In 2014

during repair of the failure due to typhoon "Seagull" disaster in the China Southern Power Grid

a death accident happened because of step voltage. To investigate the accident

an artificial single-phase short-circuit test and simulation were conducted on a 10 kV distribution grid. The software CDEGS was employed to simulate the step voltage of cross-shaped grounding device with different soil resistivity. The test and simulation results showed that:1)when the soil resistivity was about 30 Ω·m

a simple vertical grounding device was used

and the short-circuit current was 48.1 A

the step voltage would exceed the limit 80 V

which is sufficient to kill a person without any protection;2)when a cross-shaped grounding device was used and the short-circuit current was100 A

safe distance more than 8 meters

which is specified in the standard GB 26860—2011

would be necessary for person; and 3)simulation results and test data were in good agreement

indicating that simulation can be applied to the research of safe distance for distribution grid.