Skip to Main Content
An equivalent model for external systems to be used in on-line contingency studies is presented. The equivalent uses Dimo's REI network reduction technique together with a method for tracking on-line injection and network changes in the external system by modifying the parameters of the equivalent. This important characteristic results in a dependable equivalent with excellent response at all operating points. Another important aspect of this paper is the fact that for the first time the testing of on-line equivalents is carried out in a real-time environment rather than under simulated conditions. The response of the equivalent model proposed herein to the outage of a major 765KV circuit in the AEP System is reported and the results provided by the equivalent are compared to the results provided by the AEP State Estimator. The results obtained with the model presented in this paper are superior to the results obtained with other equivalent models.