以數位座標旋轉演算法為主之直流無刷馬達弦波電流無感測控制

Abstract

本論文以數位訊號處理器(Digital Signal Processor,DSP)來實現弦波直流無刷馬達之無感測速度迴路控制。首先分析馬達的等效模型和討論控制策略。然後利用擴展應電勢(Extended Electromotive Force, EEMF)推導出本篇論文所使用的位置誤差估測式，因此位置誤差估測式為一反正切(arctan)函數，故我們利用數位座標旋轉演算法(CORDIC)運算出結果。之後在PSIM建立整個無感測控制電路架構並且模擬確立其可行性後，再進入實作。在實作中我們利用光編碼器來偵測轉子位置，先完成整個磁場導向控制有感測控制系統作為比對之用。之後在有感測之情況下，利用本篇論文之角度誤差估測式加上數位座標旋轉演算法來推算得估測角度誤差值並與真正誤差進行比對。確定角度估測是正確後，再進入無感測控制實作。實作驗証結果本篇所提之無感測控制架構是可行的。

This thesis presents the implementation of a sensorless speed controller for brushless DC motor(BDCM) with sinusoidal current waveform. First, the BDCM equivalent model and the control strategies are studied, an equation for estimated position error based on EEMF is derived. After the simulation of CORDIC, EEMF and BDCM driver in PSIM, the proposed CORDIC-based sensorless control is demonstrated. Then, the conventional FOC(Flux-Oriented Control) with an encoder is implemented. After comparing the estimated angular error of CORDIC to the actual angular error and implementing the sensorless controller for BDCM, the provided experimental results also demonstrate the proposed sensorless control.