Simulation Investigation on Anti-DC Current Transformer with Double Core

Effect of anti DC bias of current transformer is important for Measurement and protection. This paper proposes a simulation model of current trans-former with double core based on simulink boxtool of matlab. The magnetization characteristics of air gap core is studied according to the Jiles- atherton theory. The effect of anti DC bias of current transformer with double core is also analyzed.

I. Introduction

Current transformer is the basic component of measurement and protection in power system, its accuracy and reliability affect the stable operation of power grid [1]-[4]. Due to the geomagnetic field, DC power transmission, high-power power electronic devices and other factors, the DC component and harmonic component in power system are increasing. When the DC component appears in the current transformer winding, the DC flux is generated in the core magnetic circuit, which leads to the DC bias [5]-[8], resulting in a significant increase in the error of the current transformer and affecting the subsequent measurement and protection devices. Therefore, it is necessary to study the current transformer with strong resistance to DC bias to ensure the stability of power system.