感應馬達之無感測器定V/f控制器的研製

本文提出一種具有滑動模式控制器的無感測器感應馬達定V/f控制法則，整體架構以定V/f控制法為基礎。在本系統中，定子電壓補償法為在任何頻率下計算馬達所需之定子電壓並進行補償，目的為維持氣隙磁通為其額定值並使馬達能有最佳輸出轉矩之能力。而定子電阻壓降的補償是依據定子電壓導向參考座標下之定子電流的直、交分量來計算。本系統所加入之滑動模式控制器，目的為減少馬達轉速之穩態誤差並提升系統對於外在干擾的免疫能力。另外，利用定子側電壓及電流的回授值來進行同步轉速與滑差頻率的估測，並藉此達成實質上為閉迴路的控制架構以提高馬達的控速精度。為驗證所提方法之效能，首先，利用MATLAB/Simulink 軟體去模擬驗證本文所提方法的可行性，接著以德州儀器公司所生產的eZdsp TMS320LF2407A數位訊號處理器為核心，來實現整體的馬達控制系統。由模擬和實驗結果證明，不管在無載或加載情況下，其結果顯示出本文所提方法在穩態響應與動態特性上均有良好之性能表現。

關鍵字

定V/f控制；定子電阻壓降補償；無感測器；滑動模式控制；數位訊號處理器

並列摘要

This paper presents a sensorless induction motor constant V/f control method with sliding mode controller. In order to maintain the air gap flux of the motor at its rated value to develop rated torque at any frequency, the stator resistance voltage drop compensation and slip frequency compensation are needed. In this paper, the direct and quadrature component of the stator current in the stator voltage oriented reference frame is calculated to implement the vector compensation for stator resistant drop. The sliding mode controller is used to reduce the steady state error of speed and increase the system robust for external noise. In addition, the voltage command and feedback current are used to estimate the synchronous speed and slip frequency. To verify the effectiveness of the proposed method, A simulation verification work is done by MATLAB/Simulink software. Then, a digital signal processor(eZdsp TMS320- LF2407A) based experimental system is developed testing the performances of the drive system. The experimental results show that good steady and transient responses, both in no-load and loading conditions, are obtained by the proposed method.