Stability and Multiconstraint Operating Region of Grid-Connected Modular Multilevel Converter under Grid Phase Disturbance

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

8 Scopus Citations
View graph of relations

Author(s)

  • Yushuang Liu
  • Meng Huang
  • Herbert Ho-Ching Iu
  • Zhihong Yan
  • Xiaoming Zha

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)12551-12564
Journal / PublicationIEEE Transactions on Power Electronics
Volume36
Issue number11
Online published10 May 2021
Publication statusPublished - Nov 2021

Abstract

Grid-connected converters may operate under grid fault conditions, such as the short/open-circuit and the transmission line switching, which may be accompanied by a phase angle difference between the grid and converter. This variation will affect the normal operation of the converter, since its phase-locked loop is not able to track the grid voltage phase angle immediately. In this paper, an instability phenomenon with unregulated AC line current is identified in a modular multilevel converter (MMC) based high-voltage direct-current transmission system when there is a sudden phase angle change on the grid side. A set of analytical constraints is developed for the MMC in terms of the Lyapunov stability, the modulation index and the maximum power transfer capability. Then, a multiconstraint operating region of the MMC under various phase disturbances is derived. Moreover, the parameter influence of the operating region is analyzed and two stability enhancing methods for the MMC system are proposed. Finally, the boundaries of the operating region and the stability enhancing methods are verified by simulations and laboratory measurements of three-phase grid-connected MMCs.

Research Area(s)

  • Circuit faults, grid phase disturbance, Modular multilevel converter (MMC), operating region, Phase locked loops, Power grids, Power system stability, Power transmission lines, stability analysis, Stability criteria, Transient analysis

Citation Format(s)

Stability and Multiconstraint Operating Region of Grid-Connected Modular Multilevel Converter under Grid Phase Disturbance. / Liu, Yushuang; Huang, Meng; Tse, Chi K. et al.
In: IEEE Transactions on Power Electronics, Vol. 36, No. 11, 11.2021, p. 12551-12564.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review