- 學位論文
應用模糊理論與滑動模式控制設計動態電壓調整器
Design of Dynamic Voltage Regulator Using Fuzzy Logic and Sliding-mode Control
摘要
電力品質對產業用電影響極大，供電品質不良易造成敏感設備損壞，導致工廠損失，因此本文對電壓驟降及電壓變動等問題提出改善之方法，達到系統電壓穩定，以提供高品質之電力給工業用戶。 本論文之目的在應用模糊理論與滑動模式控制方法分析及設計動態電壓調整器(Dynamic Voltage Regulator，DVR) 。此補償器為串聯型之架構，連接一直流電容器提供電壓來源，使用脈波寬度調變技術調整三相電壓源型變流器的輸出電壓。論文中首先以數學驗證滑動模式控制器應用於動態電壓調整器的穩定性，接著利用兩種不同的模糊理論改善傳統滑動模式控制中常見的系統抖動現象。系統在穩態時，控制器輸出一偏移量定值使動態電壓調整器作純虛功補償。在發生負載變動等暫態時，控制器額外輸出一暫態訊號使動態電壓調整器補償負載端壓降，最後系統迅速回到穩態。模擬方面使MATLAB/SIMULINK軟體來評估系統補償效果。
並列摘要
The power quality affects the industry to a great extent. Poor quality in the power supply, such as voltage fluctuations, may cause damage in sensitive equipments. How to maintain constant voltage profile at the load bus under disturbance conditions is of major concern in this work. The purpose of this thesis is to use fuzzy logic theory and sliding-mode control to design the Dynamic Voltage Regulator (DVR).This compensator employs a direct current capacitor to offer the voltage source and uses the pulse-width modulation technology to adjust the output voltage of the three-phase voltage-sourced inverter. It proves the stability of the sliding-mode controller applied to the dynamic voltage regulator in the thesis first of all. Then, it improves common chattering in traditional sliding-mode control by using two different Fuzzy Logic theories. The output of the controller is a constant offset signal in the steady state and the dynamic voltage regulator achieve pure reactive power compensation. When system is in transient state as load variation,the controller output an additional transient signal and the dynamic voltage regulator compensates the load voltage drop. The system comes back to steady state quickly. The effectiveness of the designed DVR is first investigated by digital simulations using the MATLAB/SIMULINK software.