Comparative Study of High‐Frequency Oscillations in a DC–DC Converter Topologies

ABSTRACT High‐frequency oscillations (HFOs) in isolated bidirectional DC–DC converters, such as partially isolated four port (PIFP), triple active bridge (TAB), and quad active bridge (QAB) configurations, pose significant challenges to their performance and reliability. These converters, crucial for efficient energy transfer in renewable energy systems, electric vehicles, and energy storage applications, are susceptible to HFOs due to parasitic elements and nonlinearities in switching devices. This paper investigates the causes and effects of HFOs in PIFP, TAB, and QAB converters by modelling high‐frequency transformers with parasitic element analysis and extracting parasitic elements using mathematical modelling, simulation, and experimental validation. Key parameters causing HFOs are identified, and power losses due to HFOs are estimated. An experimental 2.5‐kW hardware prototype is developed to validate the theoretical findings, providing practical insights and confirming the simulation results. The study underscores the importance of managing parasitic elements and advanced modelling to mitigate HFOs, enhancing the efficiency and reliability of isolated bidirectional DC–DC converters.