scholarly journals High-Performance 3-Phase 5-Level E-Type Multilevel–Multicell Converters for Microgrids

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 843
Author(s):  
Marco di Benedetto ◽  
Alessandro Lidozzi ◽  
Luca Solero ◽  
Fabio Crescimbini ◽  
Petar J. Grbović
Keyword(s):  
Power Density ◽  
High Performance ◽  
High Efficiency ◽  
Specific Power ◽  
Power Semiconductors ◽  
Analysis And Design ◽  
Control Interface ◽  
Output Filter ◽  
And Control

This paper focuses on the analysis and design of two multilevel–multicell converters (MMCs), named 3-phase 5-Level E-Type Multilevel–Multicell Rectifier (3Φ5L E-Type MMR) and 3-phase 5-Level E-Type Multilevel–Multicell Inverter (3Φ5L E-Type MMI) to be used in microgrid applications. The proposed 3-phase E-Type multilevel rectifier and inverter have each phase being accomplished by the combination of two I-Type topologies connected to the T-Type topology. The two cells of each phase of the rectifier and inverter are connected in interleaving using an intercell transformer (ICT) in order to reduce the volume of the output filter. Such an E-Type topology arrangement is expected to allow both the high efficiency and power density required for microgrid applications, as well as being capable of providing good performance in terms of quality of the voltage and current waveforms. The proposed hardware design and control interface are supported by the simulation results performed in Matlab/Simulink. The analysis has been then validated in terms of an experimental campaign performed on the converter prototype, which presented a power density of 8.4 kW/dm3 and a specific power of 3.24 kW/kg. The experimental results showed that the proposed converter can achieve a peak efficiency of 99% using only silicon power semiconductors.

scholarly journals Hard Switching Characteristics of SiC and GaN Devices for Future Electric Vehicle Charging Stations

2021 ◽  
Vol 335 ◽  
pp. 02007
Author(s):  
Gowthamraj Rajendran ◽  
Chockalingam Aravind Vaithilingam ◽  
Kanendra Naidu ◽  
Kameswara Satya Prakash ◽  
Md Rishad Ahmed
Keyword(s):  
Electric Vehicle ◽  
Power Density ◽  
High Performance ◽  
High Efficiency ◽  
Power Sources ◽  
Electric Vehicle Charging ◽  
Vienna Rectifier ◽  
Vehicle Charging ◽  
Switching Characteristics ◽  
Charging Stations

Wide bandgap (WBG) semiconductors offer better switching and lower losses, and it is not uncommon to utilize them for high power density, high-efficiency applications. Gallium nitride (GaN) and Silicon carbide (SiC) are the most common WBG materials that are responsible for major switching level changes relative to silicon (Si) devices. This paper explores the contrast of performance between Si, SiC, and GaN devices. The output performance of Si, SiC, and GaN power devices includes efficiency, energy bandgap, thermal conductivity, carrier mobility, saturation speed, power density, switching characteristics, and conduction losses. This article also proposes a Vienna rectifier with GaN materials, which operates as a front-end rectifier on a high-density battery charger targeted at high-performance applications such as electric vehicle charging stations, aircraft applications, and welding power sources. The system would reduce the total harmonics distortion (THD) to less than 5%, and the power factor would be increased to unity to satisfy the IEEE-519 standard.

scholarly journals Thermodynamics and Performance Projections for Intercooled/Reheat/Recuperated Gas Turbine Systems

1987 ◽  
Author(s):  
Maher A. El-Masri
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
High Efficiency ◽  
Pure Water ◽  
Water Injection ◽  
Component Technology ◽  
Specific Power ◽  
Combined Cycles ◽  
And Performance ◽  
Marine Applications

Intercooled/Recuperated gas turbine systems provide high-efficiency and power density for naval propulsion. Current aero-derivative systems are capable of about 43% thermal efficiency in this configuration. With continued progress in gas-turbine materials and cooling technology, the possibility of further improving system performance by incorporation of gas-turbine reheat arises. A preliminary scan of this class of cycles is presented and compared with non-reheat intercooled/recuperated cycles at two levels of component technology. For conservative component technology, the reheat is found to provide very modest performance advantages. With advanced components and ceramic thermal barrier coatings, the reheat is found to offer potential for specific power improvements of up to 33% and for modest efficiency gains, on the order of one percentage point, while enabling turbine inlet temperatures well below those for the most efficient non-reheat cycles. The high-performance reheat systems, however, require reheat-combustor inlet temperatures beyond current practice. The use of water-injection in the intercooler, together with an aftercooler and a water-injected evaporative-recuperator is found to produce very large gains in efficiency as well as specific power. This modification may be feasible for land-based systems, where it can compete favourably with combined cycles. Despite the difficulty of obtaining pure water for a shipboard propulsion system, those large gains may justify further studies of this system and of means to provide its water supply in marine applications.

scholarly journals Strategies for High-Performance Large-Area Perovskite Solar Cells toward Commercialization

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 295
Author(s):  
Tianzhao Dai ◽  
Qiaojun Cao ◽  
Lifeng Yang ◽  
Mahmoud Aldamasy ◽  
Meng Li ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Large Scale ◽  
High Efficiency ◽  
Perovskite Solar Cells ◽  
Growth Control ◽  
Single Crystal Silicon ◽  
Large Area ◽  
Crystal Silicon ◽  
Control Interface

Perovskite solar cells (PSCs) have received a great deal of attention in the science and technology field due to their outstanding power conversion efficiency (PCE), which increased rapidly from 3.9% to 25.5% in less than a decade, comparable to single crystal silicon solar cells. In the past ten years, much progress has been made, e.g. impressive ideas and advanced technologies have been proposed to enlarge PSC efficiency and stability. However, this outstanding progress has always been referred to as small-area (<0.1 cm2) PSCs. Little attention has been paid to the preparation processes and their micro-mechanisms for large-area (>1 cm2) PSCs. Meanwhile, scaling up is an inevitable way for large-scale application of PSCs. Therefore, we firstly summarize the current achievements for high efficiency and stability large-area perovskite solar cells, including precursor composition, deposition, growth control, interface engineering, packaging technology, etc. Then we include a brief discussion and outlook for the future development of large-area PSCs in commercialization.

scholarly journals Design, Dynamics, and Workspace of a Hybrid-Driven-Based Cable Parallel Manipulator

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Bin Zi ◽  
Jianbin Cao ◽  
Zhencai Zhu ◽  
Peter Mitrouchev
Keyword(s):  
Parallel Manipulator ◽  
High Performance ◽  
Degrees Of Freedom ◽  
High Efficiency ◽  
Parallel Manipulators ◽  
Euler Method ◽  
Heavy Load ◽  
Physical Prototype ◽  
Manipulator Design ◽  
And Control

The design, dynamics, and workspace of a hybrid-driven-based cable parallel manipulator (HDCPM) are presented. The HDCPM is able to perform high efficiency, heavy load, and high-performance motion due to the advantages of both the cable parallel manipulator and the hybrid-driven planar five-bar mechanism. The design is performed according to theories of mechanism structure synthesis for cable parallel manipulators. The dynamic formulation of the HDCPM is established on the basis of Newton-Euler method. The workspace of the manipulator is analyzed additionally. As an example, a completely restrained HDCPM with 3 degrees of freedom is studied in simulation in order to verify the validity of the proposed design, workspace, and dynamic analysis. The simulation results, compared with the theoretical analysis, and the case study previously performed show that the manipulator design is reasonable and the mathematical models are correct, which provides the theoretical basis for future physical prototype and control system design.

Modeling of a Multiple Effect Desalination System

2013 ◽  
Vol 448-453 ◽  
pp. 3519-3522
Author(s):  
Guang Yu Liu ◽  
Hai Xia Ren ◽  
An Ke Xue ◽  
Guo Qiang Shen
Keyword(s):  
High Efficiency ◽  
Water Desalination ◽  
Dynamical Process ◽  
Water Production ◽  
Variable Model ◽  
Analysis And Design ◽  
Multiple Effect ◽  
Multiple Variable ◽  
Heat Conservation

A multiple variable model is developed for a multiple-effect low temperature desalination system. Multiple-effect water desalination has been used in industry for decades due to its high efficiency and high quality of fresh water production. Here, its dynamical process is modeled based on the mass and heat conservation laws and then expressed in terms of a state space equation, enabling people to carry out analysis and design controllers.

scholarly journals Lighting Enhancement of Classrooms in Heritage School Buildings Based on the Greenship Rating Tools

2021 ◽  
Vol 58 (S) ◽  
pp. 9-20
Author(s):  
Susan Susan ◽  
Rani Prihatmanti
Keyword(s):  
Power Density ◽  
Green Building ◽  
Visual Comfort ◽  
Interior Space ◽  
Heritage Buildings ◽  
Lighting Environment ◽  
Energy Efficiency And Conservation ◽  
Indoor Lighting ◽  
And Control

This study aims to suggest some strategies for improving the quality of lighting in adaptive reuse buildings. Recently, several concerns have been raised about the lighting environment of heritage buildings that have been adaptively reused for a different function. These changes may lead to a problem for the occupants of the building, particularly on the indoor lighting quality. It is regarded as one of the most affected variables in the building of heritage that is adaptively reused. Green Building Council Indonesia (GBCI) has been concerned about this issue, particularly to the requirements related to lighting power density and control, visual comfort, outside view, and daylight. The purpose of this research is therefore to suggest some strategies for improving the quality of lighting in the two classrooms of two heritage schools in Surabaya, Indonesia, based on the Greenship Interior Space rating tool. There are three credits for lighting power density and control, and one credit for visual comfort criteria. By performing light mapping measurements, calculations, and computer simulation, this analysis is qualitative. To capture the condition of the classrooms examined, building observation was also performed. The observation shows that the existing condition gains four credits only. If adopted, the strategies proposed could achieve eight credits, which is covers 80% of the assessment points. The higher credits achieved reflect a better lighting environment and better value for energy efficiency and conservation.

scholarly journals Power Density Maximization in Medium Frequency Transformers by Using Their Maximum Flux Density for DC–DC Converters

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 470
Author(s):  
Dante Ruiz-Robles ◽  
Edgar L. Moreno-Goytia ◽  
Vicente Venegas-Rebollar ◽  
Nadia M. Salgado-Herrera
Keyword(s):  
Flux Density ◽  
Power Density ◽  
High Performance ◽  
High Efficiency ◽  
Electrical Power ◽  
Power Grids ◽  
Medium Frequency ◽  
Maximum Flux ◽  
Conventional Procedure ◽  
Core Losses

The medium frequency transformer (MTF) is a key component of various new DC–DC converters that are designed for applications in modern electrical power grids at medium and high voltage. To attain the high performance that are necessary for targeting these applications, MFTs should have high power density and high efficiency as characteristics. For this endeavor, newly designed MFT procedures, which also take advantages of new core materials, are under investigation. Differently to other design proposals, most of which use conventional transformer design procedures based on equating core losses to copper conduction losses, in this paper, an MTF with a nanocrystalline (VITROPERM 500F) core is designed with a new procedure that is oriented in aiming the maximum flux density (Bmax). The characteristics of the MFTs that are obtained by using this procedure are compared with those of the MFTFs that are designed with a conventional procedure. The results show that by using the proposed technique, we get a 25% reduction in the winding size, a higher power density, and a lower MTF building cost while maintaining a high efficiency (>98%). The design methodology is developed through a rigorous mathematical analysis that is verified with computer simulations in Matlab-Simulink and validated with experimental results from two MTF laboratory prototypes designed at a flux density of 0.9 T (75% Bmax) and 1.2 T (Bmax).

scholarly journals Strategies for Improving Anion Exchange Membrane Fuel Cell Performance by Optimizing Electrode Conditions

2022 ◽  
Author(s):  
CHUAN HU ◽  
Ho Hyun Wang ◽  
Jonghyeong Park ◽  
Haemin Kim ◽  
Nanjun Chen ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Anion Exchange ◽  
Power Density ◽  
High Performance ◽  
Anion Exchange Membrane ◽  
Specific Power ◽  
Fuel Cell Performance ◽  
Catalyst Composition ◽  
Hydrophobic Treatment ◽  
Exchange Membrane

Abstract We systematically study anion exchange membrane fuel cells (AEMFCs) based on poly(aryl-co-aryl piperidinium) (c-PAP) copolymers and provide a scalable scenario for high-performance AEMFCs, covering the optimization of the relative humidity (RH), catalyst species, catalyst interfaces, and hydrophobic treatment. Specifically, high-water-permeable c-PAP ionomers in the presence of moderate relative humidity (RH) (75%/100%) can be used to address anode flooding and cathode dry-out issues. The composition of the catalyst layer and the anode hydrophobic treatment significantly impact the power density of AEMFCs. c-PAP-based AEMFCs with optimum catalyst composition achieve a peak power density (PPD) of 2.70 W cm-2 at 80 oC in H2-O2 after hydrophobic treatment. Pt1Co1/C cathode-based AEMFCs reach a PPD of 1.80 W cm-2 along with an outstanding specific power of 13.87 W mg-1. Moreover, these AEMFCs can be operated under a 0.2 A cm-2 current density at 60 oC for over 300 h with a voltage decay rate of ~300 μv h-1.

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