基于瞬时值解析的支路电能损失与成本分摊方法

电力网络的电气支路是输送电能的重要关口式通道。目前,在这类通道送受端安装的各类功率表和电能表,只能测量和统计支路上的总功率和总能量,尚无法从数字化和智能化的角度计量出送端多个等效电源或受端多个等效负荷在支路上流通的电气成分信息,此状况制约了支路成本核算与分摊工作的公正开展。为此,该文基于瞬时值解析思路,以支路受端带两个和多个等效负荷为例,分析不同负荷瞬时电流在支路总电流中的分配关系,推导出各瞬时成分量分摊的支路瞬时电阻及其对应的瞬时损耗功率关系式,并由此获得支路电阻损失电能分摊系数;由不同负荷瞬时电流间的环流出发,分析负荷间的功率和能量穿越现象及其具体关系;综合支路成分和负荷穿越情况分析结果,可绘制出支路–负荷系统的能量分配关系总图。基于此图,考虑送受端节点电价、支路输电价格等,可核算不同负荷分摊的输电成本以及购售电全过程的经济流。最后,通过算例,给出具体的电能分配关系、支路电能损失和输电成本分摊结果以及负荷间发生的交叉补贴费用,并与其他方法进行电阻电能损失分摊系数计算结果的比较。所提方法将对开发安装于支路上的新型智能电表或对支路能量与成本核算问题进行深入研究提供理论基础。

Method of Branch Energy Loss and Cost Allocation Based on Instantaneous Value Analysis

Branches of power network are those of the most important gate-type accesses to collect and distribute electric energy. At present, all kinds of power meters and watt-hour meters installed at these accesses can only measure and count the total power and total energy of branch. They are not yet possible to calculate the power and energy distribution information on the branch for the sending sources or the receiving loads from the perspectives of digitalization and intelligence. This situation restricts the fair development of cost accounting and allocation. Therefore, based on the instantaneous value analysis and taking two and more equivalent loads at the receiving end of a branch as an example, this paper analyzed the distribution relationship of instantaneous current of different loads on the branch, and deduced the instantaneous resistances and their losing powers allocated to loads. Allocation coefficients of branch energy loss were hence obtained. This paper also discovered and analyzed the crossing phenomenon and its detailed relationship of power and energy among the loads from the instantaneous circulation, and drew the general allocation diagram of energy with synthesizing the branch energy distribution relationship. Basing on this diagram and considering the node and branch prices, the transmission costs allocated to the loads and economic flows for the whole process of purchase-sale can be accounted. Finally, the results of energy distribution relationship, branch energy loss and cost allocation, and cross-subsidies among different loads are given for an example. The comparison with other method for calculating the allocation coefficients of energy loss of branch resistance was also done. Example shows the proposed method will provide theoretical support for the development of a new type of smart meter installed in a gate-type branch or for the more in-depth research on the issue of branch energy loss and cost accounting.