High‐Frequency Oscillation Suppression in Triple Active Bridge Converters via Optimal Parallel Capacitance

ABSTRACT This study investigates the occurrence of high‐frequency oscillations (HFOs) in triple active bridge (TAB) DC‐DC converters, a critical component in DC microgrid and electric vehicle (EV) systems. The focus lies on understanding and mitigating HFOs induced by parasitic capacitance, parasitic inductance, and leakage inductance in the high‐frequency transformer, as well as addressing challenges posed by high dv/dt. To tackle these issues, a frequency‐domain model is proposed, emphasizing the regulation of dv/dt at the H‐bridge voltages to suppress HFOs. By identifying an optimal dv/dt range, the study aims to minimize HFOs. Additionally, integrating suitable parallel capacitance at the switching devices is suggested to dampen HFOs, facilitate soft switching, and reduce switching power losses. The optimization process utilizes Particle Swarm Optimization (PSO) to determine the optimal parallel capacitance, thereby enhancing the overall efficiency of the TAB DC‐DC Converter. Simulation and experimental results corroborate the effectiveness of the proposed approach, demonstrating a substantial reduction in HFOs and an enhancement in the performance of the TAB DC‐DC converter.