SESTLC

Engineering Functions

The SESTLC software package is a transmission and distribution line analyzer for rapid line parameter (constants), EMF and steady-state or fault induced voltage estimates (whether inductive and conductive). It can be used to quickly estimate line parameters, electric fields, and magnetic fields associated with arbitrary configurations of parallel transmission and distribution lines. It also estimates voltages and currents generated by electromagnetic interference on other neighboring metallic utilities, such as pipelines, railways and communications lines. The software has been designed with simplicity in mind, providing much useful information with minimal data entry, when applied to simple system configurations. This can be very helpful for preliminary analyses of more complex systems. The victim line in SESTLC is not restricted to be parallel to the transmission line; however, a simpler data entry mode is available for cases where the victim line is always parallel to the transmission line.

Keep in mind that for more complex systems or more detailed studies, the Right-Of-Way software package or the MultiFields (HIFREQ computation module) are recommended.

The main functions of SESTLC are summarized as follows:

1. Line parameter calculation
2. Electric field calculation
3. Magnetic field calculation
4. Normal or emergency Load (steady-state) condition inductive interference calculation
5. Fault condition inductive and conductive interference calculation

User Interface

The following figure shows a few typical screens that are accessible when SESTLC is loaded.

SESTLC computes the line parameters of the transmission lines, the electric and magnetic field at selected observation points, the induced stress voltages on the victim line during steady state conditions and fault conditions on the transmission lines.

The victim circuit includes its exposed portion, its left continuation portion, its right continuation portion and its termination shunt impedances at both ends. The longitudinal direction of the transmission line is along the X axis. The coordinates of the victim line are defined with respect to this coordinate system.

The exposed portion of the victim line is described by a straight parallel line (all versions of SESTLC) or by a jagged linear path, i.e. a conductor that follows an arbitrary 3D linear path (SESTLC Pro only) as shown in the input screen that follows. The path consists of any number of sections. The configuration is determined by the coordinates of the path. A jagged victim line starts from the left side and extends to the right side. See the following screen for more details.

Graphical Results

SESTLC displays computation results in a variety of plots using the Array Visualizer tool. The plots can be displayed on your screen immediately after the end of the computations or can be saved on your hard-drives to be displayed later. Below are a 3D plot of the electric field produced by a transmission line near a tower and the induced potential rise on a pipeline that is parallel to a transmission line (2D Plot).