Research On Anti-Stealing Technology Based On Line Loss Calculation And Analysis

Electric energy is the important indispensable secondary energy in today’s society.For economic purposes,the behavior of electricity stealing has always existed.In order to ensure the economic benefits of power supply enterprises,anti-electric stealing is one of the important part of the work of power supply marketing departments.The behavior of electricity stealing will certainly undercount the electric energy,which directly increases the line loss rate of power grid statistically.Through the research of anti-electric theft technology based on line loss calculation and analysis,it has very important practical and economic significance to further improve the identification ability of electric theft behavior and the location ability of electric theft point,thus reducing the loss caused by electric theft.According to the actual situation of 10 kV and 0.4kV distribution networks,this paper puts forward two line loss calculation methods and the anti power theft method based on line loss calculation and analysis.The main research contents are as follows:(1)According to the practice of 10 kV distribution network,a line loss calculation method based on forward push back method is proposed.Considering the connection of DG,the forward push back method is improved to adapt to the power flow calculation of distribution network with DG.The DG node connected to the grid through the inverter is converted into PQ node,which is included in the iterative calculation process of the forward push back method in the form of reverse load.(2)According to the practice of 0.4kV distribution network,a dynamic identification method of distribution network structure coefficient and load curve shape coefficient is proposed.Because the structure of 0.4kV distribution network is more complex and there are many problems in line parameters and energy meter data,a dynamic identification method of distribution network structure coefficient and load curve shape coefficient based on K-means clustering and Fuzzy RBF neural network is proposed.Combined with the identified structure coefficient and shape coefficient,the improved equivalent resistance method will be used to calculate the line loss of 0.4kV distribution network,so as to improve the accuracy of line loss calculation of 0.4kV distribution network.(3)Considering the characteristics of different electric stealing methods and the deficiencies of current anti-electric stealing technology,the anti-electric stealing technology graded by voltage based on line Ioss calculation and analysis is proposed.The technology identifies the possibility of power theft through line loss calculation first,and then adopts different positioning methods for suspected power theft points of 10 kV and0.4kV distribution networks respectively.For 10 kV voltage level users,the voltage offset rate and voltage correlation degree are used to locate the power stealing point,and the power flow back-calculation is used to estimate the power stealing quantity of high voltage users.For low-voltage users,the anti-electric stealing technology of 0.4kV voltage level is applied,where the electric stealing point is positioned by the method of comparing the voltage space position,and the electric quantity stolen by low-voltage users is calculate by multiplying the measured electric quantity by the correction coefficient.(4)Verification of anti-stealing technology.Several practical anti-power stealing cases of 10 kV and 0.4kV distribution networks are analyzed.The real electric stealing points are found through the positioning of electric stealing points and the calculation of stolen electric quantity,so as to verify the scientificity and effectiveness of the anti-electric stealing technology based on line loss calculation and analysis proposed in this paper.