Research On The Influence Of High Speed Electrified Railway On Power Quality Of Local Power Grid

High speed electrified railway has the advantages of high speed,low carbon,environmental protection and energy saving,which has greatly promoted the economic development and social progress.High speed electrified railway is to obtain the electric energy from the power grid,which is sent to the traction network through the traction transformer.Because of the high-speed electrified railway is asymmetric and nonlinear load,while the high-speed passenger line has large load fluctuation and strong features,energy in the process of regional power grid power quality and a great impact in the power exchange,even when serious threat to the safety of power grid.This paper mainly studies the influence of high speed electrified railway on power quality caused by harmonic and negative sequence,which is connected to the power grid: The working principle of traction transformer and the electric locomotive of high-speed electrified railway,analyzes the characteristics of negative sequence and harmonic characteristic of traction load of high speed passenger line;combined with various kinds of modeling methods at home and abroad for electrified railway passenger dedicated line harmonic model,established a set of suitable for practical engineering calculation,the measured data of power locomotive harmonic model and based on the MATLAB platform in the use of program.This modeling method is based on the electric locomotive absorption of active power and reactive power as the excitation,injected harmonic current power grid as a response,according to the measured value in the database,the mathematical expression of the locomotive harmonic current calculated by BFGS method,and by error analysis to verify correctness of the model.In this paper,based on the background of the western Liaoning power grid,this paper studies the operation of a high-speed electrified railway passenger dedicated line.According to the future network planning and the different conditions of high-speed electrified railway,this paper makes a large number of simulation,quantitative analysis of high speed electrified railway operation,the harmonic impact in regional power grid,and the negative sequence of fire in regional power grid power station and transformer,and draw relevant conclusions.