Time Domain Analysis Of Crosstalk And Electromagnetic Radiation Sensitivity Of The Automotive Wiring Harness

In modern society, a lot of electronic or electrical equipment used in variousindustries, the problem of interference between devices circuit electromagneticcompatible disciplines emerged. For the automotive industry, on the one hand thedegree of electrification vehicle equipment continues to improve, on the other handthe external electromagnetic environment is becoming increasingly complex, makingthe electromagnetic compatibility has become troubled car industry personnel. Atthe same time, own to the new energy vehicle development irreversible trend, theEMC issue of the electric vehicles and hybrid vehicles has become a major researchtopic in major car companies. A large number of high-power electronic devices,power-driven motors and high voltage power cables in the new energy vehicles madeelectromagnetic noise emission level of the car increase significantly，wherein theradiation sensitivity of automotive cable harness,the crosstalk between the harnessand the external field radiation by the harness are the main problems ofelectromagnetic compatibility. At the same time due to the increasing number ofautomotive wiring harness, which makes use of traditional methods of computationalelectromagnetics harness crosstalk and time-domain analysis of radiation sensitivitymore time consuming, is not conducive to engineering applications. To solve thisproblem, one is to enhance the performance of your computer, on the other hand is toimprove the algorithm to achieve shorter time, so this paper, the method and theequivalent harness FDTD method combined with the time-domain analysis ofautomotive wiring harness crosstalk and radiation sensitivity.This paper describes Ansys Q3D software which the core algorithm is the finiteelement method, use it to compute unit length capacitance and inductance matrix ofautomotive wiring harness and provide data to support the harness equivalentcapacitance matrix method and inductance matrix.This paper comes up with a new type of FDTD according to the time domainanalysis of non-homogeneous multi-conductor transmission lines. The differencebetween this scheme and the traditional πtype Leapfrog scheme is the discrete way ofvoltage and current along the transmission line. Thereinto, the current node is at thehead and terminal of each segment of the discreted transmission line and the voltagenode is the midpoint of each segment (T type Leapfrog). In order to improve thecalculating efficiency,this paper transforms the T type Leapfrog scheme into matrixform of semi-discretization.Introduce a new differential algorithm, it is unconditionally stable algorithm,namely the time step and space step is not limited by stable limitations, the size oftime step and space step of the unconditionally stable difference algorithm (such as Leapfrog format, Lax-Friedrichs format, Lax-Wendroff format, the first-order andsecond-order upwind upwind) may have a relatively larger compared withconditionally stable difference algorithm. This makes it beneficial to improve thecomputational efficiency. Finally, the algorithm combine with to compute thecrosstalk of the cable harness, taking a step forward to improve the computationalefficiency.Modify the existing Equivalent Cable Bundle Method to apply to the radiationsensitivity analysis of harness in time domain. The core idea of the improved“Equivalent Cable Bundle Method”: In addition to the observed cable, creat ofgroups of cable harness according to the compare size of the common modeimpedance and terminating impedance of the cable harness. Each group is equivalentto a cable, said calculate the position coordinates of each equivalent cable. Thanreduce cable bundle matrices and reduce cable bundle equivalent termination.Finally,we get the reduced model. In the end, the improved “Equivalent Cable BundleMethod” combined with the FDTD method to computing harness crosstalk, taking astep forward to improve the computational efficiency.