單晶片DSP為基礎之全數位式交流感應馬達高轉速控制

Abstract

本文設計製作一個以單晶片數位訊號處理器(DSP)為基礎之全數位式交流 感應伺服驅動器，並提出一種高轉速控制方法，可使交流感應馬達運轉 於3倍之基速，而仍能達到精密轉速的控制要求，同時具有良好的暫態與 穩態響應。伺服驅動器中採用弱磁控制技術以滿足高轉速控制的需求，且 以間接磁場導向控制法則來完成電流解耦控制。對於電流解耦控制之感應 馬達動態特性亦提出簡化的等效數學模型，並以此數學模型為基礎來設計 速度控制器。採用數位訊號處理器來實現全數位控制法則，其中包括位置 控制、高轉速控制、向量控制、軟體化的電流控制迴路以及PWM訊號產生 等。此外，本文亦完成全數位式交流感應伺服驅動器之硬體規劃與設計， 並製作一個以DSP為基礎之數位控制板及以智慧型功率模組(IPM)為基礎之 電壓源換流器，而大幅地減少硬體週邊電路的體積。實驗以一個300W的交 流感應馬達來進行，結果不僅驗證數位化電流迴路之可行性，亦達到全數 位式高轉速控制的目標。 This thesis presents the design and implementation of a fully digital-controlled ac induction servo drive by using a digital signal processor (DSP). A high speed control method is proposed to operate an ac induction motor up to triple its base speed with high performance of transient and steady-state responses. An indirect field-oriented vector control scheme with software current feedback loop is employed to perform the fast response current decoupling control of an induction motor. With an appropriate servo compensator design, the induction motor drive can achieve the desirable servo performance. Moreover, a field- weakening technique is adopted to expand the speed control range under the limited inverter ceiling voltage. In order to verify the proposed control scheme, a DSP-based digital controller and an intelligent power module (IPM) based voltage source inverter are implemented to construct the fully digital controlled ac induction servo system and minimize the hardware peripherals. DSP executes a PWM signal generation, current control, vector control and speed/position control processing. In application to a 300W induction motor drive system, experimental results show that the DSP-based fully digitized servo drive can achieve the high speed control requirement.