Abstract
Today, a more effective power network is a key solution to the right-of-way problem in terms of transmission cost reduction. Various advanced techniques and planning methods are currently adopted in power utilities for this purpose. So far, the authors have presented two approaches for the rational coordination of transfer capability with transmission reliability. One is a method to numerically evaluate the critical transferable power increased by means of lightning countermeasures in a long transmission route. The other is an index of system margin to be uniformly allocated in a power system from the adequacy point of view.
This paper newly proposes a concept of system margin from the dynamic stability point of view and a definition of probabilistic load transfer capability, both aiming for quantitative evaluation of power system alternative plans. Several different fault patterns have been taken into account with their occurrence frequency and critical transferable power. These proposals are applicable to the practices of power utilities in conjunction with the conventional planning methods. This paper also illustrates numerical examples of the proposed methods applied to a 500kV trunk model power system.
