摘要
無刷直流電機(BLDCM)是具有定子(電樞)繞組和永磁(PM)或凸極軟鐵轉子結構的新型電機,具有大轉矩、高效率、控制簡單、易維護等優點。論文從研究永磁無刷直流電機的結構出發,詳細論述了其工作原理。分析表明,與傳統直流電機有相似的控制性能,即改變電源電壓實現無級調速,控制電樞電流即可控制電磁轉矩。
系統采用電流環、速度環雙閉環的控制策略,電流環與速度環均采用 PI 控制。在比較了各種硬件控制方式的基礎上,設計了以16位定點電機優化控制芯TMS320LF2407A為核心的硬件控制系統,并完成了控制系統的軟件設計和系統調試。硬件控制系統的設計包括控制電路、電流采樣電路、轉子位置檢測電路以及驅動及逆變電路等;對各功能模塊(轉子位置捕獲、電流采樣、速度計算、弱磁、電流調節、速度調節等)的軟件實現、數字 PI 算法進行了詳細論述。
關鍵詞:永磁無刷直流電機;DSP;數字控制
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