@article{chattopadhyay_husain_2023, title={High Saliency Ratio Segmented Rotor Wound Field Synchronous Machine for Traction Applications}, DOI={10.1109/IEMDC55163.2023.10239061}, abstractNote={Wound Field Synchronous Machines present an attractive alternative to PMSMs in EV traction applications as they do not require expensive rare-earth magnets for rotor excitation. However, in high torque density designs, the saliency ratio of these machines tend to be poor due to the increased field excitation, which translates to saturation along the rotor d-axis. Therefore, the contribution of reluctance torque is small at rated torque, and the copper losses on the rotor field are high, which leads to higher cost and thermal issues. In this paper, a high saliency ratio segmented rotor wound field synchronous machine is presented with high reluctance torque, low copper loss, and low rotor mass. Details on the rotor design and optimization are presented, along with the structural analysis at the maximum speed. A detailed comparison of the proposed rotor to an optimized conventional rotor is provided. Drive cycle-based analysis has been used to demonstrate the suitability of the proposed design in EV traction applications.}, journal={2023 IEEE INTERNATIONAL ELECTRIC MACHINES & DRIVES CONFERENCE, IEMDC}, author={Chattopadhyay, Ritvik and Husain, Iqbal}, year={2023} }
 @article{chattopadhyay_islam_husain_2023, title={Torque Ripple Minimization of Wound Field Synchronous Machines using Asymmetric Rotor Pole Spacing}, DOI={10.1109/IEMDC55163.2023.10239065}, abstractNote={Motors with low torque ripple are necessary for many applications such as automotive traction, robotics, and medical instrumentation. This paper presents a novel method to mitigate torque ripple in wound field synchronous machines (WFSM) using unequally pitched rotor poles. This method retains the same basic structure of salient pole WFSM rotors and does not require additional manufacturing steps. Details on the analytical formulation for the optimal pitch for alternate rotor poles to minimize the dominant order of torque ripple harmonic, along with FEA-based analysis are presented; the results for the unequally spaced rotor are compared with that of a baseline rotor and a 3-step skewed rotor through torque ripple maps, fourier analysis of torque waveforms, analysis of airgap radial pressure, and structural FEA analysis.}, journal={2023 IEEE INTERNATIONAL ELECTRIC MACHINES & DRIVES CONFERENCE, IEMDC}, author={Chattopadhyay, Ritvik and Islam, Md Sariful and Husain, Iqbal}, year={2023} }
 @article{chattopadhyay_islam_jung_mikail_husain_2022, title={Winding Embedded Liquid Cooling for Slotless Motors in Transportation Applications}, volume={58}, ISSN={["1939-9367"]}, DOI={10.1109/TIA.2022.3191629}, abstractNote={A novel winding embedded liquid cooling (WELC) concept is presented to improve the thermal management of slotless motors for transportation applications. The concept introduces liquid cooling channels through the non-magnetic thermal plastic winding support in a slotless motor to reduce the thermal resistance between the heat source and the sink. This article demonstrates the efficacy of the WELC concept for a 11.5-kW slotless motor using computational fluid dynamics (CFD). A lumped parameter thermal network has also been developed for the WELC concept, which has been validated using the CFD analysis. The simulation results of WELC concept have been experimentally validated for an 11.5-kW slotless motor. It is shown that the WELC concept can achieve a continuous current density of 19.0 A(rms)/mm<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula> for an allowable temperature rise of 80 <inline-formula><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>C; the achieved continuous current density is 35% higher than that of a conventional axial in-slot water jacket cooling. The short time (18 s) peak current density achieved with the WELC concept is 39.8 A(rms)/mm<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula>.}, number={6}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Chattopadhyay, Ritvik and Islam, Md Sariful and Jung, Junyeong and Mikail, Rajib and Husain, Iqbal}, year={2022}, month={Nov}, pages={7110–7120} }