高轉速無感測器直流無刷馬達之智慧型控制

Abstract

本論文針對無感測器直流無刷馬達提出模糊控制器，使馬達上之轉子轉動與定子換相時序能達到同步運轉，獲得馬達最佳效能。直流無刷馬達轉速控制包含了命令模組(command module)與調整模組(regulating module)。命令模組提供換相週期與PWM責任週期控制直流無刷馬達轉速，而以模糊控制器為機制的調整模組則是在外擾的情況下調整馬達轉速。僅藉由兩個電阻量測三相馬達未激磁端的反電動勢訊號去獲得目前馬達的運轉情況取而代之使用昂貴的霍爾感測器。以模糊控制器為機制的調整模組能準確並快速的調整PWM責任週期，促使馬達負載因外在因素影響變動時，馬達依舊能穩定運轉在指定的轉速。在本論文中，為了降低微控制器C8051F330在即時(real-time)控制上的計算負擔，我們能將所有情況經由模糊控制器在離線(off-line)狀況運算過，並將結果記錄下來且建立成一查表。實驗結果顯現出以模糊控制器為調整模組相較於無調整模組以及以比例控制器為調整模組表現優越。

In this thesis, the fuzzy logic controller (FLC) for sensorless brushless dc (BLDC) motor was proposed to synchronize the rotors with the stator windings commutation sequence to obtain the optimum efficiency of motor. There are two modules proposed in the speed control of BLDC motor, i.e. command and regulating modules. Command module is to find and issue commutation period and PWM duty cycle to the BLDC motor for desired speed. The regulating module is designed as a FLC and is used to regulate the speed of BLDC motor subject to disturbances, such as loading effect. Two resistances are adopted to detect the back-EMF signal on the unexcited phase instead of using the expensive Hall sensors. The regulating module can accurately and quickly regulate the PWM duty cycle by fuzzy reasoning which makes the BLDC motor rotate smoothly at desired rotational speed even if there is an external disturbance. In order to reduce the computational load of real-time FLC for the microcontroller C8051F330, we can perform the FLC computation off-line to cover nearly all cases. These data will be recorded and organized as a Look-Up Table (LUT). The regulating module is designed by FLC yield the better results than that without regulating module, and the regulating module via P controller.