range of soil types to study the effects. Resulting measurements have been incorporated into new modeling algorithms used by TFlash.

EPRI released a beta version of the upgraded software this summer, with a final version anticipated to be available in December. The findings will also be used to produce a series of design and construction guidelines for new transmission lines and structures.

From Pure Power, Winter 2002