【作者】 李楚杉；

【导师】 汪槱生； 邓焰；

【作者基本信息】 浙江大学 ， 电气工程， 2014， 博士

【摘要】 交交功率变换是电力电子学四大变换之一,是电力电子技术领域的主要研究应用方向。带有中间直流单元的整流——逆变形式交交变流器普遍存在储能元件价格昂贵、寿命短、功率密度低等缺点,因此研究无储能元件的直接交交变流器技术一直是本领域的研究热点。本论文对交交功率变换领域的诸多拓扑结构及其应用领域进行了广泛综述,针对直接交交斩波器拓扑难以实现任意给定电压输出的问题,提出了应用于该类拓扑的,实现任意给定频率、相位、幅值交流电压输出的虚拟正交源优化电压合成策略,进而拓展了该类拓扑的应用范围,在多个交交功率变换领域得到一系列高可靠的新型直接交交变流解决方案。首先,基于最简单的Buck型交流斩波器,推导得出采用时变占空比给定控制、输出电压零序分量对消方式,在三相交流斩波器拓扑中产生需要的基频正序分量,谐波频率正序分量和谐波频率负序分量,进而得到任意频率、相位、幅值的三相交流输出电压的虚拟正交源电压优化合成策略,同时有效解决控制过程中产生的额外谐波电压。通过采用以上策略,单相结构的交流斩波器可以有效克服其原有局限,其应用范围将推广至交交功率变换的大部分领域。通过分析得出结论,在简单Buck型交流斩波器上应用该新策略,其输出电压中存在额外不可控的基波分量,因此限制了其应用。进而总结和归纳出基于虚拟正交源电压优化合成策略的直接交交变流器拓扑所应具备的基本特征,为新拓扑的引入与研究提供了理论指导。其次,论文给出了一系列工频隔离的适用于虚拟正交源优化电压合成策略的直接交交变流器拓扑,从中并进一步推衍得到使用商业化半桥模块,并且使变压器高频损耗降低的改进型推挽正激拓扑。同时,针对在电机拖动领域输出极低频电压的要求,进一步给出了一系列高频隔离的适用于虚拟正交源优化电压合成策略的直接交交变流器拓扑,并分析了该类拓扑的高频变压器在新型控制策略下的励磁状态,为高频变压器的设计提供指导。论文同时对上述直接交交变流器拓扑进行建模,得到能够用于系统快速仿真的电路精确大信号模型。同时通过在模型中引入非线性的坐标变换,实现了虚拟正交源优化电压合成策略的数学建模。通过在控制中引入附加算子,进一步实现了使用优化电压合成策略的直接交交变流器控制和传统逆变器控制的等效,从而将针对传统逆变器类电路的闭环控制策略无缝移植到新技术中,加速对以上交交变流器控制方案和应用领域的研究,实现了新型直接交交变流控制技术研究和传统逆变器控制技术研究的有机统一。再者,论文针对多个交交功率变换应用领域设计了基于新型直接交交变换技术的解决方案。论文提出了一种直接交交动态电压恢复器,并提出了基于以上装置的一整套谐波检测和补偿电压生成算法,在交流斩波器结构的电压补偿装置中成功实现了补偿电网谐波电压的功能。接下来,论文将新方案应用于对交流负载供电的领域,并开发了针对不同负载的闭环控制算法,验证了其对多种交流负载供电,特别是应用于电机调速领域的可行性。再者,论文提出了一种直接交交潮流控制器,并开发了针对该方案的最小视在功率潮流控制算法,实现了以小容量的变流器对电网潮流的大幅度控制。论文还提出了一种直接交交串联型有源电力滤波器,解决非线性负载产生的谐波电流问题。其控制方案完全模拟经典的逆变器控制,实现了针对逆变器的控制算法的无缝移植。随着研究不断深入,基于以上新方案和新电路可以继续开发更多更实用的应用场合。论文通过在交流斩波器拓扑上提出实现任意频率,相位,幅值的三相交流电压输出的虚拟正交源优化电压合成策略,使该类电路突破其原有局限,进而能够被应用到交交功率变换的大部分领域。本研究拓展了电力电子学科的一个新研究方向,为电力电子技术理论和拓扑研究提供了新思路。论文基于采用新电压合成策略的直接交交拓扑,提出了一系列新型电力电子装置。以上装置的提出,为交交功率变换的多个领域提供了高可靠的替代解决方案。最后,论文介绍了使用FPGA+DSP联合控制的通用电力电子数字控制平台的研发。该平台实现了可靠的硬件设计以及强调移植性和通用性的软件设计。针对该平台,同时开发了一套完整的基于触摸屏的人机交互界面。基于平台开发了两套针对新型直接交交变换应用的实验装置。同时,该平台由于其通用性,也能够用于绝大多数电力电子变流器的产品开发和科学研究。更多还原

【Abstract】 AC power conversion is the key technology in power electronics researches. Widely used inverter-type and the rectifier-type converters have several drawbacks such as high price, short lifetime and low power density due to the usage of large storage elements. As a result, the development of direct AC-AC converter which requires no storage elements is always one of research hotspots in this field. In this dissertation, a comprehensive review is taken to summarize the topology technologies and their applications in AC power conversion research field. Aimed to the crucial technical constraint of the direct AC-AC chopper that stops it to output arbitrary AC voltages, an Advanced Virtual Quadrature Sources (AVQS) voltage synthesis theory is proposed. It realizes AC voltage outputs with arbitrary frequency, phase and amplitude. With the help of this, The AC chopper topology can now be applied to most AC power application areas, a series of novel power electronics converters with high reliability are developed.Firstly, based on the simple Buck-type AC chopper topology, the method of how to generate fundamental positive sequence voltage, harmonic frequency positive sequence voltages and negative sequence voltages on chopper topologies are derived. Following this, the AVQS theory, which can synthesis AC voltage outputs with arbitrary frequency, phase and amplitude are proposed. At the same time, the byproduct harmonic voltages, which are generated following the modulation, are also effectively eliminated. Thus the single-phase based chopper topologies can theoretically be applied to most AC power application areas without the constraint. At the same time, the new constraint of the simple Buck-type AC chopper topology when applying the AVQS theory is addressed. Therefore, the basic characteristics of the direct AC-AC chopper topologies that are suitable for the AVQS are concluded. It offers a guideline for the selection and derivation of new available chopper topologies.Secondly, a series of line frequency isolated direct AC chopper topologies suitable for the AVQS theory is presented. Within these topologies, an improved Push-Pull forward AC chopper is proposed. Commercial bridge-type IGBT module can be implemented and the switching loss of the transformer is minimized. Then, in order to realize the extreme low frequency voltage output in electrical motor drive applications, a series of high frequency isolated direct AC chopper topologies suitable for the AVQS theory is presented. The magnetizing condition of the high frequency transformer applying the proposed control scheme is fully analyzed to guide the transformer design. After that, the precise large-signal circuit models for the above-mentioned topologies are derived to facilitate the system level simulation. Then, a nonlinear coordinate transformation is implemented to the circuit model to derive the mathematical model of the AVQS theory. At the same time, by employing an additional operator, the control of the AVQS-applied AC chopper can be equated to ones of traditional inverter circuit. Thus the well-developed closed-loop control strategy for inverter-type converter can be seamlessly transferred to the new technology to normalize the researches of control strategies for both technologies.Then, a series of novel high reliability power electronic converters based on the proposed technology for different application areas are developed. At first, a direct AC-AC based dynamic voltage restorer (DVR) is developed for the power distribution system. The algorithm for harmonics detection and compensation voltage generation is derived. The function of harmonic voltage compensation is realized by the direct AC-AC based DVR. Then, the new technology is employed as variable frequency ac supply and electrical AC motor drive. Closed-loop control schemes are developed for different types of load. The capability of the proposed solutions is verified. Again, a direct AC-AC based power flow controller (PFC) is proposed in the power transmission system. A minimum apparent power transfer control strategy is developed for the converter to realize maximum power flow control range while using the minimum volume of the converter. Finally, a direct AC-AC based series active power filter (SAPF) is proposed. The closed-loop control strategy is seamlessly transferred from the classic strategy for inverter-type converter, which shows the correctness of the developed model. Following further explorations, more potential application areas can be found for the new technology.In this dissertation, the AVQS voltage synthesis theory is proposed to enable the arbitrary AC voltage output on the AC chopper topologies. Thus the technical constraint of the AC chopper is overcome, which facilitate its applications to most AC power conversion areas. This piece of works extends a new research direction in power electronics technology, develops its theory system and provides new ideas for the topology researches. Based on a series of new AC chopper topologies applying the AVQS voltage synthesis theory, several novel power electronic converters are proposed. It offers alternative solutions with high reliability for many important AC power conversion areas.Finally, a development of FPGA+DSP based general purpose power electronics digital control platform is introduced. The platform has a robust hardware design, a high portability software design and a touch panel based human friendly user interface design. Two experimental prototypes for novel direct AC-AC power conversion technology based on the platform are designed. Due to the generality, this platform can also be implemented to the researches and products development for most types of power electronic converters.更多还原