共查询到18条相似文献,搜索用时 125 毫秒
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iW3612为一款用于LED可调光控制的离线式AC/DC高性能电源变换控制器电路,它采用数控技术来检测调光器工作类型和调光相位,通过相控的方法来调节通过LED电流的脉冲宽度(PWM),从而实现LED发光亮度的调节.iW3612工作于准谐振工作模式,因而具有工作效率高的特点.iW3612采用独有的数控技术消除了LED相控... 相似文献
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介绍了ST公司新近推出采用变压器初级侧控制技术(PSR)的单片控制集成电路HVLED805的工作原理与典型应用,该芯片具有使用方便、电路结构紧凑和外围电路简单的优点,可用于AC/DC的LED驱动和LED改型灯的应用场合。 相似文献
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本文介绍了龚氏斩控式交流调压电路在交流稳压电源中的应用,用它设计交流稳压电源只要一次AC/AC变换与现有三次或四次变换(AC/DC、DC/DC、DC/AC、AC/AC)的交流稳压电源相比具有电路简单成本低可靠性好等优点。 相似文献
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D9910AC/DCLED恒流驱动控制IC
D9910是一款高效率、高稳定的AC/DC高亮度LED灯恒流驱动控制IC,内置高精度比较器、optime控制、恒流驱动等电路,特别适合多只大功率高亮度LED串联恒流驱动。 相似文献
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本文论述了适用于场控功率器件变频信号的隔离式驱动电路,包括光耦隔离式驱动电路和磁耦隔离式驱动电路。分析了这类驱动电路的结构原理、特点及应用接线,并给出了试验波形。这类驱动电路在AC/AC、DC/AC、AC/DC变换器中具有重要应用价值。 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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柔性直流输电技术是一种以电压源换流器技术为基础开发的新型高压输电技术,在改善交直流相互影响和提高电网稳定性方面具有显著作用。文中针对重庆江北电网中存在的下网负荷分布不均、金山变电站失电风险以及220 kV侧短路电流裕度小等问题,分析了柔性直流输电的技术特点及在城市配电网中的工程应用,结合重庆江北电网运行问题,提出了交、直流两种方案解决220 kV电网中金山变电站500 kV失电后产生的过载问题,并提出了应用柔性直流输电技术解决110 kV电网中220 kV变电站负载不均衡的问题,为其他工程应用柔性直流输电技术提供指导。 相似文献
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LM3445是一种与TRIAC调光器兼容的AC/DC降压恒流LED控制器。基于LM3445的反激式LED驱动器,对于由6个串联LED组成的LED串在不使用TRIAC调光器时功率因数>0.93,效率>81%。 相似文献
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采用先进的数字仿真系统对大规模的交直流混合电力系统进行研究是一个有效的途径.为此,介绍了我国交直流混合电力系统数字仿真的发展,以及几种常用的仿真软件,包括离线仿真的MATLAB,PSCAD/EMTDC和NETOMAC,实时仿真的RTDS和HYPERSIM等,并分别对它们的交直流混合电力系统仿真能力进行了探讨和比较,提出了用户选取时应注意的问题. 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