- 學位論文
使用倍流器於電池充電之相移全橋轉換器
Phase-shifted Full-bridge Converter using Current Doubler for Battery Charging
摘要
本論文研製一1 kW全橋相移轉換器含倍流器作為定電流充電器。該倍流器採用環形鐵芯繞組之自耦變壓器(toroid-core-wound autotransformer)設計。相較單電感設計，由於轉換過渡區間(transition period)較小，可以增大有效週期(valid duty)。電池充電方法採用定電流(CC)模式，並以系統監控電池充電狀態，適時調整控制器相移訊號，以保持定電流輸出。轉換器在輕載以接近零電流切換(ZCS)模式運作；重載以零電壓切換(ZVS)模式運作，以保持轉換器高效率。本研究採用UC3875作為PWM控制器，利用相移之信號時序，調變工作週期，控制轉換器進行充電。本研究製作之全橋相移轉換器規格：輸入380V，輸出48 V，對一組48 V鉛酸電池組以定電流20 A進行充電。實驗結果證實1 kW輸出功率轉換效率達90%。
並列摘要
This thesis aims to develop a 1-kW phase-shift full-bridge converter with a toroid-core-wound autotransformer designed current doubler rectifier as a battery charger. Comparing with the use of single inductor rectifier, the valid duty of the converter can be extended because of the smaller transition period. Using constant current mode as our battery charging method, by adjusting the phase shift of the control signal we are able to maintain constant current through the whole charging period. The converter acts close to zero-current switching (ZCS) at light load and keeps the zero-voltage switching (ZVS) at heavy load, which allows the converter work in high efficiency. In this study, the controller UC3875 is employed to provide the phase-shift signals for stabilizing the output current constant. The specification of the converter is 380V input and 48V output. A 1-kW converter is implemented to verify the estimation results. A set of 48V lead-acid battery was charged by the converter with constant current of 20A, and it proves that the efficiencty under 1 kW output power was over 90%.