scholarly journals Research on Modelling and Stability Characteristics of Electric Traffic Energy System Based on ZVS-DAB Converter

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ayiguzhali Tuluhong ◽  
Weiqing Wang ◽  
Yongdong Li ◽  
Haiyun Wang ◽  
Lie Xu
Keyword(s):  
Mathematical Model ◽  
High Frequency ◽  
Heat Dissipation ◽  
Wide Band ◽  
Energy System ◽  
Wide Band Gap ◽  
Switching Speed ◽  
Zero Voltage Switching ◽  
Conduction Loss ◽  
Dual Active Bridge

We study and describe mostly used traditional simplified circuits for full-bridge Zero Voltage Switching-Dual Active Bridge (ZVS-DAB) converter and deduce their mathematical model. On this basis, we propose a high-frequency (HF) mathematical model, which takes into account conduction loss and HF characteristics of the ZVS-DAB converter model. We compare the static and dynamic stabilities of the traditional and the proposed HF mathematical model by simulation. Finally, the high-frequency planar transformer (HFPT) with good heat dissipation and the wide band gap (WBG) semiconductor SiC switches with fast switching speed are employed to build a 4.4 kw, 40 KHz experimental prototype to verify the effectiveness of the improved HF circuit of ZVS-DAB converter. The results show that the proposed HF mathematical model is superior to the traditional one, and it fully considers the HF characteristics of the circuit and effectively improves the HF oscillation, DC bias, and waveform distortion of the ZVS-DAB converter.

scholarly journals Measurement of Heat Dissipation and Thermal-Stability of Power Modules on DBC Substrates with Various Ceramics by SiC Micro-Heater Chip System and Ag Sinter Joining

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 745
Author(s):  
Dongjin Kim ◽  
Yasuyuki Yamamoto ◽  
Shijo Nagao ◽  
Naoki Wakasugi ◽  
Chuantong Chen ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Heat Dissipation ◽  
Wide Band ◽  
Middle Layer ◽  
Thermal Interface Material ◽  
Wide Band Gap ◽  
Power Cycle ◽  
Power Cycling ◽  
Power Modules ◽  
Pattern Line

This study introduced the SiC micro-heater chip as a novel thermal evaluation device for next-generation power modules and to evaluate the heat resistant performance of direct bonded copper (DBC) substrate with aluminum nitride (AlN-DBC), aluminum oxide (DBC-Al2O3) and silicon nitride (Si3N4-DBC) ceramics middle layer. The SiC micro-heater chips were structurally sound bonded on the two types of DBC substrates by Ag sinter paste and Au wire was used to interconnect the SiC and DBC substrate. The SiC micro-heater chip power modules were fixed on a water-cooling plate by a thermal interface material (TIM), a steady-state thermal resistance measurement and a power cycling test were successfully conducted. As a result, the thermal resistance of the SiC micro-heater chip power modules on the DBC-Al2O3 substrate at power over 200 W was about twice higher than DBC-Si3N4 and also higher than DBC-AlN. In addition, during the power cycle test, DBC-Al2O3 was stopped after 1000 cycles due to Pt heater pattern line was partially broken induced by the excessive rise in thermal resistance, but DBC-Si3N4 and DBC-AlN specimens were subjected to more than 20,000 cycles and not noticeable physical failure was found in both of the SiC chip and DBC substrates by a x-ray observation. The results indicated that AlN-DBC can be as an optimization substrate for the best heat dissipation/durability in wide band-gap (WBG) power devices. Our results provide an important index for industries demanding higher power and temperature power electronics.

Synthesis of Diamond on SiC by Microwave Plasma Chemical Vapor Deposition: Comparison of Silicon-Face and Carbon-Face

2020 ◽  
Vol 1014 ◽  
pp. 8-13
Author(s):  
Xue Min Zhang ◽  
Chang Ling Yan ◽  
Chun Hong Zeng ◽  
Yi Qun Wang ◽  
Bao Shun Zhang ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Wide Band ◽  
Performance Limits ◽  
Wide Band Gap ◽  
Sem Images ◽  
Plasma Chemical Vapor Deposition ◽  
Diffraction Peaks ◽  
Growth Quality

Diamond is arguably the best candidate material for heat dissipation applications, especially in high-power electronic devices. Silicon carbide (SiC) is a kind of wide band gap material, which can be used in applications of silicon (Si) components to reach the performance limits. In this paper, thin diamond films were successfully deposited on C-face and Si-face of 6H-SiC substrates respectively using MPCVD at temperatures from 800 to 1050 °C. SEM images indicated the growth quality comparison of the two faces of SiC. The diffraction peaks of the diamond (111), (220), and (311) crystal planes can be observed by XRD measurement, and the intensity of the diamond diffraction peaks grown on the C-face is stronger than that on Si-face. The growth process was analyzed by Raman spectrum. FWHM of diamond Raman spectra on Si-face and C-face are 6.07cm-1 and 5.47cm-1 respectively. All above measurement results show that the diamond grown on the C-face has higher crystal quality than that on Si-face of SiC.

HIGH FREQUENCY, HIGH TEMPERATURE FIELD-EFFECT TRANSISTORS FABRICATED FROM WIDE BAND GAP SEMICONDUCTORS

1995 ◽  
Vol 06 (01) ◽  
pp. 211-236 ◽  
Author(s):  
R.J. TREW ◽  
M.W. SHIN
Keyword(s):  
High Temperature ◽  
Band Gap ◽  
Microwave Power ◽  
High Frequency ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Wide Band ◽  
Superior Performance ◽  
Wide Band Gap ◽  
Wide Band Gap Semiconductors

Electronic and optical devices fabricated from wide band gap semiconductors have many properties ideal for high temperature, high frequency, high power, and radiation hard applications. Progress in wide band gap semiconductor materials growth has been impressive and high quality epitaxial layers are becoming available. Useful devices, particularly those fabricated from SiC, are rapidly approaching the commercialization stage. In particular, MESFETs (MEtal Semiconductor Field-Effect Transistors) fabricated from wide band gap semiconductors have the potential to be useful in microwave power amplifier and oscillator applications. In this work the microwave performance of MESFETs fabricated from SiC, GaN and semiconducting diamond is investigated with a theoretical simulator and the results compared to experimental measurements. Excellent agreement between the simulated and measured data is obtained. It is demonstrated that microwave power amplifiers fabricated from these semiconductors offer superior performance, particularly at elevated temperatures compared to similar components fabricated from the commonly employed GaAs MESFETs.

scholarly journals Operation of Current-fed Dual Active Bridge DC-DC Converters for Microgrid

2019 ◽  
Vol 8 (2) ◽  
pp. 3167-3175
Keyword(s):  
High Frequency ◽  
Soft Switching ◽  
Switching Loss ◽  
Zero Voltage Switching ◽  
Dual Active Bridge ◽  
Light Load ◽  
Zero Current Switching ◽  
Zero Current ◽  
Cell Energy ◽  
Load Conditions

Dual Active Bridge (DAB) is an isolated bidirectional DC-DC converter, which comprises two full bridge converterslinked through a high frequency transformer. It haslow stresses and permits high frequency performance because of the soft-switching. All the switches in the converter achieves the turn ON & OFF during Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) to minimize switching loss. Generally, DAB is classified as two types, namely, voltage-fed and current-fed variants. At light load conditions, soft-switching is not realized in case of voltage-fed DAB topologies. The application of current-fed DAB converters is to reduce the losses at the time of switching under light load conditions and improves the efficiency. This paper describes the various topologies of voltage-fed and current-fed DAB used for different applications in microgrid and fuel cell energy generation system by using the simulation. The performance of voltage-fed and current-fed DAB with snubber-less converters are also demonstrated and their effectiveness are validated

Optically modulated III–V nitride-based high-power IMPact Avalanche Transit Time oscillator at Millimeter-wave window frequency

2009 ◽  
Vol 1 (5) ◽  
pp. 423-429
Author(s):  
Moumita Mukherjee ◽  
Sitesh Kumar Roy
Keyword(s):  
Transit Time ◽  
High Power ◽  
High Frequency ◽  
Communication Systems ◽  
Flip Chip ◽  
Wide Band ◽  
Negative Resistance ◽  
Potential Candidate ◽  
Rf Power ◽  
Wide Band Gap

Extensive simulation experiments are carried out for the first time, to study the optical modulation of the high- frequency characteristics of III–V GaN-(gallium nitride) based top-mounted and flip-chip IMPact Avalanche Transit Time (IMPATT) oscillators at MM-wave window frequency (140.0 GHz). It is found that the un-illuminated GaN IMPATT is capable of delivering a RF power of 5.6 W with an efficiency of 23.5% at 145.0 GHz. Frequency up-chirping of 6.0 GHz and a degradation of RF power output by almost 15.0% are further observed in case of photo-illuminated FC IMPATT. The study reveals that compared to predominate electron photocurrent in top-mounted IMPATT, photo-generated leakage current dominated by hole in flip-chip IMPATT has more pronounced effect on the GaN-based device as regards the frequency chirping and decrease of negative conductance and total negative resistance per unit area of the device. The inequality in the magnitudes of electron and hole ionization rates in the wide band gap semiconductor has been found to be correlated with the above results. The study reveals that GaN IMPATT is a potential candidate for replacing conventional IMPATTs at high-frequency operation. These results are useful for practical realization of optically controlled GaN-based high-power IMPATTs for application in MM-wave communication systems.

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