Frequency-Domain Modeling of Electrical Insulation and Application to High-Voltage Power Electronics: A Review

Modern power applications, such as high-voltage direct current transmission, electrified transportation, and industrial systems, increasingly rely on wide-bandgap semiconductors, driving the need for electrical insulation systems capable of withstanding high electric fields and switching voltage waveforms. The reliable design of insulation systems is critical to ensuring the high-power density and operational stability for high-voltage power electronics. Under multifrequency voltage conditions, frequency-dependent polarization dynamics within insulation materials significantly influence the macroscopic dielectric properties and insulation performance. This article provides a comprehensive review of frequency-domain modeling methodologies for electrical insulation exposed to switching voltage waveforms with varying rising times. It examines advancements in semi-empirical equations and equivalent circuit models for characterizing frequency-dependent polarization dynamics behaviors, analyzing the strengths, limitations, and suitability for various applications. Challenges caused by the fast-rising voltage waveforms to electrical insulation are addressed by integrating frequency-domain models. Practical case studies such as electrothermal field calculations and health assessments are discussed, demonstrating the necessity of the inclusion of polarization dynamics behaviors. The review concludes with insights into emerging trends, including the development of advanced insulating materials and diagnostic techniques. This work offers valuable guidance for insulation design and reliability analysis in high-voltage power electronics applications.