- 學位論文
永磁同步馬達驅動系統之無位置感測控制與噪音降低研究
POSITION SENSORLESS CONTROL AND ACOUSTIC NOISE REDUCTION STUDY FOR PERMANENT MAGNET SYNCHRONOUS MOTOR DRIVE
摘要
摘 要 本論文旨在從事永磁同步馬達(Permanent magnet synchronous motor, PMSM)驅動系統之無位置感測控制及噪音降低研究。首先建構一以數位信號處理器為主之PMSM驅動系統，應用一強健電流控制及應電勢估測機構可得緊密之線圈電流波形追控特性，而同時估得之應電勢可供從事弦波式同步馬達之無位置感測控制。接著研製升壓型切換式整流器(Switch-mode rectifier, SMR)，提供可調控之直流鏈電壓，增進馬達驅動系統之運轉性能。 在降低低頻式SMR之振動及噪音研究方面，先由實驗中辨出主要電感之振動頻率。接著提出消除特定振動頻率及同時消除雙振動頻率之固定、交替及隨機之三階段激磁法。對於高頻SMR則採任意變化磁滯帶及任意變化切換頻率技巧之電流切換控制。各法均詳加介紹其原理及從事性能實測比較評定。 最後在無位置感測控制方面，首先應用含有PMSM轉子絕對位置之估測應電勢從事施行弦波式同步馬達之無位置感測驅動控制之依據。以此方式所得之不理想直流無刷操控特性，再經所提智慧型調控予以改善，因而獲得良好之動態及穩態操控性能。此外，本論文也提出一初始位置偵測控制機構，並從事於無位置感測PMSM之單一方向啟動控制。 關鍵詞：永磁同步馬達、無位置感測控制、強健電流控制、切換式整流器、低頻切換、隨機切換、三階段激磁、應電勢估測、智慧型調控、初始位置偵測、單一方向啟動。
並列摘要
ABSTRACT This thesis is mainly concerned with the position sensorless control and the acoustic noise reduction studies for permanent-magnet synchronous motor (PMSM) drive. First, an experimental digital signal processor (DSP) based PMSM drive is established. A robust current control and back-EMF estimation scheme are proposed to yield close and robust current tracking performance. And the motor back electromagnetic force (EMF) can be observed and employed for performing the proposed sensorless control. Secondly, the suitable front-end switch-mode rectifiers (SMRs) are developed and utilized to establish boostable and well-regulated DC-link voltage for the followed PMSM inverter. In addition to the control and performance evaluation of the SMR-fed motor drive, the vibration and acoustic noise reductions for the SMR and the inverter-fed PMSM are also studied. In vibration and acoustic noise reductions of SMR, the important audible vibration modes of the inductor employed in the low-frequency (LF) SMR are first identified from measurements. Then the controls for eliminating one specific vibration mode and two vibration modes simultaneously via deterministic and stochastic three-stage excitation approaches are studied. As to the HF SMRs, a random switching frequency ramp-comparison current-controlled PWM (RC-CCPWM) scheme and a randomly band hysteresis CCPWM scheme are developed. Theoretical bases of all proposed control approaches are derived and their comparative performances are evaluated experimentally. On the other hand, the acoustic noise reduction for the PMSM drive via random PWM approach is also conducted. As to the sensorless control aspect, the motor back-EMF estimated using the proposed scheme, which contains the absolute rotor position information, is used to perform the position sensorless control of PMSM. The nonideal position estimation is then improved by an intelligent tuning scheme, wherein the estimated rotor position is tuned to yield minimum torque current component and thus better sensorless vector control performance. In addition, the motor can be automatically and quickly started under the preset torque current limit. Moreover, to achieve unidirectional starting under position sensorless control, a simple and practical initial rotor position estimation and starting scheme is further developed. Key words: Permanent-magnet synchronous motor, position sensorless control, acoustic noise, robust current control, switch-mode rectifier, low-frequency switching, random switching, three-stage excitation, back-EMF estimation, intelligent tuning, initial rotor position estimation, unidirectional starting.