The Effect of Electromagnetic Resonance in the Instrument Modules of an Aircraft on Induced Conductive Interference

When an external electromagnetic field impacts on an aircraft, resonance phenomena occur in the onboard instrument modules of the aircraft electrical system. Electromagnetic resonance phenomena in the internal space of instrument modules can lead to a significant increase in the levels of induced conductive interference in the electrical circuits of electrical system devices and instruments, and in the wire line bundles. An increase in the levels of induced conductive interference leads to degraded quality of operation, malfunctions and failures of onboard instruments and devices. The article presents the results of computer simulation of induced conductive interference in an unshielded two-wire line in the open space of the test bench table and in the internal space of the instrument module. Based on an analysis of the obtained frequency diagrams, it is shown that the levels of induced conductive interference in the two-wire line in the internal space of the instrument module reach maximum values at electromagnetic field resonant frequencies that differ from the resonant frequencies when simulating in the open space of the test bench table. A conclusion has been drawn on the influence of electromagnetic field resonance phenomena on the levels of induced conductive interference in a two-wire line in the interior of an instrument module. It is recommended to take into account electromagnetic field resonance phenomena in aircraft instrument modules when selecting technical means for ensuring noise immunity of electrical circuits and wire line bundles.