变电容载比与下一级中压配电网络关系的量化分析

Quantitative Analysis of Relationship between Substation Capacity-to-Load and Subordinate Medium Voltage Distribution Network

变电容载比是配电网规划的重要指标,现有导则指出,下级配电网络较强时容载比可取低,但未提供量化分析方法,为此提出了一种基于最大供电能力(total supply capability,TSC)的容载比与下级中压配电网络关系的量化分析方法。在同时考虑变电站内主变转带和下级网络转带的情况下,TSC理论能够计算一个配电网满足"N-1"安全准则条件下的最大负荷供应能力。研究了网络不同强弱时的容载比数据,并通过改变馈线容量、联络位置和联络规模来探究容载比与网络强弱的关系以及容载比的变化范围,得到了容载比取低的量化结论与推荐建议,丰富和发展了现有的规划导则。

Substation capacity-to-load ratio is an important index of distribution network planning,and existing guideline indicates that capacity-to-load ratio can be lower when subordinate distribution network is strong; however,there are no quantitative analysis methods. This paper proposed a quantitative analysis method for the relationship between capacity-to-load ratio and subordinate medium voltage distribution network based on the total supply capability（ TSC） theory. TSC theory can be used to calculate the maximum load supply capacity of a distribution network under the condition of meeting the ＂N- 1 ＂security criteria,with taking the substation transformer transfer in transformer substation and the subordinate network transfer into account. This paper analyzed the capacity-to-load ratio data with different network strength,and explored the relationship between capacity-to-load ratio and network strength,as well as the range of capacity-to-load ratio through changing feeder capacity,connection location and scale. Finally,the quantitative conclusion of lower capacity-to-load ratio and its recommendations were proposed,which could enrich and develop the existing planning guidelines.