Cascaded multilevel inverter with regeneration capability and reduced number of switches

Abstract—multilevel converters are a very interesting alternative for medium and high power drives. One of the more flexible topologies of this type is the cascaded multicell converter. This paper proposes the use of a single-phase reduced cell suitable for cascaded multilevel converters. This cell uses a reduced singlephase active rectifier at the input and an H-bridge inverter at the output side. This topology presents a very good performance, effectively controlling the waveform of the input current and of the output voltage and allowing operation in the motoring and regenerative mode. The results presented in this paper confirm that this medium voltage inverter effectively eliminates low frequency input current harmonics at the primary side of the transformer and operates without problems in regenerative mod

Multilevel Converters: An Enabling Technology for High-Power Applications

| Multilevel converters are considered today as the state-of-the-art power-conversion systems for high-power and power-quality demanding applications. This paper presents a tutorial on this technology, covering the operating principle and the different power circuit topologies, modulation methods, technical issues and industry applications. Special attention is given to established technology already found in industry with more in-depth and self-contained information, while recent advances and state-of-the-art contributions are addressed with useful references. This paper serves as an introduction to the subject for the not-familiarized reader, as well as an update or reference for academics and practicing engineers working in the field of industrial and power electronics.Ministerio de Ciencia y Tecnología DPI2001-3089Ministerio de Eduación y Ciencia d TEC2006-0386

Hybrid Modulation Scheme for Cascaded H-Bridge Inverter Cells

This work proposes a switching technique for cascaded H-Bridge (CHB) cells. Single carrier Sinusoidal PWM (SCSPWM) scheme is employed in the generation of the gating signals. A sequential switching and base PWM circulation schemes are presented for this fundamental cascaded multilevel inverter topology. With these proposed concepts, it is now possible to generate equal average switching signal patterns in all the constituting power semiconductor switches. This results in equal switching loss dissipation and equal power sharing in CHB multilevel inverter modules; and therefore technically modularizes the cascaded system. A 4-cell cascaded structure has been used to exemplify the proposed switching technique. Outlines with switching functions are given for the proposed modulation strategy. For a modulation index of 0.9, a THD value of 14.62% has been achieved in the output voltage waveform of the exemplanary 4-cell cascaded configuration. Verification of the performance of the proposed control technique is done through simulations and experiments.http://dx.doi.org/10.4314/njt.v34i1.2

Z Source Inverter Topologies-A Survey

Need for alternative energy sources to satisfy the rising demand in energy consumption elicited the research in the area of power converters/inverters. An increasing interest of using Z source inverter/converter in power generation involving renewable energy sources like wind and solar energy for both off grid and grid tied schemes were originated from 2003. This paper surveys the literature of Z source inverters/converter topologies that were developed over the years

MATLAB/SIMLINK Model for Three Phase Hybrid Multilevel Inverter Based on Half Bridge Modules

Nowadays the multilevel inverters are widely used in power electronic applications. The multilevel inverters are recommended for medium and high voltage applications. Multilevel inverters have become more popular due to reduced switching losses, low costs, low harmonic distortion and high voltage capability when compared to traditional PWM inverters. This paper deals with hybrid multilevel converter which is synthesize of neutral point clamped and cascaded multilevel inverter. The hybrid multilevel converter is proposed for medium voltage large power ratings. The proposed converter consisting of voltage source inverter connected with half bridge modules at each phase. With the proposed connection large portion of energy can be preceded by the VSI by connecting single multi pulse rectifier. The smaller power shares processed within the half bridge modules. The modulation scheme for hybrid multilevel inverter is naturally achieved by using logic circuit. The modulation scheme for four-level version is analyzed in detail for higher modulation (HM), three level version is analyzed for lower modulation (LM). This modulation scheme allows unidirectional power flow in all DC sources. For unidirectional application, the diode bridges are employed at rectification input side. The modulation schemes of sinusoidal pulse width modulation (SPWM), space vector PWM (SVPWM) are analyzed by using MATLAB/SIMLINK. The comparison of THD’s for SPWM and SVPWM modulation techniques done by using MATLAB/SIMLINK. Keywords:Hybrid Converters, Multilevel Converters, PWM Modulation, Three Phase Inverters

A Modified High Voltage Gain Quasi-Impedance Source Coupled Inductor Multilevel Inverter for Photovoltaic Application

publishedVersio