A5015181756- Silicon Carbide Semiconductor Technologies
- Electromagnetic Compatibility and Noise Suppression
- Advanced DC-DC Converters
- Semiconductor materials and devices
- Multilevel Inverters and Converters
- Advancements in Semiconductor Devices and Circuit Design
- HVDC Systems and Fault Protection
- Semiconductor Quantum Structures and Devices
- Welding Techniques and Residual Stresses
- Magnetic Properties and Applications
- Gear and Bearing Dynamics Analysis
- Advanced Memory and Neural Computing
- Molecular Junctions and Nanostructures
- Silicon and Solar Cell Technologies
- Block Copolymer Self-Assembly
- Metallic Glasses and Amorphous Alloys
- Power Quality and Harmonics
- Engineering Applied Research
- Hydrogen embrittlement and corrosion behaviors in metals
- Mass Spectrometry Techniques and Applications
- Silicon Nanostructures and Photoluminescence
- Advanced Welding Techniques Analysis
- Polymer Nanocomposites and Properties
- Laser-induced spectroscopy and plasma
- Analytical chemistry methods development
University of Minnesota
2024
Florida State University
2020-2022
Samsung (South Korea)
2018
Seoul National University
2017
Hyosung Corporation (South Korea)
2014
Sungkyunkwan University
2013
Beijing Normal University
2002-2004
Block copolymer molecular weight is a crucial factor influencing micelle fragmentation kinetics. In particular, it not established how block length affects the rate, and which more important. this work, we studied separate dependence of kinetics on core corona lengths, with temperature-jump experiments by dynamic light scattering. Two series 1,2-polybutadiene-b-poly(ethylene oxide) (PB-b-PEO) copolymers were prepared, both fixed NPB (degree polymerization block) various NPEO. all, total nine...
Pulsewidth modulation (PWM)-based power electronics inverters are being widely used for various applications, including motor drives. However, the common-mode voltage (CMV) resulting from switching operations in PWM causes significant performance degradation of system and can cause potential damage to motors. Since effects CMV be more severe wide bandgap (WBG) high frequency-based converter systems, methods have been proposed mitigate CM noise issues. This work presents a multi-level...
Common-mode voltage (CMV) caused by switching operations of power converters can significantly degrade the system's stability and performance. Since effects CMV are more prominent in wide-bandgap-based applications that require fast-switching slew rates, many research articles have been proposed to mitigate CM noise generated CMV. In addition, as topologies control methods become complicated for better performance, advanced attenuation required accordingly. Therefore, this article proposes a...
High-performance desaturation or overcurrent protection circuit of the gate-drivers for Silicon Carbide (SiC) MOSFETs are essential reliable and robust operation advanced power electronics converters. The circuits current state-of-the-art gate drivers have limitations with slow response speed incapability to achieve under wide temperature variation converter switching noises. In this work, improved introduced overcome such SiC MOSFET drivers. proposed can operate at a significantly higher...
Silicon carbide (SiC) power devices have advantages, such as excellent breakdown field strength, heat dissipation characteristics, and electron saturation velocity. Thus, the SiC-based semiconductors can operate at higher switching frequencies with voltages better stability than conventional silicon (Si) resulting in a high-power density. However, high slew rate of SiC cause EMI noise problems. Conventional gate drivers cannot effectively control issues, including passive active driver...
The effects of welding parameters such as contact tip-to-work distance (CTWD), voltage, and current on the weld metal diffusible hydrogen contents (HD) were investigated rationalized by calculation heating time amount heat generated in extension length flux cored wire. As CTWD increased from 15 to 25mm, HD decreased 8.46 5.45mL/100g deposited metal. Calculations showed that, with an increase CTWD, 46 92J addition time. Increase 250 320A, however, gave little variation HD. It that no...
A SiC-based intelligent power stage (IPS) with zero-voltage-ride-through (ZVRT) and device prognosis & diagnosis (P&D) capability is proposed for electronics grid interface systems. Compared to other grid-tied converters, the IPS embeds online health monitoring of SiC into its integrated gate drivers (i2GDs). In addition, a low-latency hardware-based approach fast-response developed suppress large inrush current during ZVRT transients. The fiber-optic based robust communication architecture...
Since heterojunction transistors have been invented, devices of various materials developed with excellent performance such as AlGaAs-GaAs, Si-GeSi, etc. Here, we report a new mode operation and call it the Heterojunction Vertical Dual Carrier Field Effect Transistor (HVDCFET). The HVDCFET its integrated circuit form HVDCFEIC advantage field effect transistor operation. mobility /spl mu/ is q/kT times greater than diffusion constant D. With same injection at source or emitter junction, drift...
In this paper, detrimental effects of conventional dead-time based control multilevel power inverters for high frequency and density are analyzed. To mitigate these effects, a compensation technique is proposed on voltage-based control. Apparent Switching Frequency Doubling (ASFD) carrier-based pulse-width-modulation (PWM) considered the 5-Level Active-Neutral-Point-Clamped (ANPC) II type WBG inverter, applied to topology. method, since an error its phase voltage can be generated according...
Silicon carbide (SiC) power devices have excellent breakdown field strength, heat dissipation characteristics, and electron saturation velocity. The SiC-based semi-conductors can operate at higher switching frequencies with voltages better stability than conventional silicon (Si) devices. Therefore, converters achieve a high-power density. However, the high slew rate of SiC accompanied by high-speed operations cause EMI noise problems. Conventional gate drivers cannot effectively control...
In this paper, an improved dead-time effect compensation is proposed for WBG multilevel inverters to eliminate voltage errors by zero-current clamping (ZCC) conditions. Conventional methods based on the current direction can in conventional methods. However, with approaches, remain uncompensated during control cycles that include ZCC point and its next cycle. To address issue, additional improvement a prediction of condition. solve issue. method, output values be estimated using references...
This paper presents an intelligent gate driver (GD) with prognosis and diagnosis (PD) functions for silicon carbide (SiC) power devices. Based on monitoring a current, the PD circuit provides useful diagnoses, including GD board fault, connection verification between driven devices, open/short condition. Furthermore, it can detect oxide degradation, generating early warning signal to enable users replace aged devices fresh one. Due low-cost implementation of proposed scheme, be easily...
The principle of operation Si and SiGe resistor load flip flops ring oscillators n channel vertical dual carrier field effect transistors are reviewed. Measured data from experimental verification the is presented.
This paper proposes a new circuit of AC/DC PWM converter by adding diode rectifier to control three-phase under full load stably. Also, wiring method LCL filter according the connecting type low-frequency transformer is proposed solve problem floating state occurring from in case considering transformer. Most DC loads have electrically sensitive properties input voltage. Therefore, this system, order minimize overshoot link that may occur when power conversion device connected with load,...
Silicon carbide (SiC) power devices operate at high switching frequencies with voltages and good stabilities owing to their advantages in excellent breakdown field strength, heat dissipation characteristics, electron saturation velocity, so on. Therefore, SiC-based systems can achieve a density compared conventional Si-based systems. However, dv/dt di/dt accompanied high-speed operations cause EMI noise issues. Traditional gate drivers cannot actively control such problems. This digest...
Source coupled logic (SCL) flip flops of SOI Si "vertical dual carrier field effect transistor" (VDCFET) with effective channel length 5-30nm have been designed, fabricated and measured. These development works are presented in three accompanied papers submitted to this conference. Presented paper the measured circuit performance source CPU switching circuits VDCFET 5-30 nm, including ring oscillators "exclusive OR" circuits.
This paper proposes a multi-level active power filter (APF) for common-mode voltage (CMV) attenuation in inverter systems. The proposed system is composed of and an additional fourth leg as the APF. same 5-level Active-neutral-point-clamped (ANPC) II type architecture used both APF example inverters this paper. For CMV attention system, has to generate inject equal generated by inverter. Therefore, requires prediction algorithm PWM technique generation. more complex forms than output...