摘要
無(wú)刷直流電機(jī)(BLDCM)是具有定子(電樞)繞組和永磁(PM)或凸極軟鐵轉(zhuǎn)子結(jié)構(gòu)的新型電機(jī),具有大轉(zhuǎn)矩、高效率、控制簡(jiǎn)單、易維護(hù)等優(yōu)點(diǎn)。論文從研究永磁無(wú)刷直流電機(jī)的結(jié)構(gòu)出發(fā),詳細(xì)論述了其工作原理。分析表明,與傳統(tǒng)直流電機(jī)有相似的控制性能,即改變電源電壓實(shí)現(xiàn)無(wú)級(jí)調(diào)速,控制電樞電流即可控制電磁轉(zhuǎn)矩。
系統(tǒng)采用電流環(huán)、速度環(huán)雙閉環(huán)的控制策略,電流環(huán)與速度環(huán)均采用 PI 控制。在比較了各種硬件控制方式的基礎(chǔ)上,設(shè)計(jì)了以16位定點(diǎn)電機(jī)優(yōu)化控制芯TMS320LF2407A為核心的硬件控制系統(tǒng),并完成了控制系統(tǒng)的軟件設(shè)計(jì)和系統(tǒng)調(diào)試。硬件控制系統(tǒng)的設(shè)計(jì)包括控制電路、電流采樣電路、轉(zhuǎn)子位置檢測(cè)電路以及驅(qū)動(dòng)及逆變電路等;對(duì)各功能模塊(轉(zhuǎn)子位置捕獲、電流采樣、速度計(jì)算、弱磁、電流調(diào)節(jié)、速度調(diào)節(jié)等)的軟件實(shí)現(xiàn)、數(shù)字 PI 算法進(jìn)行了詳細(xì)論述。
關(guān)鍵詞:永磁無(wú)刷直流電機(jī);DSP;數(shù)字控制
ABSTRACT
The brushless DC motor (BLDCM) is a new style motor that has stator (armature) windings and a permanent-magnet (PM) or salient-pole soft-iron rotor. Permanent-magnet BLDCM has lots of merits, such as high torque, high efficiency,simple control, low maintenance. This dissertation analyzes in detail on structure and operation principle of permanent-magnet BLDCM. Accurate mathematic As the same as traditional DC motor, the torque produced by the motor is directly proportional to the current fed by the armature windings and generated voltage at the armature terminals is directly proportional to the motor velocity.
Double closed loop PI control strategy was adopted in this control system. Based on the compare of various control modes that are applied on permanent-magnet BLDCM, a DSP-based-control strategy has been put forward. Then the control software and system debug were completed. The design of control hardware included control circuit, current sampling circuit, position detection circuit, drive and inversion circuit. In software design, functional modules and digital PI algorithm have been discussed in detail.
Key words: Permanent-magnet BLDCM;DSP; Numerical control