Study on Step Voltage of Paddy Field under Grounding Fault of Distribution Network Based on Circuit Electric and Field Coupling Model

In the past two years, there have been frequent personal injury and death accidents caused by the break of distribution network line . With the length of distribution network line increase significantly, the potential dangers of distribution network break and grounding fault will become more prominent. In this paper, the circuit module composed of overhead lines and human resistance and capacitance is combined with the electric field module in the soil area to establish an accurate analysis model of the coupling between electric circuits and electric fields for the first time. Based on this model, the water level and ground line length in a large area of paddy field are explored and the impact of water penetration into the soil on human body electric shock is studied. The results show that with the increase of paddy field water level, soil saturation layer thickness and ground strand length will decrease the step voltage, and the decline trend will gradually slow down. In order to shorten the dangerous distance between the human body and the fault line, the paddy field water level and soil moisture should be maintained, and obstacles such as trees under the line should be removed to make the wire ground as long as possible after the wire is broken. The research results can provide a reference for the prevention of electric shock accidents when a paddy field exists under an overhead line.