An isolated AC-DC matrix converter features high efficiency and high power density. However

the excitation voltage and current of its high-frequency transformer exhibit high-frequency

time-varying

and irregular characteristics

posing challenges for accurate estimation of transformer losses. To address this issue

the internal operating principle and electromagnetic characteristics were first analyzed in depth

and a harmonic current calculation method was proposed based on the superposition theorem. On this basis

an analytical model for winding loss was established

while an analytical model for core loss was established using the modified Steinmetz equation. Consequently

an analytical loss model for the high-frequency transformer was developed. To verify effectiveness and accuracy of the established analytical loss model

a co-simulation platform was built based on MATLAB/Simulink and the finite-element simulation software Maxwell

and an experimental test platform for the high-frequency transformer in the isolated AC-DC matrix converter was also constructed. Simulation and experimental results show that the error between the calculated losses obtained from the analytical model and the finite-element simulation results is less than 8%

and the error relative to the experimental results is less than 6%

which demonstrates effectiveness and accuracy of the proposed analytical loss model.