Ground Grid / Mat Study

A Ground Grid / Mat Study will determine if your substation grounding grid design is
safe and will limit the touch and step potential to values below the IEEE – 80 Standard
-IEEE Guide for Safety in AC Substation Grounding limits.

We use SKM’s state-of-the-art GroundMat Software Module and accurately determine the touch and step potentials.This program is especially beneficial for our clients who are designing their own substation ground grids. Using too many ground rods and copper cable can be labor intensive and costly. However, using to little can be dangerous and create potential voltages when line to ground faults occur. Our ground grid analysis is an important part of power system design and analysis. Our study will validate your design and give you piece of mind.

The SKM Ground Grid program uses the following Solution Algorithms:

  • Finite element analysis of the ground conductors.

  • Finite element analysis of the ground rods.

  • Grid conductor current displacement using Matrix analysis.

The program has the following Analysis Options:

  • Earth model analysis from field measurements.

  • User specified fault current.

  • Grid and Ground potential analysis.

  • Ability to analyze multiple ground systems.

  • Ability to analyze the potential rise for each grounding system including neighboring passive grids or rods.

  • Safety analysis including surface materials, based on body weight and exposure time.

  • Option to use IEEE Std. 80-2000 or IEC Std. 479 for safety analysis.

  • Calculation of maximum permissible touch and step voltages.

  • Comprehensive report for grid and rod configuration.

  • Comprehensive report for surface potential analysis featuring station data and currents
    diffused to ground by the grid elements.

  • Danger point evaluation.

  • Touch voltage, step voltage, and earth potential analysis.

More information about the SKM program can be found at

http://www.skm.com/groundMat.html

Our report will include the following:

  • Introduction

  • Executive Summary

  • Grounding Plan and Details

  • Ground Mat Study

  • Ground Mat Computer Printout

    • Study Setup and Data

    • Touch Voltage Calculations

    • Step Voltage Calculations

The benefits of this study include:

  • Design time savings

  • Material cost savings by determining the minimum size of conductors and number of ground rods to keep the potentcial values below the IEEE limits.