Protection Issues for Power Substations from HEMP Adverse Effects

It is well known that modern society is very dependent on a reliable electric power system. However, that system can be compromised by electromagnetic threats. One threat is the effect of HEMP from a high altitude nuclear burst [1]. One concern is the late time part of HEMP, E3, which is briefly discussed here. The early time part, E1, is the major emphasis of this paper - specifically, adverse E1 effects on the control systems, housed in substation buildings. To address this concern, the EM (electromagnetic) vulnerability of substation electronics should be evaluated and hardening applied if necessary. The paper will enumerate and discuss various issues that affect the EM response of substations and its hardening. Two major concerns are E1 coupling to yard cables and E1 field leakage into the substation building.