
266 Power System Transients
3.3.2.3 Transformation Matrix
The role of the transformation matrix [T
i
] in Table 3.3a-3 and b-3, is to trans-
form modal current (i) to phasor current (I), that is
() []
i
t
(3.87)
In the solidly bonded cable, the rst three modes (columns) shown in
Table 3.3a-3 express coaxial-propagation modes (that is, the “core-to-sheath”
mode[2]). The other modes (columns) correspond to one of the transforma-
tion matrices of an untransposed three-phase overhead line [2]. Inthis case,
mode 4 expresses an earth-return mode and modes 5 and 6 correspond to
aerial modes.
The reduced transformation matrix of a cross-bonded cable ...