The Influence of Dynamic Response Characteristics of Electronic Current Transformer on Line Differential Protection

With a large number of intelligent substations put into operation, the application of Rogowski coil electronic current transformer is becoming more and more widely. However, in practice, there have been too many power grid accidents caused by its dynamic response characteristics, which lead to protection maloperation. Based on these accidents, this paper expounds the mechanism of generating dynamic additional components of Rogowski coil electronic current transformer and the principle of line differential protection,This paper analyzes the cause of protection misoperation, and builds a power grid model in PSCAD simulation platform to simulate the transmission and transformation of Rogowski coil electronic current transformer when the line is closed without load. By simulating the output results under different parameter structures, the generation mechanism of dynamic additional component is verified, and the suppression measures are found, which proposes the suggestions for preventing protection misoperation.