共查询到18条相似文献,搜索用时 656 毫秒
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近年来为了提高LED驱动电路转换效率和减小输出纹波,单级复合型电路得到深入研究与应用。针对辅助绕组支路上串联Buck电路的单级反激LED驱动电路,研究了一种输出电流谐波注入方案,以减小输出电容,使得输出电解为高频容所代。首先,介绍单级复合电路的工作原理,推导输出电压纹波与负载电流的关系,分析脉动电流的相位对电容电压纹波的影响,给出负载电流谐波注入方案的设计依据;其次,给出所述方案的实现方式与电路;最后,研制了一台150 W实验样机,验证方案的可行性与有效性。 相似文献
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针对LED驱动电源中因为使用了电解电容而降低电源使用寿命的问题,提出一种基于隔离型交错并联Boost-PFC变换器的单级无电解电容LED驱动电路拓扑,该拓扑由交错并联Boost变换器和辅助功率平衡电路组成,通过辅助功率平衡电路平衡瞬时交流输入功率和直流输出功率的差值,抑制了输出电流的低频纹波.详细分析了该拓扑结构的工作原理及开关模态.基于所提电路拓扑,分析了该电路输出电流低频纹波的产生机理,提出一种适用于该电路拓扑的低频纹波控制策略,给出了具体的实现方案,并对电路关键参数进行了设计,最后搭建了一台40 W的原理样机,实验结果表明:采用所提方案时,输出滤波电容和辅助储能电容均可降到6.6μF,输出电流纹波降至16.7%,从而可以使用容值较小的薄膜电容替代电解电容,提高了LED驱动电源的使用寿命和可靠性. 相似文献
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针对传统通信射频放大器存在成本高、效率低等问题,提出一种单级AC-DC高增益降压LED驱动电路和融合可见光通信调制的控制策略,满足低压输出的LED照明和可见光通信场合。提出的单级电路由结合开关电容网络的低纹波降压Cuk电路和同步整流Buck电路集成。融合可见光通信调制的控制策略以通信二进制相移键控技术为理论基础,通过调节输出电流平均值控制LED照明水平,利用输出电流纹波相位变化实现数据通信调制。对提出的电路和融合控制策略进行详细分析,进行电路关键参数设计。最后通过计算机仿真验证,并研制一台输入185~265 VRMS、恒流输出1A/25W的实验样机。仿真和实验结果表明,电路获得了较高降压增益,实现了融合LED照明恒流控制和可见光通信调制功能,验证了所提出的电路和融合可见光通信调制控制策略的有效性。 相似文献
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Amir Bagheran 《电力部件与系统》2020,48(6-7):682-696
Abstract The high-brightness light-emitting diodes (LEDs) require an AC/DC converter with power factor correction (PFC). The large output electrolytic capacitor, which is used to minimize the low frequency LED current ripple, degrades the operating lifetime of the LED driver. In order to increase the lifetime of an AC–DC LED driver, the electrolytic capacitor should be eliminated without significantly increasing the output current ripple. In this article, an isolated single-stage single-switch AC/DC high power factor LED driver without electrolytic capacitor is proposed in which a zeta power factor (PF) corrector is integrated with a forward converter. The detailed theoretical analysis and design procedure of the proposed single-stage PFC converter is presented. The experimental results of a 110 Vrms, 21?W prototype verify the theoretical analysis. The input PF is 0.99 in the proposed converter that complies with lighting equipment standards such as IEC-1000-3-2 for class C equipment. 相似文献
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针对传统发光二极管LED(light-emitting diode)驱动电源因低频整流桥导致效率不高的问题,提出了一种基于Cuk PFC变换器的无桥LED驱动电源。该电源由2个共用输出的Cuk变换器并联而成,不仅保留了Cuk变换器输入输出电流脉动小、可实现升降压的优点,而且相较于现有LED驱动电源,避免了大体积变压器的使用,尤其适合空间狭小的大功率照明场合。详细分析了断续导电模式DCM(discontinuous conduction mode)下无桥LED驱动电源的工作原理及电路工作特性,最后通过仿真和实验搭建的20 W样机证明了所提拓扑的正确性。 相似文献
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提出了一种基于无源均流的单开关降压式四路输出LED驱动器,并分析了其工作原理及特性。该驱动器利用多电容电路结构实现了每个LED支路的均流,因此仅需控制其中一条输出支路的电流,即可实现对其他支路的电流控制。此外,所提出的LED驱动器只使用了一个有源开关,进一步减小了电路的体积,简化了驱动控制。与传统多输出LED驱动器相比,该电路可实现非隔离单开关降压转换,使其应用范围更广。最后,搭建了一台100 W四路输出实验样机,验证了所提LED驱动器理论分析的正确性与可行性。 相似文献
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Mitsuhiro Kadota Hiroyuki Shoji Atsushi Hatakeyama Keiji Wada 《Electrical Engineering in Japan》2019,209(3-4):26-34
This article proposes an LED driver that consists of a ceramic‐capacitor‐input rectifier and a buck‐boost converter. The LED driver has an advantage of long life because it does not contain any electrolytic capacitors. However, the issue with electrolytic capacitor‐less LED driver is that the ripple of the smoothed voltage becomes large due to insufficient capacitance of the smoothing capacitor. The proposed method, which uses the discontinuous current mode of a buck‐boost converter, reduces the output current ripple under such conditions. Experimental results using a 5.7 W LED driver prototype demonstrate that the proposed method reduces the output current ripple and that the percent flicker becomes 4.4%, which is smaller than the recommended upper limit of 8%. 相似文献
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传统的二次型Boost功率因数校正变换器只能实现升压输出,在一定程度上限制了其在LED驱动电源中的应用。本文基于二次型Boost变换器提出了一种Boost型无频闪谐振降压式LED驱动电源,并分析了其工作原理及特性。该LED驱动电源利用一个有源开关管将二次型Boost变换器与一个谐振网络进行整合。与传统的二次型Boost变换器相类似,该LED驱动电源可以实现高效率和高功率因数。此外,该LED驱动电源可实现低电流纹波和降压变换输出。最后,搭建了一台84W的实验样机,最高效率可达到92.88%,验证了理论分析的正确性及可行性。 相似文献
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可靠而稳定的驱动电路是LED照明的关键.运用LED线性驱动芯片NUD4001设计了LED线性驱动电路.驱动3个2W的LED发光,驱动电流达600 mA.分析了电路的工作原理,并重点提出了包括LED驱动部分和PWM调光部分的详细设计方案.并对电路进行了相关参数的测试.结果表明,该驱动电路具有PWM线性度良好,性能稳定,纹波电流小,体积紧凑等优点.适用于各种LED照明场合. 相似文献
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Chun‐An Cheng Tsung‐Yuan Chung 《International Journal of Circuit Theory and Applications》2016,44(11):1942-1958
This paper proposes a single‐stage light‐emitting diode (LED) driver that offers power‐factor correction and digital pulse–width modulation (PWM) dimming capability for streetlight applications. The presented LED streetlight driver integrates an alternating current–direct current (AC–DC) converter with coupled inductors and a half‐bridge‐type LLC DC–DC resonant converter into a single‐stage circuit topology. The sub‐circuit of the AC–DC converter with coupled inductors is designed to be operated in discontinuous‐conduction mode for achieving input‐current shaping. Zero‐voltage switching of two active power switches and zero‐current switching of two output‐rectifier diodes in the presented LED driver decrease the switching losses; thus, the circuit efficiency is increased. A prototype driver for powering a 144‐W‐rated LED streetlight module with input utility‐line voltages ranging from 100 to 120 V is implemented and tested. The proposed streetlight driver features cost‐effectiveness, high circuit efficiency, high power factor, low levels of input‐current harmonics, and a digital PWM dimming capability ranging from 20% to 100% output rated LED power, which is fulfilled by a micro‐controller. Satisfying experimental results, including dimming tests, verify the feasibility of the proposed LED streetlight driver. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献