Comparison of Advanced Control Techniques for Grid Side Converter of Doubly-Fed Induction Generator Back-to-Back Converters to Improve Power Quality Performance during Unbalanced Voltage Dips

Abstract

A doubly-fed induction generator grid side converter is studied under voltage disturbances. During voltage dips, conventional current control techniques involving the decoupling of d-q axis in the synchronous reference frame (SRF) exhibits oscillations in the stiff dc link voltage, as well as in the active and reactive power outputs of the voltage source converter (VSC). To mitigate the oscillations, an advanced control technique called the sequence domain control (SDC) is evaluated. This approach implements individual controllers in the positive and negative sequence domains and demonstrates stabilization of the dc link voltage to a greater extent during a disturbance, but is more sluggish than the conventional control. An innovative control technique called direct power control (DPC) is also investigated. This control achieves active and reactive power stability with simple active and reactive power control variables replacing the traditional current control loops. The DPC technique is verified using a prototype in the laboratory. A modified DPC algorithm combining the benefits of DPC and SDC to eliminate the current harmonics created by DPC during system disturbances is introduced. The benefits of the proposed controllers are compared using a simulation of voltage dip on a VSC based on the IEC-61400-21 standard.

Department(s)

Electrical and Computer Engineering

Sponsor(s)

National Science Foundation (U.S.)
Missouri University of Science and Technology. Department of Electrical and Computer Engineering

Comments

This work was supported in part by the U.S. National Science Foundation under Grant ECS-0523897 and in part by the Department of Electrical and Computer Engineering, Missouri University of Science and Technology, Rolla, MO, USA.

Keywords and Phrases

Asynchronous Generators; Controllers; Counting Circuits; Electric Current Control; Electric Fault Currents; Electric Load Dispatching; Electric Power System Control; Power Control; Power Converters; Quality Control; Reactive Power; Direct Power Control (DPC); Domain Controls; Doubly Fed Induction Generators; Pulsewidth Modulation Converters; Voltage Dip; Voltage-Source Converter; Electric Machine Control; Back-To-Back Pulsewidth Modulation (PWM) Converters; Current Control; Doubly-Fed Induction Generator (DFIG); Sequence Domain Control (SDC); Voltage Source Converters (VSCs)

International Standard Serial Number (ISSN)

2168-6777; 2168-6785

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2015 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jun 2015

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