地区电网动态等值模型和等值方法的改进

Local Grid Dynamic Equivalent Model and Improvement of Equivalent Method

近年来为简化对大规模特高压互联地区电网的分析,提出了一系列电网等值方法,然而不合理的等值将造成分析电网数据的精度下降。基于上述问题,通过对常用等值方法的等值过程进行分析,找出误差来源,提出了新的改进方案,即在保证等值前后静态边界潮流不变情况下,在等值边界悬挂接地电阻和等值调节功率负荷,以此保证动态情况下外网对内网注入的功率不变。最后,将该方法应用在PSASP软件中的一个8机36节点系统,通过仿真,验证了该方法的简化性和实用性。

To simplify the analysis of the large-scale ultra- high voltage interconnected local grid, a series of power grid equivalent methods have been proposed in recent years, but the unreasonable equivalent methods could cause a decline in the accuracy of the power grid data. To address the problem, this paper, through analysis of the commonly used equivalent method process, identifies the error source, and then puts forward a new improvement scheme. By this scheme, under the condition of the invariable static boundary tide of the equivalent, grounding impedances and equivalent adjusting power loads are hung on the equivalent border to ensure the power injection of the external grid into the internal grid to remain unchanged in dynamic situations. In the end, the method is used in the software PSASP of an 8-machine and 36-node system, the simulation results show that the method is both simple and practical.