Study of ECT based on Rogowski coil used in smart substation

The electronic instrument transformers located in the process layer of smart substation may have important technical significance to the relay protection devices located in the bay layer, and it is meaningful to evaluate and analyze the transient characteristics of the electronic instrument transformers. In this paper, taking the electronic current transformer (ECT) based on Rogowski coil for a research object, its working principle and equivalent structure are introduced firstly. Furthermore, using MATLAB/SIMULINK, the ECT´s simulation model is built, and its transient responses to decaying DC component and steady-state AC component under different integral parameters are respectively simulated. On the basis of the simulation results, it can be observed that, this kind of current instrument transformer has the ability of measuring the transient current accurately, and accordingly the operating performance of the relay protection associated with this ECT can be enhanced to a certain extent. At the end of this article, some engineering application problems are investigated and discussed in brief.