Disturbance-Observer-Based DC-Bus Voltage Control for Ripple Mitigation and Improved Dynamic Response in Two-Stage Single-Phase Inverter System

Majid Ali, Muhammad Yaqoob, Lingling Cao, Ka Hong Loo

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)

Abstract

Two-stage single-phase inverter system has found many applications in distributed generators and grid-connected systems. However, the existence of double-line frequency ripple on the dc-bus voltage due to single-phase inverter's operation has given rise to some design and reliability issues. Some of these are the degradation in the quality of inverter's output voltage and shortening of dc-bus capacitor's lifetime. The problem is rooted in the controller design of the front-end dc-dc converter, which is often designed based on a simplified mathematical model of the dc-dc converter that fails to account for some complex phenomena, such as system's nonlinearities and circuit parameter variations due to temperature and aging effects. In this paper, a disturbance-observer-based control is proposed where these unmodeled effects are treated in the form of lumped disturbance and compensated for in a feed-forward manner. The major advantage of this control solution is that only minimal plant information is needed for controller design and that a decoupled composite controller can be realized, where the feedback compensator is designed to meet certain stability criteria while the disturbance-observer-based feed-forward compensator is designed to handle fast transient events. A prototype of a dual-active-bridge (DAB) dc-dc converter implemented with disturbance-observer-based control is constructed to verify its effectiveness. Experimental results show that the dynamic response of the DAB converter is significantly improved and the double-line frequency ripple on the dc-bus voltage is effectively suppressed by the proposed control solution.

Original languageEnglish
Article number8532112
Pages (from-to)6836-6845
Number of pages10
JournalIEEE Transactions on Industrial Electronics
Volume66
Issue number9
DOIs
Publication statusPublished - Sep 2019

Keywords

  • Active disturbance rejection control
  • digital control inverter
  • disturbance observer
  • dual active bridge (DAB)
  • proportional-integral control

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Cite this