具有電力解耦合功能之新型微換流器開發

Abstract

近年來大多數的微換流器都是並聯大電解電容在輸入端，達到電力解耦合的功用。但電解電容生命週期短，所以近年來採用薄膜電容取代電解電容提高可靠度。本論文提出，將薄膜電容直接串聯於調變端的新型順向式微換流器。在新電路架構中，在主電力解耦合電路中插入薄膜電容，利用主電力解耦合電路調節輸入與輸出的功率差，取代電解電容，提高穩定度，因此太陽能板輸出功率可以維持定值，維持最大功率點電壓和電流。 在論文開始，會比較分析先前電力解耦合文獻，從而取其優點保留，取其缺點改善，以此發展新電路架構，接著描述新型微換流器之操作模式，控制策略和元件設計，最後以電路模擬和實作出輸出功率為105W之具有電路解耦合功能之新型微換流器。

Nowadays, for most of single-phase micro-inverters, large electrolytic capacitors are usually placed beside the low-voltage PV panel. However, due to the short lifetime, non-electrolytic capacitor micro-inverter is request recently to increase the reliability. Thus, a forward-type micro-inverter with a series-connected power decoupling capacitor is proposed in this paper. In circuit configuration, an active power decoupling circuit (APDC) is inserted into proposed micro-inverter to handle different power between input and output, and a higher lifetime small film capacitor is put at the input terminal of the micro-inverter. Therefore, the output power of PV panel could maintain constant, and high maximum power point tracking (MPPT) performance is obtained. Reliability of the proposed micro-inverter can be increased by replacing electrolytic capacitor to film ones. In this thesis, the previous papers with APDC will be discussed at the beginning. The proposed micro-inverter can not only reserve advantages but also discard disadvantages, then the operation mode, control strategy and component design of proposed micro-inverter are introduced. Next, computer simulation results with a 100W prototype circuit are shown. Finally, experimental results with lower power rating will verify the performance of the proposed micro-inverter.