In this paper

the parameters of each power quality index of the electrified railway which is permitted to inject into power grid are calculated in detail on the basis of research project of practical engineering

regarding to influence of electrified railway on power quality of Zhangjiajie grid as well as regarding to combination of Chinese national power standard and actual operation parameters of power grid. The parameters are compared with data obtained during actual measurement

and the danger of such issues as harmonics

negative sequence and reactive power of the electrified railway to the power grid is analyzed and assessed in detail. The comprehensive treatment system for harmonic and reactive power suppression is designed and the correctness and effectiveness of this system is proved by the simulation result.