Study On Aircraft Cable Bundle Lighting Indirect Effects Simulation And Test Method

Lightning is an important factor to affect the normal safe operation of the aircraft.When the aircraft is in the lighting or struck by the lightning,its internal electrical circuit generates an inductive voltage and an inductive current which quickly transfer to the devices interface,and cause interference or damage of devices.In order to reduce harm of lightning to the aircraft,improve the flight safety,it is urgent to study the coupling characteristics of lightning on the cables of airborne electronic equipment.It has much practical reference value and great significance for the design of lightning protection for aircraft.This paper adopts the methods of the lightning current pulse of the aircraft cables simulation and the lightning indirect effects cable bundle tests to study the lightning coupling characteristics of the aircraft cables.Based on the lightning indirect effects,an optimal measuring method for lightning indirect effects of cable bundle tests is proposed,which has been proved effective by another tests designed for validation.Detailed work contents are as follows:1.Analyze the lightning direct effects and indirect effects on the aircraft.This paper briefly summarizes the domestic and foreign existing simulation methods of lightning indirect effects,test measurement methods and the research of lightning protection designed for the aircraft.2.The mechanism and test methods of the lightning indirect effects on the aircraft are studied.And the method which measures the coupling characteristics of the lightning indirect effect on cables were analyzed and studied in combination with the requisition of actual engineering tests.3.The electromagnetic coupling characteristics of the cable bundle in the airframe are studied with electromagnetic simulation software CST(Computer Simulation Technology)under different cable bundle distributions.And the simulation results are analyzed and resumed.4.In accordance with standard Section 22 of RTCA DO-160G by the Radio Technical Commission for Aeronautics(short for RTCA),the cable bundle tests of lightning indirect effects are conducted.The analysis of measurements shows that when there are shielded cables in the cables bundle,the limit voltage V_L obtained at the second wingding of the injection transformer with the lighting current is much less than the induced voltage of the actual circuit.It caused the owe voltage test of the cable bundle.5.Through the study of the limit voltage measurement method of lightning indirect effects cable bundle tests,as for the owe voltage problem in actual cable bundle tests,an optimal method was proposed for the measurement points of the limit voltage.The test method adopts that measures the opening voltage of an unshielded cable as the limit voltage in cable bundles.Afterward a brief analysis and a summary of measurement results were made.