POTENTIAL DC SYSTEM SUPPORT TO ENHANCE AC SYSTEM PERFORMANCE IN THE WESTERN UNITED-STATES

Economics dictates the heavy utilization of the major ac and dc transm ission paths in the Western United States. To achieve interconnected n etwork stability with these heavy power transfers, extensive remedial action schemes have been implemented by the various transmission proje cts. These remedial action schemes often pose an operating reliability problem as well as undesirable impacts on non-project systems since a ctivation of these schemes could result in network separation. This pa per explores the potentials of utilizing the controllability of the dc lines to reduce the complexity of the remedial schemes or to increase the stability performance of the system so that the impact of existin g and future projects on non-project systems can be minimized.