DSP全數位控制可程式電源供應器之研製

Abstract

本論文研製一以單晶片數位訊號處理器(DSP)為基礎之全數位控制可程式電源供應器。功率級主要分為兩部分，前級為一昇壓型功率因數修正電路，後級為一單相全橋式換流器架構。傳統功率因數修正電路之輸出電壓為一固定值，但在某些特殊運用中仍須具有可變輸出電壓之功率因數修正電路，本論文之前級即為研製可變輸出電壓且具有功率因數修正之電路；首先說明功率因數及修正控制原理，比較不同功率因數修正電路效率、成本、複雜度等電路特性規格後，選定一雙開關升降壓電路作為主要研究之對象，利用多迴路控制器以達到高頻寬、輸出可變之系統規格。電路後級為全橋式單相脈寬調變換流器，首先針對換流器等效電路模型作一詳盡之推導，提出濾波器值設計方法，並針對換流器之開路特性作一分析，最後提出多迴路控制器及控制器參數設計法則，藉由系統化設計流程使電源供應器具有範圍寬廣之直流及交流可變輸出。本文以PSIM模擬軟體進行所提出多迴路控制架構及其對應參數之電腦模擬驗證，並以單晶片DSP(TMS320F240)控制板實現所提出之控制法則，配合一升降壓型功率因數修正電路及單相全橋式脈寬調變換流器完成系統整體測試。模擬和實驗結果均一致顯示本文所提出控制方法的效果及優越性，理論分析亦得到驗證，而達到所預期之設計規格。

This thesis presents the design and implementation of a DSP-based fully digital-controlled programmable power supply. The power stage includes two main parts. The front stage is a boost converter with power factor correction (PFC) circuit. The back stage is a single-phase full-bridge PWM inverter. The conventional power factor correction circuit has a fixed output voltage. However, in some special applications, a PFC circuit with a changeable output voltage range is needed. First, explanation of power factor correction and control methods are mentioned. After a comparison of several power stage candidates in terms of efficiency, cost, and complexity, the buck-boost converter is chosen to be implemented. In order to achieve wide bandwidth and variable output system spec., multi-loop controllers are adopted. The output stage is a single-phase full-bridge PWM inverter. The equivalent circuit model and the design of output filter are mentioned. The design philosophy of the multi-loop controllers and respective parameters are also be mentioned. The proposed control scheme has been verified by using computer simulation with PSIM and implemented using single-chip DSP (TMS320F240) control card. Experimental verification has been carried out on Buck-Boost and inverter circuits. Simulation and experimental results both show the feasibility and superiority of the proposed multi-loop control methods.