Discrete-Time DC-Link Voltage and Current Control of a Grid-Connected Inverter with LCL-Filter and Very Small DC-Link Capacitance

Oliver Kalmbach, Christian Dirscherl and Christoph M. Hackl
Additional contact information
Oliver Kalmbach: Faculty of Electrical Engineering and Information Technology, Munich University of Applied Sciences, Lothstraße 64, 80335 München, Germany
Christian Dirscherl: Munich School of Engineering, Technical University of Munich, Lichtenbergstraße 4a, 85748 Garching, Germany
Christoph M. Hackl: Faculty of Electrical Engineering and Information Technology, Munich University of Applied Sciences, Lothstraße 64, 80335 München, Germany

Energies, 2020, vol. 13, issue 21, 1-23

Abstract: The paper presents a controller design for grid-connected inverters (GCI) with very small dc-link capacitance that are coupled to the grid via an LCL filter. The usual controller designs would fail and result in instability. The proposed controller has a cascaded structure with a current controller as inner control loop and an outer dc-link voltage controller. The controller design is performed in discrete time and it is based on a detailed stability analysis of the dc-link voltage controller to determine the controller parameters which guarantee stability for all operating points. The inner loop is a state-feedback current controller that is designed based on the discrete linear-quadratic regulator (DLQR) theory. An additional integral error feedback assures steady-state accuracy of the current control loop. The simulation and experimental results validate performance and stability of proposed controller design.

Keywords: current control; dc-link voltage control; discrete controller; discrete linear-quadratic regulator (DLQR); grid connected inverter; LCL-filter; low sampling frequency; PI voltage controller; small dc-link capacitance; stability analysis (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2020
References: View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/13/21/5613/pdf (application/pdf)
https://www.mdpi.com/1996-1073/13/21/5613/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:13:y:2020:i:21:p:5613-:d:435359

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().