Research And Design Of Power Quality Monitoring System In Electrified Railway Centralized Access Areas

In the construction of electrified railways,a large amount of non-linear loads are used,causing distortion of the current and voltage waveforms in the power grid,which leads to a threat to the power quality of the power grid.The safe and stable operation of power generation,power supply,and power equipment in power grids is affected by deterioration of power quality.After electrified railway accesses to power grid,it will lead to a series of power quality problems.Therefore,strengthening the monitoring of the power quality of electrified railways can not only guarantee the stable operation and development of power grid,but also guarantee the reliability of power supply of electrified railways.According to the power quality characteristics of electrified railways' load,this paper constructs the power quality monitoring system in electrified railway centralized access areas.The main station and sub-station of electric power quality monitoring system of electrified railway are discussed.Based on CORBA technology,the distributed system TCP/IP network monitoring platform can be formed.According to IEC61850,power quality monitoring data and substation power quality device are modeled.This paper introduces three methods of power quality identification and evaluation in the monitoring system: harmonic source identification,voltage drop source identification and power quality comprehensive evaluation.At the same time,hardware design and sampling value message decoding software design are carried out for the power quality monitoring system.The system can monitor the power quality of 220 k V buses and substations in each station along the railway.The data collected by the system can be compared with the actual situation to provide a scientific basis for power quality control.