New Features

A new option has been implemented in MALT which allows you to model buried metallic plates. This can be used to model elements such as buried tanks, and can also be used to quickly compute results for the limiting case of a very dense grounding grid.

Plates can be modeled alone or alongside cylindrical conductors. Several plates can be modeled simultaneously. Plates can be located as MAIN, RETURN or a BURIED electrodes, and can be energized with either a current or a voltage source.

The Input and Output Toolboxes were modified to allow the specification of plates in a MALT model, and to visualize the results of models containing plates.

A new option was introduced that streamlines the workflow with the program. All of the important functions (Save, Load, Run, etc…) are regrouped in one centralized window, common to all modules. This reduces the number of steps needed to accomplish some common tasks. In addition, several screens were rearranged to make them more intuitive and easier to use.

The Right-of-Way package can now be used to conduct complete AC interference studies under fault conditions, including inductive, conductive, and capacitive couplings. A new “Total Interference” module was introduced. This module generates a MALZ file (the Total Interference Model) that includes an EMF (calculated with SPLITS) applied to selected conductors. The computation results for this MALZ file thus contain both the inductive and the conductive components of the interference.

Several new features were added to the automated grounding design package AutoGroundDesign. First, the soil resistivity analysis (RESAP) and fault current determination module (FCDIST) have been integrated into the package. This means that you no longer have to determine the soil model and fault current outside of AutoGroundDesign: you can specify the soil measurements and define the network that contributes to the fault directly in the program.

A new Adaptive Patch Subdivision technique was developed to help improve the usability and reliability of the Arbitrary Soil Volumes soil model in MALT and MALZ. This technique optimizes the subdivision of the faces of all soil volumes. The Adaptive Patch Subdivision improves the accuracy of the soil computation results while minimizing the total number of patches required to achieve a specific accuracy target.

The Adaptive Patch Subdivision algorithm ensures that the patch sizes and distribution are consistent with the expected concentration of electric charges on the volume faces based on physical criteria (designated as Priority Criteria) such as conductor proximity, resistivity contrast ratios, location of patches on the volume, etc. In most cases, the adaptive patch subdivision provides the optimum computation accuracy results.

The SESCAD application is used to graphically create conductor networks with as much ease as possible; these networks can be used in the MALT, MALZ, and HIFREQ programs in the SES software packages.

The following is a short summary of the improvements that have been made to the SESCAD program:

1. Higher Precision

The numerical precision has been increased in the program allowing huge networks to be handled easily by the program without loss of precision.

2. The Select-by-Index Tool

The conductors and profiles can now be selected by their ID number. This can be useful for locating conductors or profiles from the ID numbers indicated in the error messages.

3. The Create Right-of-Way Tool

This is a multipurpose tool whose main intent is to allow creating conductors and profiles that run parallel to each other along a path. However, this tool can be useful in other tasks.

GPR Energization in MALZ

A new GPR energization option has been introduced in MALZ. This energization type effectively maintains the potential of the energized conductor with respect to remote ground to a specified value. It can be useful in many cases, including:

· The safety evaluation of a pipeline valve site during a fault occurring at nearby transmission line towers;

· Efficient evaluation of the coating stress voltages on a pipeline due to conductive interference from a grounding grid which is very close to the pipeline;

· The specification of a structure of known ground impedance, without requiring the modeling of an extensive grounding network.

Two new options for conductor impedance specification in MALZ have been introduced: distributed conductor impedance and lumped conductor impedance.

The “distributed impedance” option allows you to specify the conductor impedance directly, as a combination of resistance per unit length and reactance per unit length. This can be used to define the impedance of conductors in cases for which MALZ cannot accurately compute this impedance in terms of the length and geometry of the conductor and of its resistivity and permeability.

A new “Ground Potential Difference” (GPD) plot option has been introduced for MALZ and HIFREQ. This plot allows you to visualize the potential difference between selected conductors in the grid and a reference potential value, typically another grid conductor. This is useful to visualize the locations in the grid where large potential differences exist. It can also help determine the optimal location of equipment installations, such that they are subject to minimal electrical stresses.

The computation of the self and mutual impedances in pipe-type cable systems was improved. It now includes all effects caused by the eddy currents in the pipe wall. This affects mainly the positive sequence component of the self impedance of the cable. Also, the computation of the self impedance of hollow conductors was improved. Previously, the program would replace hollow conductors with “effective” solid conductors. This could introduce some errors for hollow conductors with a very large resistivity. TRALIN now uses the internal radius as part of its determination of the characteristics of the effective conductor, yielding very accurate results for all values of the resistivity.

A new user interface program, called SESEnviro-Plus, was developed for the SESEnviro module. This recently introduced module allows you to analyze the environmental impact of transmission lines. It can calculate the levels of radio noise, audible noise and other corona-related effects and also analyze electric and magnetic fields around transmission lines.

The new user interface program offers an integrated environment for the analysis of the environmental impact of transmission lines. You can specify data, carry out computations, and visualize the computation results all from a single interface.

In addition, the analytical capabilities of the SESEnviro module were enhanced, with the introduction of several new calculation methods for corona effects on DC lines, and with an option to account for possible phase transpositions when computing the magnetic field.

The SESBatch program executes all of the engineering runs that are defined in a batch job which can be launched manually or at a desired time in the future.

This program has undergone significant changes in the visual interface and as well as in new and improved functionalities.

The changes are summarized below:

1. Two additional tabs were added to offer more details about the runs in the batch:

· Current Run

This tab displays the progress of the program that is currently running in the batch.

· Finished Runs

This tab displays the status of each run in the batch that has been completed.

2. A program can be added to the batch while the batch is in progress.

3. Commonly-used utilities can be accessed from the Tools menu.

A multilayer soil model was implemented in HIFREQ, and is currently being tested. It will be available in the 2005 release of the software.

Also, the computation time of the program was substantially reduced for cases using the default accuracy settings. The improvement in run-time can reach up to 35% in some cases. Most algorithms in the program were also parallelized; as a result, HIFREQ can now take advantage of multi-processor machines. Improvements of up to 80% in speed were observed in some cases when running on a dual-processor computer.