【作者】 刘合祥；

【导师】 成立；

【作者基本信息】 江苏大学 ， 电力电子与电力传动， 2006， 硕士

【摘要】 随着电子信息产业技术的飞速发展，开关电源电力电子装置得到了广泛的应用，同时这种传统开关电源也对电网造成了污染，由此具有功率因数校正(Power Factor Correction，PFC)功能的低电磁污染型“绿色电源”也就应运而生。随着人们对电源质量的更高要求，高效型、体积小和污染低的开关电源已成为研发的主流技术，因此尽可能地提高DC/DC变换效率，再利用同步整流技术可以使开关电源效率大大提高。本文将PFC技术、准谐振DC/DC变换与同步整流技术相结合，设计出一款低磁污染的开关电源，既保证了较高的功率因数，改善了对电网的影响，又能保证高效率，且控制简单，可靠实用，因而具有一定的应用价值。 本文首先阐述了开关电源、功率因数校正技术和同步整流技术的发展及现状，对DC/DC变换的拓扑结构进行了选择，确定了带有隔离的准谐振(Quasi-Resonant)反激型电路，可以有效地降低损耗；接着本文对几种常见的PFC拓扑电路进行分析对比，从中选择了BOOST型电路，对工作在临界状况下的电路进行了分析，采用跟随输入电压的升压变换新技术，减小了电感体积，同时降低了开关管的电压应力，既简单又有效地实现了功率因数校正，并发现此技术值得推广；由于反激型变换器的效率一般都较低，所以本文在传统同步整流技术基础上对其加以改进，设计出一种新颖、高效的同步整流方案。对于宽电压范围启动过冲问题，本位设计出一种防止过冲的启动控制电路。最后为降低电磁干扰(Electromagnetic Interference，EMI)，达到电磁兼容(Electromagnetic Compatibility，EMC)，特设计出开关电源电路输入端的EMI滤波电路。 本文对整个电路拓扑建立小信号模型，进行了系统稳态性能分析，证明了电路系统的稳定性。文中对部分电路用OrCAD Pspice A/D仿真软件进行了仿真，选取了元器件，制作样机进行了硬件调试，分析试验数据并与仿真波形对比，实验结果令人满意，实现了高功率因数，成功地做到PFC输出电压跟随输入电压升压控制，整机效率明显提高。文末提出了下一步工作的方向和目标。 随着社会的发展及需求，新一代功率变换器必将向大功率、高功率因数、高效率、低损耗、低污染、小体积、高性能方向发展。通过本文的理论分析、电路更多还原

【Abstract】 With the rapid development of electronic information industry, power electronics equipments such as switching power supply have been widely applied. At the same time, such conventional switching power supply contaminated electrical network, consequently a novel power supply with power factor correction (PFC), a type of low electromagnetic contamination, emerges as the times require, that is "green power supply". With people’s more demand for quality of power, the power supply with high efficiency, little bulk and low contamination have became mainstream of research and development. So striving hard to improve transforming efficiency of DC/DC and utilizing Synchronous Rectifier can be able to improve transforming efficiency greatly. This paper attempts to associate PFC technology with Quasi-Resonant DC/DC Converter and Synchronous Rectifier technology, to work out a novel switching power supply with higher efficiency and low contamination, which both achieved high power factor, improved effecting on electrical network and ensured high efficiency, furthermore, it is easy to be realized and controlled in circuit. Therefore it has great value of application.Firstly, future development of switching power supply, power factor correcting and synchronous rectifier technology is described, and isolation of Quasi-Resonant Flyback Converter is selected from several topology of DC/DC, which may reduces power loss effectively. Next several common topology of PFC are contrasted with their performance, and BOOST circuit elected is analyzed with operating in critical mode, which adopts new technology of output voltage following along with changing of input, not only can bulk of inductance lessen, but also can voltage stress of switching tube decrease, and reaches power factor correcting easily and effectively, this technology should be extended. Because efficiency of Flyback Converter is lower commonly, so this paper improves on technology of common Synchronous Rectifier and schemes out a new high efficiency scheme of Synchronous Rectifier. About current surge when start in wide voltage, corresponding control circuit of start-up is designed in this paper. Finally, to depress Electromagnetic Interference (EMI) and achieve Electromagnetic Compatibility (EMC), EMI filter is designed at input of switching power supplyspecially.This paper constructs small-signal modeling according to entire circuit and analyzes systemic stabilization, which proves stability of it. Simulates parts of circuit using simulation software of OrCAD Pspice A/D, selects circuit components, designs更多还原