直流法计算潮流，分析网络结构并合理规划。主要探讨直流法如何计算潮流参数进而确定电力系统的稳定性和安全性。(The DC method is used to calculate the power flow, and the network structure is analyzed and the planning is reasonable. This paper mainly discusses how to calculate power flow parameters by DC method, and then determine the stability and security of power system.)