Sneha Narasimhan
North Carolina State University
snarasi7@ncsu.edu
Bio
Sneha Narasimhan is a Ph.D. candidate at North Carolina State University working under the guidance of Dr. Subhashish Bhattacharya. Her research focuses on developing wide-bandgap-based current source inverters for motor drive applications, strongly emphasizing advancing energy efficiency and performance. During her Ph.D. studies, Sneha gained valuable industry experience as an ABB Corporate Research Center intern. She has been recognized for her academic excellence and contributions with several prestigious awards, including the 2024 Cadence Diversity in Technology Scholarship, the 2024 NCSU COE Doctoral Scholar for Citizenship and Service, and the 2023 NCSU ECE Doctoral Scholar of the Year. Beyond her research, Sneha is deeply committed to volunteerism and leadership, actively engaging with the NCSU community and the IEEE Power Electronics Society. She is passionate about advancing technology and fostering inclusivity within her field.
Areas of Research
- Electromagnetics and Energy
Medium Voltage Current Source Inverters for Motor Drives
Motor drive systems significantly contribute to energy consumption across the United States industrial, commercial, residential, and transportation sectors. However, the widespread adoption of variable speed drives (VSDs) is hindered by high capital costs, large footprints, and limitations of traditional silicon (Si) devices, including low switching frequencies and high losses. The emergence of wide-bandgap (WBG) technologies, utilizing silicon carbide (SiC) and gallium nitride (GaN) devices, offers a promising solution to these challenges. While medium voltage (MV) VSDs typically use voltage source inverters (VSIs) for low-power applications, current source inverters (CSIs) are employed in high-power MV scenarios. However, the broader adoption of CSIs has been limited. My Ph.D. research explores the potential of SiC-based CSIs for motor drive applications, especially in high-speed machines (HSMs). Unlike Si-based drives that require mechanical gearboxes, WBG devices allow inverters to operate at higher switching frequencies, improving efficiency and power density. Three current switch configurations were evaluated for CSI applications: SiC MOSFET with a series SiC Schottky diode, MOSFETs in common-source configuration, and MOSFETs in common-drain configuration. The configurations were assessed based on static and dynamic characteristics, with the SiC MOSFET and series diode configuration emerging as the most efficient. A Half-Bridge MV module was developed using this preferred configuration, with preliminary hardware results demonstrating successful operation. My research addresses reliability concerns by proposing a short-circuit fault detection scheme based on average currents verified in hardware prototypes. An open-circuit fault detection circuit is proposed to prevent over-voltage in CSI systems. This work contributes to developing more efficient and reliable motor drive systems, particularly in emerging applications like HSMs, and supports the growing demand for energy-efficient power electronics.