A Unified Numerical Modeling Method for Dual Active Bridge Type Converter

Dual Active Bridge (DAB) Type Converter is a widely adopted topology in modern electric energy systems. It offers galvanic isolation, high conversion efficiency, and facilitates bidirectional power flow. Various methods have been proposed to enhance its efficiency, such as control-side improvements like Double-Phase-Shift (DPS) and Triple-Phase-Shift (TPS), as well as circuit-side modifications like resonant mode operation. These methods aim to extend the Zero-Voltage Switching (ZVS) range and optimize the current RMS value for improved efficiency. However, these approaches rely on accurate steady-state models.Traditionally, modeling the DAB type converter in the time domain while considering different switching modes separately has been complex and inflexible. To address this issue, this paper presents a novel Fast-Fourier-Transform-based modeling method. This approach involves calculating the system waveforms in the discrete frequency domain and subsequently converting them back into the discrete time domain, effectively bypassing the challenges posed by multi-switching modes. This proposed algorithm can be easily integrated into optimization algorithms to achieve rapid hardware or modulation optimization. Moreover, This algorithm can also be applied to a wide range of isolated converters.