方波脈寬調變及其於直流無刷馬達無感測控制之應用

Abstract

本論文首先利用電壓源變頻器(VSI)，探討一般六步方波脈寬調變之線性導通組合在輸出電壓上對於諧波大小分佈之普遍影響性，另外根據不同方式的線性導通組合對於開關導通損與切換損之影響，提出最佳之導通組合方式。相同的研究方法亦用來探討十二步方波脈寬調變之線性導通組合，並比較各方波脈寬調變於不同導通方式之諧波失真度。而後，為了更近似馬達特性，加入電感負载於電壓源變頻器，模擬不同之方波脈寬調變下之電流波形並觀察諧波失真度。 在探討不同方波脈寬調變之線性導通之優劣後，進行無感測控制技術之研究，本論文利用反電動勢電壓無感測控制技術配合方波脈寬調變，選擇較常應用之不同反電動勢電壓無感測控制電路，針對不同環境下所產生之無感測開關信號在實際位置偵測上的誤差比較後，篩選出適當之反電動勢電壓無感測控制電路。 根據所選反電動勢偵測電路之特性，選擇不同方波脈寬調變所適合之導通方式進行模擬及實作，並加以討論。

In this thesis, we used the voltage source inverter to discuss the influence of harmonics in output current with common six-step square-wave PWM (SWPWM). According to the loss and thermal characteristics of switches with various types for linear SWPWMs scheme, we propose the best types. Similarly, we discussed the performance of twelve-step SWPWM with the same method and compared the total harmonic distortion (THD) values in various types of linear SWPWMs. Then, to approximate the characteristic of motors, we added the inductance into the VSI and simulated to observe the THD values of output current in various types for linear SWPWMs. After discussing the performance of output current in various types of linear SWPWMs, we make a study of the sensorless control. In this thesis, we used back-EMF sensorless control and select different back-EMF sensorless control circuits to product commutation signals. For the errors which commutation signal compare with real position-detecting in different conditions, we can choose the suitable circuit to simulate and experiment. After above discussion, according to the characteristics of the selected back-EMF detecting circuit, we sieve out the suitable types for linear SWPWMs and simulated and experiment with various types for linear SWPWMs