直流無刷馬達無感測驅動技術之實現

Abstract

因直流無刷馬達有高功率密度、高效率以及易控制的特性，使得近年來被廣泛的應用在日常生活中。控制直流無刷馬達一般傳統的方式都是依賴安裝在馬達內部的位置感測器或是編碼器，但是這些方式存在了一些不可避免的缺點，例如體積和成本的增加以及會受到馬達運轉溫度的影響等。因此，無感測控制的方式近年來成為越來越被重視以及研究的課題。本論文主要目的是分析並且實現直流無刷馬達無感測偵測元件之驅動器研製。反電動式位置偵測法被運用在即時回授的系統中，偵測出轉子磁極的位置，以提供換相訊號。此外，無感測最常見到的啟動問題，也藉由論文中所提到的起始位置偵測方式克服了。一但起始位置被偵測出來之後，馬達便可有效率的由靜止啟動到要求的速度。這些無感測的控制方法以及由靜止啟動的過程將在實驗結果中完整呈現。

Nowadays, the BLDC motor becomes more and more attractive and be applied to many applications since it is easy to control and with high power density and high efficiency. Conventionally, the Hall-effect sensors are needed in electrical commutation. However, the Hall-effect sensors have several disadvantages, such as cost, size and reliability. Therefore, the sensorless control methods have been widely investigated in recent years. This thesis analyzes and then realizes a sensorless drive for the BLDC motor with the position estimated method to control the motor from standstill to the desired speed. In addition, the start-up problem existing in the back-EMF based method has been overcome simply by the initial position detection. Once the initial rotor position is attained, the motor can be driven from standstill effectively by a modified open-loop method. Finally, experimental results are included to demonstrate the success of the proposed sensorless control algorithm.