【作者】 顾亦磊；

【导师】 吕征宇；

【作者基本信息】 浙江大学 ， 电力电子与电力传动， 2008， 博士

【摘要】 电力电子系统集成是当今电力电子技术研究的重要课题,引领电力电子技术朝集成化、标准化和模块化方向发展。高集成度的标准模块技术的研究是电力电子系统集成工作的重要组成部分,也是影响电力电子系统集成能否成功推广的关键因素。本论文从标准模块的分类、拓扑选择的标准、适合系统集成的软开关理论、标准模块拓扑结构的选择和优化、变拓扑柔性变流器理论、小信号电路的优化等方面探讨了电力电子系统集成的技术,提出了若干新思路。电力电子系统集成的应用对象是世界上主流的电源产品,文中首先对此进行了调查和分析,分析了各种电力电子系统的要求、结构和特点。为了涵盖尽量多的应用又能够减少标准模块的种类,提出采用电压和功率两种等级交叉的方式对标准模块进行大的电气规格的分类,综合实际的应用得到14种常用的DC/DC标准模块大类。提出了DC/DC拓扑选择的4大准则,针对一些经典的DC/DC拓扑和较新的DC/DC拓扑与这四大标准的关系进行了评价。得出了电气规格和拓扑之间的直接对应关系。分析了电力电子系统集成标准模块所需要的软开关技术,为中小功率和中功率标准模块提出了控制型软开关的概念和理论,明确了控制型软开关的定义,总结和归纳出控制型软开关的五个特征,利用现有的控制型软开关拓扑检验了这五个特征理论。接着应用五个特征理论推导和构造出一系列拓扑的控制型软开关的实现方法。为小功率标准模块推荐了准谐振反激变流器作为软开关候选拓扑。针对系统集成的特殊要求,对一些经典的PWM型拓扑进行改进和改造,为系统集成提供更佳的候选拓扑及方案。首先对于较高电压输入的系统集成小功率标准模块,提出了宽范围双管反激DC/DC变流器,拓展了占空比范围,提高了宽范围适应性。其次对于较高电压输入的系统集成中小功率标准模块,又提出了宽范围双管正激变流器系列,其中包含3种非对称双管正激变流器,对其中两种变流器提出了控制型软开关的实现方法。最后为采用同步整流的低压大电流标准模块提出了一种适合并联的同步整流自驱动方案。解决了多个模块并联时会产生短路现象的问题,同时单机运行时的性能又不受损害。针对系统集成的特殊要求,对经典的谐振型拓扑进行改进和改造,为系统集成提供更佳的候选拓扑及方案。介绍了LLC-4的发展历程,并从最基本结构的非隔离LLC-4出发详细分析了LLC-4的特性。给出了LLC-4在实际产品中的应用例子（液晶电视电源和网络交换机电源）。为了拓展LLC在高输入电压的应用,为三相之后的DC/DC标准模块提供优选拓扑,探讨了带4个死区时间的三电平LLC-4。为适应高电压输出标准模块的应用构造了倍压整流LLC-4结构;为了进一步降低副边元器件的电压应力又构造了副边电压应力最小化的LLC-4,使得副边所有元器件的电压应力为输出电压的一半。构造了结构非常简单的半波整流LLC-4,进而提出了非对称多路输出LLC-4的概念,由于结构灵活多变,多路输出LLC-4非常适合带拓展性的多路输出的标准模块的应用。将“分时”的概念用于LLC-4,提出了利用磁放大器作后级调整的LLC-4,大大提高了多路输出电源的交叉调整率。针对输入或输出大低压大电流的标准模块的应用,又提出了Interleaving的LLC-4,将断续的输入或输出电流改造成连续的电流,拓展了LLC-4适用的功率等级。对以上提出的LLC-4优化的结构都给出了仿真波形或者实验波形。最后总结了LLC-4输入侧和输出侧的各种结构,列举了部分常用的LLC-4结构。为了进一步提高标准模块的通用性,探索性地提出电力电子变拓扑柔性变流器的概念和理论,明确了柔性变流器子集的概念,并给出了4个较佳的子集例子。研究了柔性变流器切换点和切换方式的选取方法。给出了一个完整的变拓扑柔性变流器的实例,并且进行了实验验证,还给出了小信号的处理方法。给出了实用的小信号测量和分析的方法,探讨了“增大中频宽度法”和“平移补偿网络法”作为微调小信号特性的有效手段。针对宽电压输入范围的Buck型变流器,提出了采用输入电压作为小信号传函的补偿量的方法,起到抵消功率级传函中V_in分量的作用,使得环路增益不随输入电压改变而改变。采用该方法,在宽输入电压范围应用下可以很好地兼顾变流器的稳定性和动态特性。针对宽输出电压范围的Buck型变流器的应用,分析了各种调节输出电压的手段,提出了采用不影响小信号传函但是又能调节输出电压的方法,采用该方法可以实现在不同输出电压时尽量一致的环路增益。最后分析了柔性变流器的小信号特征,并提出相应的解决方案。更多还原

【Abstract】 Power Electronic Systems Integration (PESI), a key research area in modern power electronics, pushes the power electronic techniques towards integration, standardization and modularization. To develop the technology of high integrated Standard Power Modules (SPM) is the important work for PESI, and it is also the key factor to make it possible that the PESI is applied in the industry successfully. Classification for the SPM, rules for topology selection, soft-switching technology for SPM, topology selection and improvement for SPM, flexible converter theory, and consideration for small-signal in SPM are studied in this dissertation, and several novel ideas are presented.PESI technology is developed in order to be applied in the mainstream power electronics products in the world. The investigation and analysis for the mainstream power electronics products are carried out, and the requirements, architectures, and features of them are proposed. SPMs are classified into 14 categories by the way of both voltage level and power level, according to practical applications. Based upon electrical specifications, four novel selection criterions of DC/DC topologies in designing power products are presented. Some classical and novel excellent topologies are evaluated according to these four criterions. Then the relation between electrical specification and DC/DC topologies is presented for power product designer to use conveniently.The needed soft-switching technology for SPM is analysis, and the conception and theory of control-type soft-switching technology are proposed for mid-to-low power or mid power applications. It clears up the definition of control-type soft-switching and presents five characteristics for control-type soft-switching in the paper. The theory of five characteristics is verified in the existing control-type soft-switching topologies. And a series of new control-type soft-switching topologies are constructed by using the theory of five characteristics. For low power SPM applications, the soft-switching converter of quasi-resonant flyback is introduced.According to the special requirements of PESI, Some classical PWM converters, which are the candidate topologies for SPMs, are improved. First of all, a novel topology of wide range dual-switch flyback converter, extending the available duty cycle, is proposed for high voltage low power SPM applications. Second, for low-to-mid power SPM applications, a family of wide rang dual-switch forward converters, including 3 kind of asymmetrical topologies, are proposed. The control-type soft-switching technologies are developed for the two asymmetrical topologies thereinto. At last, paper presents a synchronous rectifier driving scheme, which not only solves the problem of short circuit when modules run in parallel but also keeps synchronous rectifier driving performance same as that of self-driven for low voltage high current SPM applications.According to the special requirements of PESI, Some classical resonant converters, which are the candidate topologies for SPMs, are improved. The developing course of LLC-4 is introduced, and the detailed operating principle is analyzed based on the non-isolated LLC-4 topology. The examples that LLC-4 is applied in the practical products of LCD power and POE are presented. Three-level LLC-4 with four dead times is proposed for high input voltage applications such as the DC/DC SPMs after three-phase rectifier. Voltage doubler LLC-4 is proposed for high output voltage SPM applications. To further decrease the voltage stresses of the secondary side components, LLC-4 with minimized voltage stress for secondary side is proposed. In this topology, voltage stresses of secondary side diodes and secondary side capacitors are half of output voltages. A simple architecture of LLC-4 with half-wave rectifier is proposed. Multi-output LLC-4 including this architecture is named asymmetrical multi-output LLC-4. It is fit for multi-output SPMs with expansibility applications. Strategy of time-sharing magamp is adopted in LLC-4 with multi-output for increasing the adaptability of the very topology to such application as multi-output with high cross-regulation requirement. For high power, low voltage high current input or output SPM application, interleaving LLC-4 is proposed, in which, input current or output current can be ameliorated from DCM to CCM. Simulations or experiments are performed for all the above topologies. Finally, various input topologies and output topologies for LLC-4 are summed up.In order to further improve the wide range adaptability of SPM, a novel conception of flexible converter and its theory are proposed. The conception of topology subset is cleared up, and 4 examples of topology subset are presented. Switching point and switching mode for the flexible converter are studied in this dissertation. An example of flexible converter with two selectable topologies is presented, and verified in an experimental prototype. The compatible issue of small signal is presented and solved as well.Useful methods of measurement and analysis for small-signal in power electronics are introduced. "Enlarging the width of mid frequency part" and "moving the gain bode plot of compensation network" are proposed for slightly adjusting the small-signal performance. For wide voltage range input Buck converter, a method is proposed that input voltage is used as compensation value to balance the value of Vin in the transfer function of the power stage. Thus, loop gain will not change at various input voltage, and not only good stability but also good dynamic performance can be achieved in wide input voltage range applications. For wide voltage range output Buck converter, various ways to adjust the output voltage are analyzed. The way can adjust the output voltage but will not influence the small signal transfer function is proposed. Thus, the loop gain will not change at various output voltage. Finally the small-signal issues of flexible converters are discussed, and the related solutions are proposed as well.更多还原