Design and Simulation of Electromagnetic Wide-range Current Transformer

Due to core excitation characteristics, the accuracy of current transformer varies greatly in different primary currents. In order to make the measurement of transformer more accurate in a wide range, a new realization method for electromagnetic transformer is proposed. This method improved passive zero flux current transformer, made the resistance of compensation winding a suitable fixed value. So the error of current transformer could be greatly reduced under wide range. On this basis, in the current range where the error still did not meet the requirement, turn compensation was added to carry out fine tuning to satisfy error requirement. The results show that this wide range current transformer is highly accurate at 1%-200% rated currents. Meanwhile, the magnetic flux in main core is greatly reduced, it not only realizes the essential function of zero flux transformer reducing the excitation current, but also avoids the dynamic adjustment of compensation resistance.