在常规连续潮流计算过程中假定线路电阻始终不变,这是不符合实际的,因为输电线路电阻是随外界环境以及潮流分布的改变而改变,其本质是温度的变化。以此为背景,连续潮流模拟潮流缓慢变化的过程,在这一过程中应计及输电线路电阻的变化,使连续潮流的计算更具实际意义。为分析其对连续潮流计算产生的影响程度,提出将输电线路电阻视为潮流的状态变量,首先建立包含电阻参数的电热耦合潮流模型,并进一步提出电热耦合连续潮流模型。在模型的迭代过程中不断计算与修正输电线路电阻值,体现电热耦合的思想。应用常规潮流方法以及电热耦合连续潮流方法分别进行算例对比与分析,结果表明计及输电线路温度及电阻变化将对连续潮流计算结果产生非常显著的影响,应该引起重视。
In the conventional calculation of continuation power flow, resistances of transmission lines are assumed to be invariable, which is not true. The reason is that line resistance would be changed in terms of the temperature with the varying of the environment around and the power distribution. With this background, continuation power flow simulates a gradual varying process in which the change of line resistance must be considered, which makes the calculation have practical significance. In order to analyze the influence on continuation power flow calculation by change of line resistance, this paper presents the electro-thermal power flow model and electro-thermal continuation power flow model in which the line resistance is considered as state variable of power grid. In the models, line resistances are calculated and corrected for the consideration of electro-thermal coupling. The case study and comparison of the calculations by two methods show that there exist significantly differences of the results which must be brought to the forefront.