Application Research Of Line Loss Fine Calculation And The Evaluation Method

Recently, the rapid development of industrialization and urbanization makes energy consumption growing fast, the economic and social development is facing serious resources and environment double restriction, so the energy conservation and emission reduction has become the extremely urgent task currently. As the large energy consumer, the energy saving effect of power industry has the pivotal role for completing the overall consumption target. For the energy conservation and emission reduction of power industry, the key mission is to reduce power loss and saving energy, which generates in each part of network system, from transmission, substation, distribution to utilization. The electricity distribution system which links the terminal of electric power transmission to user, also most closely contacts with users, is the key part of energy conservation and loss reduction.The main content of distribution system energy conservation and loss reduction is to improve the level of line loss management. The line loss is the comprehensive technical economic index of power grid enterprise, which involves different aspects and has complex influence factors as well as multiple evaluation indexes. As the essence of loss reduction of power industry, a precise line loss calculation method acts as the technology guarantee of line loss management. The line loss statistics based on traditional calculation method and relying on the past experience for qualitative line loss analysis cannot satisfy the current complex distribution system. For the line with actually complex structure and large numbers of distribution transformers, guiding the energy-saving reconstruct not only should consider the accuracy of line loss calculation method for the line loss result, but also should take the detailed analysis of line loss assessment. So how to obtain the line loss evaluation result in view of both integrity and independence has the important reference value of the energy conservation and loss reduction work.Considering the practical demand of energy conservation and loss reduction, a fine line loss calculation method based on the automatic metering system is proposed in this paper. The method integrates the topology of the network and the line real-time measurement data obtain from the automatic metering system. The method of backward and forward update is used for line loss calculation, and the root mean square coefficient method is used for transformer loss calculation. Meanwhile, the method programmed by MATLAB 2013a environment is chosen for arithmetic realization. Comparing with the traditional calculation method, the suggested method takes the comprehensive real-time data acquisition into fully account, and the output of calculation is rich precision, which can truly reflect to actual power loss in transmission line. In addition, based on the analysis of various influence factors of line loss, a distribution network line loss evaluation system including the grid structure, technical equipment and grid economic operation indexes is established, which takes the substandard lines of fine loss calculation as the analysis objects, and evaluated in view of the comprehensive weights and fuzzy theory. Furthermore, the lines under reconstruction are assessed by five kinds of evaluation methods to realize the reconstruction emergency order and transform differentiation through the cascade sorting step by step. Finally, the established model is applied to line loss fine calculation and line loss evaluation of qingyuan medium voltage distribution power system, which could be the guidance for energy saving reconstruction and loss reduction.