New approach to calculation of electric field in three-core power cables

Based on the principle of superposition, a novel approach is presented to calculate the electric field in three-core cables so that the electric field problem under any conductor voltage conditions (V Z, VB, VC) can be reduced to a field computation for a basic conductor voltage condition, i.e. VZ=1, VB=0, VC=0 (1, 0, 0). The present approach not only simplifies the computation procedure, but can also express the potential and field stress at any point as a function of ωt when the field problem is investigated in a three-core belted cable under three-phase power frequency voltages. The maximum percentage potential error is shown to be not more than 0.05%, and the field deviation angle is generally not more than 0.1°, even when interconductor spacing is very small