【作者】 王林兵；

【导师】 何湘宁；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2007， 博士

【摘要】 电力电子系统集成是电力电子技术发展的一个重要趋势，系统集成DC-DC模块化组合变流器的研究是其中的重要课题之一。为了克服在高压大功率场合单个功率变换器具有输入输出电流脉动大、功率器件的电压应力高、损耗大、变换器电磁干扰严重等缺点，本文研究了具有自然输入(输出)均压与输出(输入)均流功能的DC-DC模块化组合变流器。模块化功率变换器的主要优点有：功率器件的电压与电流应力低；通过引进一定的冗余模块，极大的提高了系统的可靠性；标准的功率变换器模块可以减小生产成本与开发时间；功率模块可以很容易的再组合来满足多种输入输出功率等级的需要；可以提高系统的效率与功率密度，特别当引进交错控制技术的时候。本文通过大量的实验研究验证了两种输入端并联输出端串联的模块化直流变换器和一种输入端串联输出端并联的模块化直流变换器的优点。在这三种结构中，每个单元模块在输入端(或者输出端)并联来提高系统的功率等级，在输出端(或者输入端)串联来满足系统的高电压等级需要。本文主要以全桥变换器单元为研究对象，来揭示输入并联输出串联以及输入串联输出并联模块化直流功率变换器的特点，其结论可以推广到正激、推挽等电路。文中的控制方式引入了交错控制技术与恒定占空比技术，优化了系统性能。文章首先研究了输入端并联输出端对称串联的模块化全桥变换器，得出了这种变换器具有各模块单元输出端二极管电压应力低、开关管电流应力小、输出均压、输入均流、输入输出滤波器体积小等优点。其次研究了输入端并联输出端不对称串联的模块化变换器，得出了这种结构的变换器具有输入端并联输出端对称串联的模块化全桥变换器的优点外，还有输出滤波电感数量少、动态响应速度高、系统损耗小等优点。然后研究了输入端串联输出端并联的模块化变换器，得出了这种变换器具有控制简单、输入端开关管电压应力低、输入均压、输出均流、输入输出滤波器体积小等优点。针对模块组合变换器系统复杂，控制器设计难度大的特点，本文提出了基于能量贡献等效的系统降阶控制方法，降低了控制系统的设计难度。为了验证本文方案的实用性，分析了模块元件参数差异对于系统性能的影响。论文的一些研究成果在航空静止变流器与模块式不间断电源中进行了应用实验。更多还原

【Abstract】 Power electronics system integration is seen as an important development trend in power electronics technique nowadays. Research on modular and combined DC-DC converters is one of the most important projects in the power electronic system integration.To overcome the disadvantages of the large input and output current ripple fluctuation、high voltage stresses of the secondary-side diodes、large losses of the power devices、high electromagnetic interference etc in the single power converter of high voltage area, modular and combined DC-DC converters with naturally input (output) voltage and output(input) current sharing are studied in this paper. The main advantages of the modular power converters include: low voltage and current stresses of the power devices; significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and developing time; power systems can be easily reconfigured to support varying input-output specifications; and higher efficiency and power density of the overall system, especially with interleaving control methods.The advantages of the two types of the input-parallel and output-series and one type of the input-series and output-parallel modular DC-DC converter are verified by a plenty of experimental research work. The system power level is enlarged by the parallel structure of each modular at the input-end (or output-end), and the voltage level is enlarged by the series structure of each modular at the output-end (input-end). As a single-unit of the modular combined converters, Full-bridge converters are main research objects chosen to discover the characteristics of the input-parallel and output-series as well as that of the input-series and output-parallel modular DC-DC converters, and the research conclusions can be extended and applied to the circuit structures of the half-bridge、forward、push-pull and so on. The interleaving control techniques and constant duty cycle strategies are adopted to achieve better performance of the system.In this paper, firstly the full-bridge modular DC-DC converters connected in input-parallel and output-series symmetrically are studied, and the research conclusions exhibit the following advantages: low voltage stresses in transformer secondary side diodes; low current stresses of the power devices; output voltage sharing; input current sharing; small volume of input and output filter. Secondly the Full-Bridge modular DC-DC converters connected in input-parallel and output-series dissymmetrical are studied, and the research conclusions exhibit the following advantages: small number of inductors; fast dynamic response time and low losses of the system besides that in the full-bridge modular DC-DC converters connected in input-parallel and output-series symmetrically. Thirdly the Full-Bridge modular DC-DC converters connected in input-series and output-parallel are studied, and the research conclusions exhibit the following advantages: the simplicity of the control strategy; low voltage stresses in transformer primary side MOSFET; input voltage sharing; output current sharing; small volume of input and output filter.A reduced-order system model and responding control method using the equivalent energy contribution is presented to alleviate the hardness of designing controller resulting from the complicated modular combined system.The effect on the system quality brought about by the parameter difference existing in the components of each modular is studied to verify the practicality of the scheme.Some research results of this paper are obtained from an aeronautical static converter and a modular uninterrupted power supply (UPS).更多还原