Summary: | 碩士 === 國立臺灣海洋大學 === 系統工程暨造船學系 === 104 === In order to obtain fast and stable operation in three-phase sensorless direct cureent brushless permanent magnet motors (BLDCPMMs), generally they need encoders to detect position / angle and speed signals. Due to higher cost and additional assemble dimension, the volume of the motor system become large. Hence, sensorless driving method is presented in this study to obtain position / angle and speed signals in closed-loop velocity control. The amount of magnetic flux and torque of the motors can be calculated, and then through proportional-integral (PI) controllers of torque and flux. They pass into coordinate converter with field oriented control to obtain the proper voltage of space vector pulse width modulation for switching power transistors in motor drivers, and then can obtain a stable speed response. Additionally, in order to estimate accuracy electrical angles, fuzzy logic control, sliding mode control, and fuzzy logic sliding mode control are presented in this thesis to design electrical angle observers, and simulation results are verified by using MATLAB/SIMULINK. Finally, the electrical angle observer with an optimal fuzzy logic sliding mode controller combines with the velocity closed-loop PI controller can validate electrical angle precision of the rotors in the 80W three-phase radial-flux sensorless BLDCPMMs. In simulation results, the maximum error of the electrical angles can converge to ± 1.7∘ degrees; furtherore, the speed error can modified within ± 2 rpm when speed command setup at 9000 rpm.
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