- 學位論文
應用單晶片PIC18F2431於無感測直流無刷馬達之驅動設計
Design of Drive System for Sensorless Brushless DC Motor Using Single-Chip PIC18F2431
摘要
本論文應用單晶片PIC18F2431設計一套無感測直流無刷馬達驅動系統。直流無刷馬達具有高轉矩與無碳刷換向的優點，在控制上又具備近似直流馬達的特性，因此在工業應用上有逐漸取代直流馬達的趨勢。在驅動技術上，產業界主要利用霍爾元件偵測轉子磁極位置方式進行驅動，但裝設霍爾元件須提供部份空間，且霍爾元件容易受工作環境影響而發生誤動作現象。 本論文所提出的方法，主要利用單晶片微處理器偵測馬達反電動勢訊號以得知轉子位置，並產生對應的三相脈波寬度調變（Pulse Width Modulation, PWM）波形，以驅動三相全橋式變頻電路，進而使馬達運轉，再透過改變三相PWM波形的週期與責任週期即可達成馬達的變速控制。 利用單晶片微處理器進行數位式的驅動控制，除了可以減少許多空間和成本，更由於單晶片微處理器能處理複雜的運算式，這使得單晶片微處理器在馬達控制上擁有更多的發展空間。本論文以實驗室馬達為例進行研究，並利用啟動特性實驗以驗証所提出方法的可行性。另外，本論文也利用負載變動實驗觀察系統的響應狀況，結果說明本論文所提出的驅動系統能快速反應負載的變動。
並列摘要
This thesis proposes the use of a single-chip microprocessor (PIC18F2431) to design a drive system of sensorless brushless DC (BLDC) motor. The BLDC motor has the advantages of high torque and no carbon brush, and it also can be controlled like a DC motor. Therefore, the BLDC motor is gradually used to replace the inductor motor in industry. In general, the Hall sensor is used to detect the position of rotor pole in industrial circles. However, it must provide some spaces to install Hall sensor. In addition, the Hall sensor is sensitive to the operation environment that will result in inaccuracy action. Instead of Hall sensor, this thesis employs single-chip microprocessor to detect the back electromotive force (BEMF) signals of motor in order to acquire rotor position. When the BEMF signals are obtained, the system can generate corresponding PWM signals to drive the three-phase full-bridge inverter circuit. The speed control of BLDC motor can then be accomplished through tuning the period and duty period of PWM signals. The digital control method using single-chip microprocessor can save much space and some of the expenses, and it can also deal with complex mathematics that greatly promotes the control performance of motor. To verify the feasibility of the proposed method, the step response is implemented in this thesis. In addition, the load variation experiment is also implemented to realize the response of the proposed system. Results show that the proposed drive system can make a fast response to the load variation.