Abstract In this study, a novel single-stage bridgeless single-ended primary-inductor converter (SEPIC) model is designed to perform effective power factor correction while driving brushless direct current (BLDC) motors. The traditional SEPIC converter model produces a non-pulsating input current that operates with both conductors in a continuous-conduction mode(CCM). However, the proposed SEPIC converter is designed to function as an AC-DC converter; specifically, it is a cascade combination of the boost and buck-boost converters. Functionally, during discontinuous-condution mode (DCM), the boost converter becomes operational, whereas the buck-boost converter operates during the continuous-condution mode. Using the proposed SEPIC model, naturally the computed power factor is improved, which makes it employable for driving BLDC motors. During the implementation of the proposed model, the rotation of the permanent magnet BLDC motor was regulated through the continuous-conduction mode of operation of the bridgeless rectifier. On conducting both the simulation and hardware design process, comparisons were made based on the power factors obtained using the traditional buck-boost converters and those obtained using the SEPIC models presented herein. The SEPIC model proved its higher efficiency over the traditional converters from the viewpoint of the evaluated power factor values and minimized conduction losses. The newly modeled SEPIC model, which was designed for power factor correction, has been noted for its applicability in low power household applications. A power factor of 0.9 is obtained for the hardware implementation of the proposed converter, and a working model of the proposed converter is found to exhibit superior performance when compared with simulated models of the buck–boost converter and SEPIC.

中文翻译：

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功率因数校正无桥变换器模型分析

摘要 在本研究中，设计了一种新颖的单级无桥单端初级电感转换器 (SEPIC) 模型，以在驱动无刷直流 (BLDC) 电机时执行有效的功率因数校正。传统的 SEPIC 转换器模型产生非脉动输入电流，该电流以连续传导模式 (CCM) 与两个导体一起运行。然而，所提出的 SEPIC 转换器被设计为用作 AC-DC 转换器；具体来说，它是升压和降压-升压转换器的级联组合。在功能上，在非连续导通模式 (DCM) 期间，升压转换器开始运行，而降压-升压转换器在连续导通模式期间运行。使用所提出的 SEPIC 模型，计算出的功率因数自然会得到改善，这使其可用于驱动 BLDC 电机。在所提出的模型的实施过程中，永磁 BLDC 电机的旋转通过无桥整流器的连续传导操作模式进行调节。在进行仿真和硬件设计过程时，根据使用传统降压-升压转换器获得的功率因数和使用此处介绍的 SEPIC 模型获得的功率因数进行了比较。从评估的功率因数值和最小化传导损耗的角度来看，SEPIC 模型证明了其比传统转换器更高的效率。新建模的 SEPIC 模型专为功率因数校正而设计，因其在低功率家庭应用中的适用性而著称。所提出的转换器的硬件实现获得了 0.9 的功率因数，