Instantaneous Flux and Current Control for a Three-Phase Dual-Active Bridge DC–DC Converter

The three-phase dual-active bridge converter is a promising topology for the high-power high-frequency dc–dc conversion, due to the soft-switching capability and inherent galvanic isolation. With the state-of-the-art instantaneous current control (ICC) based on the single phase-shift (SPS) operation, a bidirectional power flow can be controlled dynamically between two dc ports without inducing overshoots in the transformer currents. However, a transient dc-bias flux may still occur in the transformer, which may cause the transformer core saturation in the dynamic operation such as start-up, power-off, and abrupt load changes. To analyze and address this issue, this paper presents a set of model-based methods to avoid inducing the dc-bias flux in various transient situations. The proposed double-side SPS operation could nullify the dc-bias flux in abrupt load changes and even instant powe…