Multi-layer soil structure analysis for substation and power generating station sites

The multi-layer soil structure model is fundamental to design of grounding systems of substations and power generating stations. Potential distribution of ground surface generated by a point current source is derived using electromagnetic field theory, and also the relationship between the apparent soil resistivity measured by Wenner four-electrode configuration and the measurement electrode span is deduced. A nonlinear target function is introduced, and the problem to analyze structure parameters is transferred into how to obtain the extremum of the nonlinear target function. A suitable calculation method is used to acquire soil structure parameters. The studied analysis software is applied to actual substation sites; the analyzed result has a good agreement with the actual engineering result.