This paper uses the charge simulation technique to calculate the poten
tial and electric field stress distribution at the surfaces of the con
ductors and the dielectric of an unshielded three-core power cable. Th
e conductors and the sheath are simulated by a suitable finite number
of complex line charges. The unshielded three-core cable is placed on
a grounded plane and at varying heights above it to calculate the elec
tric field as a function of the height of the insulated cable from the
ground. The maximum value of the electric field stress at the grounde
d plane due to the presence of the insulated three-core cable is detec
ted to check the discharge activities at the grounded plane surface. C
omparison is made with field stresses arising from a single-core unshi
elded insulated cable which are given in the literature. The charge si
mulation technique is found to be satisfactory to model and calculate
accurately the field stresses in a three-core unshielded power cable.