基于“即插即用”接口和特征模型的现代电网分层在线动态建模方法研究

The new features of the modern power system, i.e., diversity, time-variation and complexity, have put forward a new demand of the power system dynamic modeling. It requires the improvement of the accuracy in harmony with the increase in efficiency. According to the new requirements and the challenge the conventional dynamic modeling is facing, we propose to study the hierarchical online dynamic modeling scheme for the modern power system. It can be described as follows: (1) The “plug and play” interface is proposed to promote the efficiency of the network integration. Because the conventional methods usually need complex and time consuming calculations to match the boundary load flow, which would result in the low efficiency and even disconvergence. (2) The characteristic modeling method is studied to balance the contradiction between the accuracy of the dynamic simulation and the simplicity of the model structure. It can avoid the complicated model structure and the difficulty of the parameter identification in the conventional dynamic equivalent methods. (3) The aggregation methods of the characteristic models are studied to reduce the complexity of the low-level power network model. The effect of the transmission element will be considered during the research process to maintain the accuracy of the aggregation model. This cutting-edge project adapts to the latest changes of modern power system. It would broaden the thinking of power system modeling research and expand the scope of the application.

现代电网多样性、时变性和复杂性的特点，要求对电力系统进行兼顾精度和速度的在线动态建模。本项目面向现代电网在线动态建模的新需求以及传统电网动态建模的困难，研究现代电网分层在线动态建模方法。针对现有模型合并、潮流匹配算法计算量较大、耗时较长的问题，提出并研究“即插即用”接口，在几乎不需要计算的前提下完成上、下层电网之间的模型拼接和潮流匹配，有效提高在线建模速度。针对现有基于元件机理进行动态等效建模可能导致模型结构复杂、参数估计困难的问题，引入模型结构简单、工程实现容易的特征建模方法，对下层电网进行在线实时的等效建模，有效平衡等效模型精确度和简洁度之间的矛盾。针对实际电网上、下层级之间网络拓扑结构复杂的问题，研究计及传输元件影响的特征模型聚合方法，进一步降低模型的复杂度并提高在线建模效率。本项目适应现代电网的新变化，拓展了现代电网建模的研究思路和适用范围。

本项目面向现代电网在线动态建模要兼顾速度与精度的新需求，提出了基于“即插即用”接口模型的分层在线建模方案以及基于非机理差分方程模型的下层电网在线动态等效建模方法。开展的主要研究工作如下：（1）在上、下层电网模型的拼接方面。提出了基于虚拟电气元件的“即插即用”接口模型。在几乎不需要计算的前提下完成上、下层电网之间的模型拼接和潮流匹配，有效提高在线建模速度，克服了现有模型合并、潮流匹配算法计算量较大、耗时较长的问题。（2）在下层电网的动态等效建模方面。引入模型结构简单、工程实现容易的非机理建模方法，通过理论分析和仿真对比，确定了非机理模型的输入输出变量。利用电网扰动数据建立下层电网的差分方程模型，规避了现有基于元件机理动态等效建模方法可能导致模型结构复杂以及参数辨识难度大的问题，有效平衡等效模型精确度和简洁度之间的矛盾。（3）在下层电网等效模型聚合方面。针对实际电网上、下层级之间网络拓扑结构复杂的问题，提出了计及传输元件影响的非机理差分方程模型聚合方法，而且聚合前后的模型阶次保持不变，进一步降低下层模型的复杂度并提高在线建模效率。