直流無刷馬達與變頻器的控制技術

Control Techniques for Brushless DC Motor and Inverter

林詠凱(Yong-Kai Lin 林詠凱)

指導教授 ： 賴炎生

國立臺北科技大學/電資學院/電機工程系研究所/博士(2010年)

https://doi.org/10.6841/NTUT.2010.00212

摘要

本文旨在探討直流無刷馬達以及變頻器的控制技術。本文提出了適用於直流無刷馬達驅動器的無感測器控制技術以及降低換相電流漣波技術，並且提出應用於變頻器的盲時消除技術以及變頻器的三相電流重建技術。
本文首先分析直流無刷馬達驅動器之脈波寬度調變訊號與馬達浮接相電壓的關係，並且由分析的結果發展出一個不需要轉軸感測器以及濾波器的直流無刷馬達控制技術；使其無需任何的相位補償以及系統參數便能具有寬廣的調速範圍。而實驗結果亦證實採用本文之無感測器控制技術時，直流無刷馬達在導通責任週期由5 %變化至95 %的情況下皆能穩定運轉。
其次，本文分析換相電流漣波的產生原因，並且提出一個可降低直流無刷馬達之換相電流漣波的控制技術；藉由降低直流無刷馬達之換相電流漣波的方式，進而改善其換相轉矩漣波。並且由實驗結果證實了在採用本文之降低換相電流漣波技術的情況下，直流無刷馬達換相時的相電流漣波最低可降至電流命令的0.1 p.u.。
接著，本文提出一應用於變頻器的盲時消除技術，藉以減少變頻器的輸出電壓損失以及降低其輸出電流諧波。同時以平均電流的觀念，克服電流零交越處因電流漣波造成電流極性判斷不易的缺點，並且不需要回授馬達的電流訊號。而實驗結果亦證實採用本文之盲時消除技術時，變頻器的電流總諧波失真最低可下降至0.7 %。
最後，本文提出了可使用於變頻器的電流重建技術，其僅以單一電流感測器便能重建變頻器的三相電流訊號；本文所提出的方法除了能有效拓展向量空間中的電流可重建範圍，更可以減少變頻器所產生的共模電壓。而由於本文所提出的方法只需要一個電流感測器，所以可大幅降低變頻器的硬體製作成本。並且實驗結果可以證實採用本文之電流重建技術時，當參考電壓向量由1.15 p.u.至0.103 p.u.的情況下皆能重建變頻器的三相電流訊號。

關鍵字

直流無刷馬達 ； 無感測器控制 ； 電流漣波 ； 變頻器 ； 盲時消除技術 ； 電流重建

並列摘要

The objective of this dissertation is to investigate the control techniques of Brushless DC Motor (BLDCM) and inverter. A sensorless control technique and a current ripple reduction technique for BLDCM drive are proposed. Moreover, a dead time elimination technique and a current reconstruction technique for inverter are also presented.
The relationship between pulse width modulation signal and floating phase voltage of BLDCM are analyzed for the development of sensorless technique which requires neither position sensor nor filter. Therefore, it does not need any phase compensation and system parameter for wide range speed control. The experimental results confirm that the BLDCM can be operated stably by the proposed method while duty ratio varying from 5 % to 95 %.
Moreover, the causes of commutation current ripple are analyzed and a current ripple reduction technique is proposed. Commutation torque ripple is improved by reducing commutation current ripple for BLDCM drive. The experimental results show that the lowest commutation current ripple can be reduced to 0.1 p.u. of its reference by the proposed method.
A dead time elimination technique which reduces voltage loss and current distortion for inverter is also presented. At the same time, the concept of current averaging without feedback current signal is used to overcome the issue that the current polarity is difficult to judge at zero crossing point due to current ripple. The experimental results illustrate that the lowest Total Harmonic Disstortion of inverter current is reduced to 0.7 % using proposed method.
Finally, a current reconstruction technique which only uses one current sensor to reconstruct three phase current signals is proposed. The proposed technique can not only spread the detection range for current sensing in vector space, but also decrease the common mode voltage which generated by inverter. Since only one current sensor is require for the proposed method, the cost can be reduced significantly. The experimental results demonstrate that three-phase current of inverter can be reconstructed by the proposed method while reference voltage vector varying from 1.15 p.u. to 0.103 p.u..

並列關鍵字

Brushless DC motor ； sensorless control ； current ripple ； inverter ； dead time elimination ； current reconstruction

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