750/330kV受端电网合理分区规模研究

Study on the reasonable partition scale of 750/330 kV receiving-end power grid

随着330 kV受端电网主变台数增加,电网联系日益紧密,西北电网330 kV母线短路电流水平逐年增高,电网分区运行成为限制电网短路电流的重要措施。通过总结分析陕甘青地区典型的750/330 kV受端电网结构特点,考虑主变台数、主变容量及站间距离长度等因素,构建了单站独立供电、两站分区或三站链式分区的受端电网分区等值模型。通过分析典型分区模型短路电流水平及分区内主变负载率情况,确定了分区内主变台数的上下限,提出750/330 kV受端电网合理分区规模为2~3座750 kV变电站和约4~6台主变带一片330 kV电网。最后通过青海实际750/330 kV电网验证了所提750/330 kV受端电网分区规模的有效性。

With the increasing of the number of main transformers, the 330 kV receiving-end power grid increasingly interconnected, the short-circuit current level of Northwest power grid increases year by year, the network partition becomes an important measure to limit the short-circuit current of the receiving-end power grid. Through the analysis of the characteristics of the summary in Shaanxi, Gansu and Qinghai region typical 750/330 kV receiving-end power grid and considering main transformer units, main transformer capacity and line length factors, this paper constructs the receiving-end grid zoning equivalent model for single station independent power supply, two-station partition or three-station chain partition. Through the analysis of short-circuit current level of typical partition model and main transformer load rate in partition, it determines the upper limit and lower limit of the partition of main transformer units, and proposes that 750/330 kV receiving end grid partition should be 2 to 3 seat 750 kV substation, about 4 to 6 main transformer with a piece of 330 kV power grid reasonable partition scale. Finally, through Qingbai actual 750/330 kV power grid, the effectiveness of the proposed 750/330 kV receiving-end grid partition scale is verified.