@article{wang_zhou_li_zhao_huang_callanan_husna_agarwal_2009, title={10-kV SiC MOSFET-Based Boost Converter}, volume={45}, ISSN={["1939-9367"]}, DOI={10.1109/tia.2009.2031915}, abstractNote={10-kV silicon carbide (SiC) MOSFETs are currently being developed by a number of organizations in the U.S. with prospective applications in high-voltage and high-frequency power-electronic systems. The aim of this paper is to demonstrate the high-frequency and high-temperature capability of 10-kV SiC MOSFETs in the application of a dc/dc boost converter. In this study, 10-kV SiC MOSFET and junction barrier Schottky (JBS) diode were characterized and modeled in SPICE. Following this, a dc/dc boost converter based on a 10-kV 10-A MOSFET and a 10-kV 5-A JBS diode was designed and tested under continuous operation for frequencies up to 25 kHz. The boost converter had an output voltage of 4 kV, an output power of 4 kW, and operated with a junction temperature of 174degC for the SiC MOSFET. The fast-switching speed, low losses, and high-temperature operation capability of 10-kV SiC MOSFETs demonstrated in the dc/dc boost converter make them attractive for high-frequency and high-voltage power-conversion applications.}, number={6}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Wang, Jun and Zhou, Xiaohu and Li, Jun and Zhao, Tiefu and Huang, Alex Q. and Callanan, Robert and Husna, Fatima and Agarwal, Anant}, year={2009}, pages={2056–2063} }
 @inproceedings{wang_du_bhattacharya_huang_2009, title={Characterization, modeling of 10-kV SiC JBS diodes and their application prospect in X-ray generators}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-72449197461&partnerID=MN8TOARS}, DOI={10.1109/ecce.2009.5315963}, abstractNote={The 10-kV Silicon Carbide (SiC) Junction Barrier Schottky (JBS) diodes are currently being developed by a number of organizations in the United States with the aim to enable their applications in high voltage power conversions. The aim of this paper is to characterize and model the 10-kV SiC JBS diode so that their prospect and benefits in power electronic systems can be provided. Using the SPICE model of the 10-kV 5A SiC JBS diode, the advantages of 10-kV SiC JBS diodes in the application of X-ray generators were shown by PSPICE simulations for the first time. The simulation results predict that the 10-kV SiC JBS diodes based high voltage rectifiers in X-ray generators can greatly reduce the number of series diodes required and power loss than compared to the 1-kV silicon ultra fast recovery diodes based rectifiers.}, booktitle={2009 IEEE Energy Conversion Congress and Exposition, ECCE 2009}, author={Wang, J. and Du, Y. and Bhattacharya, Subhashish and Huang, A.Q.}, year={2009}, pages={1488–1493} }
 @article{wang_huang_2009, title={Design and Characterization of High-Voltage Silicon Carbide Emitter Turn-off Thyristor}, volume={24}, ISSN={["1941-0107"]}, DOI={10.1109/TPEL.2009.2013861}, abstractNote={A novel MOS-controlled silicon carbide (SiC) thyristor device, the SiC emitter turn-off thyristor (ETO), as a promising technology for future high-voltage and high-frequency switching applications has been developed. The world's first 4.5-kV SiC p-type ETO prototype based on a 0.36 cm2 SiC p-type gate turn-off (GTO) shows a forward voltage drop of 4.6 V at a current density of 25 A/cm2 and a turn-off energy loss of 9.88 mJ. The low loss shows that the SiC ETO could operate at a 4-kHz frequency with a conventional thermal management system. This frequency capability is about four times higher than the 4.5-kV-class silicon power devices. The numerical simulations and theoretical analysis have been carried out to show the potentially improved performance of the high-voltage SiC ETOs. The results show that the high-voltage (10-kV) SiC n-type ETO has much better tradeoff performance than that of the p-type ETO due to a smaller current gain of the lower bipolar transistor in the SiC n-type GTO. Further improvement of the 10-kV SiC n-type ETO can be made with the optimum design of the drift layer carrier lifetime and buffer layer doping concentration of the 10-kV SiC GTO. The theoretical analysis and numerical simulation shows the SiC ETO also has the excellent reverse bias safe operating area. The experimental and theoretical studies show that the SiC ETO is a promising candidate for high-voltage (> 5 kV) power conversion applications.}, number={5-6}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={Wang, Jun and Huang, Alex Q.}, year={2009}, pages={1189–1197} }
 @article{sung_wang_huang_baliga_2009, title={Design and investigation of frequency capability of 15kV 4H-SiC IGBT}, ISBN={["978-1-4244-3525-8"]}, ISSN={["1943-653X"]}, DOI={10.1109/ispsd.2009.5158054}, abstractNote={15kV 4H-SiC n-channel asymmetric and symmetric IGBTs were designed to minimize the on state and switching power loss. A Current Enhancement Layer was adopted to reduce the forward voltage drop for each IGBTs. For the asymmetric IGBT, it was found that the frequency capability of the device was affected most by adjusting the buffer region parameters such as doping concentration, thickness, and lifetime. For the symmetric IGBT, the p+ substrate doping concentration and drift region lifetime were investigated to obtain maximum switching frequency capability. A comparison of frequency capabilities between power MOSFETs, asymmetric, and symmetric IGBTs has been made. IGBTs provide lower power loss than power MOSFETs up to approximately 7 kHz.}, journal={2009 21ST INTERNATIONAL SYMPOSIUM ON POWER SEMICONDUCTOR DEVICES & ICS}, author={Sung, Woongje and Wang, Jun and Huang, Alex Q. and Baliga, B. Jayant}, year={2009}, pages={271–274} }
 @article{wang_huang_baliga_2009, title={RBSOA Study of High Voltage SiC Bipolar Devices}, ISBN={["978-1-4244-3525-8"]}, ISSN={["1063-6854"]}, DOI={10.1109/ispsd.2009.5158052}, abstractNote={Rapid improvement of 4H-SiC material quality and maturation of SiC device processing have enabled the development of high voltage SiC bipolar devices for high voltage switching applications. As one of the major concern of bipolar devices, the onset of dynamic avalanche breakdown and reverse biased safe operating area (RBSOA) of SiC pnp and npn transistors have been systematically analyzed in this paper. The theoretical analysis predicts the onset power density of dynamic avalanche breakdown of SiC bipolar devices is more than twenty times larger than that of Si bipolar devices, and SiC bipolar devices have a near square RBSOA. The predicted rugged turn-off behavior of SiC bipolar devices is verified by numerical simulations of 10-kV SiC emitter turn-off thyristors (ETOs). The excellent ruggedness of SiC bipolar devices make them attractive for high voltage (≥10-kV) switching applications.}, journal={2009 21ST INTERNATIONAL SYMPOSIUM ON POWER SEMICONDUCTOR DEVICES & ICS}, author={Wang, Jun and Huang, Alex Q. and Baliga, B. Jayant}, year={2009}, pages={263–266} }
 @article{wang_huang_sung_liu_baliga_2009, title={Smart Grid Technologies}, volume={3}, ISSN={["1941-0115"]}, DOI={10.1109/MIE.2009.932583}, abstractNote={The need for power semiconductor devices with high-voltage, high- frequency, and high-temperature operation capability is growing, especially for advanced power conversion and military applications, and hence the size and weight of the power electronic system are reduced. Development of 15-kV SiC IGBTs and their impact on utility applications is discussed.}, number={2}, journal={IEEE INDUSTRIAL ELECTRONICS MAGAZINE}, author={Wang, Jun and Huang, Alex Q. and Sung, Woongje and Liu, Yu and Baliga, B. Jayant}, year={2009}, month={Jun}, pages={16–23} }
 @article{wang_zhao_li_huang_callanan_husna_agarwal_2008, title={Characterization, modeling, and application of 10-kV SiC MOSFET}, volume={55}, ISSN={["1557-9646"]}, DOI={10.1109/TED.2008.926650}, abstractNote={Ten-kilovolt SiC MOSFETs are currently under development by a number of organizations in the United States, with the aim of enabling their applications in high-voltage high-frequency power conversions. The aim of this paper is to obtain the key device characteristics of SiC MOSFETs so that their realistic application prospect can be provided. In particular, the emphasis is on obtaining their losses in various operation conditions from the extensive characterization study and a proposed behavioral SPICE model. Using the validated MOSFET SPICE model, a 20-kHz 370-W dc/dc boost converter based on a 10-kV 4H-SiC DMOSFET and diodes is designed and experimentally demonstrated. In the steady state of the boost converter, the total power loss in the 15.45-mm2 SiC MOSFET is 23.6 W for the input power of 428 W. The characterization study of the experimental SiC MOSFET and the experiment of the SiC MOSFET-based boost converter indicate that the turn-on losses of SiC MOSFETs are the dominant factors in determining their maximum operation frequency in hard-switched circuits with conventional thermal management. Replacing a 10-kV SiC PiN diode with a 10-kV SiC JBS diode as a boost diode and using a small external gate resistor, the turn-on loss of the SiC MOSFET can be reduced, and the 10-kV 5-A SiC MOSFET-based boost converter is predicted to be capable of a 20-kHz operation with a 5-kV dc output voltage and a 1.25-kW output power by the PSpice simulation with the MOSFET model. The low losses and fast switching speed of 10-kV SiC MOSFETs shown in the characterization study and the preliminary demonstration of the boost converter make them attractive in high-frequency high-voltage power-conversion applications.}, number={8}, journal={IEEE TRANSACTIONS ON ELECTRON DEVICES}, author={Wang, Jun and Zhao, Tiefu and Li, Jun and Huang, Alex Q. and Callanan, Robert and Husna, Fatima and Agarwal, Anant}, year={2008}, month={Aug}, pages={1798–1806} }
 @article{zhang_wang_jonas_callanan_sumakeris_ryu_das_agarwal_palmour_huang_2008, title={Design and characterization of high-voltage 4H-SiC p-IGBTs}, volume={55}, ISSN={["1557-9646"]}, DOI={10.1109/TED.2008.926627}, abstractNote={High-voltage p-channel 4H-SiC insulated gate bipolar transistors (IGBTs) have been fabricated and characterized. The devices have a forward voltage drop of 7.2 V at 100 A/cm2 and a -16 V gate bias at 25degC, corresponding to a specific on-resistance of 72 mOmega ldr cm2 and a differential on-resistance of 26 mmOmega ldr cm2. Hole mobility of 12 cm2/V ldr s in the inversion channel with a threshold voltage of -6 V was achieved by optimizing the n+ well doping profile and gate oxidation process. A novel current enhancement layer was adopted to reduce the JFET resistance and enhance conductivity modulation by improving hole current spreading and suppressing the electron current conduction through the top n-p-n transistor. Inductive switching results have shown that the p-IGBT exhibited a turn-off time of ~1 mus and a turn-off energy loss of 12 m J at 4-kV dc-link voltage and 6-A load current at 25degC. The turn-off trajectory from the measured inductive load switching waveforms and numerical simulations shows that the p-IGBT had a near-square reverse bias safe operating area. Numerical simulations have been conducted to achieve an improved tradeoff between forward voltage drop and switching off energy by investigating the effects of drift layer lifetime and p-buffer layer parameters. The advantages of SiC p-IGBTs, such as the potential of very low ON-state resistance, slightly positive temperature coefficient, high switching speed, small switching losses, and large safe operating area, make them suitable and attractive for high-power high-frequency applications.}, number={8}, journal={IEEE TRANSACTIONS ON ELECTRON DEVICES}, author={Zhang, Qingchun and Wang, Jun and Jonas, Charlotte and Callanan, Robert and Sumakeris, Joseph J. and Ryu, Sei-Hyung and Das, Mrinal and Agarwal, Anant and Palmour, John and Huang, Alex Q.}, year={2008}, month={Aug}, pages={1912–1919} }
 @inproceedings{zhao_wang_huang_agarwal_2007, title={Comparisons of SiC MOSFET and Si IGBT based motor drive systems}, ISBN={9781424412600}, DOI={10.1109/07ias.2007.51}, abstractNote={With the rapid development of silicon carbide (SiC) material quality, SiC power devices are gaining tremendous attentions in power electronics. In this paper, a SiC device based motor drive system is performed to provide a quantitative estimate of the system improvement. Two 60 kW motor drive systems based on SiC MOSFET/Schottky diode and Si IGBTs are designed. The power losses of the two inverters with sinusoidal pulse width modulation (SPWM) control are calculated analytically. By comparing the efficiencies, sizes and temperatures of the two designed systems, SiC device shows the superior advantages of smaller loss, better efficiency and smaller size in the same motor drive application.}, booktitle={Conference record of the 2007 IEEE Industry Applications Conference forty-second IAS annual meeting}, publisher={New York:  IEEE}, author={Zhao, T. F. and Wang, J. and Huang, A. Q. and Agarwal, A.}, year={2007}, pages={331–335} }
 @article{rahman_wang_2002, title={Fuzzy neural network models for liquefaction prediction}, volume={22}, ISSN={["0267-7261"]}, DOI={10.1016/S0267-7261(02)00059-3}, abstractNote={Integrated fuzzy neural network models are developed for the assessment of liquefaction potential of a site. The models are trained with large databases of liquefaction case histories. A two-stage training algorithm is used to develop a fuzzy neural network model. In the preliminary training stage, the training case histories are used to determine initial network parameters. In the final training stage, the training case histories are processed one by one to develop membership functions for the network parameters. During the testing phase, input variables are described in linguistic terms such as 'high' and 'low'. The prediction is made in terms of a liquefaction index representing the degree of liquefaction described in fuzzy terms such as 'highly likely', 'likely', or 'unlikely'. The results from the model are compared with actual field observations and misclassified cases are identified. The models are found to have good predictive ability and are expected to be very useful for a preliminary evaluation of liquefaction potential of a site for which the input parameters are not well defined.}, number={8}, journal={SOIL DYNAMICS AND EARTHQUAKE ENGINEERING}, author={Rahman, MS and Wang, J}, year={2002}, month={Sep}, pages={685–694} }
 @article{rahman_wang_deng_carter_2001, title={A neural network model for the uplift capacity of suction caissons}, volume={28}, ISSN={["0266-352X"]}, DOI={10.1016/S0266-352X(00)00033-1}, abstractNote={Suction caissons are frequently used for the anchorage of large compliant offshore structures. The uplift capacity of the suction caissons is a critical issue in these applications, and reliable methods of predicting the capacity are required in order to produce effective designs. In this paper a back-propagation neural network model is developed to predict the uplift capacity of suction foundations. A database containing the results from a number of model and centrifuge tests is used. The results of this study indicate that the neural network model serves as a reliable and simple predictive tool for the uplift capacity of suction caissons. As more data becomes available, the model itself can be improved to make more accurate capacity prediction for a wider range of load and site conditions. The neural network predictions are also compared with finite element based predictions.}, number={4}, journal={COMPUTERS AND GEOTECHNICS}, author={Rahman, MS and Wang, J and Deng, W and Carter, JP}, year={2001}, pages={269–287} }
 @article{wang_rahman_1999, title={A neural network model for liquefaction-induced horizontal ground displacement}, volume={18}, ISSN={["0267-7261"]}, DOI={10.1016/S0267-7261(99)00027-5}, abstractNote={The horizontal ground displacement generated by seismically induced liquefaction is known to produce significant damage to engineered structures. A backpropagation neural network model is developed to predict the horizontal ground displacements. A large database containing the case histories of lateral spreads observed in eight major earthquakes is used. The results of this study indicate that the neural network model serves as a reliable and simple predictive tool for the amount of horizontal ground displacement. As more data become available, the model itself can be improved to make more accurate displacement prediction for a wider range of earthquake and site conditions.}, number={8}, journal={SOIL DYNAMICS AND EARTHQUAKE ENGINEERING}, author={Wang, J and Rahman, MS}, year={1999}, month={Dec}, pages={555–568} }
 @article{gabr_wang_zhao_1997, title={Buckling of Piles with General Power Distribution of Lateral Subgrade Reaction}, volume={123}, DOI={10.1061/(asce)1090-0241(1997)123:2(123)}, abstractNote={A model for evaluating the critical buckling capacity of long slender friction piles is developed with lateral soil support included based on the concept of the subgrade reaction. A general power distribution of the coefficient of the subgrade reaction (kh), with depth, is utilized in the model. The lateral force-deflection (P-y) behavior is assumed to be linear. A parametric study was conducted to demonstrate the effect of ω value, defining the distribution of the horizontal subgrade reaction, on the evaluated buckling capacity. In the case of the free top and fully embedded condition with embedment length (h) greater than 10 m, a 59% increase in the buckling capacity (Pcr) was predicted as ω was increased from 0 (constant horizontal subgrade reaction distribution) to 1 (linearly increasing horizontal subgrade reaction). Results also indicated that the boundary conditions at the pile tip have a minimal effect on Pcr when the nondimensional embedded length (h′) exceeded 3.3 for the free top, 5.6 for the f...}, number={2}, journal={Journal of Geotechnical and Geoenvironmental Engineering}, publisher={American Society of Civil Engineers (ASCE)}, author={Gabr, M. A. and Wang, J. J. and Zhao, M.}, year={1997}, month={Feb}, pages={123–130} }