Analytical Calculation of Leakage Reactance in High-Frequency Transformers Considering Frequency-Dependent and Winding-Structure Characteristics

Leakage reactance is determined by leakage inductance and frequency. The leakage inductance of the high- frequency transformer is greatly affected by the high-frequency eddy current effect of windings and structure of winding. However, there are no effective calculation and adjustment methods considering the frequency-dependent and winding- structure characteristics of leakage inductance. Based on the flux linkage method, a leakage reactance calculation method for transformers with arbitrary winding structures was proposed, considering the high frequency effect of winding. After analyzing the magnetic field intensity distribution in different winding configurations, a control method for reducing leakage reactance by interleaved windings was proposed. Based on the magnetic circuit method, this paper studied the influence of the magnetic guide plate on the leakage inductance, and proposed a method to increase the leakage reactance by inserting the magnetic guide plate. These methods were validated by 3D finite-element analysis simulation, as well as by measurements.