Design and Simulation Analysis of Wide-range Current Transformer with Adaptively Adjustable Air Gap Length

This paper proposes a wide-range current transformer structure with adaptively adjustable air gap length. The length of the air gap of the iron core of this structure can be automatically adjusted with the current harmonic ratio of the secondary side of the current transformer, so that the current transformer has good anti-saturation characteristics; on the other hand, the output voltage value of the detection winding can be adjusted after proportional calculation. The secondary side current is compensated to ensure the accuracy of its measurement. At the end of the article, the structure of the current transformer is simulated and analyzed. The calculation results show that the measurement error of the secondary side current after compensation can reach the design requirements of the 0.2-level standard current transformer during the change of the primary current from 100% to 350%. This structure can effectively broaden the range of the current transformer and improve its measurement accuracy.