Abstract—Simulation studies of modern electrified ship propulsion systems using the discrete switching models of cycloconverters are very time-consuming and require expertise and accuracy in modeling all the details of the ship’s electric power system. Alternatively, data-driven models of cycloconverter-based Variable-Frequency-Drive (VFD) systems are proposed, which may simplify the modeling and improve simulation efficiency and speed. The data-driven models can be established based on several measurements or a few runs of the detailed simulations, but their subsequent use enables very fast and efficient systemlevel studies. In this paper, the data-driven models of cycloconverter-based VFDs are analyzed in terms of their accuracy and numerical efficiency with respect to their detailed switching model counterparts for harmonic studies of an example ship propulsion system. The advantages and drawbacks of both modeling techniques are demonstrated through time-domain and frequency-domain electromagnetic transient simulations conducted in MATLAB/Simulink using the Simscape Electrical toolbox.