④IEEE IEEE Recommended Practice for Excitation System Models for Power System Stability Studies IEEE Power Engineering Society Sponsored by the Energy Development and Power Generation Committee IEEE IEEE Std 421.5TM-2005 3 Park Avenue New York,NY 10016-5997,USA (Revision of IEEE Std421.5-1992) 21 April 2006IEEE Std 421.5™-2005 (Revision of IEEE Std 421.5-1992) IEEE Recommended Practice for Excitation System Models for Power System Stability Studies I E E E 3 Park Avenue New York, NY 10016-5997, USA 21 April 2006 IEEE Power Engineering Society Sponsored by the Energy Development and Power Generation Committee