Based on the on-site detection requirements of winding current and generation mechanism of the harmonic current in the converter station

this paper presents a system for detecting harmonic current in the grid side windings of the converter transformer to obtain the winding current harmonic and analyzes its influence on power loss

internal temperature rise and vibration noise of the transformer. The technologies of current signal extraction

signal synchronous acquisition

optical fiber transmission

and harmonic cluster frequency algorithm are combined in the winding harmonic current detection system. Under the steady-state operation condition of bipolar equilibrium constant power

the effectiveness of the detection system is verified by the results of on-site detection and the simulation analysis of the harmonic characteristics. Based on this

the harmonic current of the grid side winding is detected and analyzed during the process of dc transmission power rise. The results show that

with the increase of DC transmission power

the distortion rates of 11 th

17 th

19 th

23 rd

29 th

31 st

35 th

37 th

41 st

43 rd

47 th and 49 th harmonics have a significant decline trend

and the total harmonic distortion rate reduces gradually.