In this chapter, we present a review of recent progress in the modelling of lightning strikes to tall structures. Since some tall structures are struck by lightning several tens of time per year, they can be used as ground-truth to measure and calibrate the location accuracy of lightning location systems. In addition, knowledge of the transient processes in tall objects when they are subjected to a lightning strike allows us to use them to calibrate the lightning return-stroke currents reported by lightning detection and location systems. Tall objects constitute also a primary source of data from which channel-base lightning current statistics are obtained. These statistics are in turn used to improve the design of lightning protection devices and systems.

Chapter Contents:

• 25.1 Introduction
• 25.2 Modelling lightning strikes to tall structures
• 25.2.1 Engineering models
• 25.2.1.1 Extension of engineering models based on a distributed source representation
• 25.2.1.2 Extension of engineering models based on a lumped series voltage source
• 25.2.1.3 On the representation of the elevated strike object
• 25.2.1.4 Current distribution along the channel as predicted by engineering models
• 25.2.1.5 Determination of reflection coefficients at the top and the bottom of the strike object
• 25.2.2 Electromagnetic models
• 25.2.3 Hybrid electromagnetic model
• 25.3 Electromagnetic field computation
• 25.3.1 Electromagnetic field expressions for a perfectly conducting ground
• 25.3.1.1 Turn-on term
• 25.3.1.2 Comparison between different engineering models
• 25.3.1.3 Effect of the tower
• 25.3.2 Electromagnetic field computation for a finitely conducting ground
• 25.3.2.1 Dedicated algorithms
• 25.3.2.2 Simplified approaches
• 25.3.2.3 Numerical methods
• 25.4 Review of lightning current data and associated electromagnetic fields
• 25.4.1 Experimental data
• 25.4.2 Data from short towers
• 25.4.3 Summary of Berger's data
• 25.4.4 Other data obtained using short towers (≤100 m)
• 25.4.5 Data from tall towers
• 25.5 Summary
• References

Inspec keywords: lightning; lightning protection; poles and towers

Other keywords: lightning strike modelling; lightning location systems; location systems; lightning return-stroke currents; lightning detection; transient processes; tall towers; channel-base lightning current statistics; lightning protection devices

Subjects: Power line supports, insulators and connectors; Atmospheric electricity; Power system protection