scholarly journals Generalized Cascaded Symmetric and Level Doubling Multilevel Converter Topology with Reduced THD for Photovoltaic Applications

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 161 ◽  
Author(s):  
Karthikeyan D ◽  
Vijayakumar K ◽  
Jagabar M
Keyword(s):  
Low Voltage ◽  
Harmonic Distortion ◽  
Prototype Model ◽  
Switched Capacitor ◽  
Multilevel Converter ◽  
Dc Offset ◽  
Modulation Technique ◽  
Photovoltaic Applications ◽  
Converter Topologies ◽  
Converter Topology

In this paper, two different converter topologies for a basic new switched capacitor diode converter with a reduced number of power electronics components, suitable for grid connected photovoltaic applications were proposed. The two different structures of switched diode multilevel converter proposed were: (i) cascaded switched diode and (ii) cascaded switched diode with doubling circuit. The switched-diode multilevel converter was compared with other recent converters. In addition, a new dc offset nearest level modulation technique was proposed. This proposed dc offset technique offers low voltage total harmonic distortion (THD) and high RMS output voltage. The proposed modulation technique was compared with conventional nearest level modulation (NLM) and modified NLM control techniques. The performance of the proposed dc offset modulation technique was implemented using a FPGA Spartan 3E controller and tested with a novel switched capacitor-diode multilevel converter. However, to prove the authenticity of the switched-diode multilevel converter and modulation technique, a laboratory-based prototype model for 7-level and 13-level converters was developed.

scholarly journals Modular Multilevel Converter for Low-Voltage Ride-Through Support in AC Networks

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5314
Author(s):  
Victor Ramon França Bezerra de Souza ◽  
Luciano Sales Barros ◽  
Flavio Bezerra Costa
Keyword(s):  
Low Voltage ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Control Loops ◽  
Low Voltage Ride Through ◽  
Ac Networks ◽  
Converter Topologies ◽  
Converter Topology

New grid-connected systems have imposed additional requirements regarding reliability, power quality, high levels of power processing capacity, and fault support, where power converters have a crucial role in fulfilling these requirements. Overcoming one of these challenges, this paper proposes a new alternative application to improve the low-voltage ride-through (LVRT) support based on the arm impedance employment of the modular multilevel converter (MMC) by attenuating the fault impacts, avoiding overcurrents and overvoltages. This proposal does not require additional hardware or control loops for LVRT support, only using PI controllers. This paper evaluates symmetrical and asymmetrical grid fault impacts on the converter DC side of four converter topologies: two-level voltage source converter topology (2L-VSC), neutral point clamped (NPC), MMC, and 2L-VSC equipped with a DC-chopper, employing the same control structure for the four topologies, highlighting that the MMC contributed better to LVRT improvement under severe grid conditions.

scholarly journals Series Active Filter Design Based on Asymmetric Hybrid Modular Multilevel Converter for Traction System

Electronics ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 134 ◽  
Author(s):  
Muhammad Ali ◽  
Muhammad Khan ◽  
Jianming Xu ◽  
Muhammad Faiz ◽  
Yaqoob Ali ◽  
...  
Keyword(s):  
Low Voltage ◽  
Filter Design ◽  
Switching Frequency ◽  
Modular Multilevel Converter ◽  
Multilevel Converter ◽  
Medium Voltage ◽  
Converter Topologies ◽  
Asymmetric Hybrid ◽  
Simulation Results ◽  
Traction System

This paper presents a comparative analysis of a new topology based on an asymmetric hybrid modular multilevel converter (AHMMC) with recently proposed multilevel converter topologies. The analysis is based on various parameters for medium voltage-high power electric traction system. Among recently proposed topologies, few converters have been analysed through simulation results. In addition, the study investigates AHMMC converter which is a cascade arrangement of H-bridge with five-level cascaded converter module (FCCM) in more detail. The key features of the proposed AHMMC includes: reduced switch losses by minimizing the switching frequency as well as the components count, and improved power factor with minimum harmonic distortion. Extensive simulation results and low voltage laboratory prototype validates the working principle of the proposed converter topology. Furthermore, the paper concludes with the comparison factors evaluation of the discussed converter topologies for medium voltage traction applications.

scholarly journals Performance Comparison of 2L-VSC, 3L-NPC, and 3L-MMC Converter Topologies for Interfacing Grid-Connected Systems

2021 ◽  
Author(s):  
Victor R. F. B. de Souza ◽  
Luciano S. Barros ◽  
Flavio B. Costa
Keyword(s):  
Reactive Power ◽  
Harmonic Distortion ◽  
Performance Comparison ◽  
Test Results ◽  
Multilevel Converter ◽  
Simulation Test ◽  
Comparative Performance ◽  
Higher Power ◽  
Converter Topologies ◽  
Level Converter

Nowadays, power converters play a fundamental role in the conditioning and processing of active and reactive power, and are directly related to power quality indexes. In this sense, new multi-level converter topologies have been integrated in order to provide higher power processing capacity with lower harmonic distortion, switch stress, heating, and losses. The use of these structures compared to conventional two-level converters is especially suitable for high power of the order of megawatt. Considering the relevance of this approach, this paper presents a comparative performance analysis among the conventional two-level topology (2L-VSC) and two multilevel topologies in a grid-connected system: neutral point clamped (NPC) and modular multilevel converter (MMC). Simulation test results present the impacts on voltages and currents for the switches and the whole system, as well as the evaluation of the total harmonic distortion (THD) in order to highlight the crucial points of each topology for this kind of application.

An Improved Symmetric H-Bridge Multilevel Converter Topology; An Attempt to Reduce Power Losses

2018 ◽  
Vol 27 (12) ◽  
pp. 1850187 ◽  
Author(s):  
Rasoul Shalchi Alishah ◽  
Seyed Hossein Hosseini ◽  
Ebrahim Babaei ◽  
Mehran Sabahi ◽  
Jaber Fallah Ardashir
Keyword(s):  
Harmonic Distortion ◽  
Power Losses ◽  
Multilevel Converter ◽  
Switching Losses ◽  
Current Path ◽  
Comparison Results ◽  
Converter Topology ◽  
Gate Driver ◽  
Level Converter ◽  
Symmetric Structures

In this paper, a new structure for multilevel converter based on improved H-bridge converter is presented. The proposed topology is a symmetric topology since the values of all voltage sources are equal. The proposed symmetric structure is a general topology which can be extended for any number of voltage levels at output voltage waveform to obtain the least value of total harmonic distortion (THD). Reduction of switching losses, conduction losses, the number of on-state switches in the current path, utilized DC voltage sources, and gate driver circuits are the main advantages of proposed symmetric structures in comparison with other symmetric topologies. All mathematical analysis on the proposed structure is presented in terms of power losses and maximum blocked voltage by switches. The comparison results with other recently presented symmetric topologies and traditional multilevel converter structures are provided. Experimental results for a thirteen-level converter based on presented structure are provided to validate the practicality of the suggested multilevel structure.

scholarly journals A Survey on Bidirectional DC/DC Power Converter Topologies for the Future Hybrid and All Electric Aircrafts

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4883
Author(s):  
Álvaro Ojeda-Rodríguez ◽  
Pablo González-Vizuete ◽  
Joaquín Bernal-Méndez ◽  
María A. Martín-Prats
Keyword(s):  
Power Density ◽  
Power Distribution ◽  
Distribution Systems ◽  
High Efficiency ◽  
Low Voltage ◽  
Power Level ◽  
Power Converter ◽  
Dc Power ◽  
Converter Topologies ◽  
Converter Topology

DC-DC isolated converters allowing a bidirectional flow of energy between High-Voltage DC and Low-Voltage DC networks have been proposed to be integrated in future on board power distribution systems. These converters must meet the specially stringent efficiency and power density requirements that are typical of the aeronautic industry. This makes it specially challenging to determine which converter topology is best suited for each particular application. This work presents a thorough review of several topologies of bidirectional DC-DC power converters that are considered good candidates to meet certain important aeronautic requirements, as those related with high efficiency and high power density. We perform simulations on virtual prototypes, constructed by using detailed component models, and optimized following design criteria that are in accordance with those typically imposed by aeronautic requirements. This comparative analysis is aimed to clearly identify the advantages and drawbacks of each topology, and to relate them with the required voltage and power levels. As an outcome, we point out the topologies that, for the required power level at the chosen switching frequencies, yield higher efficiency in the whole range of required operation points and that are expected to allow more important weight reductions.

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