Effects of interaction of power converters coupled via power grid: A design-oriented study

Cheng Wan, Meng Huang, Chi Kong Tse, Xinbo Ruan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

48 Citations (Scopus)

Abstract

Voltage-source converters are commonly employed as rectifiers for providing a regulated dc voltage from an ac power source. In a typical microdistribution system, the power grid is nonideal and often presents itself as a voltage source with significant impedance. Thus, power converters connected to the grid interact with each other via the nonideal grid. In this paper, we study how stability can be compromised in a system of interacting grid-connected converters, which are used typically as rectifiers. Specifically, the stable operating regions in the selected parameter space may shrink when grid-connected converters interact under certain conditions. We consider the effect of both source (grid) impedance and transmission line impedance between converters, and derive bifurcation boundaries in the parameter space. A small-signal model in the dq-frame is adopted to analyze the interacting system using an impedance-based approach. It is shown that the system of interacting converters can become unstable. Moreover, results are presented in design-oriented forms so as to facilitate the identification of variation trends of stable operation boundaries. Experimental results verify the instability phenomenon.
Original languageEnglish
Article number6881708
Pages (from-to)3589-3600
Number of pages12
JournalIEEE Transactions on Power Electronics
Volume30
Issue number7
DOIs
Publication statusPublished - 1 Jul 2015

Keywords

  • Grid-connected converters
  • interacting systems
  • power converters
  • stability analysis

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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