TY - JOUR
T1 - Equivalent Thermal Conductivity Prediction of Form-Wound Windings with Litz Wire including Transposition Effects
AU - Yi, Xuan
AU - Yang, Tianyu
AU - Xiao, Jianqiao
AU - Miljkovic, Nenad
AU - King, William P.
AU - Haran, Kiruba S.
N1 - Manuscript received March 3, 2020; revised May 31, 2020; accepted July 29, 2020. Date of publication January 22, 2021; date of current version March 17, 2021. This work was supported by the National Science Foundation Engineering Research Center for Power Optimization of Electro-Thermal Systems (POETS) with cooperative agreements under Grant EEC-1449548. Paper 2020-EMC-0421.R1, presented at the 2019 International Electric Machines and Drives Conference (IEMDC), San Diego, CA, USA, May 12–15, and approved for publication in the IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS by the Electric Machines Committee of the IEEE Industry Applications Society. (Corresponding author: Jianqiao Xiao.) Xuan Yi, Jianqiao Xiao, and Kiruba S. Haran are with the Department of Electrical and Computer Engineering, University of Illinois at Urbana - Champaign, Urbana, IL 61801 USA (e-mail: [email protected]; [email protected]; [email protected]).
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Litz wire has been widely used in high-frequency electrical machines and transformers to minimize induced current loss and maintain high efficiency. Its heat dissipation capability can be a key design factor for high-power-density, high-frequency electrical machines. Although litz wire equivalent thermal conductivity has been studied, its transposition arrangement on heat dissipation enhancement is usually neglected. This article focuses on developing an analytical model to predict litz wire equivalent thermal conductivity including transposition effects. 3-D finite element models and hardware experiments are used to validate the proposed analytical model. Fast and accurate litz wire thermal conductivity prediction values can be obtained. The transposed and parallel arrangement effects on litz wire equivalent thermal conductivity are compared and discussed. This study shows that the transposition arrangement could improve litz wire heat dissipation capability by 10% to 30%, demonstrating that electrical machine power density can be potentially increased by up to 14%. The proposed method can advance winding design to push the boundaries of electrical machine power density.
AB - Litz wire has been widely used in high-frequency electrical machines and transformers to minimize induced current loss and maintain high efficiency. Its heat dissipation capability can be a key design factor for high-power-density, high-frequency electrical machines. Although litz wire equivalent thermal conductivity has been studied, its transposition arrangement on heat dissipation enhancement is usually neglected. This article focuses on developing an analytical model to predict litz wire equivalent thermal conductivity including transposition effects. 3-D finite element models and hardware experiments are used to validate the proposed analytical model. Fast and accurate litz wire thermal conductivity prediction values can be obtained. The transposed and parallel arrangement effects on litz wire equivalent thermal conductivity are compared and discussed. This study shows that the transposition arrangement could improve litz wire heat dissipation capability by 10% to 30%, demonstrating that electrical machine power density can be potentially increased by up to 14%. The proposed method can advance winding design to push the boundaries of electrical machine power density.
KW - Electrical machine
KW - form-wound winding
KW - litz wire
KW - thermal conductivity
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U2 - 10.1109/TIA.2021.3053500
DO - 10.1109/TIA.2021.3053500
M3 - Article
AN - SCOPUS:85100496793
SN - 0093-9994
VL - 57
SP - 1440
EP - 1449
JO - IEEE Transactions on Industry Applications
JF - IEEE Transactions on Industry Applications
IS - 2
M1 - 9333635
ER -