Analysis of power quality issues of electrified railway

Electrified railway has advantages of high speed, heavy load, high energy utilization and good economic benefits. However, its access to grid will bring about power quality problems such as harmonics, three-phase imbalance and reactive power, which goes against safe and economic operation of power system. In this paper, power quality issues especially harmonics, negative-sequence and reactive power have been discussed and possible improvement methods are given. And methods still in research stage have been given a introduction aiming at providing a reference for the following study. Also, considerations for selecting improvement methods have been given. This paper aims to provide a reference for power quality evaluation and treatment of electrified railway.