太陽能發電系統因部分遮蔽或裝設角度不一等原因，常使太陽能電池模組間產生不匹配與電能轉換器無法運轉於系統最大功率點的問題，導致太陽能電池模組整體輸出效率降低，故如何解決太陽能板不匹配之問題並提升電能轉換器系統效率，以有效利用能源為太陽能發電系統關鍵技術之一。
本文利用數位信號處理器設計一具柔切型多輸入太陽能電池市電併聯供電系統，實現分散式最大功率追蹤策略，使每一太陽能串列模組能夠操作於最大功率點，以減少因遮蔽等因素造成不匹配的問題。所提架構屬於兩級式變流器系統，前級升壓型轉換器主要功能為執行最大功率追蹤，並使用諧振型柔切與同步整流技術提高轉換效率；後級則為全橋式變流器，使用單極性正弦脈波寬度調變切換方式控制功率開關，以電流控制方式與市電併聯，使輸出電壓與電流能夠達到單位功因實功與較低之電流總諧波失真。
在系統硬體實作方面，本文以兩組輸入電能轉換器為例，驗證所提方法的可行性，所實現之系統每一電能轉換器輸入端容量為600W，總裝置容量為1.2 kW。模擬與實驗結果證實本文所提之太陽能發電系統可操作於市電併聯與獨立負載供電，並具有良好之效率與功因特性表現。

Effects of the partial shading or different installing angles of the solar photovoltaic (PV) modules often result in problems of PV module mismatch and operations of power converter being not at maximal power point. The overall output efficiency of the solar PV generation system is thus reduced. So how to solve the PV module mismatch problems and improve system efficiency of the power converter is one of the crucial technologies for the PV generation system.
In order to reduce the shading effects and mismatch problems, this thesis implements a multi-input grid-connected PV system and accomplish distributed maximum power point tracking (MPPT) strategy by using digital signal processor. The structure of the circuit is divided into two-stage converter system. The front end of the system is a boost converter performing MPPT and resonant soft-switching functions with synchronous rectification to improve the efficiency of the system. The back end of the system is a full-bridge inverter which is connected to grid using current-control mode by unipolar PWM switching. The power output has lower current total harmonic distortion (THD) and near-unity power factor.
On the hardware implementation of the proposed system, this thesis takes two input converters for an example to verify the feasibility of the proposed method. Each converter on the system input side is realized with the capacity of 600W, and the total system output capacity is 1.2 kW. The simulated and experimental results show that promising power factors and efficiencies of the system can be achieved for both on-grid and off-grid operations.

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