基于变量代换的辐射型配电网潮流算法

Power Flow Algorithm of Radial Distribution Networks Based on Variable Substitution

为实现配电管理系统对配电网潮流的高效计算要求,基于变量代换和稀疏技术提出了一种高效的辐射型配电网潮流计算改进算法。该算法根据辐射型配电网特有的拓扑结构和特点,利用变量代换将潮流计算中2/3的不平衡量方程变成线性方程,从而使得其形成的雅可比矩阵非零元素为常数,不用重复计算。而另外1/3的不平衡量方程也相对简单,使得雅可比矩阵非零元素易于计算,从而简化了计算和易于编程。由于雅可比矩阵中非零元素较少且都相对固定,易于稀疏表示。最后,通过不同测试系统仿真比较,证明了该算法的计算时间仅为传统牛顿-拉夫逊算法的10%左右,且明显小于前推回代算法的计算时间,以及其收敛性也优于传统牛顿-拉夫逊算法和前推回代算法。

In order to efficiently calculate the power flow for distribution networks, we propose an efficient power flow algorithm of radial distribution networks based on the variable substitution and sparse technique. According to the radial topology structure and the characteristics of distribution network, the 2/3 of unbalanced equations can be transformed into the linear equations by using variable substitution in the proposed algorithm, which makes the Jacobian matrix non-zero elements to be constant without recalculation. The other 1/3 of unbalanced equations are also relatively simple. Thus, it is very convenient and easy to calculate the Jacobian matrix non-zero elements. Therefore, the calculation and programming are simplified. Because the Jacobian matrix is sparse one, it is easy to compute by sparse technique. Finally, compared with the traditional Newton-Raphson method and the backward/forward sweep method in different test systems, it is demonstrated from the simulation results that the computing time of the proposed algorithm is only about 10% of the tra- ditional Newton-Raphson method and is less than the computing time of the backward/forward sweep method, and its convergence is superior to that from the traditional Newton-Raphson method and the backward/forward sweep method.