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I mean what saftware can I use. Can I use HIFREQ moudle of the CDEGS program to modle? Should I model the truck as 6 grid math which are commected to each other?

How can I calculate a discharge current for a car (truck) which is located underneath of a transmission line(230 kV)?

A galvanized steel seems to have higher resistivity with respect to copper.

This gradient control mat is for an air breaker switch for a 138 kV transmission line. I was told that the main reason for installing below the surface soil is to keep away from stealing those coppers.

By installing below the sufrface of the soil, we can reduce the touch voltage level.

To etablish an equipotential zone, a ground mat should be installed under the operation area of equipment and then connctect the mat to main grid. My question is that where the mat should be installed on the surface of the soil or below the sufrface of the soil. What are the difference between...

How far do we need to model the distribution lines in Malz, Hifreq module of CDEGS software? What is base for end points in the distrbution lines when we model?

The software calculate the potential difference between the ground potential rise (GPR) and the nearest conductor as touch voltage.

Take a look at the follwing document. http://www.iacforum.org/pdfs/Licensure72403.pdf

The FOP that uses the soil model can be resulted in lower or hihger grid impedance. So a realastic soil model is imporant in the calculation of the grid resistance.

The soil resistivities were measured along 4 traverses (lines), each with several probe spacings of course. Then we combined all those 4 data and treat them as one data by eliminating bad data. For example the shallow data associated with long lines are not a good representation for the area...

Fall-of-Potential(FOP) measurments should be compared to a simulated(using a software)FOP. For simulation of FOP we need to define a soil resistivity model. Usually 4 soil measurment traverses are used. 2 short traverses( representation for shallow layers soil model)within the station and two...

Is it ok to modify the soil layered structure model data(soil resistivity measurment model)to obtain agreement with Fall-of-Potential(FOP)measuements?

In general, the GPR of an extensive grounding system is influenced more by the deeper layer soil resistivity. For Simulation we can ignore the seasonal varation of the surface layer soil resistivity and consider the reresentatives of only deeper layers(using either summer/fall /winter/spring...

The top layer is wet from melted snow. We are assuming a 3-layer model. The worse case soil model is considered to occour in spring when the top crushed rock layer is wet from melted snow while the ground grid remains in frozen soil( surronded with higher soil resistivity). For the sake of the...

The frozen soil depth is in the range of 0.5-1.2 meters and the top layer with a tickness of 0.2 is a thawed layer.

I am considering soil resistivity cases due to seasonal variations. For example in our case, the worse case soil model is considered to occour in spring when the top crushed rocl=k layer is wet from melted snow while the ground grid remains in frozen soil.

In terms of safty analysis, what is the worst case soil model(the soil model can be more than two layers) for substation grounding?

The neutral conductor from 12kV to facility has small resistance compare to Grid resistance(5.2) and facility resistance than can be of order 15 ohm. So most of fault currents circulate within phases and only small fraction goes via soil. So, the GPR of the station due to fault at HV side can be...

The high GPR of 11070 V was due to transfer GPR of the station to the facility through the shield wire.