近年環保與節能意識興起，電動車之推廣使市場持續擴大，對馬達在不同負載下的性能與效能有更高的要求，因此追求更寬廣的調速範圍為馬達設計重要指標，其中定功率區間操作範圍為決定馬達特性曲線之重要因素。內藏型永磁同步馬達因高轉矩密度、高功率密度與較容易弱磁，使其成為目前電動車馬達應用趨勢。
本文針對表面型永磁同步馬達搭配轉子變磁通架構，以其低速區有高轉矩與高效率之優勢，並搭配變磁通控制維持高轉速之輸出功率，以延伸其定功率區間。其變磁通架構係透過無線傳輸線圈使定子側交流電經由磁感應傳輸至轉子側線圈，再以整流電路供應轉子場繞組直流電以進行變磁通控制。本文針對特定永磁馬達進行性能改善，首先提高磁石強度以提升低速轉矩輸出；接著針對永磁轉子加入變磁通繞組，並進行優化。最後，將優化之馬達與僅使用定子弱磁控制之原馬達進行效率地圖與輸出功率之比較，以達成高轉矩與高轉速之寬廣輸出範圍。

In recent years, with increasing consciousness of environment friendly and energy saving issues, electric vehicles have become a popular choice in the market, which triggers higher demands for the performance and efficiency of motors under different loads. Therefore, the pursuit of higher speed and constant power speed range is important index of motor design. Because interior permanent magnet motor have high torque density, high power density and easy to flux weakening control, it becomes the trend of electric vehicle motor.
This thesis focuses on surface permanent magnet motor equipped with wireless power transfer, which has the advantages of high torque and high efficiency at low speeds and uses the variable flux control to maintain the power at high speeds. The variable flux control uses a wireless transfer coil to transmit the current from stator side to rotor side via magnetic induction. For the purpose of performance improvement of permanent magnet motor, first, magnet with higher strength is chosen to increase the torque at low speeds; next, a variable flux winding in rotor side is added and then optimized. At the end, to achieve a wide output range of high torque and high speeds, the efficiency map and the output power of the optimized motor are compared with those of the original motor that only uses the stator field weakening control.

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