冷阴极荧光灯电子镇流器的分析与设计.pdf

大连理工大学
硕士学位论文
冷阴极荧光灯电子镇流器的分析与设计
姓名:王海林
申请学位级别:硕士
专业:电工理论与新技术
指导教师:李国锋
20070615
大连理工大学硕士学位论文
摘要
冷阴极荧光灯作为一种新型的气体放电灯,是目前极为高效的显示器背景照明光源
之一,具有高亮度、长寿命、低功耗、瞬时启动等优良性能,符合国家绿色照明工程的
倡导,将在未来的日常照明领域占据重要地位。
冷阴极荧光灯的工作原理与热阴极荧光灯类似,只是工作电压更高,工作电流较小。
然而驱动这些小型的冷阴极荧光灯管是相当棘手的事,它们对起弧电压和工作电压有特
殊的要求。本论文的主要任务就是研究与冷阴极荧光灯相匹配的电子镇流器装置。
本文介绍了冷阴极荧光灯的发光原理、国内外研究现状和发展趋势:分析了 Royer、
半桥、全桥和推挽等4种驱动电路的拓扑结构,并对半桥拓扑进行了设计、验证。
电流谐波和功率因数是电子镇流器两个非常重要的技术指标。现代高功率因数电子
镇流器结构中普遍釆用功率因数校正和半桥逆变谐振电路拓扑。文中阐述了功率因数校
正(PFC)电路的工作原理和特点,分别设计了逐流式PPFC电路和基于TDA4863的
APFC电路,通过对比分析,达到了预期设计目标。
本文借鉴日光灯电子镇流器的设计思路,采用适配器加逆变器的一体化方案,比传
统低压输入方案体积更小,效率更高。论文从实际应用出发,设计了采用分立元件构成
的市电输入半桥自激振荡CCFL电子镇流器。分析了它的工作原理,给出了设计过程,
提供了外部元器件选择指导,并研制了一台样机,利用该样机验证了分析的正确性。
本文还研究了用于CCFL半桥驱动的UBA2070芯片的性能、特点和工作原理;并
对基于此芯片的2管CCFL驱动电路的构成进行了设计;在设计中规划了主电路的构
成,并在电路中实现了软启动、调光、过压、过流保护等实用功能。实验结果显示这种
电子镇流器具有连续的交流电网输入电流、适当的功率因数校正和合理的总谐波失真,
达到了设计标准。
关键词:冷阴极荧光灯;电子镇流器:半桥驱动;功率因数校正;调光
冷阴极荧光灯电子镇流器的分析与设计
Analysis and Design of an Electronic Ballast for the Cold Cathode
Fluorescent Lamp(CCFL
Abstract
The Cold Cathode Fluorescent Lamp(CCFL) one of novel gas discharge lamps, which
presents good performances such as high lightness, longevity of service, low power
consumption, inst an aneous startup and so on, is one of the current very efficient light sources
for background illumination(acki h )of display units. The merits held by CCFL tally with
the advocate for national"green illumination engineering, which makes it hold a very
important position in the future daily illumination field
CCFL hardly has any difference on the working principle with Heat Cathode Fluorescent
Lamp(HCF except for its hiher working voltage and lower working current. But how to
drive the minitype light tube of CCFL is a very tough job because of its special demands on
the arc and working voltages. For solving the problem, the paper aims to work out the
electronic ballast device matching with CCFL.
This paper first introduces the luminescence principle of CCPL, its investigation
background and actuality, and its development trend. This study also analyzes and compares
several topology frames in common use including Royer, half-bridge and full-bridge
topologies; designes and experiments with the half bridge topology
Current harmonic and power factor are two of the very important techmical indexes, and
the power factor correction(PFC)and half-bridge inverter circuit topology are commonly
used in modern high power factor electronic ballasts. So the paper expatiates on the principle
and characteristic of PFC circuit and gives the circuit design method of PPFC and APFC. The
results of contrast analysis indicate that the design satisfies the expected objective.
The design approach for CCFL borrows some ideas for designing electronic ballast of
fluorescent lamp, in which the scheme of adaptor plus inverter is adopted. Compared with the
conventional scheme of lowvoltage inpu this desin owns the merits lie smaller volume
and higher efficiency. Aimed at actual application of CCFL, the half-bridge self-excited
scillation electric ballast consisted of separated elements is supplied with household
electricity. The working principle, the design process and the guide for selection of elements
a