Instantaneous Pulse Pattern Control for Optimized Dynamic Performance of Three-Phase Dual-Active Bridge Converter

The three-phase dual-active bridge (DAB3) converter is an isolated bidirectional dc-dc converter used in high-power dc microgrid. Without fast dynamic control of the DAB3, the required dc-link capacitance to maintain dc voltage of microgrid under transient conditions increases, resulting in a higher risk of excessive current of short-circuit accidents. Consequently, dynamic control methods for the DAB3 have been extensively studied, leading to the development of the state-of-the-art generalized instantaneous flux and current control (GIFCC). The GIFCC dynamically regulates the phase current and magnetizing flux-linkage of the transformer under both single phase-shift (SPS) and triple phase-shift (TPS) modulations. However, it applies different control laws depending on the transition type, leading to degradation of dynamic performance and complicating integration with outer-loop power or voltage regulators. To optimize dynamic performance under both TPS and SPS modulations, this article proposes the instantaneous pulse pattern control (IPPC) for the DAB3, which interprets TPS and SPS modulations as a dual-flux regulation problem. The IPPC handles both SPS and TPS modulations seamlessly based on a single control law, minimizing transient times to one-sixth of the switching period, regardless of the modulation scheme. Simulation and experimental tests validate significant reductions in transient times with the proposed IPPC in comparisons to the GIFCC.