本文探討一數位化控制之雙自由度降壓型直流/直流轉換器,採用前饋補償型式的雙自由度控制器,使系統在命令追隨及負載調節方面均能同時具有良好的控制特性。藉由電壓模式、平均電流模式及峰值電流模式控制來實現。 本文將推導降壓型轉換器的數學模型,以設計電壓控制模式、平均電流控制模式及峰值電流模式控制的數位控制器。其次,利用雙自由度控制器系統化設計流程,由模擬及實驗結果驗證此控制器之性能。系統中利用數位信號處理器為控制平台,研製輸入電壓12V,輸出電壓3.3V,最大輸出電流為20A的降壓型轉換器。由實驗結果顯示,所研製的數位式雙自由度降壓型直流/直流轉換器同時具有良好的命令追蹤及負載調節控制特性。
The objective of this thesis is to design and implement the two-degree-of-freedom digital controller for buck converter. Therefore, the converter provides satisfied tracking and load regulation performance. The controller is designed and implemented for the buck converter under voltage mode control, average current mode control and peak current mode control. The mathematic models of the buck converter under voltage mode control, average current mode control and peak current mode control are derived in order to design the related controllers. Moreover, two-degree-of-freedom controllers are designed and verified by simulation and experimental results. The specifications of the designed and implemented buck converter include: input voltage = 12 V, output voltage = 3.3 V and output current = 20 A. Experimental results derived from the DSP-based system demonstrate that the buck converter based upon the designed two-degree-of-freedom digital controller provides satisfied tracking and load regulation performance.