基於SIMPLIS環境之閉迴路升壓型功率因數校正轉換器之小訊號分析及驗證

Abstract

在現今這個科技日新月異的社會之下，功率因數校正轉換器在工業應用上也是越發常見與重要，但在設計此轉換器階段時候卻需要花許多時間進行驗證與分析。模擬軟體可以幫助設計者驗證與設計功率因數校正控制器，在SIMPLIS模擬環境中，相較於使用交流電壓源作為輸入電壓源，使用直流電壓源進行模擬分析與驗證可以省下許多模擬時間，但是對於頻率響應並非都可以使用直流電壓作為輸入源進行小訊號分析。本篇論文比較三種使用直流源與交流源作為輸入的閉迴路轉移函數來判斷何時可以使用直流源取代交流源作為輸入電壓。三種閉迴路轉移函數分別為:功率因數校正轉換器輸出阻抗、功率因數校正轉換器輸入阻抗以及外環電壓迴路轉移函數。此外，本篇論文針對小訊號輸入阻抗部分提出新的功率因數校正轉換器輸入阻抗模型，相較於過往文獻所提出的模型，本篇論文所提出的輸入阻抗小訊號模型具有更低的計算複雜度以及可以與模擬結果從低頻至高頻皆相符。本篇論文同時也建立升壓型轉換器之小訊號模型，並添加許多非理想參數至小訊號模型內，用以推導更為精準的轉移函數方程式來幫助設計者縮短驗證設計時間。對於這些轉移函數，理論的推導結果與頻率響應的模擬結果在切換頻率以下都非常相符。在本論文中也有對於各個轉移函數示範如何於SIMPLIS內模擬頻率響應的波德圖。對於穩定性分析方面，本論文分析使用平均電流模式控制之升壓型功率因數校正轉換器具有輸入濾波器與不具有輸入濾波器穩定性，來判斷輸入濾波器使否會影響本文所提出的電路架構。最後，本論文驗證使用快速傅立葉能將時域波形轉換成波德圖的增益值，此方法能幫助設計者在無法快速於SIMPLIS內找到週期性訊號用以獲得波德圖時候經由轉換時域的波形資料進行增益值的計算。

Power factor correction (PFC) boost converters are commonly used for industrial applications but the verification of the design can be time consuming. Simulation is a helpful tool for designers in verifying a PFC controller and design. Using a dc source during simulation can significantly reduce the simulation time compared with using an ac source, however it cannot be used in all cases without loss of accuracy. There were three different closed loop transfer functions that were compared with dc input and ac input in this research to determine when to use a dc source as the input to reduce the simulation time, they are PFC output impedance, PFC input impedance and outer loop. A PFC input impedance model was proposed in this research, it has low computational complexity compared with other models and can match with simulation results over the full frequency range. This research also derived the small-signal model of a non-ideal boost converter and the PFC controller to derive all transfer functions. The theoretical results matches the simulation results well for the full frequency range. The simulation techniques of all transfer functions are also shown. This research judged the stability of the PFC boost converter with average current mode (ACM) control with and without an input filter to observe whether the input filter effected the system stability or not. Last, this research verified that performing fast Fourier transform can calculate magnitude of bode plot, it is useful as ac analysis cannot work in some situations where SIMPLIS cannot easily find the periodic signal sometimes.