An investigation into the compensation of asymmetric systems

The design criterion for high-voltage systems is normally a three-phase fault with the loss of one line (N-1), which reduces transmitted power and security limits. In many situations, this criterion can appear inappropriate, especially when it is a question of one-phase or two-phase contingencies. Considering the three-phase system as three independent single-phase circuits and associated system design, the one-phase-loss situation is corrected with classic compensation strategies. The costs resulting from this approach will be less onerous and the security region of the system increased significantly. This paper gives an outline of the object and the scope of the study of compensated asymmetric performance of a transmission system under contingency conditions and the remedial measures required.