To improve the compensation characteristic and dynamic response of active power filter（APF）

we put forward a selective harmonic current control strategy for APF to track those components to be compensated. According to the characteristics of normal and high speed locomotives

we adopted a detection method of harmonic currents based on synchronous rotating reference coordinates and VPI control scheme for selective harmonics compensation so as to reduce calculation of current control.Therefore

in the case of harmonic currents larger than the APF capability

the control system could selectively compensate only the most harmful harmonics. MATLAB simulation studies show that the total harmonic distortion of current will decrease from 33.9% to 2.99%

the problems of reactive power and negative sequence can be solved

thus it is verified the VPI control scheme can improve the compensation accuracy and select the main harmonics from the mixed reference

the advantages of smaller tracking error and faster dynamic response can improve electric energy quality.