Correction Method of Step Voltage Considering Equivalent Circuit of Human Body

The value of the step voltage affected by human parameters and soil parameters will mislead the personal safety risk assessment model. This paper studies the influencing factors of the step voltage based on the step voltage test and compare the difference between the equivalent circuits with and without human body resistance, which gives a human body influence coefficient k: The ratio of the step voltage with or without the human body equivalent circuit. The formula of k about soil resistivity, skin resistance, electrode radius and burial depth were fitted by FEM simulation data. The error of the expression was verified by the FEM analysis result that the error was not more than 5% (allowable value range). The study draws the conclusion that the step voltage is significantly reduced when the human body equivalent circuit exists. The fitting formula shows that the reduction in areas with high soil resistivity is greater than that in low. The conclusion provides data support to Step voltage monitoring alarm.