An Adaptive Resonant Regulator for Single-phase Grid-Tied VSCs

Research output: Research - peer-reviewJournal article

Abstract

The proportional-resonant (PR) controller is highly popular for controlling grid-connected voltage source converters. The resonant part of this controller provides an infinite gain at the nominal frequency and, in this way, ensures a zero steady-state tracking error when the grid frequency is at its nominal value. In the presence of frequency drifts, nevertheless, a zero tracking error may not be guaranteed. To deal with this problem, the resonance frequency of the PR controller may be updated using the frequency estimated by the synchronization unit, which is often a PLL. In recent years, however, there is a growing attention towards eliminating the need for a dedicated synchronization unit and designing integrated synchronization and control structures as they benefit from a simpler and more compact structure. In this letter, based on a structural resemblance between a resonant current regulator and second-order generalized integrator-based frequency-locked loop (SOGI-FLL), a frequency-adaptive resonant controller is presented. The tuning procedure of the proposed controller is briefly discussed, and some experimental results are presented to verify its effectiveness.
Close

Details

The proportional-resonant (PR) controller is highly popular for controlling grid-connected voltage source converters. The resonant part of this controller provides an infinite gain at the nominal frequency and, in this way, ensures a zero steady-state tracking error when the grid frequency is at its nominal value. In the presence of frequency drifts, nevertheless, a zero tracking error may not be guaranteed. To deal with this problem, the resonance frequency of the PR controller may be updated using the frequency estimated by the synchronization unit, which is often a PLL. In recent years, however, there is a growing attention towards eliminating the need for a dedicated synchronization unit and designing integrated synchronization and control structures as they benefit from a simpler and more compact structure. In this letter, based on a structural resemblance between a resonant current regulator and second-order generalized integrator-based frequency-locked loop (SOGI-FLL), a frequency-adaptive resonant controller is presented. The tuning procedure of the proposed controller is briefly discussed, and some experimental results are presented to verify its effectiveness.
Original languageEnglish
JournalI E E E Transactions on Power Electronics
Volume33
Issue number3
Pages (from-to)1867 - 1873
Number of pages7
ISSN0885-8993
DOI
StatePublished - Mar 2018
Publication categoryResearch
Peer-reviewedYes

    Research areas

  • Current control, Frequency-locked loop (FLL), Resonant controller, Single-phase systems, Synchronization, Voltage source converter (VSC)
ID: 261461955