Calculation method research about theoretical line loss' boundary of distribution network

Based on mastering the supply power and the maximum load of the 10kV distribution transformers, this paper calculated the maximum and minimum load shape coefficient of the transformers and segmented lines, and obtained the upper and lower limitation of the theoretical line loss with average current method. In the largest variable loss calculating process, this paper put forward an effective iterative fitting algorithm. Firstly, it fitted out the ultimate load curve of the transformer high voltage side, then it fitted through iteration out the ultimate load curve of the superior branch lines and calculated the maximum shape coefficient, considering the influence of transformers loss on the line load curve in the calculation process. The calculation method provided theory evidence for enterprise line loss management level evaluation and vulnerable spot location in the line loss management and enterprise future line loss rate indicator setting.