【作者】 杨金刚；

【导师】 房大中；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2010， 博士

【摘要】 现代互联电网规模的不断扩大,电力系统中发生的物理现象也越来越复杂,在线动态安全分析技术逐渐被提上日程,使得对高速仿真技术的需求越来越迫切。本文提出一种新型快速的电力系统仿真方法——基于树形结构和双向迭代技术的电力系统分区仿真算法。该方法的主要内容包括树形结构的构建、各电力系统元件的结构化描述、变量修正量的标准表达式、分区计算流程、直流线路的处理方法等。各部分内容的具体阐述如下:根据实际电网内部强关联,外部弱连接的地理区域特性,提出一种较为实用的网络分割方法来实现大规模互联电网的划分,并将分割后的子网络按照树形层次模型来描述。在树形结构中,各树结点之间的连线代表了分区间的关联关系、动态元件与相应子区的关联关系。提出了一种基于树形层次模型和双向迭代技术的分区仿真算法,该方法通过前向简化技术对树形结构的枝结点形成其对上一层树结点的接口表达关系,通过后向回代技术将根结点的计算结果传递给各枝结点,实现一次双向迭代过程。较为系统地介绍了各电力系统元件在树形结构中的位置及相应变量修正量的标准表达式,这种描述方法具有结构化、标准化的特点,便于程序的实现。该算法在我国实际电网上的计算结果与商业仿真软件BPA的计算结果进行了比较,验证了该算法的合理性与有效性。根据电力系统稳定分析中的其它计算方法,将分区仿真技术进行了扩展,形成分区QSS仿真及分区轨迹灵敏度仿真,通过对各仿真算法计算特点的详细分析,实现了树形结构标准表达式的公式推导及分区计算流程,为电力系统预防控制的快速分析提供了强有力的计算工具。此外,考虑到交直流混合大电网将成为我国电力建设的发展趋势,将直流输电技术对本文所提的树形结构模型的影响进行了详细的分析,并形成了交直流混联系统的树形层次模型。通过对直流输电方程进行结构化处理,形成树形结构所需的修正量的标准表达式,实现了交直流混联系统的分区仿真计算。最后,本文还对连续潮流算法进行了一些研究,提出了“局部弧长”参数化方法及固定“对角线”的步长控制方式,并将本文的核心内容“分区计算”引入其中,形成一种改进的连续潮流算法,通过在我国东北电网和华北电网上的计算分析,验证了所提方法的有效性和合理性。更多还原

【Abstract】 As the large-scale power grid has been basically established recently, the representation of power system stability problem is getting much complicated than before, the online dynamic security analysis (DSA) is attracted too much attention, and the high speed simulation method is extremely required. A new fast simulation approach, hierachical tree model and bi-directional iteration based power system area-partitioning simulation approach, was proposed in this dissertation. It is composed of the construction of tree model, structured description of the power components, standard formulation of the variable’s correction factors, the calculation procedure and the settlement of high voltage DC transmission line. The details of the above are summarized as follows.Taking advantage of the power network inherent characteristic, strongly internal conjunction and loosely external connection, a practical area-division method is proposed to partition the large-scale power network into many subareas, which are represented by the hierachical tree model. In the tree model, the connection lines between the tree nodes denote the relationship among the subareas and the dynamic component in the power system.A bi-directional iteration technique was introduced to calculate the correction factors of variables in the proposed simulation method by the tree-traversing procedure, called forward reduction and backward evaluation. It is systematically described the power components’location in the tree structure and the computation model, the feature of this description approach are normalized and structured, and expediently to program the calculation procedure. In case studies, the simulation result obtained by the proposed approach is compared with that of BPA, a kind of power system commercial simulation software validates the correctness and efficiency of the new approach.The area partitioning based simulation method is extended to the other analytical methods in the power system stability evaluation, such as quasi steady state simulation and trajectory sensitivity simulation method. By the particular analysis of their computation characteristic, it is achieved that the standard formulation and the calculation procedure of the above two simulation method in the tree model, and it would be potentially useful in developing fast calculation tool for preventive control in the power system.As the development of AC/DC transmission technology, the AC/DC mixed huge power network will come true in our country, so the DC line’s affection on the proposed tree structure is fully evaluated and form a modified tree model for AC/DC mixed network. By the bi-directional iteration technology, the DC transmission equation is converted into standard formulation in the tree structure, and achieved the AC/DC mixed power system simulation.Finally, it is deeply researched on the continuous power flow method in this dissertation and achieved some success, denoted as“local-arc”parameter and fixed diagonal step-controlling method, besides; the area-partitioning calculation method is introduced, and formed a novel continuous power flow method, which is tested on the Northeast and North China power system.更多还原