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 Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

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 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 An Experimental Comparison of the Effects of Nanocrystalline Core Geometry on the Performance and Dispersion Inductance of the MFTs Applied in DC-DC Converters

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 453
Author(s):  
Dante Ruiz-Robles ◽  
Carlos Figueroa-Barrera ◽  
Edgar L. Moreno-Goytia ◽  
Vicente Venegas-Rebollar
Keyword(s):  
Power Density ◽  
High Efficiency ◽  
Experimental Comparison ◽  
Experimental Development ◽  
Solid State Transformers ◽  
The Core ◽  
New Information ◽  
Core Losses ◽  
Analysis Design ◽  
And Performance

The development of Medium Frequency Transformers (MFTs) from a novel perspective is essential for the advancement of today´s various relevant applications such as the emerging solid-state transformers, along with interfaces for the interconnection of photovoltaic parks and electric vehicles. The analysis, design and implementation of MFTs pursuing the achievement of characteristics such as high power density, high efficiency, and a specific dispersion inductance is a key goal for designers. There are several parameters and design methods that influence the final performance of an MFT, such as the geometry and material of the core. The advantages/disadvantages of each material/geometry combination, about the dispersion inductance for instance, are not well known, even considering a single material but various geometries. This paper presents the analysis, design and experimental development of three nanocrystalline-core MFTs, each one with a different core geometry (toroidal, type CC and shell-type). The purpose of this work is to evaluate and compare the most favourable characteristics and performance of each type of geometry, tested at 5 kHz and 1.75 kVA. The cases studied, in simulation and experimentation with scaled prototypes, focus on evaluating the power density, the core losses, the winding losses, the geometric dimensions, and the dispersion inductance obtained in each MFT, as well as its performances operating with sinusoidal and square waveforms. The results show that: 1) the toroid core has higher efficiency; 2) the shell core has the lowest dispersion inductance and is easier to build, and 3) the CC type has the highest dispersion inductance. This new information is a step to further understand how to get more controllable, more efficient MFTS, with a higher power density and lower cost, depending on the intended application of cutting-edge DC-DC DAB-type converters.

Field and Application Experience of the Titan 130 Industrial Gas Turbine

2001 ◽  
Author(s):  
George Rocha ◽  
Rainer Kurz
Keyword(s):  
Gas Turbine ◽  
Development Strategy ◽  
High Performance ◽  
High Efficiency ◽  
Electrical Power ◽  
Field Evaluation ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Evaluation Program ◽  
Industrial Gas Turbine

The two-shaft Titan 130 industrial gas turbine was introduced into commercial service in 1998 and has gained field experience in mechanical-drive and compressor-set applications. A single-shaft configuration is also available for electrical power generation applications. The 14-MW class two-shaft engine is nominally rated at 19,500 hp with a simple-cycle efficiency of more than 35% at ISO operating conditions. It is available with two combustor options: a dry, low-pollutant emissions combustion system featuring Solar’s proven SoLoNOx technology or a diffusion-flame type combustor adapted from Solar’s proven Mars gas turbine. The Titan 130 gas turbine design is an aerodynamic scale of the existing Taurus 70 product. The unit features a modified Mars air compressor and turbine section components directly scaled from the Taurus 70, resulting in a low-risk product design well-suited for industrial service applications. A major element of the development strategy included an extended field evaluation trial in actual operating conditions to demonstrate overall product durability. The first Titan 130 mechanical-drive package was placed into service at a natural gas pipeline compressor station and successfully completed a planned 8000-hour field evaluation program. Extensive inspection and operating data have been evaluated and the unit continues to operate in normal commercial service. A mechanical-drive package requires the successful marriage between the driver and the driven equipment. Most applications require a combination of high efficiency and high performance flexibility. Emphasis was placed on providing excellent gas compressor coverage for this product. The successful application of such a compression system is discussed and supported by site test data. This paper provides details of the Titan 130 field evaluation program, design enhancements and typical compressor set application performance characteristics.

scholarly journals Power and Spectral Range Characteristics for Optical Power Converters

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4395
Author(s):  
Simon Fafard ◽  
Denis Masson ◽  
Jan-Gustav Werthen ◽  
James Liu ◽  
Ta-Chung Wu ◽  
...  
Keyword(s):  
Laser Diode ◽  
Spectral Range ◽  
High Performance ◽  
High Efficiency ◽  
Power Converters ◽  
Electrical Power ◽  
Optical Power ◽  
Power Outputs ◽  
External Loads ◽  
Power Class

High-performance optical power converters (OPCs) enable isolated electrical power and power beaming applications at new wavelengths and higher output powers. Broadcom’s vertical epitaxial heterostructure architecture (VEHSA) multi-junction OPCs permit optical-to-electrical conversion at high efficiency and at manageable external loads. This study provides details of how the power outputs have been extended from <1 W to a power class at ~3 W and another class at >20 W. The work also provides details of how the spectral range options have been extended from 800–830 nm to other key laser diode wavelengths such as 960–990 nm and 1500–1600 nm.

High-Performance Hardware Interpolation Architecture for High Efficiency Video Coding Decoder

2016 ◽  
Vol 11 (9) ◽  
pp. 764
Author(s):  
Lella Aicha Ayadi ◽  
Nihel Neji ◽  
Hassen Loukil ◽  
Mouhamed Ali Ben Ayed ◽  
Nouri Masmoudi
Keyword(s):  
Video Coding ◽  
High Performance ◽  
High Efficiency ◽  
High Efficiency Video Coding

scholarly journals ZVS Auxiliary Circuit for a 10 kW Unregulated LLC Full-Bridge Operating at Resonant Frequency for Aircraft Application

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1850 ◽  
Author(s):  
Yann E. Bouvier ◽  
Diego Serrano ◽  
Uroš Borović ◽  
Gonzalo Moreno ◽  
Miroslav Vasić ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Power Density ◽  
High Efficiency ◽  
Harmonic Approximation ◽  
Maximum Efficiency ◽  
Voltage Gain ◽  
Load Range ◽  
Transition Analysis ◽  
Aircraft Application ◽  
Auxiliary Circuit

In modern aircraft designs, following the More Electrical Aircraft (MEA) philosophy, there is a growing need for new high-power converters. In this context, innovative solutions to provide high efficiency and power density are required. This paper proposes an unregulated LLC full-bridge operating at resonant frequency to obtain a constant gain at all loads. The first harmonic approximation (FHA) model is not accurate enough to estimate the voltage gain in converters with high parasitic resistance. A modified FHA model is proposed for voltage gain analysis, and time-based models are used to calculate the instantaneous current required for the ZVS transition analysis. A method using charge instead of current is proposed and used for this ZVS analysis. Using this method, an auxiliary circuit is proposed to achieve complete ZVS within the whole load range, avoiding a gapped transformer design and increasing the efficiency and power density. A 28 Vdc output voltage prototype, with 10 kW peak output power, has been developed to validate the theoretical analysis and the proposed auxiliary circuit. The maximum efficiency (96.3%) is achieved at the nominal power of 5 kW.

scholarly journals Analysis and Pareto Frontier Based Tradeoff Design of an Integrated Magnetic Structure for a CLLC Resonant Converter

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1756
Author(s):  
Gang Wang ◽  
Qiyu Hu ◽  
Chunyu Xu ◽  
Bin Zhao ◽  
Xiaobao Su
Keyword(s):  
Magnetic Structure ◽  
Power Density ◽  
High Efficiency ◽  
Pareto Frontier ◽  
Optimization Procedure ◽  
Magnetic Core ◽  
Pareto Optimization ◽  
High Power Density ◽  
Resonant Converter ◽  
Conduction Loss

This paper proposes an integrated magnetic structure for a CLLC resonant converter. With the proposed integrated magnetic structure, two resonant inductances and the transformer are integrated into one magnetic core, which improves the power density of the CLLC resonant converter. In the proposed integrated magnetic structure, two resonant inductances are decoupled with the transformer and can be adjusted by the number of turns in each inductance. Furthermore, two resonant inductances are coupled to reduce the number of turns in each inductance. As a result, the conduction loss can be reduced. The trade-off design of the integrated magnetic structure is carried out based on the Pareto optimization procedure. With the Pareto optimization procedure, both high efficiency and high-power density can be achieved. The proposed integrated magnetic structure is validated by theoretical analysis, simulations, and experiments.

Sign in / Sign up

Export Citation Format

Share Document