@article{kumar_bhattacharya_baliga_2022, title={Influence of the Inverter Dead-time on the Reverse Recovery Characteristics of 3.3-kV SiC MOSFETs and JBSFETs}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE50734.2022.9947390}, abstractNote={The switching behavior of the high voltage (HV) SiC MOSFETs is superior to that of HV silicon IGBTs. In medium voltage high switching frequency power conversion applications, the reverse recovery effect of the body diode results in large switching losses. In this work, the reverse recovery behavior of the body diode of the recently developed 3.3 kV SiC MOSFETs is investigated at varying junction temperature and current levels. Two solutions are proposed to reduce the reverse recovery losses - by using the optimized dead-time and by integrating Schottky diode in the MOSFETs. The experimental results validate the proposed solutions. A device physics-based numerical model is used to explain the improvement in the body diode reverse recovery characteristics at the smaller dead-time.}, journal={2022 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Kumar, Ashish and Bhattacharya, Subhashish and Baliga, Jayant}, year={2022} }
 @article{pandey_pandey_narayan_2021, title={Designing organotrialkoxysilane-functionalized microscale enzyme carrier: Spherical polymersomes with tunable catalytic potential}, ISSN={["2044-5326"]}, DOI={10.1557/s43578-021-00296-1}, abstractNote={This manuscript describes fabrication of a cross-linked and nanoengineered three-dimensional matrix of polymersomes for encapsulation of macromolecular cargo such as enzymes. Our approach involves the integration of glucose oxidase (GOx) enzyme into networks of a polysaccharide-silica matrix. Direct chemical cross-linking occurs between the residual groups of alginate polymer and the alkoxysilane moieties in a palladium nanoparticle dispersion; a transformation in the chemical configuration of the alginate hydrogel along with precise control over the pore size distribution facilitate immobilization of enzyme. The activity of the polymersomes was evaluated by enzymatic oxidation of the glucose substrate in phosphate buffer through loading different concentrations of GOx. In situ generated H_2O_2 was decomposed by the as-synthesized Prussian blue nanoparticles, which serve as an excellent peroxidase mimetic. The functional enzyme polymersome system was utilized for in vitro detection of blood glucose values. Graphic abstract}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Pandey, P. C. and Pandey, Ashsish Kumar and Narayan, Roger J.}, year={2021}, month={Jul} }
 @article{kokkonda_kumar_anurag_kolli_parashar_bhattacharya_2021, title={Medium Voltage Shore-to-Ship Connection System Enabled by Series Connected 3.3 kV SiC MOSFETs}, ISSN={["1048-2334"]}, DOI={10.1109/APEC42165.2021.9487119}, abstractNote={Increasing concern about the environmental impact of ships has made Shore-to-Ship (STS) power an attractive solution for ship owners and port authorities worldwide in reducing emissions at ports. Existing shore-to-ship solutions for 0.1 MVA to 5 MVA applications employ silicon (Si) IGBT based static frequency converters. Recent developments in high voltage silicon carbide (SiC) devices have facilitated improvement in efficiency and power density of medium voltage (MV) converters in various applications. This paper proposes an MV STS system enabled by series connection of three 3.3 kV SiC MOSFETs, which shows the potential for improved power density and efficiency compared to existing Si IGBT based solutions. A 100 kVA 3-phase two-level voltage source converter (VSC) with series connected 3.3 kV SiC MOSFETs is designed and demonstrated. Experimental results for the series connected 3.3kV SiC MOSFET based converter is shown at 6 kV dc link voltage to validate the design and operation of such a system. Successful demonstration of a MV converter system enabled by series connection of high voltage SiC MOSFETs can open up opportunities to replace conventional Si IGBT based converters with SiC MOSFET based converters in applications interfacing with medium voltage grid.}, journal={2021 THIRTY-SIXTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2021)}, author={Kokkonda, Raj Kumar and Kumar, Ashish and Anurag, Anup and Kolli, Nithin and Parashar, Sanket and Bhattacharya, Subhashish}, year={2021}, pages={1380–1387} }
 @article{kumar_bhattacharya_baliga_veliadis_2021, title={Performance Comparison and Demonstration of 3-L Voltage Source Inverters Using 3.3 kV SiC MOSFETs for 2.3 kV High Speed Induction Motor Drive Applications}, ISSN={["1048-2334"]}, DOI={10.1109/APEC42165.2021.9487135}, abstractNote={Medium voltage direct-drive high-speed motor results in better efficiency and reduces the compressor system’s footprint in the oil and gas industry. This paper investigates the employment and the performance evaluation of the recently developed 3.3 kV SiC MOSFET power modules for a 2.3 kV three-phase high-speed motor drive application. Performance of the three popular three-level (3-L) converter topology, namely NPC, ANPC, and T-type, enabled by the 3.3 kV SiC MOSFETs and diodes is evaluated and compared with a 3.3 kV IGBT-based 2.3 kV drive system. At 10 kHz switching frequency, the test results show that the 3.3 kV SiC MOSFET-based 3-L NPC inverter has superior performance to the other 3-L converters at the motor frequency of 300 Hz. The 3.3 kV SiC MOSFET-based drive system is shown to have a significant improvement in reliability, power density, and efficiency in comparison to the 3.3 kV IGBT-based drive system. The 3.3 kV MOSFET module is demonstrated successfully using the heat run test in the 3-L inverter pole at 10 kHz switching frequency in the laboratory.}, journal={2021 THIRTY-SIXTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2021)}, author={Kumar, Ashish and Bhattacharya, Subhashish and Baliga, Jayant and Veliadis, Victor}, year={2021}, pages={1103–1110} }
 @article{kumar_bhattacharya_baliga_veliadis_2021, title={Performance Evaluation of 10 kV SiC Current Switch Based PWM Current Source Inverter for 4.16 kV Motor Drive Applications}, ISSN={["1048-2334"]}, DOI={10.1109/APEC42165.2021.9487162}, abstractNote={Series-connected 6.5 kV symmetric gate-commutated thyristor (SGCTs) are widely used as the reverse blocking switch (referred to as the current switch in this paper) in 4.16 kV PWM current source inverter (CSI) based motor drive applications up to 420 Hz switching frequency. Modern 10 kV SiC MOSFETs and SiC diodes have the potential to be implemented as the current switch with lower switching loss and a smaller count of the active switches in the 4.16 kV CSI-based drives. In this paper, a 10 kV SiC current switch is presented to enable a medium voltage (MV) PWM-CSI for 4.16 kV motor drive applications. The higher switching frequency capability of the 10 kV SiC current switch reduces the output current harmonics and the dc link inductor size significantly. Experimental tests have shown that the electrical and thermal performance of the 10 kV SiC current switch-based CSI is shown to be reasonably acceptable and near to 10 kV SiC MOSFET-based VSI drives at 10 kHz switching frequency.}, journal={2021 THIRTY-SIXTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC 2021)}, author={Kumar, Ashish and Bhattacharya, Subhashish and Baliga, Jayant and Veliadis, Victor}, year={2021}, pages={1219–1226} }
 @article{krishna_kumar_parashar_bhattacharya_2021, title={Performance Evaluation of a Novel High Voltage Monolithically Integrated SiC MOSFET-DIODE for Solar String Inverters}, ISSN={["2150-6078"]}, DOI={10.1109/ECCE-Asia49820.2021.9479330}, abstractNote={There has been an increase in large-scale solar power plants around the world. Most large-scale solar power plants operate at a DC bus voltage of 1000Vor less. It has been shown in current literature that an increase in DC bus voltage enhances the performance of the solar string inverters. The commercially available Si-based string inverters use complex multi-level inverter topologies to reduce the filtering requirements, eliminating the high-frequency operation of SiC MOSFETs. But SiC MOSFETs are associated with reverse recovery losses owed to its body diode. A novel device namely, Integrated MOSFET-DIODE was developed to eliminate this loss, where the reverse conduction is through a SiC diode rather than the MOSFET’s body diode. This paper demonstrates the advantages of a novel Integrated MOSFET-DIODE over Si devices and SiC MOSFETs in applying solar string inverters.}, journal={2021 IEEE 12TH ENERGY CONVERSION CONGRESS AND EXPOSITION - ASIA (ECCE ASIA)}, author={Krishna, Vineeth and Kumar, Ashish and Parashar, Sanket and Bhattacharya, Subhashish}, year={2021}, pages={2345–2351} }