Assessment Of Transmission Line Tower Grounding Device’s Impact On Personal Security And Protective Measures Research

With the rapid development of the power grid scale，the hybrid transmissiongrid of AC and DC is taking shape, because of urban and rural integration indeveloped areas, growing density of high-voltage transmission line constructionmake the transmission lines inevitably have to pass through the towns, factories,neighborhoods and schools near by densely populated areas. Under the effect oflightning, filthy, insulation deterioration and other factors, when high-voltagetransmission line subject to ground short-circuit fault, ground short-circuit currentflow through grounding device, resulting in ground potential rise of the fault point,forming dangerous contact voltage in the tower, producing a step voltage in thevicinity of the ground, posing a threat to the people in the vicinity. Due to thelimitations of science and technology, early power system workers put moreemphasis on power plants, substations’touch voltage and step voltage, high-voltageline towers located in the mountain where sparsely populated, the main considerationis tower lightning safety, personal safety is rarely considered.The paper first put analysis on personal electric shock theory, the root cause ofelectric shock to human health research the different responses to human healthpower frequency that the different responses and severity of the ground short-circuitcurrent and lightning surge current impact to human health, research the type oftransmission line tower grounding device, depth and soil parameters, using the finiteelement method to study the potential distribution in the vicinity of the commontransmission line tower grounding device by ANSYS software. Then combining thefield research data of 500kV Jin-da line, calculating the touch voltage and stepvoltage of typical grounding devices, assessing the personal security effect oftypical towers, using numerical methods and MATLAB, study step voltage and touchvoltage distribution of a single eathernet port of grounding grid. Finally, accordingto the above theoretical calculation and simulation analysis, propose reasonableimprovement measures and protection methods.This work reveals the root cause of the human electric shock casualty is thecurrent flowing through the body, causing the human heart fibrillation; assess thepersonal security effect of 500kV Jin-da line typical tower, propose new measures toimprove tower grounding device models and other reasonable measures.