Research On Traction Power Supply System Adaptability With Power Supply System

The electrified railway is an important part of the transportation in our country, and it gets power from power system. As a special kind of electricity load, the power quality issues have been discussed by power department and railway department. On the one hand, the randomness and high power characteristics of traction load affect the power quality of external power, causing interference to the other power load of the power system and even destroy it, which requires the railway department to provide appropriate power quality control measures. On the other hand, with the substantial increase in electrified railway traction load, it puts forward higher requirements on external power source to ensure the normal operation of the railway.This paper analyzes the characteristics of the traction power supply system and the external power source, and collects the eigenvalue of traction load’s electric parameters. Starting from the national power quality standards to make harmonics, negative sequence, the integrated voltage loss restrictions as the limiting conditions, the paper calculates and finds the relationship between the traction transformer capacity and system short circuit capacity which connects to the points of common connection in several conditions of typical traction transformer wiring. According to the actual construction of the railway, the paper sums up the railway’s demand for power supply ability and proposes the recommended scheme of traction power supply system to access the external power source. After analyzing the limitation of the recommended scheme, the recommended scheme is optimized by using combined cophase power supply technology.Referring to the actual railway and taking the former railway reconstructions as an example, the paper uses NeHarm version 1.0 to model the "traction power supply system & power supply system", and finds the power quality issues of power system which is caused by traction power supply system. According to the power quality issues, two feasible schemes are given in the combination with the recommended scheme. The paper compares two schemes from the technical and economical aspects, and discusses the advantages when using combined cophase power supply technology.In the railway construction process, the research on traction power supply system adaptability with power supply system plays an important role to provide the reference for access scheme of traction power supply system. The adaptation research not only studies the power supply to minimize the impact between the two sides, but also studies the best economical optimized method under the condition of meeting the demand of railway normal operation.