Stability Issue of Cascaded Systems with Consideration of Switching Ripple Interaction

Xin Li, Xinbo Ruan, Xiaoling Xiong, Qian Jin, Chi K. Tse

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

Impedance-based criteria are often used for assessing the stability of cascaded converter systems. In this paper, it is pointed out that the switching ripple interaction (SRI) between the source converter and the load converter in a cascaded system would change the gain of the pulsewidth modulation of the source converter, causing the cut-off frequency and the phase margin of the source converter to change accordingly. Thus, even if a cascaded system is shown to be stable under an impedance-based criterion, it can, in fact, be unstable due to the SRI. This paper proposes an adaptive modulation sample-and-hold method for eliminating the effect of the SRI. A 48 V-12 V-5 V cascaded system consisting of two buck converters is tested for verification.

Original languageEnglish
Article number8494812
Pages (from-to)7040-7052
Number of pages13
JournalIEEE Transactions on Power Electronics
Volume34
Issue number7
DOIs
Publication statusPublished - Jul 2019

Keywords

  • Adaptive
  • Cascaded system
  • Sample-and-hold, stability issue
  • Switching ripple interaction (SRI)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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