VFTC generated by the operation of GIS disconnector forms electromagnetic disturbance to the secondary equipment in the form of radiation coupling which will

in case of serious situation

cause various types of faults and is easy to cause damage of insulation of GIS equipment. However

at present there is only the study of VFTC measurement in GIS at low voltage and no report on site measurement study at UHV level. Therefore

the study of design of electronic current transformer for UHV VFTC measurement is performed in this paper. Firstly

the transient characteristics（amplitude

frequency band and response speed）of the VFTC are analyzed. Based on the principle of Rogowski coil

a kind of electronic current transformer for UHV VFTC measurement is designed. Then

on the basis of comparing various Rogowski coil type electronic transformers

it is finally determined to be the external integral PCB type Rogowski coil.The design of the current transformer includes structural parameters and electrical parameters. The former is related to the manufacturing process of PCB. According to the process requirements

the inner and outer radius of the coil

the number of turns

the thickness of PCB and the size of copper foil are determined

in which the size of copper foil is the key design parameter. While

the latter are self-induction of coil

internal resistance

distributed capacitance and sampling resistance

etc. The sampling resistance

which is determined in accordance with the measurement frequency requirement and the resistance of the coil itself

is the key electrical design parameter.The design procedures of PCB Rogowski coil and the calculation process of corresponding parameters are summ-rized in this paper. For verifying the correctness of the design

the spectrum characteristics of PCB Rogowski coil are verified. The verification results show that using outer integral PCB Rogowski coil can meet the measurement requirements of UHV VFTC. It provides a strong theoretical support for the subsequent field measurement of VFTC.