Calculation of 3D capacitances of wires with hybrid MoM/MAS approach

Abstract

In car related EMC problems, it is important to estimate radiation from, or coupling into, the cable harness, which comprises of a large number of wires located in close proximity. When wires are considered, decreasing the length of a wire segment does not improve accuracy if any other object is located extremely close to the surface of the wire. In this case, charge is distributed non-uniformly along the perimeter. The surface of the wire segment must be divided into strips, and charges at each strip must be found independently. A "thick wire" approach, which includes additional segmentation along the perimeter, can bring an enormous increase in the number of unknowns. We report on the implementation of a thick wire approach based on the method of auxiliary sources (MAS). Results of investigations are given as recommendations in graphical and tabular views, which show the accuracy of the calculated values for benchmark problems. These recommendations will be used in the latest versions (v. 1.14 and higher) of the three dimensional static solver Satic3D developed at EMCoS.