以單晶片DSP實現感應馬達之空間向量脈寬調變控制設計

Abstract

本文設計製作了一個以空間向量脈寬調變 (space vector pulse width modulation, SVPWM) 技術為切換方式的換流器。SVPWM切換方式具有高電壓利用率、低諧波及低切換損失等優點，相較於傳統SPWM切換方式，大大地提升了換流器的效率。在功率級部分，主要是以智慧型功率模組 (IPM) 為核心，搭配驅動介面電路、保護電路及動態煞車電路等來實現，其工作原理分析、設計過程都在本文中有詳盡的描述。在數位控制級部分，硬體上使用德州儀器 (TI) 公司所研發生產的數位訊號處理器TMS320F240來實現，此單晶片DSP不但運算速度快，且幾乎支援馬達控制所有的功能，使用起來非常方便；在軟體規劃上則是以SVPWM為架構的程式撰寫，其中包含一個主程式，作系統的設定及速度命令的讀取，與兩個中斷向量，分別作SVPWM計算及閉迴路控制。在控制結構部分，則使用比例積分 (PI) 閉迴路定電壓/頻率速度控制，其參數是應用學習自動機方法來調整，從最初任意給定的參數，慢慢經過調整而到最佳化。最後，將三個部分結合起來，驗證此換流器的可行性，比較開迴路、閉迴路的差異與經由學習自動機方法來作參數調整之效果，及分析各種相對應的馬達相電壓、相電流的輸出波形。

This thesis presents the design and implementation of an inverter by using the space vector pulse width modulation (SVPWM) method employing a digital signal processor (DSP). Compared with commonly used SPWM method, SVPWM has the advantages of higher voltage utilization, lower harmonic and lower switching loss. Also, it increases the efficiency of an inverter. In this thesis, the part of power stage is mainly composed by the intelligent power module (IPM), the driving interface, the protection circuit and the dynamic braking circuit. In the part of digital control stage, the DSP chip TMS320F240 produced by TI company, which is very suitable for motor control in high speed, is employed. The software in DSP is coded with the constant voltage/frequency SVPWM architecture, including one main program, which configures the system and the command input, and two interrupt vectors, which execute SVPWM calculation and closed-loop control, respectively. In the part of control method, the proportional and integral (PI) closed-loop speed control is employed, and the controller parameters are tuned by learning automata method . To verify the performance of the inverter with SVPWM method, the phase voltage waveforms, current waveforms and speed response of the motor have been discussed.