Improving the quality of electricity supply systems in stationary objects of railway transport

Abstract

THE PURPOSE. Development of a methodology for modeling the modes of power supply systems for railways equipped with devices to improve the quality of electricity in the networks supplying stationary objects of railway transport. Two design solutions were considered that ensure the reduction of unbalance and voltage deviations on the 0,4 kV buses of substations supplying these objects. The first of them was based on the use of suction transformers, and the second - on the use of lines with a grounded phase.METHODS. The studies were carried out using the Fazonord software package, which provides complex modeling in phase coordinates of the modes of power supply systems.RESULTS. The results obtained made it possible to draw the following conclusions: when using suction transformers, which were included in the rail cut, the average value of the unbalance coefficient in negative sequence on the 0.4 kV buses of the object's substation decreased by 2,5% compared to the absence of such devices; in the presence of transformers, which were included in the return wire, this indicator decreased by 19%. The use of lines with a grounded phase instead of a two-wire-rail line made it possible to improve the quality of electricity on 0.4 kV buses, while the maximum of the unbalance coefficient in the negative sequence was reduced by 40%.CONCLUSION. On the basis of computer modeling, it is shown that the use of suction transformers with a return wire and 25 kV lines with a grounded phase makes it possible to improve the quality of the electric power industry in the power supply systems of stationary objects of railway transport.

Keywords

• power supply systems for stationary railway facilities
• drop-off transformers
• power lines with a grounded phase and «two wires-rail»