The construction of electric railway can save resources effectively

reduce environmental pollution anddrive developmentofthenationaleconomywhich

however

brings many such harm to the power system asharmonic

negative sequence and reactive power etc. and affects power supply quality and stable operation of the grid. Aiming at power quality problems in traction power supply system

a compensation principle based on railway power conditioner is proposed in this paper. The mathematical model for reactive power and negative sequence compensation based on Scott transformer is set up. On this basis

the steady-state model of railway power conditioner based on dq-axis and corresponding controller is proposed. The model achieves active and reactive power for decoupling control. The reactive power and negative sequence compensation strategy proposed in this paper are simulated and analyzed by the use of Matlab/Simulink softwareandthesuperiorityofthecontrolsystemisverifiedbythesimulationandexperimentalresult.