以FPGA實現直流/直流降壓型轉換器之數位可適性控制

Abstract

本論文欲探討直流/直流降壓型轉換器(DC/DC Buck Converter)的數位控制器設計，及設計過程中必須考量的問題。 文中以Xilinx公司生產的FPGA開發板(Spartan 3A)來實現數位控制器的三個主要部份－類比/數位轉換器(A/D Converter)、數位補償器(Digital Compensator)、數位脈波寬度調變(DPWM)。依受控體規格－輸入電壓12V，輸出電感560nH，輸出電容4800µF，觀察參考電壓為1V時的穩定負載、動態負載等輸出波形。 直流/直流降壓型轉換器之控制模式為電壓模式，本文將推導出其小訊號模型，根據受控體規格設計出適合的補償器，並根據增益規劃(Gain Scheduling)概念，建立一查表(Lookup Table)，視負載狀況調整補償器參數，達到簡單的可適性控制(Adaptive Control)。

The thesis focuses on the design of digital controller for DC/DC Buck converter，and discusses what should be taken into consideration during the design process. In the thesis，the FPGA board (Spartan 3A) manufactured by Xilinx incorporation is used to implement the three parts of the digital controller－ A/D converter，digital compensator，digital pulse width modulator. With the specification for the control plan－ input voltage 12V，output inductance 560nH，output capacitance 4800uF,the output waveform for fixed load，dynamic load at 1V reference voltage is observed. The control mode of DC/DC Buck converter is using Voltage Mode. The small signal model is derived in the thesis and is used to make the proper design for the compensator, also, a lookup table is made from it according to the concept of Gain Scheduling. Parameters of the compensator is adjusted according to the load condition to achieve simple adaptive-control.