Hybrid-DC Electric Springs for DC Voltage Regulation and Harmonic Cancellation in DC Microgrids

Ming Hao Wang, Shuo Yan, Siew Chong Tan, Shu Yuen Ron Hui

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)

Abstract

DC electric springs (DCES) are emerging technologies for the (i) regulation of mains voltage against the intermittent renewable generations and (ii) harmonic cancellation in dc microgrids. When conventional converter topologies (e.g., half-bridge or full-bridge converter) are adopted as DCES, the battery storage of the DCES has to process both the dc power and the ac harmonic power. The pulsating ac power can severely reduce the lifetime of the battery. To address this issue, a hybrid-DCES (H-DCES) is proposed in this paper to perform (i) and (ii) in a decoupled manner. With a modified topology and control method, the H-DCES can divert the ac current to the ground and retains the function of manipulating noncritical load for dc voltage regulation. The immediate benefits of this H-DCES are the reduction of storage capacity and a prolonged lifetime of the battery. Both the operating principle and the mathematical model of the proposed H-DCES are analyzed in this paper. A prototype of the H-DCES is practically tested in a 48-V dc grid. The experimental results show that the H-DCES can realize the decoupled operation of dc voltage regulation and harmonic cancellation. Simulation studies further demonstrate that the H-DCES requires less storage capacity than its counterparts.

Original languageEnglish
Article number7875458
Pages (from-to)1167-1177
Number of pages11
JournalIEEE Transactions on Power Electronics
Volume33
Issue number2
DOIs
Publication statusPublished - Feb 2018

Keywords

  • Active power filter (APF)
  • dc grids
  • distributed power systems
  • power decoupling
  • smart load
  • stability

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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