Simulation Of The Electromagnetic Compatibility Of Electrical Wiring Interconnection System On More-electric Aircraft

On more electric aircraft(MEA), the traditional hydraulic and pneumatic power units are partially replaced by electrical units. Based on the concept of power transmission in wire, which is using wires to replace hydraulic and pneumatic pipeline for energy transmission and using high voltage DC power supply to replace the traditional low voltage AC power supply, MEA is becoming the trend of modern aircraft. However, more nonlinear electric equipment and more electric cables on MEA make the harmonic emission and crosstalk of cables more serious.More cables are exposed to complex electromagnetic environment because of the use of electric heating, electro-deicing system and electric braking system. The electromagnetic compatibility(EMC)problem caused by Electrical Wiring Interconnection System(EWIS) in MEA is studied as follows:1.Firstly, the characteristics of the EMC problems on MEA are analyzed. The difference of radiation performance between single-line power supply system of MEA and the double-line power supply system of traditional aircraft is discussed. The result shows that the electromagnetic field radiated by single-line power supply system is much higher than that radiated by double-line power supply system. Take inverter for an example, when the high frequency harmonic wave created by the inverter transmits through the cable, the electric field induced by the cables in each sensitive cabin on MEA is simulated and analyzed, the result shows that the electromagnetic interference produced by cable disturbs the normal work of the equipments possibly. Finally the interference path loss(IPL) between cables and antennas is discussed, the simulation results show that the electromagnetic field reduced by cables do no harm to antennas;2. Secondly, based on the generalized equivalent cable bundle method, different conditions which may influence the cross-talk among cables are discussed, including different height of cables away from floor, different distance between cables, different signal and different type of cable. Four Methods that can reduce the crosstalk among cables of EWIS are discussed, those are adding ground wire between emission and receiving cables, using multi-point ground method, using cables with shield and connecting filter to each port of the disturbed cable, the results show that adding filter and using multi-point ground method are better.3.Thirdly, the indirect effect of lightening to the connection wires of Electro-Impulse Deicing system(EIDS) and electric braking system(EBS) are analyzed. Firstly, compared with the current reduced on the port of parallel wire, the current reduced on the port of EIDS’s wires is more serious. Secondly, for electric braking system, the current reduced on the port of shield wire is much lower than that reduced on the port of bare wire. Thirdly, when the lightening hit the EIDS directly, the current reduced on the port of EIDS’s wire is analyzed. Fourthly, when lightning strikes in the space, the current reduced on the port of EIDS’ and EBS’s wires are discussed, the results show that the effect of lightening should be taken into consideration.