Control strategy for grid connected inverters under unbalanced network conditions - A DOb based decoupled current approach

Özsoy, Emre and Padmanaban, Sanjeevikumar and Mihet-Popa, Lucian and Fedák, Viliam and Ahmad, Fiaz and Rasool, Akhtar and Şabanoviç, Asif (2017) Control strategy for grid connected inverters under unbalanced network conditions - A DOb based decoupled current approach. (Preprint)

Warning
There is a more recent version of this item available.
[thumbnail of This is an open access article distributed under the Creative Commons Attribution License] PDF (This is an open access article distributed under the Creative Commons Attribution License)
2017_RA446_preprints201706.0088.v1.pdf

Download (476kB)

Abstract

Penetration of grid connected inverters (GCI) has arisen in power systems due to increasing integration of renewable sources. However, restrictive grid codes require that renewable sources connected to the grid with power electronic systems must be properly connected and appropriate currents must be injected to support stability of the grid under grid faults. Simultaneous injection of symmetrical positive and negative sequence currents is mandatory to support stabilization of grid at the instant of grid faults. Conventional synchronously rotating frame dq current controllers are insufficient under grid faults due to low bandwidth of PI controllers. This paper proposes a new grid current control strategy for grid connected voltage source inverters under unbalanced grid voltage conditions. A proportional current controller with a first order low pass filter disturbance observer (DOb) is proposed which establishes positive sequence power requirements and independently control negative sequence current components under unbalanced voltage conditions. The method does not need any parameter, since it estimates nonlinear terms with low pass filter DOb. Simulations are implemented in Matlab/Simulink platform demonstrating the effectiveness of proposed method.
Item Type: Article
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK1-4661 Electrical engineering. Electronics Nuclear engineering
Divisions: Faculty of Engineering and Natural Sciences > Academic programs > Mechatronics
Faculty of Engineering and Natural Sciences
Depositing User: Asif Şabanoviç
Date Deposited: 19 Aug 2017 22:13
Last Modified: 22 May 2019 13:52
URI: https://research.sabanciuniv.edu/id/eprint/32559

Available Versions of this Item

Actions (login required)

View Item
View Item