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This study presents a new multilevel inverter (MLI) with reduced devices, for low/medium- and high-voltage applications. The proposed MLI is evolved from existing cross-connected source-based multilevel inverter (CCS-MLI), results in reduced switches, driver circuits, diodes, and DC voltage sources when compared with the classical CHB, CCS-MLI, and other MLIs. Owing to reduced device numbers, the complexity, size, cost, and maintenance of the proposed topology are greatly reduced. The detailed analysis and working of the proposed topology is presented along with its comparison with classical, CCS-MLI, and other MLIs. Different algorithms are presented for selecting appropriate magnitudes of DC voltage sources to generate different voltage levels in the output. The proposed MLI is suitable for grid integration of renewable energy sources. The concept is presented through modelling and simulation in MATLAB/Simulation environment and validated through real-time simulator OPAL-RT (OP-4500). [ABSTRACT FROM AUTHOR]

Reduced part count multilevel inverters (RPC-MLIs), an emerging technology for grid interfacing applications of renewable energy sources. RPC-MLIs overcome the limitations of conventional two-level and classical multilevel inverters (NPC, FC and CHB) by the use of reduced part counts for generation of same number of levels in the output. Focus of this paper is on to present review of the RPC-MLIs for researchers and engineers and classification of all the topologies. RPC-MLIs are compared considering its circuit complexity and performance. The comparison exposes advantages and disadvantages of topologies, as well as a wide spectrum for future research. This paper also draws the most potential topology in the field of grid integrated applications. Promising topology is simulated here under the same load and input source condition using real time simulator. [ABSTRACT FROM AUTHOR]

Abstract: Suitable integration of more than one energy sources is an interesting and challenging task that attracts attention of the researchers. Integration of several energy sources profoundly depends on the power electronic converters which interface multiple energy sources having different V–I characteristics. Therefore, suitable integration and better utilization of energy source demands, well designed and efficient interfacing circuitry. In this paper, a non isolated multiple source DC/DC converter (MSC) is proposed. The generation of MSC using pulsating source cells as a building block has been discussed briefly. The proposed converter is proficient for energy diversification from renewable and storage energy sources individually or simultaneously. It has the capability to operate either in buck, boost or buck–boost mode of operation with possibility of bidirectional power flow. It offers simplicity in structure with inherent bypass circuit, flexibility in control scheme and reliability in operation. In addition, a power management control algorithm for proposed converter has also been discussed. The proposed concept has been investigated through detailed device level simulation using MATLAB/Simulink environment. Experimental implementation and validation have been carried out on a low power prototype using digital signal processor (DSP) TMS320F2812. [Copyright &y& Elsevier]

Renewable energy systems have developed wide interest to supply electricity in remote areas as well as for distributed power generation particularly during peak loads. Fuel-cell-based power generation is also gaining popularity in residential applications as well as distributed power generation due to its cleanliness, portability, and suitability for electricity and heat generation. Development of a suitable power electronic interface to make the technology viable is still a challenge. This paper presents modeling, simulation, and experimental study of a fuel cell (FC) power plant (FCPP) suitable for stand-alone application as well as for microgrid/grid interface. A single-stage pulsewidth modulation inverter is selected as power electronic interface between FC and grid. A mathematical model is developed in per unit system to define the power limits in terms of FC, converter, and power system parameters. The simulation model is developed in MATLAB environment with control scheme implementation in \ssi qd reference frame for investigation. A prototype of single-stage FCPP is developed in the laboratory to validate the results. [ABSTRACT FROM AUTHOR]

This paper presents a new topological structure for symmetrical cascaded multilevel inverters. The proposed circuit consists of cross-connected separate symmetrical DC sources which can generate number of levels equal to that of a cascaded H-bridge topology with reduced number of power switches. It is especially suitable for utility interfacing of renewable energy sources. It also offers the possibility of a transformer less and filter less operation. The working principle of the proposed topology is explained with the help of a single-phase five level inverter. Simulation results are obtained in matlab/simulink environment and are verified experimentally on a laboratory prototype. An exhaustive comparison of the proposed topology is made with the classical cascaded H-bridge topology, especially with the considerations of conduction losses and cost-effectiveness. The proposed topology results in the reduction of number of power switches, losses, installation area, and converter cost and thus can be implemented as an effective and efficient power electronic interface for renewable sources of energy with the utility grid. [ABSTRACT FROM AUTHOR]

Abstract: The issue of renewable energy is becoming significant due to increasing power demand, instability of the rising oil prices and environmental problems. Among the various renewable energy sources, fuel cell is gaining more popularity due to their higher efficiency, cleanliness and cost-effective supply of power demanded by the consumers. This paper presents a comprehensive review of different fuel cell technologies with their working principle, advantages, disadvantages and suitability of applications for residential/grid-connected system, transportation, industries and commercial applications. Development of mathematical model of fuel cell required for simulation study is discussed. This paper also focuses on the necessity of a suitable power-conditioning unit required to interface the fuel cell system with standalone/grid applications. [Copyright &y& Elsevier]