摘要
永磁無刷直流電機因結構簡單無需碳刷機械換相、調速性能好、運行效率高、成本低廉、體積小、安裝維護方便的特點，在農業(yè)、工業(yè)、國防和家用電器等領域的應用的范圍越來越廣。為了檢測電機轉子的位置通常需在電機內部安裝三個霍爾傳感器，而霍爾傳感器對溫度很敏感，容易損壞。為此，國內外對無位置傳感器檢測無刷直流電機轉子位置的控制策略進行了大量研究，但提出的方法都存在啟動性能差，容易堵轉和回退且常有失步現(xiàn)象，而且需要復雜的軟件計算，成本較高。
為了解決上述問題本文引用了一種通過檢測線電壓差獲得轉子位置的方法，提出的方法能在2%的額定轉速下準確檢測到轉子位置，從而可以利用簡單軟件實現(xiàn)電機的快速啟動。
本文主要研究了適用于空調內風機和外風機的無轉子位置傳感器的永磁無刷直流電機的啟動控制。首先從電機的基本電氣特性方程入手，詳細推導了無刷直流電機的數(shù)學模型。并在此基礎上進一步分析和推導出了該方法的數(shù)學表達式。
其次為了驗證本方法的正確性和可行性，得到線電壓差的數(shù)學模型，然后通過MATLAB對系統(tǒng)進行了建模并進行了相應的仿真。由得到了仿真結果可以看出理論分析和仿真上是完全可行的，從而為后續(xù)工作提供了強大的理論支持。
接著分別從硬件電路（電源電路）和軟件設計電路兩個方面進行了分析與設計。給出了硬件電路的原理電路和參數(shù)計算方法。同時，軟件方面為了克服無法計算零啟動時轉子位置，啟動時采用三段式啟動，并對啟動過程進行軟件跟蹤及啟動失敗的處理，確保了啟動的萬無一失。
最后，筆者裝配了一臺空調的室內風機控制系統(tǒng)，對研究成果——電源板和驅動板進行了實際的測試。最終，完成了無刷直流電機的零啟動和控制試驗。試驗結果表明：系統(tǒng)硬件工作正常，軟件設計合理，啟動速度低且平穩(wěn)無明顯抖動?？傮w看來，本文所做的工作得到了預期的結果。


關鍵詞 無刷直流電機；線電壓差；轉子位置；零啟動


Abstract
Brushless DC motor(BLDCM) has a simple structure without carbon brush mechanical commutation, exeellent speed adjusting performance, high operating effieieney, low cost , small in size , easy installation and maintenance etc. So in the field of agriculture, industry, defence and domestic electric appliances and so on, its application is getting more and more widespread. But, in order to detecting the rotor position must be installed three hall sensors in the motor. But hall sensors is very sensitive to temperature and damage easily. Therefore, Domestic and foreign began to do a large amount of research in detection of the sensorless brushless DC motor of rotor positions. But, these Control strategies still exist in the following defects, zero start-up performance is poor, easy to wager turn and back and often lose step phenomenon, And using complex software to get the rotor position increased costs.
The paper quote a new approach to get the rotor position signals by detecting the line voltage difference of ZCP to solve appeal problems.This method can get the rotor position at 2% rated speed. So, the motor can start-up from zero speed rapidly use this method.
The paper main study the BLDC startup control system ,it is suitable for the fans without rotor position sensor of inside or outside aire conditioning. First,this paper detailed the mathematical model of the BLDC basic on electrical characteristics of the motor.And getting the Mathematical expression of the method basis to further analysis and inferred.
Second, this paper get a system model for line voltage difference method through MATLAB and the corresponding simulation in order to verify this method is correct and feasible, get line voltage difference of the mathematical model. we can see this method in the theoretical analysis and the simulation is completely feasible by the simulation results, which provides a strong theoretical support for follow-up work.
Then, this paper analysis and design the hardware circuit (power circuit) and software. And it also presents the principle of the hardware circuit and the method of the parameters calculation. At the same time, software in order to overcome this situation that can not calculate the rotor position in the zero start-up stage, and the three-steps startup by using in software start-up stage ,and process tracking and failed to start treatment in this stage, ensure the start-up foolproof.
Finally, BLDC drive PCB and power PCB have been tested through the sample machine that is setted up by myself. At last completed the brushless dc motor starting and control experiments. The results show that the system hardware is working normally, the software design is reasonable, startup in a low speed and stable and no obvious speed jitter. In conclusion, this study has reached the desired goals.



Keywords BLDC; line voltage difference; rotor position;zero staet-up

目錄
摘要 I
Abstract III
第1章 緒論 - 7 -
1.1 永磁無刷直流電機在國內外發(fā)展和現(xiàn)狀 - 1 -
1.2 課題的由來 2
1.2.1 無位置傳感器位置檢測 - 2 -
1.2.2 無位置傳感器的無刷直流電機的啟動 - 2 -
1.2.3 轉矩脈動 - 2 -
1.2.4 最佳換相 - 3 -
1.3 本課題的研究現(xiàn)狀 - 3 -
1.3.1 無位置傳感器位置檢測 - 3 -
1.3.2 無位置傳感器的零啟動 - 5 -
1.4 本課題研究的主要內容 - 5 -
1.4.1 無刷直流電機原理和線電壓差檢測法的分析..