This paper describes some experiences with and the impact of the addition of power system
dynamic models to application testing of EHV transmission line protection systems. These
models provide useful information, especially in highly stressed systems, during frequency
excursions, or where there are applications of synchronizing or synchronism-check functions.
This paper reviews the various forms of test signals that may be applied to relays. It also
discusses factors to consider when reducing complex power systems to lumped components. The
reduced system should retain features that impose significant challenges to the protection system,
while keeping the system simple enough to be modeled by reasonably sized test facilities.
The value of application testing for protection systems is well recognized, especially for complex
protection systems. The degree of complexity of test simulations should be balanced with the
possible benefit of discovering limitations or challenges that may affect specific applications in a
C. Henville, A. Hiebert, R. Folkers, R. Wierckx, In Proc. 30th Annual Western Protective Relay Conference, October 2003 (WPRC 2003), Spokane USA, October 2003, Paper No. 8