Stability Assessment of a System Comprising a Single Machine and Inverter with Scalable Ratings

Brian Johnson, Yashen Lin, Vahan Gevorgian, Victor Purba, Sairaj Dhople

Research output: Contribution to conferencePaper

27 Scopus Citations


From the inception of power systems, synchronous machines have acted as the foundation of large-scale electrical infrastructures and their physical properties have formed the cornerstone of system operations. However, power electronics interfaces are playing a growing role as they are the primary interface for several types of renewable energy sources and storage technologies. As the role of power electronics in systems continues to grow, it is crucial to investigate the properties of bulk power systems in low inertia settings. In this paper, we assess the properties of coupled machine-inverter systems by studying an elementary system comprised of a synchronous generator, three-phase inverter, and a load. Furthermore, the inverter model is formulated such that its power rating can be scaled continuously across power levels while preserving its closed-loop response. Accordingly, the properties of the machine-inverter system can be assessed for varying ratios of machine-to-inverter power ratings and, hence, differing levels of inertia. After linearizing the model and assessing its eigenvalues, we show that system stability is highly dependent on the interaction between the inverter current controller and machine exciter, thus uncovering a key concern with mixed machine-inverter systems and motivating the need for next-generation grid-stabilizing inverter controls.
Original languageAmerican English
Number of pages8
StatePublished - 2017
EventIEEE North American Power Symposium - Morgantown, West Virginia
Duration: 17 Sep 201719 Sep 2017


ConferenceIEEE North American Power Symposium
CityMorgantown, West Virginia

Bibliographical note

See NREL/CP-5D00-70963 for paper as published in IEEE proceedings

NREL Publication Number

  • NREL/CP-5D00-67974


  • electric grid
  • inverter
  • stability
  • sycnhronous generator


Dive into the research topics of 'Stability Assessment of a System Comprising a Single Machine and Inverter with Scalable Ratings'. Together they form a unique fingerprint.

Cite this