Benefits of excitation control system testing at AEP´s Rockport plant

Excitation control systems (ECS) play an important role in the transient and oscillatory stability of generating units and interconnected systems. For this season, comprehensive testing of the ECS was conducted at AEP´s Rockport plant, Indiana. Analyses of the ECS tests indicate that, with the ECS equipment as found, a permanent 100 MW plant curtailment would have been needed during two-unit plant operation to assure satisfactory stability performance. This curtailment was avoided by retuning the voltage regulators of both Rockport units before the second unit was placed in service. The Rockport ECS testing, analysis, and tuning efforts are described