The Study On Calculation Method Of Theoretical Energy Loss In Low-voltage Distribution Network

The distribution lines loss rate is the comprehensive sign of the industrial economic effectiveness of the power system and technique, manage level. Exact computing of rate of theoretical net loss provides the engineers in power system with data to make out content of lines loss and adopt exact measure to reduce net loss.The low-distribution networks structure were more complicate, and had many branches, many kinds of loads, historical data were not whole. Based on the characteristic above mentioned, the paper classifies the types of loads and makes up the representative curve of load and pointed out a choosing representative day method based on fuzzy clustering theory. Subsequently, the paper pointed out a method—improved equal electric resistance method. The basic thought of 0.4kV lower distribution lines is using to replace the power energy of 10kV distribution lines with power energy of the distribution transformer and to replace capacity of distribution transformer with power device capacity of user to calculate distribution lines equal resistance.In addition, considering the unbalance in three phrases of main line, the paper adopts the real-time value of unbalance in three phrases to compute lines loss and pointed out the concept-real-time unbalance in three phrases coefficient. Computing of lines loss in low-voltage network is more improved based on method of improved equal electric resistance method. Due to mostly low-voltage network is lack of current date in the representative day. So the paper brings forward a method that is calculating dynamic value of unbalance in three phrases based on load classification.Finally, with VC6.0 and SQL server 2000, a graphical low-voltage network theoretical line loss calculation software is developed. This software has characteristics of strong function, good human-computer interaction interface, convenient operation, beautiful graphical effect.