本文所使用之雙半橋無隔離型雙向直流/直流轉換器電路，其傳統的開關控制信號為硬切式，但本文採用不同的控制方式，使所有開關皆能達到零電壓切換，以提高電路轉換效率。除了利用電壓回授控制責任週期達到穩壓外，還採用電流回授控制相移角度，實現輕載至滿載皆能達成高轉換效率。此外，文章內推導電路的小信號模型，並設計數位PID補償器維持電路穩定操作。在充電策略方面則採用第一階段定電流-第二階段定電流-定電壓三階段式充電，如此一來既可實現快速充電的需求，又可兼顧磷酸鋰鐵電池的壽命。由於控制策略過於複雜且功能甚多，難以一般IC實現，故採用DSP為中央控制器，最後完成一台10 kW、輕載效率在96%以上、滿載效率高達98%以上、具有ECAN通訊功能、應用於微電網之數位控制高效率雙向直流/直流轉換器。

This thesis presents a non-isolated bidirectional dual half-bridge (DHB) DC/DC converter. Unlike the traditional control with hard switchings, zero-voltage-switching (ZVS) is fulfilled with a novel control method to improve the conversion efficiency. In addition to regulate the output voltage by adjusting the duty cycles via voltage feedback loop, the phase-shift control via current feedback loop can achieve high efficiency under wide-range load variations. A small signal model of the presented converter is constructed to design a digital PID compensator. To satisfy the demands for fast charging and long lifetime of LiFePO4 batteries, a three-stage charging scheme is adopted. Finally, a digital signal processor (DSP) is used to implement a 10-kW prototype converter with E-CAN communication function for micro-grid system applications. The experimental results show that the light-load efficiency is over 96%, and the rated-load efficiency is over 98%.

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