- 學位論文
三相四開關直流無刷馬達之無速度感測控制
Speed Sensorless Control for Four-Switch Three-Phase Brushless DC Motor
摘要
馬達驅動系統一直是工業發展不可或缺的重要一環，降低馬達驅動器的製造成本也是不變的趨勢。而本論文還提出新的無轉子位置量測器的換相控制技術。此無感測控制是偵測兩相浮動電壓訊號的交越點，以求出轉子所需要的換相時機。此無感測控制只需要兩個電壓訊號，不需要任何轉子位置感測器，不僅可以減少感測器和配線成本，還可以增加系統的可靠度。本論文針對三相四開關的直流無刷馬達驅動器所設計的非對稱脈寬調變技術和新型的無位置感測控制，不僅減少了電力開關的數量，且不需要額外的轉子位置感測器，已經實現了一個相當經濟的直流無刷馬達驅動器。 若直流無刷馬達是使用霍爾元件(Hall Sensor)或其低解析度的轉子位置感測器，在直流無刷馬達運轉時，其轉速的取樣率會隨這轉速改變而改變。而本論文所提出的考慮變取樣現象的模糊PI控制器是由三個模糊控制器和三個不同PI控制組成。模糊控制器根據馬達轉速將轉速誤差模糊化後，再由PI控制器根據模糊化後的轉速誤差求得輸出命令，再將三個PI控制器的輸出加總；如此在馬達轉速改變時，模糊控制器會給PI控制器適當的轉速誤差，以達到更強健的速度控制。而本文所提的模糊PI控制器，以馬達轉速為參考，減少模糊邏輯設計的複雜度，使整個理論更容易實踐。 最後本論文將所提之非對稱脈寬調變技術與新型的無感測控制，分別用德州儀器公司(Texas Instruments, TI, Incorporated)的數位訊號處理器（Digital Signal Processor, DSP），和美商賽靈思(Xilinx)的場域可程式閘道陣列（Field Programmable Gate Array, FPGA）來實現，主要說明本文所提之無位置感測的換相控制，不需要複雜的計算，所以之需要低成本的DSP或FPGA就可以完成。本論文所提出的馬達驅動器，從變頻器的架構、轉子位置感測到控制器的使用，都減少了其元件數量和硬體需求，以達到最經濟的直流無刷馬達驅動器。
並列摘要
This dissertation proposes a novel asymmetric pulse width modulation (PWM) scheme for four-switch three-phase (FSTP) brushless dc (BLDC) motor drives. This PWM scheme not only achieves the BLDC motor using FSTP inverter, but also does not need any current sensor and complex algorithm, so it can make the lowest manufacture cost of the inverter. Furthermore, this dissertation proposes a novel commutation control for the FSTP BLDC motor drive without position sensor. This sensorless control detects the crossing point of two floating voltages, and estimates the commutation timing. This sensorless control only needs two voltage sensors, so it not only reduces the cost of position sensors, but also increases the reliability of whole system. When the BLDC motor drive uses Hall sensors as position sensors, sampling rates of the rotor speed will change with the rotor speed of BLDC motors. The fuzzy PI controller presented in this dissertation includes three fuzzy logics and three PI controllers. When the speed of BLDC motors changes, fuzzy logics will give PI controllers suitable speed errors to achieve robust control. The fuzzy logic of the fuzzy PI controller presented in this dissertation is based on the rotor speed, and therefore the controller reduces the complex of fuzzy logics and is easy to be implemented. Finally, we implement our novel asymmetric PWM scheme and novel sensorless control in DSP (Digital Signal Processor) which is designed by Texas Instruments, TI, incorporated and FPGA (Field Programmable Gate Array) which is designed by Xilinx to prove that the sensorless control does not need complex calculation, and can be implemented in very low cost controller.