Voltage balance for five-level DCC based on mixed-integer linear programming

In power converters, the modulation stage commands the switching devices to drive the converter outputs to the voltage required by the inner controllers in order to achieve their objectives. However, in multilevel converters, the modulation may be in charge of an additional goal since it also has to...

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Detalles Bibliográficos
Autores: Montero-Robina, Pablo, Gordillo Álvarez, Francisco, Gómez-Estern Aguilar, Fabio, Salas Gómez, Francisco
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2021
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/125197
Acceso en línea:https://hdl.handle.net/11441/125197
https://doi.org/10.1016/j.ijepes.2020.106302
Access Level:acceso abierto
Palabra clave:Multilevel converter
Diode-clamped converter
Mixed-Integer linear optimization
Capacitor voltage balance
Five-level converter
Modulation and control of power converters
Descripción
Sumario:In power converters, the modulation stage commands the switching devices to drive the converter outputs to the voltage required by the inner controllers in order to achieve their objectives. However, in multilevel converters, the modulation may be in charge of an additional goal since it also has to tackle with the capacitor voltage balancing issue. This paper formulates the modulation of multilevel three-phase power converters, specifically five-level diode-clamped converters (DCC), as a mixed-integer linear optimization problem. In this paper, it is shown that the presented optimization problem can deal with the capacitor voltage balance at the same time that the number of commutations is minimized. The problem is solved offline and its solution is stored in a lookup table to be used during normal operation. Then, an online procedure to obtain the levels that modulate each phase from the lookup table is given. Comparisons with model predictive control, space-vector-based algorithms and other modulation approaches are presented in simulations. Several experimental results are presented showing the feasibility of this approach with changes in the operating conditions.