A Coordinate Control Strategy for Circulating Current Suppression in Multiparalleled Three-Phase Inverters

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Abstract

This paper addresses the zero-sequence circulating current control in the multiparalleled three-phase voltage-source inverters. The model of the zero-sequence circulating current in the N-paralleled (N ≥ 3) inverters is derived. It is shown that the circulating current is not only susceptible to the mismatches of circuit parameters, but it is also influenced by the interactions of circulating current controllers used by other paralleled inverters. To eliminate these adverse effects on the circulating current control loop, a coordinate control strategy for the N-paralleled inverter is proposed based on the zero-vector feedforward method with the space-vector pulse width modulation. Moreover, a virtual inverter method is introduced to facilitate the implementation of the proposed controller, which decouples the interactions of circulating current controllers in the paralleled inverters. Finally, experimental results obtained from three-paralleled, grid-connected inverters validate the effectiveness of theoretical analysis and proposed approach. An effective mitigation of the circulating current is demonstrated for the paralleled inverters under the unequal operating conditions.
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This paper addresses the zero-sequence circulating current control in the multiparalleled three-phase voltage-source inverters. The model of the zero-sequence circulating current in the N-paralleled (N ≥ 3) inverters is derived. It is shown that the circulating current is not only susceptible to the mismatches of circuit parameters, but it is also influenced by the interactions of circulating current controllers used by other paralleled inverters. To eliminate these adverse effects on the circulating current control loop, a coordinate control strategy for the N-paralleled inverter is proposed based on the zero-vector feedforward method with the space-vector pulse width modulation. Moreover, a virtual inverter method is introduced to facilitate the implementation of the proposed controller, which decouples the interactions of circulating current controllers in the paralleled inverters. Finally, experimental results obtained from three-paralleled, grid-connected inverters validate the effectiveness of theoretical analysis and proposed approach. An effective mitigation of the circulating current is demonstrated for the paralleled inverters under the unequal operating conditions.
Original languageEnglish
JournalI E E E Transactions on Industrial Electronics
Volume64
Issue number1
Pages (from-to)838-847
Number of pages10
ISSN0278-0046
DOI
StatePublished - Jan 2017
Publication categoryResearch
Peer-reviewedYes

    Research areas

  • Zero-vector feedforward, Circulating current, Coordinated control strategy, Paralleled operation, Three-phase voltage-source inverters (VSCs)
ID: 255323846