【作者】 吴新科；

【导师】 钱照明；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2006， 博士

【摘要】 本文是在电力电子系统集成课题的背景下进行的研究，全文可以分为两部分。第一部分主要对用于中功率范围的单相功率因数校正器(PFC)的拓扑进行优选，并且对后级宽输入电压范围的DC／DC拓扑进行了研究。第二部分主要对DC／DC变流器的小信号模型进行进一步研究，并且在小信号分析的基础上，研究了DC／DC变流器模块和级联系统的稳定性，同时对PFC变流器的小信号特性也进行了探讨。对于中功率范围的PFC变流器，Boost型的拓扑以其高效率，宽输入范围，低谐波而广泛应用。本文对提高Boost型PFC的效率的方法进行了探讨，并且以高效率为主要的优选准则，综合考虑拓扑的复杂程度，辅助网络的体积，以及是否便于集成，适用功率范围等方面，对现有的boost型PFC拓扑进行了比较，并且归纳出了通用性较好的拓扑。通过比较和优化，按照不同功率等级的PFC应用场合，总结出了若干个适合标准化的Boost型PFC拓扑，传统的DC／DC变流器的效率对输入电压的范围比较敏感，用于宽输入电压范围场合时，效率很低。为了能够使得DC／DC能够适应很宽的输入电压范围(100V—400V)，本文提出一种新的混合调制的控制的方式，通过将窄范围设计的DC／DC变流器单元原边并联，结合副边的桥式整流结构，能够获得很宽的输入电压范围，并且可以降低副边整流器件的电压应力，从而采用低耐压的器件，降低导通损耗，提高效率。本文还对峰值电流模式控制的DC／DC变流器的模型进行了进一步研究，提出了一种改进的小信号模型，能够更为准确的预测变流器的环路特性。本文对平均电流模式控制的DC／DC变流器进行了建模，采用与峰值电流控制变流器建模相似的方法，得出了改进的平均电流模式控制的变流器的模型。通过比较和分析，将两种电流模式控制的模型进行归一化处理，得出了通用的电流模式控制的小信号模型。在这个小信号模型的基础上，对峰值电流模式控制的DC／DC变流器在不同性质负载下的稳定性进行分析和判断，并提出了阻性负载条件下设计用于负阻性负载的DC／DC变流器的设计方法。同样，通过分析输入滤波器对DC／DC变流器环路的影响，得出了更为简单的滤波器设计标准。本文最后对Boost型PFC变流器进行了建模。在通用的电流模式控制变流器模型的基础上，增加了输入电压的前馈环路。虽然PFC不存在DC／DC变流器的稳态工作点，但是通过分析发现，直流输入情况下的平均电流控制的变流器模型可以代替用于交流输入的PFC的模型。通过分析在直流输入时的小信号模型的稳定性，就可近似得出PFC变流器的小信号稳定性。更多还原

【Abstract】 This dissertation includes two parts. Part I, topology optimizations for boost type PFC converter and front end DC/DC converter with wide input voltage range. Part II, modeling for peak current mode (PCM) control and average current mode (ACM) control, with the generalized small signal model for current mode controlled converter the stability of the PCM converter is analyzed. The small signal model for PFC converter is built based on the DC/DC model with a little modification, and the stability of pfc converter is analyzed.In the power level higher than 500 watt, the Boost type PFC topology is more preferred due to its high power factor, low thd, wide power range. However the conventional Boost PFC converter suffers from high conduction loss when it is used in universal line voltage. Due to the wide input voltage range (90Vac-265Vac) the efficiency at low line is much lower than high line. The optimization focus on the efficiency improvement, meanwhile the complexity of circuit, the volume of auxiliary network, and power level limitation are considered. Based on the optimization some generalized Boost type PFC topology is deduced and analyzed, which can be used as general topology in system integration application in different power level.In conventional front end DC/DC full bridge converters the efficiency is sensitive to the input voltage range. Therefore when these dc/dc topologies used in wide voltage range (100V-400V) the efficiency falls significantly. To achieve high efficiency at such wide input voltage range, a new rectifier structure at secondary side and a hybrid control strategy are proposed. with the new rectifier structure and new control strategy the voltage stress of rectifier devices is reduced to half. Therefore the conduction loss of secondary side is reduced, and the efficiency is improved.In part 2, an improved small signal model for PCM converter is proposed using geometry method. This low frequency small signal model is more precise than the conventional PCM model. Also the ACM small signal model is built using similar method. with the synthesis of the PCM and ACM model, a general small signal symbolic model is got. using the general model for current mode control, the stability of PCM controlled converter is analyzed with different load, and the design criterion for loop compensation with different load condition is proposed. A simple design criterion for EMI filter is proposed for PCM DC/DC converter based on the proposed small signal model.The small signal model for Boost type PFC converter with ACM control is built. Analysis and experimental results verify that the small signal for PFC converter is almost identical to that of DC/DC converter with same control method. The design criterion for voltage loop band width is proposed based on the synthesizing analysis.更多还原