具負載估測之降壓型直流轉換器順滑控制設計

Abstract

本論文研究之順滑模態控制器應用在降壓型直流轉換器，利用既有之積分型順滑模態控制器，並加入負載估測器以估測負載值，保持對不確定量之強健性。本文利用此順滑模態控制器產生之控制訊號，轉成固定頻率之脈波寬度調變訊號以控制降壓型直流轉換器之開關切換，使其輸出電壓到達期望值，且不因負載變動影響系統之輸出狀態。利用MATLAB/SIMULINK模擬上述降壓型直流轉換器與順滑模態控制器及負載估測器，由模擬結果驗證系統在不同負載變動下，輸出電壓均能達到設定值，且估測器能正確估測到負載值。此外能透過調整控制器之參數以改善暫態響應。

In this thesis, a general DC-DC Buck converter model is derived by the state space average method, which is valid for continuous conduction mode. A sliding mode controller with an integral term of error function is proposed for constant frequency PWM-based DC-DC Buck converter. To reduce the influence of system uncertainty, a first-order estimator is also applied to estimate the unknown payload. With the sliding mode control, the system trajectory could be successfully driven to the sliding surface in a finite time even though the payload changes. In the sliding mode, the system is stabilized and the output voltage reaches the desired value, which fulfills the control goal. Finally, the proposed control scheme is demonstrated by the numerical simulation results.