Model-predictive direct power control of doubly-fed induction generators under unbalanced grid voltage conditions in wind energy applications

Jiefeng Hu, Jianguo Zhu, David G. Dorrell

Research output: Journal article publicationJournal articleAcademic researchpeer-review

60 Citations (Scopus)

Abstract

Unbalanced grid voltage conditions in wind farms degrade the performance of the wind turbines and inject severely distorted current into the power system. This study proposes a new model-predictive direct power control strategy for a doubly-fed induction generator (DFIG) under unbalanced grid voltage conditions. An optimised cost function is derived in order to select an appropriate voltage vector. This directly regulates the instantaneous active and reactive powers in the stationary stator reference frame without the requirement for coordinate transformation, proportional-integral regulators, switching table or pulse-width modulation modulators. After that, the behaviour of the DFIGs under unbalanced grid voltage is investigated. A power compensation scheme is developed, which does not require the extraction of the negative stator current sequence. This can achieve several different control objectives; that is, obtaining sinusoidal and symmetrical stator currents, and the cancellation of electromagnetic torque oscillations. The effectiveness of the proposed control strategy is validated experimentally on a 20 kW laboratory DFIG prototype.
Original languageEnglish
Pages (from-to)687-695
Number of pages9
JournalIET Renewable Power Generation
Volume8
Issue number6
DOIs
Publication statusPublished - 1 Jan 2014
Externally publishedYes

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment

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