Approach Lighting System Lightning Mitigation and Individual Control Cabinet Protection

The mitigation of the impact of lightning and the individual control cabinet (ICC) protection of an approach lighting system (ALS) against over-voltage is the focus of this paper. It is the objective of this paper to evaluate three proposed ALS topologies and select the grounding configuration which optimally mitigates the high voltage and current levels caused by lightning, as well as to assess the over-voltage reduction capability of a metal-oxide varistor and its ability to provide protection to the individual control cabinet to prevent damage. Simulation of the grounding system of each ALS topology using a sensitivity study, which incorporates changes in conductor and environmental characteristics, is performed to determine the robustness of each ALS topology. Performance of a hands-on destructive test is also carried out to obtain practical results to compare with simulation results. This paper provides the foundation for improving the current ALS grounding and protective measures by updating standards and specifications to promote increased reliability and safety, as well as reduced equipment cost.