Sliding-Mode Control in Natural Frame With Reduced Number of Sensors for Three-Phase Grid-Tied LCL-Interfaced Inverters


ALTIN N., ÖZDEMİR Ş., Komurcugil H., SEFA İ.

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol.66, no.4, pp.2903-2913, 2019 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 66 Issue: 4
  • Publication Date: 2019
  • Doi Number: 10.1109/tie.2018.2847675
  • Journal Name: IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.2903-2913
  • Keywords: Damping, grid-tied inverter, proportional-resonant (PR) control, sliding-mode control (SMC), VARIABLE-STRUCTURE CONTROL, CONNECTED VSI, CONTROL STRATEGY, DESIGN

Abstract

In this paper, a sliding-mode control (SMC) strategy is proposed for three-phase grid-tied LCL-filtered voltage source inverters in the natural frame. The SMC in the natural frame is based on controlling the sliding surface functions of phase-legs a and b. The sliding surface function of phase-leg c is obtained from the sliding surface functions of phase-legs a and b. This eliminates the need for sensing capacitor voltage and grid current of phase-leg c. The capacitor voltage references are generated by the proportional-resonant (PR) controllers which result in zero steady-state error in the grid current. The feasibility and performance of the proposed SMC strategy is investigated under steady-state, transient, unbalanced, and distorted grid conditions. Experimental results taken from a 9.8 kW system are provided to demonstrate the validity of the proposed SMC strategy.