全數位控制高效諧振式升壓型DC/DC轉換器

Abstract

本文主題為全數位化高效率諧振式直流/直流升壓轉換器之研製，其電路架構前級利用全橋相移式電路產生方波，再透過高頻變壓器升壓、隔離，後級應用LC諧振電路軟切換達到提升升壓效率的目的。此轉換器可應用於太陽能板升壓、燃料電池及各種升壓系統。內容探討諧振電路特性的原理與分析其變頻與相移模式，根據模擬所得的增益曲線，重載下以載波頻率調變，輕載下以載波相位調變做控制，證實此電路應用於開關控制中能夠有效提升效率。 為了驗證上述電路的特性，選擇額定輸出功率為300W之全橋升壓諧振轉換器原型機，同時利用數位控制器TMS320F28035實作輸出電壓電流回授偵測和全橋相移開關導通頻率控制。計算實測結果數據可得出最低效率在30W到300W間為87.9%，在210W負載時可達最高之效率為96.3%。

This thesis concluded the design and implementation of high efficiency resonant boost DC-DC converter. Its circuit structure contained 2 stages. The full bridge phase-shift circuit was equipped the front one for producing the rectangle waves, which then were raised to high voltage and segregated. The second stage using the LC resonant circuit efficiently stepped up. This converter is widely applied to solar panel, fuel cell and a variety of step-up systems. In the contents discussed the principle of resonant circuit and analysed the frequency conversion and phase-shift modes. According to the gain curve collected via simulation, it testified that it was doable to improve the efficiency of the switches control.The experimental results revealed that the lowest efficiency was around 87.9% as the load was varied between 30W and 300W, and the highest efficiency was 96.3% as the load was at 210W.