Research On Dynamic Line Loss And Its Reducing Strategy For Distribution Power Network Of Muping District

In the face of global energy security, deterioration of the ecological environment and tremendous pressure on the climate change, the energy conservation has been more emphasized heavily recently. As the transmission medium of electricity, power grid shoulders the responsibility of power loss reduction.Optimizing the operation of power grid, improving the power quality and realizing the transmission of the power grid at low loss, has become one of the momentous guiding ideology of the State Grid Corporation of China in response to the construction of a conservation oriented society.Theoretical line loss calculation plays a major role in line loss management and formulating reasonable line loss evaluation index, and also has an important significance in assessment of of various loss reduction measures at technical and economic the drop loss measures for technical and economic.But it is tough for the traditional line loss calculation method to accurately calculate the line loss of distribution network or need a long time even for a one-time-only calculation.Therefore, finding a fast and accurate method for distribution network loss calculation could be necessary, which is integrant for the development of distribution network in the new situation.This paper firstly introduces the basic theory of line loss calculation, line loss calculation definition, classification, significance and influential factors.Then, it will be followed by a mathematical model, established from the characteristics of transformer, transmission line, and load, to calculate the line loss.After a statement of the current calculation method about line loss of distribution networks, combined with the comparison of the various methods of computing, it proposed three improved distribution network line loss calculation methods. The calculation accuracy and speed of the three improved methods are analyzed by IEEE33 node distribution network. The case analysis indicates that the method 1can ensure high accuracy under the condition of the known load active and reactive power, while the method 3 has a higher accuracy in the case of the known load active. Finally, the applicability and effectiveness of the proposed method are verified by a practical power distribution network.The proposed distribution network theoretical line loss calculation method is used to analyze the influences of reduced load peak valley difference, increase the conductor cross-sectional area, switch to low loss transformer and reasonable reactive power compensation on distribution network line loss effect. The simulation results show that: with the decrease of the load peak valley difference, the transformer copper loss and iron loss are reduced; the loss of the circuit and the transformer copper loss are obvious, while the iron loss of the transformer is not obvious. Adopting larger sectional area of the wire, under the condition of constant load, line loss decreased significantly, while transformer copper loss remains invariably and transformer iron loss varies with voltage changes. After replacing the low loss transformer, copper loss and iron loss are intuitively declined. The line loss reduces as the transformer loss reduce, leading to the decline of transmission current. Improve the load power factor can reduce the transmission line current, so the line loss and the transformer copper loss decreases with the increase of load power factor. But due to the power factor is improved so as to reduce the loss of voltage on transmission line, transformer iron loss increases.