DSP based Minimum Input Power Control of Induction Motors

本計畫報告旨在要以DSP TMS320LF2407A 為基礎實現 感應電動機最小輸入功率控制系統，採用間接向量控制方式， 藉由量測變頻器直流匯流排電壓及電流計算功率；最小輸入功 率控制方法為損失模式控制加上搜尋控制組合而成的混合控 制方式，先利用損失模式估測出搜尋控制所需的激磁電流起始 值，在降低激磁電流的同時也量測匯流排電壓及電流做功率計 算，直到量測的功率有向上的趨勢時，搜尋動作將停止，即搜 尋到感應電動機的最佳工作點。此控制方式的優點為簡單、易 實現及有較佳的收斂時間，再配合上電壓空間向量波寬調變技 術，使切換損失達到最小。從實作結果來看，本計畫所提DSP 為基礎感應電動機之最小輸入功率控制的確有效，惟控制效果 仍有改善空間。The induction motor (IM) is a high-efficiency machine when working close to its rated operating point. However at torques and/or speeds far from the rated values the efficiency is greatly reduced. This thesis presents a simple and useful techniques for the minimum input power method of the indirect vector-controlled induction motor drives. The minimum input power method is named Hybrid Technique which combines Loss Model Control (LMC) and Search Control (SC) method. We use the LMC approach to obtain the initial value of the flux and subsequently adjust it by the Search Control method. The hybrid technique is simple, easily realizable, and offer fast convergence. The inverter switching method is Space Vector PWM which makes the lower harmonic losses. Experimental results show the effectiveness of the proposed technique. However, there is room for improvement