| Title |
Voltage balancing in three-level neutral-point-clamped converters via Luenberger observer |
| Authors |
Umbria, Francisco , Gordillo, Francisco , GÓMEZ-ESTERN AGUILAR, FABIO, Salas, Francisco , Portillo, Ramon , Vazquez, Sergio |
| External publication |
No |
| Means |
Control Eng. Practice |
| Scope |
Article |
| Nature |
Científica |
| JCR Quartile |
2 |
| SJR Quartile |
1 |
| JCR Impact |
1.81400 |
| SJR Impact |
1.20500 |
| Web |
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893821717&doi=10.1016%2fj.conengprac.2013.12.003&partnerID=40&md5=df9f436bdd46f64cc41a6978963354fb |
| Publication date |
01/04/2014 |
| ISI |
000332906400004 |
| Scopus Id |
2-s2.0-84893821717 |
| DOI |
10.1016/j.conengprac.2013.12.003 |
| Abstract |
This paper addresses the problems associated with the dc-link capacitor voltages of the three-level neutral-point-clamped power converter: the imbalance of the capacitor voltages as well as the presence of an ac-voltage low-frequency oscillation in the dc link of the converter. In order to cope with them, a mathematical analysis of the capacitor voltage difference dynamics, based on a direct average continuous model, is carried out, considering a singular perturbation approach. The analysis leads to a final expression where a sinusoidal disturbance appears explicitly. Consequently, the two problems can be handled together using the ordinary formulation of a problem of regulating the output of a system subject to sinusoidal disturbances, applying classical control theory to design the controller. In this way, the controller is designed including the disturbance estimate provided by a Luenberger observer to asymptotically cancel the disturbance, while also keeping the capacitor voltages balanced. Experiments for a synchronous three-level neutral-point-clamped converter prototype are carried out to evaluate the performance and usefulness of the converter working as a grid-connected inverter under the proposed control law. (C) 2013 Elsevier Ltd. All rights reserved. |
| Keywords |
Multilevel power converter; Neutral-point-clamped (NPC) converter; Voltage balancing; Disturbance rejection; Luenberger observer |
| Universidad Loyola members |
|
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