在過去十年，隨著電動車市場需求的成長，永磁同步馬達廣受青睞。然而，永磁體價格波動使業界開始尋求替代方案，繞線式轉子同步馬達逐漸引起關注，因其不需仰賴永磁體，且可透過外部電路調整轉子磁場進行弱磁控制，比永磁同步馬達在控制層面更簡單，並具有成本與策略上的優勢。
然而，繞線式轉子同步馬達採用滑環與碳刷進行機械式傳輸，容易在高速運轉下產生火花並導致磨損，需定期維護。為解決此問題，本研究引入旋轉變壓器，實現非接觸式能量傳輸，並整合繞線式轉子同步馬達與旋轉變壓器的設計。
在旋轉變壓器部分，為降低傳統矽鋼片堆疊方法導致的鐵損，本研究設計了新的矽鋼片堆疊方式，並使用ANSYS MAXWELL進行3D模擬驗證。同時，在繞線式轉子同步電機的設計上，也採用新方法並透過模擬進行優化。這些改進使繞線式轉子同步馬達具備了更高的穩定性與效率，為未來取代永磁馬達提供了可能性。

In the past decade, permanent magnet synchronous motors (PMSMs) have gained popularity with the growing demand for electric vehicles. However, fluctuations in the price of permanent magnets have driven the search for alternatives. Wound-rotor synchronous motors (WRSMs) have attracted attention as they eliminate the reliance on permanent magnets and allow for field weakening control via external circuits, offering simpler control strategies and cost advantages compared to PMSMs.
Despite these benefits, WRSMs utilize slip rings and brushes for mechanical power transmission, which can cause sparking and wear, especially at high-speed operation, necessitating frequent maintenance. To address these issues, this study introduces a rotary transformer for contactless power transmission, integrating its design with WRSMs.
To enhance the efficiency of the rotary transformer, an adhesive steel sheet lamination stacking method is proposed to reduce iron losses associated with conventional stacking techniques.

[1] "EV Motor Power and Motor Materials Tracker," Adamas intelligence., 2019.
[2] https://www.mirdc.org.tw/FileDownLoad/IndustryNews/201133103147603.pdf
[3] https://www.idtechex.com/en/research-report/electric-motors-for-electric-vehicles-2025-2035-technologies-materials-markets-and-forecasts/1031
[4] https://about-motors.com/motorcontrol/wrsm/
[5] T. Raminosoa and R. Wiles, "Contactless Rotor Excitation for Traction Motors," 2018 IEEE Energy Conversion Congress and Exposition (ECCE), Portland, OR, USA, 2018, pp. 6448-6453, doi: 10.1109/ECCE.2018.8557553.
[6] https://www.elprocus.com/types-of-losses-in-a-transformer-and-their-efficiency/
[7] https://eepower.com/technical-articles/transformer-losses-and-efficiency/#
[8] Stefan Botha, "Three Phase Rotary Transformer for a Rotor Tied Doubly fed Induction Machine"
[9] Y. Zhang, J. Yang, D. Jiang, D. Li and R. Qu, "Design, Manufacture, and Test of a Rotary Transformer for Contactless Power Transfer System," in IEEE Transactions on Magnetics, vol. 58, no. 2, pp. 1-6, Feb. 2022, Art no. 8400206, doi: 10.1109/TMAG.2021.3094135.
[10] T. Raminosoa and R. Wiles, "Contactless Rotor Excitation for Traction Motors," 2018 IEEE Energy Conversion Congress and Exposition (ECCE)
[11] S. Ditze, A. Endruschat, T. Schriefer, A. Rosskopf and T. Heckel, "Inductive power transfer system with a rotary transformer for contactless energy transfer on rotating applications," 2016 IEEE International Symposium on Circuits and Systems (ISCAS), Montreal, QC, Canada, 2016
[12] Y. Zhang, J. Yang, D. Jiang, D. Li and R. Qu, "Design, Manufacture, and Test of a Rotary Transformer for Contactless Power Transfer System," in IEEE Transactions on Magnetics
[13] S. Botha, "Three phase rotary transformer for a rotor tied doubly fed induction Machine," Stellenbosch: Stellenbosch University, 2022.
[14] J. Haruna and T. Raminosoa, "Modeling and steady-state analysis of a rotary transformer-based field excitation system for wound rotor synchronous machine," in 2019 IEEE Transportation Electrification Conference and Expo (ITEC), 2019: IEEE, pp. 1-8.
[15] H. Krupp and A. Mertens, "Rotary transformer design for brushless electrically excited synchronous machines," in 2015 IEEE Vehicle Power and Propulsion Conference (VPPC), 2015: IEEE, pp. 1-6.
[16] S. Udema and C. Fräger, "Rotary transformer for contactless excitation of synchronous machines fed through neutral conductor," in 2019 IEEE International Electric Machines & Drives Conference (IEMDC), 2019: IEEE, pp. 1724-1730.
[17] M.R. Park, D.M. Kim, Y.H. Jung, M.S. Lim, and J.P. Hong, "Modeling, design and control of wound-field synchronous motor for high energy efficiency of electric vehicle," in 2019 IEEE Energy Conversion Congress and Exposition (ECCE), 2019: IEEE, pp. 3960-3967.
[18] R. Manko, S. Čorović, and D. Miljavec, "Analysis and design of rotary transformer for wireless power transmission," in 2020 IEEE Problems of Automated Electrodrive. Theory and Practice (PAEP), 2020: IEEE, pp. 1-6.
[19] M. Tosi, N. Bianchi, and H. Herzog, "Rotary transformer design for brushless electrically excited synchronous machines," University of Padua, Padua, 2014.
[20] https://www.sohu.com/a/468335104_121124371