基于图论的非隔离多端口变换器拓扑自动演绎方法研究

In order to efficiently transfer power among different ports in the micro grid with high use of renewable energy, multi-port converters with high performance are urgently demanded. Unfortunately, the number of multi-port converters derived in the past researches is limited, and thus the different requirements of various micro grid systems cannot be all satisfied, resulting in undesired system performance. Based on this, a new automatic method to conveniently derive and associate non-isolated multi-port converters on the basis of components with the aid of graph theory and computer algorithms, is explored in this project. Three main aspects are focused to realize the method. Firstly, according to the correspondence between topology and graph, the optimization of constructing the available topologies from components will be studied to avoid the unnecessary exhaustion. Secondly, with the help of graph theory model, this project will develop an automatic method to judge the effectiveness of the available topologies, so that the effective topologies which can work normally will be quickly and precisely selected out. Finally, the extraction and comparison of circuit features of the effective topologies will be further explored to identify their similarity on performance characteristics. This association process is very beneficial for engineers to conduct the topology selection in the practice. With this project, a lot of favorable integrated non-isolated multi-port converters will be evolved after topology derivation, and thanks to the topology association, it is easier to select out a preferred one for a specific application. Therefore, the proposed automatic topology derivation and association method will be helpful to the popularization of the renewable energy. Besides, it can also be extended to other power electronics converters to conveniently derive and associate new topologies.

为实现可再生能源微电网中不同端口之间电能的高效变换，迫切需要性能优异的多端口变换器。然而，现有多端口变换器的数量较少，无法满足不同应用下的多样化需求，不利于微电网系统优化。针对此现状，本项目重点研究如何以元件为组合对象、应用数学图论和计算机算法自动高效地完成非隔离多端口变换器的拓扑演绎。研究内容包括：①利用拓扑与图之间的对应关系，探索由元件构建可行拓扑的优化方法，避免大量无用的穷举工作；②基于图论模型，研究可行拓扑的有效性自动判定机制，快速准确地从可行拓扑中筛选出有效拓扑；③探索有效拓扑电路特征的提取和比对方法，建立不同拓扑间的特性联系，为拓扑优选奠定基础。项目通过拓扑构建、拓扑判定与拓扑关联三方面研究，将实现高集成非隔离多端口变换器“由少到多”的提升、降低“从多中选优”的难度，有助于可再生能源的应用与推广；同时，力图探索出一种高效的拓扑自动开发新方法，为其他变换器拓扑的演绎研究提供参考。

随着可再生能源微电网的发展，迫切需要众多性能优异的非隔离多端口变换器以实现不同应用场合下端口间电能的高效变换，但是目前已推演得到的非隔离多端口变换器较少，在推演效率和元件集成方面还有很大的提升空间，亟需进一步深入探索高效的拓扑演绎方法以快速地实现性能优异的未知拓扑结构的推演与关联。针对此现状，本项目重点研究如何以元件为组合对象、应用数学图论和计算机算法自动高效地完成非隔离多端口变换器的拓扑演绎。研究内容包括：①利用拓扑与图之间的对应关系，探索由元件构建可行拓扑的优化方法，避免大量无用的穷举工作；②基于图论模型，研究可行拓扑的有效性自动判定机制，快速准确地从可行拓扑中筛选出有效拓扑；③探索有效拓扑电路特征的提取和比对方法，建立不同拓扑间的特性联系，为拓扑优选奠定基础。通过项目的开展，已探索出了一种基于图论的变换器拓扑自动演绎新方法，并将其分别应用于单电感多端口变换器、共用开关管多端口变换器与单开关直流变换器中进行了拓扑自动推演，构建出了大量具有优异性能的拓扑结构。同时，还基于图搜索算法从变换器拓扑、子结构和元件三个层面分别提出了等效拓扑、LC滤波结构和冗余开关的自动辨识方法，实现了推演结果的关联与归类。相比于传统的人工拓扑构建方法，项目提出的拓扑自动构建方法具有系统性、全面性与高效性等优点，有望加速多端口变换器拓扑的全面挖掘，并为其他变换器的拓扑自动演绎研究提供可参考的理论，因此具有重要的科学意义。另一方面，项目挖掘出了众多性能优异的高集成拓扑结构并为特性相关的拓扑建立了联系，可供不同的微电网系统及其他工程应用择优选用，具有良好的应用前景。在本项目资助下，共发表了SCI索引论文12篇、EI索引论文5篇，申请或授权国内发明专利4项，培养了4位优秀的研究生。