| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 93 === The thesis proposes a novel design and optimal driving current wave for a brushless DC wheel-motor. First, we obtain the realization of current and back EMF waveform from the torque equation of motor constructed by energy method. The wheel motor has a maximum torque as the current and the back EMF waveform are proportional, i.e., the optimal current waveform follows the back EMF waveform. Second, we establish a 3-D model by the finite element analysis software, and obtain the results of simulation of the back EMF waveform. In the 3-D finite element analysis model, we decompose the back EMF waveform into different order of partial sums to analyze the corresponding torque and torque ripple. Then, the best current waveform is determined. Finally, we fabricate a prototype for the wheel motor and drive it with square, sinusoidal, and optimal current waveforms to test the wheel-motor’s performance.
It is shown by experiment that the back EMF waveform is similar to that obtained by finite element analysis, which reveals that the wheel motor must produce satisfactory torque. However, the torque from experiments reduces about 20% because of the malfunction of encoder signals. More improvement of the wheel motor is to expected before the implementation on a passenger car.
|
|---|
