基于同伦法和改进的牛顿—拉夫逊法相结合的直流网络潮流分析

Power Flow Analysis of HVDC Grid Based on Combination of Homotopy and Improved Newton-Raphson Algorithm

鉴于直流网络潮流算法的研究总体上尚处于起步阶段,特别是在收敛速度和初值选取方面仍存在缺陷,从网络分析角度出发建立直流网络方程组,在分析直流网络潮流模型的基础上进行变量分类,推演出改进的直流网络潮流算法。该算法利用同伦方法的全局收敛性获取网络的初始值,并结合改进的牛顿-拉夫逊法快速收敛到稳定解,使其同时满足计算稳定性和收敛速度的要求,适用于直流系统的在线计算和分析。算例仿真分析表明,该算法对初值要求低、收敛速度快,结果正确有效。

Generally, the research on the algorithm of DC network power flow is still in its primary stage. Especially, there are drawbacks in aspects of convergence rate and initial value selection. From the viewpoint of the network analysis, this paper establishes DC network equations, classifies the variable quantities based on the analysis of DC network power flow model as well as deduces the improved DC power flow algorithm. In this algorithm, the global convergence of the homotopy method can be used to acquire the initial values. Then the stable solution can be obtained through the improved Newton-Raphson method. In this way, the requirements of computational stability and convergence rate can be satisfied at the same time. So, this algorithm applies to the online calculation and analysis for DC system. The examples of simulation results show that this algorithm is correct and effective with the fast convergence rate and the low initial value requirement.