低功耗反激软开关变换器的研究

发布时间：2019-03-22 17:28

【摘要】：目前,开关电源以体积小、轻量化和高效率等特点,被广泛应用于计算机、通信、电力、交通、机械、航空航天、医疗等领域。随着现代便携式设备的使用越来越广泛,对开关电源的性能要求也随之提高,体积以及转换效率需要达到更高的标准才能满足市场的需求。传统的整流滤波电路功率因数低,产生的谐波电流大,对电网造成严重的谐波污染。在变换器器前级加入功率因数校正器(PFC),可以有效的提高变换器功率因数,满足电网谐波相关标准。另外,变换器工作频率越高,开关损耗也同步增加,在不降低变换器工作频率的情况下,提高变换器的整体效率,就要依赖软开关技术和同步整流技术。由此,功率因数校正(PFC)技术、同步整流技术和软开关技术是目前开关电源研究中的热点方向。本文研究的低功耗反激软开关变换器的电路结构为,输入前级是Boost型PFC电路,中间级是ZCS-PWM(零电流开关)反激软开关电路,后级是同步整流输出电路。文章首先通过对无源功率因数校正(PFC)与有源功率校正(APFC)技术对比,确定本次方案采用APFC。接着介绍了软开关技术与同步整流技术的提出与发展。论文详细分析了Boost型APFC电路原理,并且对反激软开关电路工作过程分阶段研究,并且给出了推导过程和工作波形分析图。然后,设计了一台前级带APFC后级同步整流输出的反激软开关变换器的样机,给出了电路主要元器件的设计方法。最后对系统进行仿真和样机实验测试,给出了电路关键点的测试波形,同时测试了样机的功率因数值、谐波电流数据、输入电压调整率、输出负载调整率和整机效率等数据。通过对仿真波形和测试数据的分析,表明了样机的各项测试指标符合预期的设计要求,从而验证了方案的正确性。文章最后,对本次课题的工作做了总结,并提出了未来的研究方向。
[Abstract]:At present, switching power supply is widely used in computer, communication, power, traffic, machinery, aerospace, medical and other fields because of its small size, lightweight and high efficiency. With the increasing use of modern portable devices, the performance requirements of switching power supply are also improved, and the volume and conversion efficiency need to reach a higher standard in order to meet the needs of the market. The traditional rectifying and filtering circuit has low power factor and large harmonic current, which causes serious harmonic pollution to the power network. Adding the power factor corrector (PFC),) to the front stage of the converter can effectively improve the power factor of the converter and meet the harmonic correlation standard of the power grid. In addition, the higher the working frequency of the converter, the more the switching loss also increases synchronously. Without decreasing the working frequency of the converter, the improvement of the overall efficiency of the converter depends on the soft-switching technology and the synchronous rectifier technology. Therefore, power factor correction (PFC) technology, synchronous rectifier technology and soft-switching technology are the hot topics in the research of switching power supply. The circuit structure of the low-power flyback soft-switching converter studied in this paper is that the input front stage is boost-type PFC circuit, the intermediate stage is ZCS-PWM (zero-current-switching) flyback soft-switching circuit, and the second stage is synchronous rectifier output circuit. In this paper, the passive power factor correction (PFC) and active power correction (APFC) techniques are compared to determine that this scheme adopts APFC.. Then the paper introduces the development of soft switching technology and synchronous rectifier technology. In this paper, the principle of boost type APFC circuit is analyzed in detail, and the working process of flyback soft-switching circuit is studied in stages, and the derivation process and working waveform analysis diagram are given. Then, a prototype of a flyback soft-switching converter with the back-stage synchronous rectifier output of APFC is designed, and the design method of the main components of the circuit is given. Finally, the system is simulated and the test waveform of the key points of the circuit is given. At the same time, the power factor of the prototype, the harmonic current data, the input voltage regulation, the output load regulation and the efficiency of the whole machine are tested. Through the analysis of the simulation waveform and test data, it is shown that the test indexes of the prototype accord with the expected design requirements, and the correctness of the scheme is verified. Finally, the work of this topic is summarized, and the future research direction is put forward.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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