An Asymmetrical Step-Up Multilevel Inverter Based on Switched-Capacitor Network

This paper presents a transformerless step-upmultilevel inverter based on a switched-capacitor structure. One of the main contributions of the proposed topology is replacing the separated DC voltage sourcewith capacitorswhich are charged at predetermined time intervals. Therefore, a high-level stair...

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Detalles Bibliográficos
Autores: Taghvaie, Amir, Alijani, Ahmad, Adabi, M. Ebrahim, Rezanejad, Mohammad, Adabi, Jafar, Rouzbehi, Kumars, Pouresmaeil, Edris
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/89700
Acceso en línea:https://hdl.handle.net/11441/89700
https://doi.org/10.3390/su11123453
Access Level:acceso abierto
Palabra clave:Multilevel inverters
Self-balanced
Single source
Transformerless
Descripción
Sumario:This paper presents a transformerless step-upmultilevel inverter based on a switched-capacitor structure. One of the main contributions of the proposed topology is replacing the separated DC voltage sourcewith capacitorswhich are charged at predetermined time intervals. Therefore, a high-level staircase voltage waveform can be achieved by discharging some of these capacitors on the load. The other contribution of the proposed structure is to eliminate themagnetic elements which traditionally boost the input DC voltage. In addition, asymmetrical or unequal amounts of capacitor voltages create more voltage levels, which enable voltage level increments without increasing the number of semiconductor devices. This paper introduces a self-balanced boost Switched-CapacitorsMultilevel Inverter (SCMLI) which is able to create a nearly sinusoidal voltage waveform with a maximum voltage of up to 45 times that of the input voltage DC source. Higher level output voltage levels are also achievable by extending the circuit topology. After determination of the switching angles and selecting the proper switching states for each level, an offline NLC method is used for modulation, which eases the control implementation. Analysis, simulation and experiments are carried out for a 91-level inverter (45 levels for positive and negative voltages and one for zero voltage) are presented.