Research And Analysis For The Influence Of Electric Railway On The Regional Power Grid Based On ETAP

The electric railway has become a vital infrastructure in the transportation of our country and even world,which is the state economy development backbone.Due to the use of AC-DC type in Chinese electric locomotive,it contains a large number of rectifier and inverter,which has the characteristics of nonlinear,three-phase unbalance,impact and so on.It generates a lot of problems during the operation,such as harmonic,negative sequence current,voltage fluctuation and flicker,affecting the power quality of regional power grid.Therefore,we should analyze the problems of the electric railway,which can improve the power quality of the area effectively.It also has a certain guiding significance to the management of power quality in the practical engineering.In this paper,the influence of the harmonic and three-phase unbalance on the power system has been studied,taking Ankang area as an example.First of all,we use ETAP model to build the system single line diagram,the 13 field measured data of the whole network is simulated and analyzed for the harmonic load and three-phase unbalanced load of electrified railway,which compared with the measured data,verifying whether the simulation model in ETAP is correct or not.Secondly,according to the network topology parameters,we analyze the reasons why generating harmonics and three-phase imbalance in the electrified railway,which is divided four kind of operating modes,completely for special line power supply under winter big load,winter small load,part for spare line power supply winter big load and winter small load.Moreover,we present grid harmonic and unbalanced solutions that passive filter is installed in 110 k V bus and SVC parameters are configured reasonably,comparing the simulation results with the measured data,in order to improve power quality in eliminating harmonics,compensating reactive power and balancing three-phase load in the region.This will offer the reference to improve the power quality of electrified railway,which is quite practical.