Optimal Long Line Series Compensation

The purpose of this paper is to evaluate the effectiveness of the capacitive series compensation of long lines from both the technical and economical points of view. It will be shown that the achieved increase in the transmission line capacity using this technique will be economically justified only for certain ranges of line length, line voltage and other design parameters. A procedure is also presented to find the optimal degree of series compensation and the location of the compensating condensers. The objective function for the optimization is considered to be the equivalent cost of the increase in the line maximum power limit minus the cost of the compensating condensers. Information is also given about the effect of different electrical and economical design parameters on the optimal compensation conditions.