本論文主要針對電動輔助自行車常用的無刷直流馬達(Brushless DC Motor, BLDCM)驅動器，設計一個脈寬調變(PWM)同步整流切換技術，降低馬達在運轉過程中，反流器切換所產生的導通損失。本文所提出的新型切換方法，可以明顯減少反流器在馬達運轉時熱能的產生，而提高整體運轉時的效率。與現有的無刷直流馬達控制電路比較而言，不需要改變現有的電路配置，或是添加額外電路，僅需要改變馬達運轉的電子換相訊號即可實現。除了提出同步整流技術運用在馬達控制器外，本論文亦利用模糊控制理論設計電動輔助自行車之行車控制器。以自行設計電路感測車速與踩踏速度訊號作為輸入值，判斷騎乘者目前行車狀況，藉此來驅動馬達提供相對之輔助動力。其精準量測以及針對騎乘者騎乘設計的方法，可改善目前市面上速度磁圈或扭力感測計判斷的缺點。最後經由實際電動輔助自行車測試，續行力可提升13%；溫升可降低22%，實驗結果証明同步整流馬達控制器與智慧型行車控制器的可行性。This thesis proposes a novel method of synchronous rectification switching technology for the brushless DC motor (BLDCM) of the assist electronic bike (Pedelec). The propose method could reduce the conduction loss generated and improve overall efficiency by switching inverter. This method could reduce the heat generated by inverter when the motor is operating significantly. Compared with the common used BLDCM controller, the proposed method effectively improves efficiency and reduces cost without additional circuits. It can be realized by changing the operation of the electronic commutation signals. This thesis designs not only synchronous rectification in motor drive, but also the fuzzy controller in the Pedelec. The bike speed and pedaling rate are taken to determine the status of rider, such that properly assistant force could be provided by motor diver. This method which has accurate measures and is designed for the riding behavior of riders can improve the drawback of the speed sensor or the hall sensor in the market. Finally, it is tested by using the Pedelec, the endurance can improve 13% and the temperature rise can reduce 22%. The feasibility of the proposed method is demonstrated by both simulation and experimental results.