The slightest design error can cause incalculable damage, in terms of both people and equipment.

In other words, we need a detailed knowledge of the electrical power system while designing a zero-error earthing system.

The earthing system, fundamentally speaking, provides the lowest resistance path to the faulty current flow and protect humans as well as equipment. And the earthmat design for any complex grid needs special attention - conventional earthing design practices cannot meet the criterion for complex shaped grids. In fact, it needs a special algorithm for designing earthmats with uneven spacing and complex grids.

TECHLABS provides various technical solutions for studying earthing design-related problems. A few of our services in this area are:

• Measurement of onsite soil resistance, interpreting data and performing soil resistivity analysis.
  
  
• Design and preparation of necessary earthing layouts of earthmat/earthing system for substations, power plants and transmission lines; generating multiple alternative designs for earthmat, evaluating the earthmat for optimal and economical design.
  
  
• Analyzing problems involving electromagnetic fields, electromagnetic interference, grounding and various aspects of cathodic protection and anode bed analysis with a global perspective.
  
  
• Conducting simulation studies for earth and conductor potentials, and electromagnetic fields generated by an arbitrary network of energized conductors for both above or below ground for normal, fault, lightning and transient conditions.

PRODUCT INFORMATION…

CDEGS software package is a powerful set of integrated engineering modules that analyze all kinds of grounding, electromagnetic compatibility and interface problems. Furthermore it performs line parameters, corona, radio and audio noise computation, as well as solves lighting and surge transient problems. :

• Soil resistivity measurement and grounding analysis in arbitrary soil types.
  
• Inductive, conductive and capacitive interface in shared corridors.
  
• Line and cable constant, corona, radio and audible noise.
  
• Load, fault and transient current distribution.
  
• Frequency and time domain analysis of electromagnetic fields generated by arbitrary conductor networks.

CYMGRD, Substation Grounding Program

CYMGRD is CYME's substation grounding grid design and analysis module specially designed to help engineers optimize the design of new grids and reinforce existing grids, of any shape, by virtue of easy-to-use, built-in ‘Danger Point’ evaluation facilities. The program conforms to IEEE Std. 80-200, Std. 81 and Std. 837-2.

The use of CYMGRD allows the rapid analysis of various design alternatives to choose an economical solution for any particular installation.

User-friendly data entry, efficient analysis algorithms and powerful graphical facilities render CYMGRD an efficient tool that helps the engineer arrive at technically sound and economical designs.

Analytical Capabilities

• Finite element analysis of the Ground Grid Conductors, Rods and wire assembly.
• Computation of Rg and GPR (Ground Potential Rise).
• Touch and surface potential analysis, inside and outside the grid perimeter, with color display in 2D or 3D representation.
• Step voltage analysis.
• Uniform or two-layer Soil Model from field measurements or user-defined values.
• Computation of reduction factor (Cs).
• Library of the most common types of surface layer materials.
• Library of typical station soil resistivity values.
• Safety assessment calculations for maximum Touch and Step Voltages as per IEEE 80-2000.
• Current Split Factor ( SF) calculated from substation configuration data as per IEEE Std. 80-2000.
• Computation of the Decrement Factor (DF) from bus (X/R) ratio and shock duration data as per IEEE Std. 80-2000.
• DC component of asymmetrical fault current taken into account in the computations.
• Electrode analysis for the optimal sizing of Conductors and Rods based on the most common type of electrode material as per IEEE Std. 80-2000 and Std. 837-2002.
• Supports symmetrical or asymmetrical grids of any shape.
• Arbitrarily located ground Rods.
  • Ability to model Return electrodes and distinct electrodes.

GROUND MAT - Substation Grounding Software

The Ground Mat program follows IEEE Guide 80 / IEC 490 standards, uses finite element analysis of multiple connected or unconnected grids and rods, and uses matrix analysis for conductor current displacement. The program analyzes unlimited layers in the earth models. Soil resistivity measurement data can be curve-fitted to a multiple layer earth model for analysis. The main benefits are:

• Provide the means to carry electric currents into the earth under normal and fault conditions without exceeding any operating and equipment limits or adversely affecting continuity of service.
• Assure people in the vicinity of grounded facilities are not exposed to the danger of critical electric shock.

Analytical Capabilities

Analyze Multiple Studies

The Analyze Multiple Study option performs the calculations for multiple study folders.

Output Results in the Graphic Plots

The Ground Mat analysis program produces 3D graphic plots to display study results intuitively. Each study includes a 3D earth potential plot, a 3D touch voltage plot and a 3D and 2D step voltage plot. The 3D plots are color-coded to help one see the problem areas immediately.

Graphical Results – Earth Potential Plot

The following plot illustrates the earth potential distribution for a simple case study from. It is interesting to see that the earth potentials above the energized grid segments are higher than that of the unconnected grid segments.

It is interesting to see that the touch voltages above the energized grid segments are lower than that of the unconnected grid segments. The increased earth potential above the grid makes the difference between the grid and the earth smaller - and therefore safer.

Graphical Results – Step Voltage Plot

This illustrates the 3D and 2D step voltage distribution. The 3D view shows the relative height of the step voltage across the site area, while the 2D view shows the step voltage values in each mesh.