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This paper presents a new reconfiguration module for asymmetrical multilevel inverters in which the capacitors are used as the dc links to create the levels for staircase waveforms. This configuration of the multilevel converter makes a reduction in dc sources. On the other hand, it is possible to generate 13 levels with lower dc sources. The proposed module of the multilevel inverter generates 13 levels with two unequal dc sources (2VDC and 1VDC). It also involves two chargeable capacitors and 14 semiconductor switches. The capacitors are self-charging without any extra circuit. The lower number of components makes it desirable to be used in wide range of applications. The module is schematized as two back-to-back T-type inverters and some other switches around it. Also, it can be connected as a cascade modular which leads to a modular topology with more voltage levels at higher voltages. The proposed module makes the inherent creation of the negative voltage levels without any additional circuit (such as H-bridge circuit). Nearest level control switching modulation scheme is applied to achieve high-quality sinusoidal output voltage. Simulations are executed in MATLAB/Simulink and a prototype is implemented in the power electronics laboratory in which the simulation and experimental results show a good performance. [ABSTRACT FROM AUTHOR]

Multiterminal converters eliminate using several single-input-single-output converters and simplify their topologies and reduce their cost. In this paper, a new family of multi-input converters based on three switches leg is introduced. Inputs of the proposed converters are similar and they are topologically interchangeable and have boost or buck operation modes. The proposed converter has one output that operates as an inverter. Here, all operating modes of the proposed converters and their effects on each other are investigated, in details. Also, an appropriate switching technique for the converters is given. A detailed comparison between conventional and proposed two-input converters is also presented. A two-input, one-output prototype converter has been implemented to validate the given analyses and to verify the proposed converter's performance. The experimental results are in good agreement with the theoretical and simulated analyses. [ABSTRACT FROM AUTHOR]

In this paper, a novel cascaded seven-level inverter topology with a single input source integrating switched-capacitor techniques is presented. Compared with the traditional cascade multilevel inverter, the proposed topology replaces all the separate dc sources with capacitors, leaving only one H-bridge cell with a real dc voltage source and only adds two charging switches. The capacitor charging circuit contains only power switches, so that the capacitor charging time is independent of the load. The capacitor voltage can be controlled at a desired level without complex voltage control algorithm and only use the most common carrier phase-shifted sinusoidal pulse width modulation strategy. The operation principle and the charging–discharging characteristic analysis are discussed in detail. A 1-kW experimental prototype is built and tested to verify the feasibility and effectiveness of the proposed topology. [ABSTRACT FROM AUTHOR]

In this paper, a number of alternate-cascaded switched-inductor and tapped-inductor networks have been proposed for Z-source inverters. The resulting topologies have enhanced voltage-boost capability while retaining the usual voltage-buck flexibility of a conventional voltage-source inverter. The enhanced capability is achieved by using lower rated components that can more readily be found. These components are assembled without direct series connection and hence avoid unbalanced voltage sharing problems and losses linked to balancing resistive circuits. The component count is, however, high, meaning that the proposed inverters should only be considered when a design requires multiple lower rated components rather than a few higher rated ones. Analysis, simulation, and experimental results have already validated the concepts discussed. [ABSTRACT FROM PUBLISHER]

Power converters consisting of naturally commutated thyristors such as cycloconverters and current source inverters were the first to be used in driving electrical motors with variable speed, but now, due to their inferior performance compared to forced commutated converters, their use is restricted in the high voltage/high power range where the performance and cost of forced commutated switching devices are not yet competitive. Hybrid cycloconverters proposed recently are capable of improving the performance of cycloconverters by adding an auxiliary forced commutated inverter with reduced installed power. It will be shown that the new topology is not only able to improve the quality of the output voltage but is also able to enhance the control over the circulating current and, therefore, for some of the cycloconverter arrangements, to improve the input power quality. This paper evaluates the performance of a few standard and hybrid cycloconverter arrangements using both simulation and experimental results. [ABSTRACT FROM AUTHOR]