Closed-Loop Control of DC-DC Dual-Active-Bridge Converters Driving Single-Phase Inverters

Abstract

A solid-state transformer (SST) is a high-frequency power electronic converter that is used as a distribution power transformer. A common three-stage configuration of an SST consists of ac-dc rectifier, isolated dc-dc dual-active-bridge (DAB) converter, and dc-ac inverter. This study addresses the controller design issue for a dc-dc DAB converter when driving a regulated single-phase dc-ac inverter. Since the switching frequency of the inverter stage is much higher than that of the DAB stage, the single-phase inverter is modeled as a double-line-frequency (e.g., 120 Hz) current sink. The effect of 120-Hz current by the single-phase inverter is studied. The limitation of a PI-controller, low gain at 120 Hz, is investigated. Two methods are proposed to improve the regulation of the output voltage of DAB converters. The first one uses a bandstop filter and feedforward, while the second method uses an additional proportional-resonant controller in the feedback loop. Theoretical analysis, simulation, and experiment results are provided.

Department(s)

Electrical and Computer Engineering

Keywords and Phrases

Closed-Loop Control; Controller Designs; DC-DC Power Converter; High-Frequency Power; Power Smoothing; Pulse Width Modulation Converters; Single-Phase Inverters; Solid State Transformers (SST); Electric Rectifiers; Power Transformers; DC-DC Converters; DC-DC Power Converters; Inverters; Harmonic Analysis; Feedforward Neural Networks; Switching Frequency; Voltage Control; Frequency Conversion; Capacitance; Solid-State Rectifiers; AC-DC Power Convertors; Band-Stop Filters; Closed Loop Systems; DC-AC Power Convertors; DC-DC Power Convertors; Invertors; PI Control

International Standard Serial Number (ISSN)

0885-8993; 1941-0107

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2014 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Feb 2014

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