共查询到18条相似文献,搜索用时 234 毫秒
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无电解电容AC/DC LED驱动电源中减小输出电流脉动的前馈控制策略 总被引:1,自引:0,他引:1
高可靠性、高效率、高功率因数、低成本的LED驱动电源是保证发光二极管(light emitting diode,LED)发光品质和性能的关键。一种无频闪无电解电容AC/DC LED驱动电源已经被提出,它包括一个无电解电容的功率因数校正(power factor correction,PFC)变换器和一个在其输出端并联的双向变换器,式中双向变换器是用来吸收 PFC 变换器输出电流中的低频交流脉动电流,以达到消除LED照明频闪的目的。为了减小双向变换器输出侧的储能电容,储能电容设计为含有较大电压纹波的形式。该文在此基础上,分析双向变换器输出侧储能电容电压大纹波致使双向变换器的占空比中存在相应的谐波成分,其电流内环无法提供这些成分,只能通过增大双向变换器输入电流的跟踪稳态误差来满足这些谐波的需求,最终引起LED驱动电流畸变,会引发频闪问题。为了提高双向变换器输入电流对两倍输入频率交流电流吸收的准确性,减小LED驱动电流脉动,对双向变换器进行稳态分析,提出一种基于电流基准的前馈控制策略,实验结果验证了此方法的正确性。 相似文献
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两级单相逆变器的前级DC/DC变换器输入电流会含有较大的低频纹波电流,这会严重影响直流侧电源的寿命。此处基于电流反馈双半桥(CF-DHB)DC/DC变换器和全桥逆变器构成的两级DC/AC变换器,提出一种新的抑制输入电流纹波的方法,根据变换器的瞬时功率特性,计算出消除电流纹波所需的移相角,进而消除控制器输出量中的纹波分量。能够在保证交流输出电压质量的同时,显著抑制输入电流纹波,并且能够消除负载突变时的电流振荡。实验验证了所提控制方法的有效性。 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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iW3620是一种利用先进的数字控制技术和在峰值电流型PWM反激式变换器中利用初级侧控制技术的高性能AC/DC离线式LED驱动器。文中介绍了iW3620的功能特点和基于iW3620的AC/DC离线式LED照明电源的设计。 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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Hongbo Ma Jih‐Sheng Lai Quanyuan Feng Wensong Yu Cong Zheng 《International Journal of Circuit Theory and Applications》2013,41(5):514-534
The AC–DC power supply for LED lighting application requires a long lifetime while maintaining high‐efficiency, high power factor and low cost. However, a typical design uses electrolytic capacitor as storage capacitor, which is not only bulky but also with short life span, thus hampering performance improvement of the entire LED lighting system. In this article, a SEPIC‐derived power factor correction topology is proposed as the first stage for driving multiple lighting LED lamps. Along with a relatively large voltage ripple allowable in a two‐stage design, the proposal of LED lamp driver is able to eliminate the electrolytic capacitor while maintaining high power factor and high efficiency. To further increase the efficiency of LED driver, we introduced and used the twin‐bus buck converter as the second‐stage current regulator with Pulse Width Modulation (PWM) dimming function. The basic operating principle and the deign consideration are discussed in detail. A 50‐W prototype has been built and tested to verify the proposal. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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级联H桥AC/DC型电力电子变压器中的高频直流环节通常采用双有源桥电路DAB(dual-active bridge),并通过移相控制方式进行能量传递。单移相控制会在DAB中引入回流功率,增加系统损耗。在由理想直流电压源供电的DAB中,通过改进的移相控制可以显著抑制回流功率。然而在电力电子变压器PET(power electronic transformer)中,交流电网侧的PWM整流环节会引入二次脉动功率,导致其高频直流环节的输入/输出电压变比存在低频脉动,使得现有的回流功率抑制方法难以获得期望效果。针对这一问题,分析了在PET模块电容电压存在低频脉动的情况下,采用单移相和扩展移相两种控制方式下的回流功率分布特征;同时,结合功率通道型三相AC/DC电力电子变压器,提出了功率解耦和扩展移相协同控制的回流功率抑制方法;通过功率解耦控制,抑制模块电容电压中的低频脉动,维持高频直流环节输入/输出电压变比恒定,并结合扩展移相控制,抑制PET中的回流功率。仿真和实验结果验证了所提方案可以有效抑制三相AC/DC型PET中高频直流环节内的低频脉动功率及回流功率。 相似文献
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随着LED照明领域的不断拓展和人们对健康光源的迫切需要,LED光源的频闪问题备受关注。流经LED光源的纹波电流不但会引起频闪,还会对光度、比色性能和光效等造成不良影响。无电解电容LED驱动电源纹波补偿控制能有效兼顾长寿命和低纹波等性能指标的优化设计,从而为人们提供高效节能且更加健康的LED光源。通过归纳分析无电解电容AC-DC LED驱动电源的关键技术和纹波补偿控制策略,对大功率无电解化LED驱动电源合理化指标要求、拓扑结构、小信号模型、自适应数字电流预测控制、自适应纹波补偿控制和高频能量同步传输控制等进行了展望,并针对工程应用提出了相应的实现思路,以期助推绿色健康LED驱动电源的研究。 相似文献
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Abstract—Electrolytic capacitor is a key factor that limits the life-time of the driver in a high-power light-emitting diode (LED) lighting. This article presents a high-power LED lighting driver on a digital signal processor without an electrolytic capacitor. The driver is composed of three stage circuits. The first stage is the boost power factor correction converter to achieve a high power factor. As it does not use an electrolytic capacitor, the output voltage ripple is larger, which directly affects the overall performance of the LED driver. Consequently, it must be optimized through the second and third stages. The second stage is the two-output LLC (Double inductance and capacitance) resonant converter, which is driven by a digital signal processor. This stage provides galvanic isolation and reduces voltage. The third stage is the two-input buck converter based on digital signal processor control that reduces the low-frequency ripple generated from the first two stages. Moreover, the regulation of each LED string current is achieved at this stage. The simulation and experimental results show that this LED lighting driver can achieve a high power factor and good constant current characteristics. 相似文献
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电力电子变换器机内辅助开关电源设计与实验 总被引:2,自引:0,他引:2
论述了峰值电流控制RCD钳位反激变换器的原理,并首次提出了RCD钳位等关键电路参数设计准则,设计并研制成功的15W 220V 50Hz AC/270V DC/ 15V DC(0.8A),-15V DC(0.15A), 5V DC(0.2A)机内辅助开关电源具有功率密度高,变换效率高,过载与短路能力强,可靠性高等优良的综合性能,在AC/AC,DC/AC,AC/DC、DC/DC等四类电力电子变换器中均具有重要应用价值。 相似文献