以CPLD為基礎之永磁同步馬達直接轉矩控制IC之研製

Abstract

本論文以複雜型可程式化邏輯晶片(Complex Programmable Logic Device, CPLD)實現應用於永磁同步馬達修正式直接轉矩控制IC，電路實現方式採用階層式、模組化的設計方式，降低其複雜度，並以電路並用的概念，降低邏輯閘數量，達到最佳化的目的。直接轉矩控制(Direct Torque Control, DTC)是以轉矩及磁通量做為輸入命令的一種控制方法，經由遲滯控制器的運算及電壓向量切換表直接地求出符合命令所需的電壓向量。本文主要針對傳統直接轉矩控制變頻之電流迴路，進一步設計成修正式直接轉矩控制，並討論其無感測特性，藉由MATLAB/Simulink軟體進行控制架構的模擬與實驗結果分析，以期所設計的控制系統能達到快速的系統反應外，還有較好的穏態電流及轉矩響應和固定的切換頻率。本文同時分析系統需求，探討位元長度與控制IC之規格。在周邊方面處理方面，可直接將電流回授量及速度回授量由類比/數位轉換器及增量光編碼器取得。本文所設計的IC具有可程式化的特點，經由微處理器等外部通訊介面設定可對此控制IC調整及觀測各個參數及變數，所有參數及變數可在線及即時讀出或寫入內部暫存器，即可進行永磁馬達的伺服控制。

This thesis presents the design and implementation of a modified direct torque control(MDTC) IC for permanent magnet synchronous motors using complex programmable logic device. By using the hierarchical and modular realization strategy, the designed circuits can be re-used to reduce the design complexity and the total gate counts for optimum design. Direct torque control is a control scheme that the error between the estimated and command torque controls the stator flux and voltage vector to obtain the desired torque. The thesis also presents the modified DTC, which achieves a constant switching frequency operation and excellent current and torque performance at steady state. Bit length effect of the control IC has been analyzed. Current feedback from the analog-to-digital converter and position feedback from the quadrature encoder can be directly interfaced to the developed motor control IC. The control parameters of the proposed control IC can be on-line programmed for different operation conditions via the serial interface. Besides, all registers in this IC can be observed to verify the effectiveness of the control strategy. Matlab/Simulink simulation and experimental results are presented to substantiate the proposed scheme.