High-Frequency Transformer Modeling: Methods, Parameter Extraction and Validation—A Review

High-frequency transient events in power systems are becoming increasingly significant due to lightning impulses, growing penetration of renewable energy sources, high-voltage direct current (HVDC) transmission systems, and power-electronic-interfaced equipment. Transformers operating in modern power systems, particularly those connected to power-electronic converters, HVDC systems and renewable-energy applications, may be exposed to steep-front voltage waveforms and high dv/dt stresses. These non-sinusoidal and repetitive transient conditions may cause severe dielectric stresses within transformer windings and insulation systems. High-frequency transformer models are therefore essential for analyzing transient behavior both at transformer terminals and within the windings. Such models consider winding geometry, electrostatic and electromagnetic couplings, and frequency-dependent parameters to represent transient voltage distributions with sufficient accuracy. Their reliability is critical for insulation coordination, transient overvoltage assessment, and transformer design. This paper presents a review of high-frequency transformer modeling approaches reported in the literature. White-Box, Gray-Box, and Black-Box models are examined together with analytical, finite element method (FEM)-based and measurement-based parameter extraction techniques. Time-domain and frequency-domain validation strategies are also discussed. Finally, the applicability, limitations, operational requirements, research gaps and future trends of existing modeling approaches are evaluated.