The activity in the high-voltage environment is at risk of being injured by electric shock. The safety of personnel in and around electric power installations has been a prime concern. Specifically, this safety is generally in terms of the allowable touch and step voltages. These voltages are related to the ground resistance of human foot. In order to increase the safety of personnel, a high resistivity surface layer of gravel normally exists in the substation switchyards or other high-voltage areas. The thickness of this layer will affect the calculation of the ground resistance of human foot. Among them, the electromagnetic field and humidity factors are also considered in this paper. As a result, the surface layer of gravel can be used to reduce the earthing resistance of human foot. The equivalent model of human foot was modeled by the circular plate conductor in the past, which considered the beauty of the environment. Most of the transmission lines are in the surface, so the transmission line generated by the discrete current will affect the earthing resistance estimation. Thus, the proposed paper will consider the composition of the Green’s function which is the mathematical calculus popularized by the basic theorem of calculus. On the other hand, the damp ingredients and temperatures on the surface will also be considered in this paper. This paper researches into the proposed method for estimating the ground resistance of human foot and proposes an equivalent model for calculating the earthing resistance of human foot. A comparison of the method is also shown in this paper.

1. ANSI IEEE Std, “IEEE guide for safety in ac substation earthing,” 1989. [Online]. Available: https://goo.gl/gFGZzC
2. B. Thapar, V. Gerez, and H. Kejriwal, “Reduction factor for the ground resistance of the foot in substation yards,” IEEE Transactions on Power Delivery, vol. 9, no. 1, pp. 360–368, 1994. doi: https://doi.org/10.1109/61.277707
3. B. Thapar, V. Gerez, A. Balakrishnan, and D. Blank, “Finite expression and models for footing resistance in substations,” IEEE Transactions on Power Delivery, vol. 7, no. 1, pp. 219–224, 1992. doi: https://doi.org/10.1109/61.108911
4. B. Thapar, V. Gerez, and P. Emmanuel, “Ground resistance of the foot in substation yards,” IEEE Transactions on Power Delivery, vol. 8, no. 1, pp. 1–6, 1993. doi: https://doi.org/10.1109/61.180312
5. H. Shiau and M. Genge, “Step potential and bodycurrent near a buried horizontal bare conductor in a two-layer earth,” IIT Research Institute, Chicago, IL, Tech. Rep., 1977.
6. W. E. Byerly, Fourier’s Series and Spherical, Cylindrical, and Ellipsoidal Harmonics. New York, NY: Dover Publications, Incorporated, 1893.
7. J. Zaborszky, “Efficiency of grounding grids with nonuniform soil,” Electrical Engineering, vol. 75, no. 3, pp. 227–227, 1956. doi: 10.1109/EE.1956.6442491
8. K. Tanaka, Y. Mizuno, and K. Naito, “Measurement of power frequency electric and magnetic fields near power facilities in several countries,” IEEE Transactions on Power Delivery, vol. 26, no. 3, pp. 1508–1513, 2011. doi: https://doi.org/10.1109/tpwrd.2010.2078836
9. M. R. Teague, “Deterministic phase retrieval: A greens function solution,” Journal Optical Society of America, vol. 73, no. 11, pp. 1434–1441, 1983. doi: https://doi.org/10.1364/josa.73.001434
10. G. Anastasi, M. Conti, M. Di Francesco, and A. Passarella, “Energy conservation in wireless sensor networks: A survey,” Ad Hoc Networks, vol. 7, no. 3, pp. 537–568, 2009.
11. P. G. Huray, Maxwells Equations. New York, NY: Willey, IEEE Hardcover, 2009.
12. H. Dwight, “Calculation of resistances to ground,” Transactions of the American Institute of Electrical Engineers, vol. 55, no. 12, pp. 1319 1328, 1936. doi: https://doi.org/10.1109/ee.1936.6539232

Z.-X. Wang and J.-M. Lin, “Application of the Green’s Function in attenuation factor to solve the status of human health on the earth,” International Journal of Technology and Engineering Studies, vol. 4, no. 1, pp. 32-41. doi: https://dx.doi.org/10.20469/ijtes.4.10005-1