Structural archetypes for coherency: A framework for comparing power system equivalents

✍ Scribed by John F. Dorsey; Robert A. Schlueter

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 412 KB
• Volume: 20
• Category: Article
• ISSN: 0005-1098
• DOI: 10.1016/0005-1098(84)90049-9

✦ Synopsis

The power system model is divided into a study system (SS) and an external group (EG). Three structural archetypes for coherency (SAC) are defined. Each SAC is a set of structural conditions on the power system which when satisfied cause the EG to remain coherent for disturbances confined to the SS. The validity of each SAC for both nonlinear and linear models of the power system is determined. The SAC provide a framework for comparing the three principal methods of determining reduced-order dynamic equivalents of power systems: coherency analysis, modal analysis and the singular perturbation decomposition (SPD) based on the separation of high and low frequency modes. It is shown that satisfaction of any of the three SAC causes the coherency and modal equivalents to be identical. Satisfaction of one particular SAC, termed strict synchronizing coherency, causes the coherency, modal and SPD equivalents to all be identical. The concept of a hierarchy of equivalents, based on the SAC is introduced and briefly discussed.