Abstract: The human-body capacitor is an important parameter in electrostatic discharging model (ESD). In the tunnel environment, multiple electricmirror images of dielectric medium were employed, and the humanbody capacitors of the system were calculated, based on the uniqueness of electric field solutions. The capacitors’ dependence on humanbody, tunnel shape, the humanbody position in relation to the tunnel, and dielectric constant, was also investigated. The calculations show that the humanbody capacitor is very sensitive to the figure of the humanbody and the shape of the tunnel, but not closely related to the humanbody position in the tunnel. Furthermore, the humanbody capacitor depends on the dielectric constant of the environment and the capacitor maximum peak which is 115 times than that in free space appears at εr=7(the dielectric constant of dry coal is εr=63), which reveals the importance of electrostatic safety in the tunnels of mines.

Key words: electrostatic discharging model (ESD); humanbody capacitor; mines; electricmirror image