Computation of Internal Impedances of Arbitrarily Shaped Conductors

SESImpedance is a Finite Element Method (FEM) based program that computes the internal impedance per unit length of long conductors of constant cross-section, with arbitrary geometry and composition. The calculations fully account for skin effect, and can be carried out at low or high frequency.

This object-oriented application is highly interactive and visual. Complex solid and hollow conductors with various electrical characteristics can easily be modeled and analyzed by:

  • Importing drawings from SESCAD (MALZ input files) or creating directly in SESImpedance using the available predefined shapes and editing CAD operations in various systems of units.
  • Defining new materials or using the built-in Material Database to specify the material type of the various parts of the conductor.
  • Controlling the Computation Parameters such as frequency and Adaptive Mesh Refinement Options for achieving highly accurate internal resistance and reactance results.

Examples of conductors that can be modeled using SESImpedance include:

  • Conductors made of different materials (such as ACSR) possibly including insulating material (e.g. OPGW).
  • Conductors comprised of many sub-conductors, such as stranded conductors.
  • Conductors of non-circular shapes, e.g. elliptical conductors or rail tracks.

Coated Stranded OPGW

CentraCore Optical Ground Wire

Rail Track

Creating and Editing Polygon Part Type

Conductor geometries are drawn in SESImpedance using simple shapes (known as Parts) such as Rectangles, Ellipses and Polygons by editing the vertices of polygons interactively and graphically.

At each refinement step, the Laplace Smoothing technique is applied to the generated mesh.

In addition, a routine controls the number of segments that define not only the Circles and Ellipses, but all other parts as well. The number of segments is internally optimized in order for the program to generate a better initial mesh.

SESImpedance also computes and reports the characteristics of an equivalent conductor of circular cross-section that has the same internal impedance as the specified conductor, making it possible to use SESImpedance results in applications that are restricted to circular conductors. Several options are available to define the radius of this Equivalent Circular Conductor.