Study On The Power Line Model In Simulation System For Distribution Network

The construction of Smart Distribution Grid is an important part in the development of Smart Grid. One of the most important features of Smart Grid is that it brings in distributed power, which needs establish a distribution grid simulation system to research the influence on distribution grid. Transmission line model is one of the most important models in distribution grid simulation system.In this paper, Smart Grid simulation system uses multi-π transmission line as its model. Based on the analysis, it can be concluded that the π numbers of line is proportional to the oscillation frequency of line, wave impedance and length of line. According to the relationship between the proportion, it can be derived that principles for determining π number in multi-π transmission line modelTraveling wave fault location simulation needs lines with high precision, so this paper fixes the π number in multi-π transmission line model. In this fixed multi-π transmission line model, this paper puts forward to the theory of traveling wave fault location simulation, which according to the conclusion that the ratio of oscillation frequency in another point short circuit grounding and terminal short-circuit, is equal to the ratio of distance that between short circuit grounding point and the beginning and the total line length.This paper establishes distribution grid simulation model and confirm practicability of theory for multi-π transmission line which uses ATP simulation software, and he simulation results, of which in fault line selection small current neutral grounded system, verify that π number in multi-π transmission line satisfies the fault line selection requirements; then it establishes multi-π transmission line model for traveling wave fault location simulation, the simulation results coincide with the theoretical analysis, finally simulation verified the correctness of principle and practical in multi-π transmission line model.