Use of Special Protection Systems for Major Palo Verde Network Hub Congestion Management in the U.S. Southwest

This paper presents information concerning the specific application of a special protection system (SPS). The information in this paper includes the technical concept behind the SPS, the system analysis justifying the application and an illustration of real life operation utilizing a special protection system to maximize the scheduling generation capability (SGC) for the Palo Verde network hub located in the Southwest Region of the United States. Implementation of this SPS which initiates direct generator tripping (DGT) can minimize the adverse impacts due to a double circuit outage in the common corridor and can prevent further wide-spread cascading outages on the existing system. As an additional benefit, the SPS will maximize transmission system transfer capability. This paper discusses the operating studies and the associated technical advantages that can be achieved by utilizing this type of special protection system in the WECC major southwest network hub.