Development of a dynamic equivalent model for Ontario's external system

The equivalent models for external systems used in energy management systems (EMS) are typically suitable for static (load flow) security assessment and do not accurately capture the dynamics associated with inter-area modes. Due to the recent trend in employing on-line dynamic security assessment (DSA) tools, new external equivalents, which can be implemented in the EMS and that can meet both static and DSA requirements, need to be developed. This work demonstrates procedures and steps used to develop a dynamic equivalent for Ontario's external system. Several key quality assurance tests, which can be readily implemented using industry standard tools, are proposed to validate the performance of the developed equivalent, thus making the approach more general and repeatable by other interconnected systems.