This paper presents the obtained results of experimental tests and modelling of lightning disturbances that were propagated in a model of aircraft cable bundle and caused by multiple lightning return-strokes interactions. The work is a continuation of previous research, which was concerned mainly with the interaction of lightning discharge with a single return-stroke. The section of the cable harness arranged above the metal plate was investigated. In one of its wires, a multiple-stroke current representing indirect lightning effects was injected from an impulse current generator dedicated to avionics immunity tests. Overvoltages induced at the ends of other wires surrounded by a braided shield, as well as the influence of line parameters and shield grounding condition on the shape and level of observed transients, were examined. The computer simulation results match the measurement data with satisfactory accuracy, and therefore, the presented model can be used to estimate indirect lightning effects in the wiring harness of avionics.

Experimental and computer investigations were conducted into long-duration impulse current distribution in the lightning protection system, supplying network, and electrical installation of a test house that was equipped with household appliances. Long-duration impulse currents simulating lightning continuing currents were injected from the unique current generator into the test object. The current distributions in the elements of the test object were measured using current shunts, coaxial cables, and digital oscilloscopes, then they were modeled using the ATP-EMTP software package. The obtained results show a quite good agreement between the measured and computed current waveforms. The relationships between the values of currents at different points of the conductive installation are similar, as reported in previous studies on the fast-changing lightning return stroke component distribution, although the efficiency of the lightning protection system (LPS) is a few percent better for the long continuing current component in the case of a strongly conductive ground at the test site in Huta Poręby, part of the Rzeszów University of Technology. Due to the relatively low content of high-frequency components in the long continuing current spectrum, the waveshape of this lightning component is practically the same throughout the entire tested installation.