Equivalent line limit calculation using available thermal transfer capability

Power system equivalents have been used for faster simulations, but not much interest was on calculating equivalent line limits and this limits the use of equivalents in simulations. Authors used total transfer capability in assigning equivalent line limits in previous papers and this paper utilizes available transfer capability in doing so. A detailed procedure of the proposed method is described with a small 4-bus case. An exact solution case and a non-exact solution case examples are provided. For non-exact solution cases, solutions are bounded with upper and lower estimates. Also, the proposed method applied to the IEEE 118-bus case and results are provided and compared with those with total transfer capability.