基于分区等值模型的500 kV受端电网分区供电理论

随着电网联系越来越紧密，电磁环网带来的短路电流超标问题凸显。合理的电网结构是限制电网短路电流的基础，通过分析总结我国受端电网的典型分区结构，基于电路等值理论构建了单站供电、两站手拉手、三站链式或环网等受端电网典型分区供电模型。对不同分区模型不同位置故障时的短路电流进行理论计算，并通过与实际电网短路电流计算结果进行比较验证了等值模型和计算方法的正确性。兼顾供电可靠性和短路电流水平，并考虑分区内电源接入和站间线路长度，提出500 kV受端电网分区以2~3站的4~6台主变压器为宜，该原则下若分区内仍存在短路电流超标问题则进一步采取线路串抗的限流措施。

Study on the Theory of Partition Power Supply of 500 kV Received Power Grids Based on Partition Equivalent Models

The short circuit problem caused by electromagnetic loop network emerges with the development of power grid. A reasonable grid structure is important to limit short circuit current of a power grid. Through analysis on several partition structure of received power grids of different areas, typical received power grid partition model of single 500 kV station, two 500 kV stations and three chain-link or circular 500 kV stations are built based on equivalent circuit theory. To verify basic accuracy of proposed model and method, the short-circuit current of typical power grid partition models at different positions are calculated. Comparison is made between calculation results and actual measurement. Considering power plant access, theoretical principles of received power grid partition is proposed. It is advised that 500 kV power grid can be partitioned by 2~3 stations and 4~6 transformers of 500 kV. Additional serial reactance can be used if the short-circuit current does not meet operation requirements under advised partition principles.