本文旨在設計埋入型永磁式同步電動機，定子槽數為36槽，轉子為4極。轉子的磁鐵為埋入型，磁鐵結構為V字及一字混合型，具有凸極效應，調整d軸電流為負值以提高電磁轉矩，提升電動機運轉效率。在設計方面，轉子採用三段組合，每段錯置3.5度機械角，改善反電動勢諧波含量及轉矩漣波。
本文藉由轉子旋轉座標系統將abc軸轉換成qd軸模式，將三相電流轉換為qd軸電流，並用轉速閉迴路控制及qd軸電流閉迴路控制。文中採用Matlab/Simulink 模擬軟體分析埋入型永磁式同步電動機直軸電流為零及每安培最大轉矩(MTPA)之轉速電流閉迴路控制之差異，驗證本文控制策略可行性。
JMAG-Designer 磁路分析軟體用來分析永磁式同步電動機之參數：Lq=80μH及Ld=49μH。永磁式同步電動機在轉速為2500rpm 時之反電動勢為9.95 V 和磁通鏈19(mV/rad/s)。永磁式同步電動機之實測參數：Lq=66.35μH及Ld=40μH，永磁式同步電動機在轉速為2500rpm之反電動勢為8.4V和磁通16(mV/rad/s)。Lq與Ld不等值，以此驗證此永磁式同步電動機具有凸極效應。本文控制器採用數位訊號處理器(TMS320F28075)為控制核心，並透過C語言撰寫永磁式同步電動機的”d 軸電流為零”及MTPA”之轉速電流閉迴路控制策略。實測上，埋入型三相永磁式同步電動機在轉速為2500rpm 及電磁轉矩為5.2N-m時，d軸電流為0之轉速電流閉迴路控制時，電動機的運轉效率為82%。在MTPA之轉速電流閉迴路控制時，電動機的運轉效率為85%。由實驗結果得知，MTPA控制的運轉效率較佳。

The paper aims to design Interior Permanent Magnet Synchronous Motors (IPMSM). IPMSM consists of stator and rotor, which is 36-slot and 4-pole respectively. The magnets of the rotor are embedded type and structure of magnets is V-II mixed type. The embedded type contributes to the salient pole effect. Thus, controlling the d-axis current is less than zero can increase the electromagnetic torque and efficiency of the machine. In order to reduce the torque ripple and total harmonic distortion of back EMF, the rotor of the IPMSM is designed as three-step-skew. When the skew angle is designed at 3.5 degree , it results in the lowest THD of back EMF.
To utilize speed closed-loop and q-axis and d-axis current closed-loop control, three-axes was transferred into quadrature-axis and direct-axis by adopting Park's transformation method. Matlab/Simulink is performed to simulate the proposed IPMSM system and verify the feasibility of FOC and MTPA control strategy respectively.
JMAG software is performed to analyze the parameters of IPMSM, the q-axis inductance is 80μH and d-axis inductance is 49μH. When the speed of the IPMSM reaches at 2500 rpm, the back EMF is 9.95 V and the flux linkeage is 19(mV/rad/s). Regarding the experimental results, the q-axis inductance is 66.35μH and d-axis inductance is 40μH. When the speed of the IPMSM reaches at 2500 rpm, the back EMF is 8.4 V and the flux linkeage is 16(mV/rad/s). Both results show that q-axis inductance is not equivalent to d-axis inductance.Thus, it proves salient pole effect of IPMSM. A digital signal processor TMS320F28075 serves as core of control in the entire system. The closed-loop control strategy of speed and current of the IPMSM is written in C language. The speed and the load is set at 2500 rpm and 5.2 N-m respectively. The efficiency of the IPMSM using FOC strategy is 82%. The efficiency of the IPMSM using MTPA strategy is 85%. The experimental results show that MTPA control strategy is better than FOC control strategy.

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