复杂配电网潮流的降规模计算

为了减少大规模配电网潮流分析的计算量,探讨了电压降和线损的简化计算方法.文章证明了当流过馈线段的末梢节点的功率不为零时,用双方向等效电压降模型计算沿线电压降时能得到准确的结果,而用双方向等效线损模型计算时却不能得到准确的线损结果.因此提出了一种可有效地避免线损计算误差的方法.该方法是一种利用双方向等效电压降模型的计算结果进一步计算馈线沿线各负荷点的电压,并用递推方法计算该馈线段上各条支路的线损的方法.采用文中提出的方法可大大减少参与迭代计算的节点数,而且各负荷点的电压以及配电网的线损都不需要迭代就可以直接计算得到,从而精确得到整个配电网的线损.经对198节点的实际配电网的计算,验证了该方法的有效性和精确性,且比等效线损模型优越.

ANALYSIS OF LARGE SCALE DISTRIBUTION NETWORKS WITH REDUCED CALCULATION

To reduce the calculation amount of power flow in large-scale distribution networks, a simplified calculation method for voltage drop and line losses are researched. It is proved that when the power flowing through the feeder terminal is not zero, the accurate calculation result of voltage drop along the line can be obtained by bilateral equivalent voltage drop model (BVDM), but the accurate calculation result for line loss by use of bilateral equivalent line loss model (BLLM) cannot be obtained. A new approach is presented to solve such problem. The voltage drop of a feeder is worked out by BVDM, on the basis of which, the voltage at each load position is calculated. A recurrence formula is deduced to calculate the loss of the branches on the feeder. By use of the presented method the number of nodes having a hand in the iteration is obviously reduced and the voltage at each load point and the line losses of distribution network can be directly obtained without iteration, thereby the line losses of the whole distribution network can be accurately determined. The calculation results of a real distribution network with 198 nodes are given and compared with those by BLLM method and power flow method without simplification. The comparison results show that the presented method is effective and accurate and better than BLLM.