A Comparative Study of Different Optimization Methods for Resonance Half-Bridge Converter

The LLC resonance half-bridge converter is one of the most popular DC-DC converters and could easily inspire researchers to design a high-efficiency and high-power-density converter. LLC resonance converters have diverse operation modes based on switching frequency and load that cause designing and optimizing procedure to vary in different modes. In this paper, different operation modes of the LLC half-bridge converter that investigate different optimization procedures are introduced. The results of applying some usual optimization methods implies that for each operation mode some specific methods are more appropriate to achieve high efficiency. To verify the results of each optimization, numerous simulations are done by Pspice and MATLAB and the efficiencies are calculated to compare them. Finally, to verify the result of optimization, the experimental results of a laboratory prototype are provided.

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High Temperature Silicon-on-Insulator Gate Driver for SiC-FET Power Modules

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/hiten-paper4-jmayorga ◽

2011 ◽

Vol 2011 (HITEN) ◽

pp. 000152-000158

Author(s):

J. Valle Mayorga ◽

C. Gutshall ◽

K. Phan ◽

I. Escorcia ◽

H. A. Mantooth ◽

...

Keyword(s):

Power Density ◽

High Power ◽

High Efficiency ◽

Low Voltage ◽

Silicon On Insulator ◽

Switching Frequency ◽

Cmos Process ◽

High Power Density ◽

Power Modules ◽

Gate Driver

SiC power semiconductors have the capability of greatly outperforming Si-based power devices. Faster switching and smaller on-state losses coupled with higher voltage blocking and temperature capabilities, make SiC a very attractive semiconductor for high performance, high power density power modules. However, the temperature capabilities and increased power density are fully utilized only when the gate driver is placed next to the SiC devices. This requires the gate driver to successfully operate under these extreme conditions with reduced or no heat sinking requirements, allowing the full realization of a high efficiency, high power density SiC power module. In addition, since SiC devices are usually connected in a half or full bridge configuration, the gate driver should provide electrical isolation between the high and low voltage sections of the driver itself. This paper presents a 225 degrees Celsius operable, Silicon-On-Insulator (SOI) high voltage isolated gate driver IC for SiC devices. The IC was designed and fabricated in a 1 μm, partially depleted, CMOS process. The presented gate driver consists of a primary and a secondary side which are electrically isolated by the use of a transformer. The gate driver IC has been tested at a switching frequency of 200 kHz at 225 degrees Celsius while exhibiting a dv/dt noise immunity of at least 45 kV/μs.

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Hybrid Multimodule DC-DC Converters for Ultrafast Electric Vehicle Chargers

Energies ◽

10.3390/en13184949 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4949

Author(s):

Mena ElMenshawy ◽

Ahmed Massoud

Keyword(s):

Power Density ◽

High Power ◽

High Efficiency ◽

Controller Design ◽

Power Level ◽

Power Converter ◽

Total Power ◽

Switching Frequency ◽

High Power Density ◽

High Switching Frequency

To increase the adoption of electric vehicles (EVs), significant efforts in terms of reducing the charging time are required. Consequently, ultrafast charging (UFC) stations require extensive investigation, particularly considering their higher power level requirements. Accordingly, this paper introduces a hybrid multimodule DC-DC converter-based dual-active bridge (DAB) topology for EV-UFC to achieve high-efficiency and high-power density. The hybrid concept is achieved through employing two different groups of multimodule converters. The first is designed to be in charge of a high fraction of the total required power, operating at a relatively low switching frequency, while the second is designed for a small fraction of the total power, operating at a relatively high switching frequency. To support the power converter controller design, a generalized small-signal model for the hybrid converter is studied. Also, cross feedback output current sharing (CFOCS) control for the hybrid input-series output-parallel (ISOP) converters is examined to ensure uniform power-sharing and ensure the desired fraction of power handled by each multimodule group. The control scheme for a hybrid eight-module ISOP converter of 200 kW is investigated using a reflex charging scheme. The power loss analysis of the hybrid converter is provided and compared to conventional multimodule DC-DC converters. It has been shown that the presented converter can achieve both high efficiency (99.6%) and high power density (10.3 kW/L), compromising between the two other conventional converters. Simulation results are provided using the MatLab/Simulink software to elucidate the presented concept considering parameter mismatches.

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High Frequency, High Efficiency, and High Power Density GaN-Based LLC Resonant Converter: State-of-the-Art and Perspectives

Applied Sciences ◽

10.3390/app112311350 ◽

2021 ◽

Vol 11 (23) ◽

pp. 11350

Author(s):

Seyed Abolfazl Mortazavizadeh ◽

Simone Palazzo ◽

Arturo Amendola ◽

Enzo De Santis ◽

Dario Di Ruzza ◽

...

Keyword(s):

Power Density ◽

High Power ◽

High Frequency ◽

High Efficiency ◽

Resonant Converters ◽

Switching Frequency ◽

High Power Density ◽

Resonant Converter ◽

Gan Hemt ◽

Llc Resonant Converter

Soft switching for both primary and secondary side devices is available by using LLC converters. This resonant converter is an ideal candidate for today’s high frequency, high efficiency, and high power density applications like adapters, Uninterrupted Power Supplies (UPS), Solid State Transformers (SST), electric vehicle battery chargers, renewable energy systems, servers, and telecom systems. Using Gallium-Nitride (GaN)-based power switches in this converter merits more and more switching frequency, power density, and efficiency. Therefore, the present paper focused on GaN-based LLC resonant converters. The converter structure, operation regions, design steps, and drive system are described precisely. Then its losses are discussed, and the magnets and inductance characteristics are investigated. After that, various interleaved topologies, as a solution to improve power density and decrease current ripples, have been discussed. Also, some challenges and concerns related to GaN-based LLC converters have been reviewed. Commercially available power transistors based on various technologies, i.e., GaN HEMT, Silicon (Si) MOSFET, and Silicon Carbide (SiC) have been compared. Finally, the LLC resonant converter has been simulated by taking advantage of LTspice and GaN HEMT merits, as compared with Si MOSFETs.

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

Nature Communications ◽

10.1038/s41467-021-24587-7 ◽

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.

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