A Multistructure Multimode Three-Phase Dual-Active-Bridge Converter Targeting Wide-Range High-Efficiency Performance

Abstract

Three-phase dual-active-bridge (3p-DAB) converter is an attractive topology for bidirectional power conversion in high-power applications. However, conduction loss and switching loss are two main loss mechanisms that severely affect its efficiency performance, and adoption of any single modulation scheme or topology cannot minimize these losses over a wide operating range. For this purpose, a reconfigurable topology of 3p-DAB converter is proposed in this paper that utilizes a reconfigurable and tunable resonant network to offer multiple degreesof-freedom (DoF) in minimizing conduction and switching losses over a wide range of operating conditions. The converter is designed such that for 40 % to 100 % of the rated output power, it operates as a tunable 3p-DAB resonant immittance converter with its output power controlled by varying switching frequency and tuning the resonant frequency of a resonant immittance network to track the switching frequency. Below 40 % of the rated output power, the converter transforms to a tunable 3p-DAB series resonant converter with its output power controlled by varying the impedance of a series resonant network while keeping the switching frequency and phase-shift constant. The combination of both operation modes jointly leads to wide-range zero circulating current and soft-switching of all the switches, and hence a wide-range high-efficiency performance as validated by the experimental results.

Review of Dual-Active-Bridge Converters With Topological Modifications

“…In [322], a reconfigurable and tunable resonant network was utilized in the DAB3 topology to achieve zero circulating current and full range ZVS. The network is a ∆-connected network consisting of two types of impedances.…”

“…The network is a ∆-connected network consisting of two types of impedances. In [323]- [325], the reconfigurable and tunable resonant network in [322] and the full bridge parallel structure in [140] and [141] were both utilized to mitigate the power loss. Modified auxiliaryresonant commutated poles were applied to the DAB3 converters in [326] and [327] to overcome the challenge of limited ZVS range.…”

Advanced Modulation Scheme of a Dual-Active-Bridge Series Resonant Converter (DABSRC) for Enhanced Performance

“…In addition, the frequency-based modulation scheme proposed in [33][34][35][36][37] had the drawback of having too much frequency variation. Another hybrid frequencyand phase-shift modulation scheme with a reconfigurable and tunable resonant network was introduced in [38], but it had a few drawbacks, such as complex control, a higher component count, and a bigger footprint. Similarly, the closed-loop SPS modulation scheme reported in [33] had the drawback of a vast frequency range, and it failed to reduce the circulating current.…”

Design and parameter configuration of modular multilevel dynamic DC transformer for renewable energy sources

“…In [21, 22], a non‐isolated autotransformer is proposed, where only part of the power transferred goes through the voltage conversion process, thus reducing the loss. In [23], a hybrid‐cascaded DC transformer consists of semiconductor switches and stacks of sub‐modules are given. It is based on hybrid frequency modulation, where the modulation wave has at least two frequency components.…”