Newtonian Mechanics Based Transient Stability PART V: Inner-group Machine

This paper analyzes the mechanisms of the inner-group machine. It is first clarified that the inner-group machine is created from the difference between the equivalent system and the original system. The inner-group machine stability is analyzed based on the machine paradigms. In particular, strict correlation between the inner-group machine trajectory and the inner-group machine transient energy conversion is established through the I-CR system modeling. Then, the transient characteristics of the inner-group machine are analyzed. It is clarified that the inner-group motions might be inseparable or separable, and the inner-group machine DLP will occur later than the EDLP and IDLP. Simulation results show that the severity of the original system cannot be simply evaluated through its equivalent system once any inner-group motion becomes fierce.