基于无光耦反激变换器的LED驱动电源设计

传统的采用反激变换器作为主电路的LED电源中,为了实现恒流控制及输入和输出的隔离,需要通过光电耦合器把副边信号反馈回原边进行电路控制。但是光耦的体积大,且工作时电流传输比容易受到温度的影响,为了减少电路器件,降低温度对电路的影响,本文采用基于原边控制的无光耦反激变换器作为电源主电路。由于没有光电耦合器,降低了成本,减小了电源的体积,提高了功率密度,降低了温度对电源的影响。此电源能实现LED的亮度控制,并且能通过恒压控制实现LED的开路保护。     

介质阻挡放电负载调功原理分析

利用电路谐振产生高频高幅值的正弦波电压的介质阻挡放电电源,通过调整电源的逆变电路的直流输入电压,同时逆变电路开关频率跟踪电路谐振频率,可以实现介质阻挡放电负载功率的近似线性调整。研究表明,随着逆变器直流输入电压的增加,负载放电电流逐渐增大,负载功率逐渐接近于给定直流电压下的电源输出的最大功率,负载功率因数逐渐增大,逆变器输出因数逐渐接近于1,电源效率逐渐增加。     

An efficient full-bridge resonant converter for light emitting diode (LED) application with simple current control

New power control is introduced in the full-bridge dc-dc converter to drive an LED lamp in this paper. LEDs are semiconductor devices that behave like a constant voltage load with low equivalent series resistance (ESR). Hence, they require precise control for current regulation. In the proposed driver, the LED lamp is driven by two voltage sources connected in series through a series resonant circuit. It processes the majority of lamp power through the full-bridge diode rectifier and supplies small power through a center-tapped rectifier. The LED lamp current is controlled at the selected operating current by using center-tapped rectifier output voltage. In addition, pulse-width modulation (PWM) dimming is implemented. The proposed topology features zero-voltage switching (ZVS), regulation of lamp current, dimming operation, and high efficiency. The working principle, performance, and prototype validation are given for the proposed LED driver.     

二ED矿灯恒流稳压电源电路设计

介绍目前矿灯的应用现状以及存在的问题,指出LED矿灯是传统矿灯的最佳替代产品。设计一种大功率LED矿灯的电源电路,并提出了一种可以驱动两个串联的LED灯的可调恒流稳压电路的设计方案,该电路经整流滤波后再利用开关稳压器LM2576-ADJ和集成运放LM358分别解决。TLED矿灯的稳压和限流问题,并且允许输入电压在13V-38V范围内波动的情况下LED灯仍可正常工作,电路简单,实用性强。     

一种带原边电流控制的单级LED驱动电源的设计

在输入输出需要隔离的LED照明应用中,传统控制环路中均用到体积较大的光耦元件传递副边反馈信息,但这种控制降低了电路的响应速度,增大了LED驱动电源的体积,降低了功率密度,同时光耦的电流传输比易受到外界温度的影响。为了减小电路尺寸、降低成本以及降低温度对驱动电源的影响,采用基于无光耦原边控制的带漏感能量回馈支路的Buck-Boost-Flyback单级功率因数校正(PFC)变换器作为LED的驱动电源,这样既降低了成本,又提升了驱动电源的性能。分析了该单级PFC变换器的关键工作过程,并对核心元件参数值进行了具体的数学推导,设计了输入市电在85~265 V、50 V输出的8 W原理样机,通过实验证实了分析的正确性。     

Power Quality Improvement in Three-phase Telecommunication Power Supply System

This article proposes power quality improvement in a three-phase AC mains-fed telecommunication power supply by using an improved power quality converter. Conventional telecommunication tower power supplies suffer from power quality problems, such as high input current harmonic distortion, low power factor, and voltage distortions at the utility interface. To mitigate these problems, modern AC-DC converters with power factor correction circuits are used at the utility interface. An integrated boost converter is used as a power factor corrector with an isolated DC-DC converter at the load end to form the proposed telecommunication power supply. The power factor correction converter mitigates the harmonic contents of the AC mains current and improves the power factor, whereas the isolated converter provides regulated load voltage and isolation. Voltage control is used for regulating the DC voltage of the isolated converter, while the power factor correction integrated boost converter employs a current control loop to shape input current to sinusoidal in-phase with voltage. The design, modeling, and simulation results are presented to demonstrate the effectiveness of the power supply at various AC mains voltages and loads. A prototype of the front-end converter is developed, and recorded test results are presented here to validate the simulated performance.     

基于有源PFC原理的升压型DC/DC空间电源设计

采用有源PFC工作原理实现了一种升压型DC/DC变换器模块。作为空间电源完成由蓄电池输出电压50￣90V范围到稳定的128V输出,所采用的核心控制芯片为L4981A。该变换器的设计采用了双闭环控制,其特点是采用电压误差放大器环节实现输出电压稳定,采用电流环误差放大器环节实现输入电流跟踪输入电压且连续。试验结果表明,该变换器的输入电流连续,输出电压精度高,负载调整率高,电压调整率高,纹波电压较低,EMI强度较低,输出功率达到1.5kW。     

四级交错单相APFC的EL模型无源控制

传统线性控制策略的有源功率因数校正器(APFC)电流响应慢,动态性能和均流效果较差。针对以上缺陷,根据四级交错APFC功率电路拓扑结构,建立了电流连续模式下变换器的Eul-er-Lagrange(EL)数学模型,证明了四级交错APFC的无源性,采用状态反馈和阻尼注入的方法设计了无源控制器,并给出了仿真和实验。结果表明,所提控制方案在负载变化范围较宽的应用场合中,电流的动态响应快速,输出直流电压保持不变,很好地实现了APFC的功率因数校正和直流恒压输出功能,均流效果良好,每级APFC的电流偏差低于平均电流的10%。该控制方案不需要比例积分环节,控制简单,对输入电压,负载及系统元件参数的扰动具有较强的鲁棒性。     

The compact d.c. electrothermal model of power MOSFETs for SPICE

This paper concerns the problem of modelling of power MOS transistors in SPICE. In the paper the new form of the electrothermal d.c. model (ETM) of the considered class of power devices is proposed. The ETM is based on the modified Shichman–Hodges model, in which the generation current, the breakdown voltage, the sub‐threshold region, the thermally dependent series resistances and self‐heating are included. The device inner temperature calculated from the thermal model is the sum of the ambient temperature and the product of the electrical power dissipated inside the device and its thermal resistance. The presented model has been verified experimentally. The results of calculations and measurements of MTD15N06V (ON Semiconductor) and IRF840 (International Rectifier) transistors are given as well. Copyright © 2009 John Wiley & Sons, Ltd.     

A single‐stage LED lamp driver with low DC bus voltage for general lighting applications

In this paper, we study the feasibility of a single‐stage lighting LED lamp driver with low DC bus voltage. The operating principles and design considerations for the LED lamp driver in this study are analyzed and discussed in detail. A laboratory prototype has been built and tested. Using the prototype, high efficiency, high‐power factor and LED current control were achieved using a wide AC input voltage range from 90 to 270 V. Copyright © 2010 John Wiley & Sons, Ltd.     

一种无电解电容高压大功率LED驱动电源

传统的发光二极管(LED)驱动电源普遍采用电解电容作为储能元件,其相对较短的寿命成为制约LED驱动电源寿命的重要因素。为此,提出采用一种新型的电流型五电平DC-DC电路来搭建LED驱动电源。不仅去除了电解电容,延长了LED驱动电源的使用寿命,还能实现高输入功率因数和恒流驱动LED负载。详细分析了这种LED驱动电源的工作原理以及多电平PWM调制技术。最后基于PSIM仿真环境搭建系统模型,仿真结果验证了LED驱动电源拓扑的可行性。     

A single‐stage LED streetlight driver with PFC and digital PWM dimming capability

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.     

高功率因数谐振式无桥型LED驱动电源

针对传统LED驱动电源交流输入侧整流二极管导通损耗大的问题,提出了一种高功率因数谐振式无桥型LED驱动电源。该驱动电源利用谐振网络实现了正负极性增益,即无论是正电压输入还是负电压输入,负载端均可以实现正电压输出,进而实现了无桥输入。同时,利用谐振电容电荷平衡实现了各输出支路均流,解决了并联LED串的均流驱动问题。该驱动电源中的双向有源开关仅采用一个控制信号,简化了控制电路。对该LED驱动电源的工作模态及工作特性进行了理论分析。该驱动电源具有结构简单、输出升降压、电气隔离等优点。最后,搭建了一台98 W的实验样机,验证了理论分析的正确性及可行性。     

基于电力线载波的LED路灯监控系统设计

随着城市的发展,人们对路灯的节能减排及智能控制的要求越来越高,针对这种情况,设计了一套基于电力线载波技术的LED路灯监控系统。采用电力线载波芯片RISE3501结合ATmegal6微型控制器的方式,完成了集中控制器和终端控制器的软硬件设计,实现了LED远程开关灯、调光等控制,并对RISE3501芯片载波电源电流和电压波形进行了测试,。最后对采用智能监控系统的LED路灯的经济效益进行了分析。     

恒功率输出自耦反激式DC/DC变换器

研究了一种自耦反激式DC/DC变换器,可用作小功率高强度气体放电(High Intensity Discharge,简称HID)灯的电子镇流器。针对该电路的结构和工作特性,提出一种由运算放大器根据输入电压和负载变化而引入负反馈,以达到近似恒功率控制的控制策略。实验结果表明,当负载和输入电压在一定范围内变化时,采用该变换器结构和控制策略可使输出功率变化很小,且具有较高的效率。     

一种新型高性能开关电源的设计与实现

采用单端反激式变换器结构和电流连续工作模式,设计并实现了一种基于LD7532A PWM控制芯片的高效率、高功率密度和高可靠性的开关电源装置。该电源装置的交流输入电压为90 V～264 V,工作频率65 kHz,输出功率40 W,输出电压19 V。该装置的实验测试结果表明,所设计的开关电源装置的效率在85. 7%左右,空载损耗低于0. 3 W,满载输出电压纹波值小于60 mV,输出电压稳定。     

输入串联输出并联的直流变换器控制策略研究

输入串联输出并联型直流变换器能降低开关管的开关应力,适用于高输入电压、大功率的直流变换场合。为了保证该变换器的可靠工作,必须确保其输入分压电容均压和输出电流均流。文中首先从能量的角度出发,分析了输入串联输出并联型直流变换器的输入均压和输出均流之间的关系,指出输出均流控制不能保证输入均压,而输入均压控制可以确保输出均流;然后提出一种新的输入均压的控制方法,在保证输入均压和输出均流的同时,该方法可以实现输入电压的均压控制与输出电压的调节相解耦,有利于分别独立设计各个输入电容电压和输出电压的闭环控制,同时交错控制下的电流纹波抵消效应使输出滤波电容得到了减小;仿真和实验结果验证了该方法的有效性。     

25kV高精度直流负高压源设计

介绍了一种用于工业分析的高精度直流负高压电源,电源输出电压25 kV,最大输出电流100 mA。电源通过BOOST电路校正功率因数和调节电压,用移相全桥把直流电逆变成高频方波,然后经高频变压器升压后倍压整流得到直流高压。用特殊材料和工艺设计制作的高频高压变压器解决了分布参数影响和绝缘耐压等难题,满足了高频高压和大功率输出的需要。实验运行表明:该装置输入功率因数高、输出电压稳定、纹波系数小。     

一种精确调光的LED电源设计

设计了一种输出电流精确可调的LED电源.系统功率变换部分由PFC和DC/DC两级组成,实现PWM控制输出恒定电流;设计了D/A转换电路和模拟调光电路,将PWM调光信号转换为线性调光电压,实现LED电源输出电流精确可调;采用ATmega8单片机设计了智能调光系统,可以接受RS485总线的调光指令实现256级调光.统测试表明,该电源系统在较大范围内输出电流精确可调,并具有故障检测功能,适合驱动大功率LED路灯、隧道灯.