The determination of induced voltage due to lightning with the aid of computer modelling

There are several areas where computer modelling can give insight to or help solve lightning problems. A widespread application of computer modelling is in the prediction of lightning induced transients in wiring. This helps identify protection requirements at inputs to electronic equipment, and also to help define adequate test levels for such equipment. AEA has many years of experience of using analysis for lightning transient prediction, using the code INDCAL, and although the applications are normally in aerospace they have also included ground installations, particularly those where there are strong safety considerations (as opposed say to simply the cost of damage or down-time). This paper takes a brief look at how codes are used in this way, and then gives a more detailed indication of how 2D modelling can be used to predict the magnitudes of lightning induced voltages in buildings. The application of these predictions in helping to protect sensitive equipment is discussed