主動箝位順向式變流器之研製

Design and Implementation of Active Clamp Forward Inverter

劉育昇(Yu-Sheng Liu)

指導教授 ： 吳黎明

健行科技大學/電資學院/電機工程所/碩士(2012年)

摘要

本論文主旨為研製一主動箝位順向式變流器，適合做為小型直流分散式電源之獨立運轉與市電併聯應用。所提變流器為單級架構，直流側為主動箝位順向式轉換電路，以追隨M形正弦波命令方式將低壓輸入轉換為高壓增益輸出，並利用箝位電容與變壓器洩漏電感產生共振作用，將漏磁能量回收，同時使功率開關產生零電壓導通效果，增加電路效率。交流側電路由全橋電路組成，兩對開關以低頻相互切換，再經低通濾波電路處理後，產出交流弦波輸出。交流側電路因低頻切換，切換損失少，亦可提高效率。實驗環境建構以全數位方式實現主動箝位順向式變流器之系統控制，控制核心採用德州儀器(TI，Texas Instruments)所生產的32位元數位信號處理器(DSP，TMS320F28027)，提高變流器系統可靠度。 本文經由理論分析、設計與模擬過程，實作一組規格150W/24Vdc,in/200Vdc,out之主動箝位轉換器，繼將實作經驗用於設計與製作額定200W/24Vdc,in /110Vac 的微型變流器，進行控制方法測試與驗證；其中獨立運轉模式採AC電壓迴授控制，市電併聯模式採AC弦波電流波形控制，以高功因饋入市電。經由實驗及測試，獲得理論預測與實驗一致的結果，原型變流器的功率開關在全負載範圍內皆可零電壓導通，電路轉換效率最高可達88.3%以上，輸出功因大於99%。

關鍵字

主動箝位 ； 順向式 ； 單級變流器 ； 數位控制

並列摘要

The aim of this thesis is to develop a small scale DC-AC inverter based on active clamp forward topology for either stand-alone or grid-connected applications. The proposed inverter is characterized by a single stage structure in which active clamp forward conversion is adopted on the DC side and a full bridge inversion associated with LC filter is applied on the AC side. While the forward conversion part is operated at M-type high frequency sinusoidal pulse width modulation, the full bridge inversion part is switched at utility frequency. A step-up transformer is used not only to isolate the input from the output but also increase the voltage level from the DC input to the AC output. Except simplicity in structure, advantages of the proposed inverter include zero voltage switching for main and auxiliary switches in the forward converter, low switching losses in the full-bridge inverter, and regeneration of leakage magnetic energy in the transformer through resonance.
To realize the inverter, an independent active clamp forward converter with rating 150W/24Vdc,in/200Vdc,out is constructed first. The theoretical analysis and simulation experience gained from the converter is then implanted to design and implement the micro-inverter with rating 200W/24Vdc,in /110Vac based on the device of 32-bits digital signal processor TMS320F28027. For stand-alone application, the inverter is controlled by AC voltage feedback. For grid-connected operation, the AC waveform of load current is monitored to ensure high power factor is maintained at the interconnection of inverter output and utility network. As a result, the experimental measurements confirm the theoretical prediction. All the inverter switches can be transited at zero voltage over full power range. The inverter efficiency reaches as high as 88.3% and the output power factor is above 99%

並列關鍵字

Active clamp ； Forward ； Single-stage inverter ； Digital control

參考文獻

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