  Consideration of generation, load and network uncertainties in modern
transmission network expansion planning (TNEP) is gaining interest due to
large-scale integration of renewable energy sources with the existing grid.
However, it is a formidable task when iterative AC formulation is used.
Computational burden for solving the usual ACTNEP with these uncertainties is
such that, it is almost impossible to obtain a solution even for a medium-sized
system within a viable time frame. In this work, a two-stage solution
methodology is proposed to obtain quick, good-quality, sub-optimal solutions
with reasonable computational burden. Probabilistic formulation is used to
account for the different uncertainties. Probabilistic TNEP is solved by
2m+1-point estimate method along with a modified artificial bee colony (MABC)
algorithm, for Garver 6 bus and IEEE 24 bus systems. In both the systems, rated
wind generation is considered to be more than one-tenth of the total generation
capacity. When compared with the conventional single stage and existing
solution methods, the proposed methodology is able to obtain almost identical
solutions with extremely low computational burdens. Therefore, the proposed
method provides a tool for efficient solution of future probabilistic ACTNEP
problems with greater level of complexity.
