The ASPEN Line Constants Program™ calculates electrical parameters of overhead transmission lines and underground cables with unsurpassed accuracy and ease of use. The graphical interface shows you the layout of circuits and ground wires of overhead lines as well as the physical construction of cables. You can manipulate any of the elements with the mouse and get the line and cable parameters by executing a single command.
The program can model overhead transmission lines with:

• One or more single-, 2- or 3-phase circuits on the same or adjacent right of ways.
• One or more ground wires, both segmented and unsegmented.
• Bundled conductors.
• Transposed and untransposed circuits.
• Any number of line sections with phase transpositions between them.

It can model underground circuits with:

• Pipe-type, oil-filled and plastic cable with single core or three cores.
• Cable sheaths that are single-point bonded, solidly bonded or cross-bonded.

For both lines and cables, the power frequency can be 25, 50 or 60 Hz. The length measurements can be in English or metric units. The program keeps a permanent record of the lines and cables. At any time, you can open a line or cable, change its configuration and parameters, and ask the program to compute and display the following parameters:

• Branch impedance and admittance matrices in the phase domain.
• Nodal capacitance and susceptance matrices in the phase domain.
• Positive- and zero-sequence self impedance and capacitance.
• Zero-sequence mutual impedance (for transmission lines only).

The program calculates the electrical parameters of overhead lines and underground cables using Carson's formula and Amatani's method, respectively. These methods are well accepted in the electrical power industry, and they are being used within the Electromagnetic Transients Program (EMTP).
Carson's method for overhead lines gives more accurate results than the commonly-used hand formulas, especially for zero-sequence mutual parameters, and for positive sequence parameters when ground wires are present. Amatani's method is known for its ability to model cable circuits with complex sheath and pipe configurations.
The line and cable configurations are shown graphically. An interactive graphics interface allows you to directly manipulate the lines and cables by pointing and clicking with the mouse. This feature makes the program extremely easy to learn and to use.
ASPEN Line Constants Program is a native 32-bit Windows application written in C++. It runs on Windows XP, Vista and Windows 7.