本論文旨在研製高頻分時多相串聯-串聯電源轉換器，並以無鐵芯平板變壓器作為主要傳送功率之架構，以達薄型、輕量化之目的。並說明研製平板線圈以及效率最佳化之考量，且初級側開關具零電壓切換功能，減少電路高頻操作之切換損耗；次級側方面使用同步整流技術以減少導通損耗。初、次級側開關以氮化鎵功率元件替換傳統矽材料功率開關，減少電源轉換器體積以及高頻的切換損耗，提升整體電路的功率密度。於平板變壓器的基礎下，透過Maxwell軟體模擬線圈之幾何形狀並透過分析以獲得高品質因數的線圈架構。藉由改善線圈繞製次序設計方式，減少線圈損耗，並提高變壓器耦合係數以提升傳輸效率。最後分析不同匝數比之線圈對於諧振電流與元件損耗之影響，以取得最佳化平板變壓器設計。由實驗結果得知，整體最大輸出功率100W，最高電能轉換效率為87.8%，並驗證線圈參數對於損耗之影響。

This thesis presents a high frequency time-division multi-phase series – series power converter, and using coreless planar transformer as the main structure of transmission power that achieve the purpose of thinning size. Explain how to choose the best planar coils and optimize overall circuit efficiency. In order to reduce its switching loss at high frequency, primary side switches achieve Zero-Voltage-Switching(ZVS). Synchronous rectifier is utilized on the secondary side to minimize the conduction loss. Gallium Nitride devices are used both at primary and secondary switches to reduce the converter volume and switching losses to achieve high power density. Based on the planar transformer design, analyze the geometric shape of coils through Maxwell to obtain higher quality factor coils. Reducing copper loss of primary and secondary side, and increase the coupling coefficient to improve transmission efficiency by changing the winding configuration. Eventually, analyze the effect of coils with different turns-ratio for resonant tank current and element loss to select optimal planar transformer. According to the experimental result, the maximum output power of overall systems is 100W and the highest power transmission efficiency can be up to 87.8%, and verify effect of the coils parameter for overall loss.

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