Showing 42 results for Author: Shajjad S. Chowdhury
Sep, 2026
Conference Paper
In this study, we present a resonant rotary transformer (RT) with an integrated rectifier for brushless excitation of wound rotor synchronous motors in electric vehicle applications. The primary-side of the RT employs an LCC resonant tank with Litz-wire winding and a high-frequency ferrite backplate, while the high-speed rotating secondary integrates the coil and rectifier…
Sep, 2026
Conference Paper
This paper proposes a four-phase wireless power transfer (FPWPT) system for high-power energy transfer applications. Compared with conventional circular three-phase WPT systems, the proposed FPWPT reduces magnetic flux density and heat flux while improving space utilization by fully occupying square or rectangular areas. Each phase coil can be implemented in a rectangular…
Sep, 2026
ORNL Report
As artificial intelligence (AI) computing densities continue to increase, industry is pursuing megawatt-scale rack architectures that require tightly coordinated advances in electrical power delivery, thermal management, operations, and infrastructure integration. This document summarizes the primary technical challenges for achieving this target.
Aug, 2026
Conference Paper
This paper investigates the use of intermediate coils positioned between the primary and secondary coils in Wireless Power Transfer (WPT) systems for electric vehicle (EV) charging, with the objective of improving power transfer efficiency and robustness under misalignment conditions. An optimized 1 kW power system that operates at 85 kHz is developed and the misalignment…
Jul, 2026
Conference Paper
This work presents the prototyping and testing of a high-speed outer rotor surface permanent magnet motor. The motor employs non-heavy rare-earth permanent magnets and operates at a rated speed of 6,666 rpm. In-slot ceramic heat exchangers are used to cool the windings. The external rotor configuration provides substantial space within the stator bore, which is used for po…
Jun, 2026
Conference Paper
Multi‑gear transmission systems are commonly used in electric traction drives for medium and heavy‑duty vehicles, while most passenger‑vehicle electric drivetrains rely on a single fixed ratio to reduce cost, weight, and complexity. Using multiple gear ratios can enable downsizing of the motor and inverter while still meeting performance requirements. Additionally, appropr…
Jun, 2026
Conference Paper
The ever-increasing demand for compact, efficient, and high-performance traction drive systems for transportation applications has accelerated the development of integrated electric drives. In these systems, the electric machine and inverter are integrated within a single housing, offering significant advantages in electrical performance, volume, weight, cost, and overall…
Mar, 2026
Conference Paper
This paper presents an integrated on-board charger for dual motor based electric vehicle (EV) power train with silicon carbide semiconductor switch-based traction inverters. The proposed charger architecture reconfigures the traction inverters to be used in the battery charging mode, thereby eliminating several high frequency switches and their accessories. The motor windi…
Mar, 2026
Conference Paper
This article proposes an inverse segmented motor drive (SgMD) utilizing dual active neutral point clamped (ANPC) inverters. In the proposed configuration, the neutral point current and common-mode (CM) voltage is topologically canceled, achieving zero total neutral point current and CM voltage under ideal conditions. Also, the zero total neutral point current minimizes the…
Mar, 2026
Conference Paper
Minimizing parasitic inductance of power modules is needed to advance their electrical performance. Innovation in the past decade has driven down the inductance of SiC half-bridge power modules to around 1–2 nH by using multilayer, embedded, and hybrid structures. Further reduction becomes difficult, mainly limited by the excessive interconnects required for the planar pla…
Mar, 2026
Conference Paper
This work presents the detailed design of an outer rotor motor and integrated drive for passenger electric vehicles. The motor uses non-heavy rare earth permanent magnets and operates at a top speed of 20,000rpm. In-slot ceramic heat exchangers are utilized for the cooling of the windings. The external rotor configuration of the motor leaves a significant amount of space i…
Mar, 2026
Conference Paper
This paper presents a multiport converter (MPC) based power supply to charge the 12 V and 24 V auxiliary batteries in heavy duty (HD) fuel cell (FC) electric vehicle (EV) power train. Compared to conventional auxiliary power supply architectures, the proposed architecture shares the power electronic components of the main power train yet preserves the isolation and all oth…