Comparison of Positive-Sequence Analysis With EMT Analysis for Integrated Transmission and DER-Rich Distribution Systems

With increased penetration of residential distributed energy resources, the need to analyze the sufficiency of positive-sequence analysis in emulating the electromagnetic transient (EMT) study results is vital for conducting grid planning studies. One of the approaches to evaluate the efficacy of positive-sequence simulations includes EMT analysis-based parameterization of positive-sequence models. Consequently, this work provides a detailed approach to parameterize the positive-sequence models with reference to results from utility benchmarked EMT data. With such benchmarked models incorporated in an integrated transmission-distribution system, fault studies are carried out to understand and examine the capabilities of positive-sequence simulations. The proposed study is carried out on a modified IEEE 9-Bus system developed in DIgSILENT PowerFactory. This paper finds that positive-sequence simulation cannot accurately capture the stalling of single-phase induction motors. Besides, this work recommends that the readers reparametrize the positive-sequence models for cases with fractional tripping of distributed energy resources and different fault characteristics to accurately coincide with the inferences of the EMT results.