In this article, an integrated parallel buck–boost and boost converter (IPB ³ C) is proposed as an electrolytic-capacitor-less light-emitting diode (LED) driver. The IPB ³ C provides a high power factor (PF) and low total harmonic distortion (THD). The driver is composed of two converters that are connected in parallel, using just one controlled switch. The buck–boost duty is to deliver constant power to the LED, while ensuring a good PF. The boost converter is employed to cancel the low-frequency ripple at the LED. In return, this decreases the flicker effect and only a relatively small capacitance is needed to fulfill the standard requirements. The buck–boost converter handles the full power of the LED, while the boost converter handles only a portion of the LED power. Thus, better efficiency is ensured by this parallel configuration compared to conventional cascaded integrated converters. Moreover, the voltage across the switch is low, as it is the higher, whether buck–boost or boost converter, but not the addition of both. In this article, the IPB ³ C is analyzed, and its design methodology is presented. A universal input voltage range prototype of the proposed converter supplying an LED lamp of 108-V/ 0.35-A is presented. The prototype shows high PF, nearly equal to one, very small THD, nearly zero, output voltage ripple of 4.5%, output current ripple of 19%, and high efficiency, equal to 92.4%. Moreover, the converter requires the use of a bulk capacitance of only 68 μF, while the required output capacitance is just 1 μF.

中文翻译：

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具有低功耗处理的高效无电解电容器离线 LED 驱动器

在本文中，提出了一种集成并联降压-升压和升压转换器 (IPB ³ C) 作为无电解电容器的发光二极管 (LED) 驱动器。IPB ³ C 提供高功率因数 (PF) 和低总谐波失真 (THD)。驱动器由两个并联的转换器组成，仅使用一个受控开关。降压-升压任务是为 LED 提供恒定功率，同时确保良好的 PF。升压转换器用于消除 LED 的低频纹波。作为回报，这减少了闪烁效应，并且只需要相对较小的电容即可满足标准要求。降压-升压转换器处理 LED 的全部功率，而升压转换器仅处理 LED 功率的一部分。因此，与传统的级联集成转换器相比，这种并行配置可确保更高的效率。此外，开关两端的电压很低，因为它越高，无论是降压-升压转换器还是升压转换器，但不是两者相加。在本文中，IPB ³ C 进行了分析，并提出了其设计方法。提出的转换器的通用输入电压范围原型为 108-V/0.35-A 的 LED 灯供电。样机显示出高PF，几乎等于1，非常小的THD，几乎为零，输出电压纹波为4.5%，输出电流纹波为19%，效率高，等于92.4%。此外，转换器仅需要使用 68 μF 的大容量电容，而所需的输出电容仅为 1 μF。