For avoiding transmission of the harmonic of the traction power supply system onto the substation of the superior system and unfavorable influence to the power quality of public grid

a kind of design scheme of reactive power filter mounted on traction substation is proposed to control the transmission issue of harmonic of the traction power supply system to the system substation. Based on actually measured data of the system substation

the monotonous harmonic filter is designed to eliminate the low-order harmonics and concurrently act as reactive power compensation function. In the design the influence of such factors as parameter deviation of filter and reactance variation of system are considered;the trap high pass filter is designed to suppress high order characteristic harmonics and harmonic resonance.During the design period

the influence of system frequency deviation and capacitor deviation on the impedance feature of trap high pass filter in the fault condition is considered. On the basis of PSCAD combined simulation model

the characteristic harmonics

harmonic resonance as well as harmonic control of traction substation are simulated. It is shown by the simulation result that the designed reactive power can suppress effectively the characteristic harmonics and harmonic resonance.