Enhancing stability simulation for NERC Reliability Standard TPL-001-4 compliance

On October 17, 2013, the Federal Energy Regulatory Commission (FERC) approved the North American Electric Reliability Corporation (NERC) Reliability Standard for transmission planning, TPL-001-4. With respect to transient stability assessment, TPL-001-4 requires more extensive annual assessments, establishment of criteria for transient stability, simulation of actual actions of protective relays and Special Protection Systems (SPS), inclusion of protection system failure and relay failure contingencies, and criteria or methodology for identification of system instability such as cascading, voltage instability, or uncontrolled islanding. To comply with this new Reliability Standard, several aspects of transient stability study need to be enhanced: (1) selection of study cases, and of contingencies potentially causing reliability violations or producing more severe system impacts including cascading; (2) inclusion of actual actions of protection systems and SPS; (3) automation of procedure to identify transient stability violations based on the established criteria; and (4) mechanism for identifying and simulating cascading.