New approach to the assessment of frequency of electronic systems damage due to nearby lightning strokes

The paper deals with the assessment of expected frequency of damage or malfunction of electronic systems inside a structure due to lightning overvoltages both induced in the system by its direct coupling with the electromagnetic impulsive field radiated by the lightning current (lightning electromagnetic impulse-LEMP) and induced on incoming lines connected to the system. The frequency of damage has been calculated as the product of the number of strokes influencing the system from different distances and the probability of damage by a single stroke. In the calculation, the simultaneous action of the stroke by direct coupling with the system and by coupling with incoming line has been considered. The results relevant to the frequency of damage have been compared with those resulting from the application of the Rusck approach.