A new aggregation approach for the single machine equivalent to calculate the decelerating energy of the stable-domain

This paper proposes a new aggregation approach for the single machine equivalent (SIME) method. To assess the transient stability of the power systems rapidly, observers sometimes need to aggregate a multi-machine system into a simplified system. However, there is more than one approach for aggregation and thus observers cannot know which way is the most appropriate. This paper first explains the basic theory of the single machine equivalent (SIME) method. Next, a new aggregation approach is proposed which can be applied not only to the unstable-domain, but also to the stable-domain, and simulations are carried out to verify the validity of the proposed scheme.