Analysis, Design, and Experimental Results of the Semidual-Active-Bridge Converter

Abstract

A new soft-switching circuit topology derived from the popular dual-active-bridge converter (DAB) topology is proposed for applications requiring only unidirectional power flow such as the dc-dc stage of a photovoltaic power converter, and battery charger for electric vehicles. The topology named as the semidual active bridge (S-DAB) is obtained by replacing the fully active (four switches) bridge on the load side of a DAB by a semiactive (two switches and two diodes) bridge. In addition to the reduced number of active switches, the topology offers several other advantages including extended zero-voltage switching (ZVS), and smaller output filter requirement. The operating principles, waveforms in different intervals and expression for power transfer, which differ significantly from the basic DAB topology, are presented in detail. The ZVS characteristics and requirements are analyzed in detail and compared to those of DAB. A small-signal model of the new configuration is also derived. The analysis and performance of S-DAB are validated through extensive simulation and experimental results from a 1-kW hardware prototype.Index Terms-Bidirectional converters, dc-dc conversion, dual active bridge, photovoltaic converter, soft-switching.

A Modular Multilevel Converter with Power Mismatch Control for Grid-Connected Photovoltaic Systems

“…In the conventional two-level DAB, two active bridges across a high frequency transformer produce two square waves which are phase-shifted to control the power flow. On the advances in DAB, [28] proposes a semi-dual active bridge (S-DAB) dc-dc converter for unidirectional power flow (e.g., PV application) where the load-side bridge has two switches and two diodes instead of four active switches used in conventional DAB. Operating principle and characteristic advantages are similar to conventional DAB but the S-DAB lacks a multilevel topology (e.g., a NPC stage) suitable for medium or high-voltage applications.…”

“…The controller parameters can be found from Equation (28). The square of measured dc-link voltage is compared with the reference * obtained from Equation (23) to regulate the dclink voltage.…”

“…The controller parameters can be found from Equation (28). The square of measured dc-link voltage V 2 dc ij is compared with the reference V * 2 dc ij obtained from Equation (23) shown in Equation (29), where e d is the d-axis component of grid voltage and ∑ P * g ij is calculated from Equation (30) to Equation (31):…”

Analysis of a Multilevel Dual Active Bridge (ML-DAB) DC-DC Converter Using Symmetric Modulation

“…A silicon carbide junction gate field-effect transistor (SiC-JFET) based 25-kW, high switching frequency DAB has been proposed in [11], where both primary and secondary bridges produce two-level voltages, although the secondary side bridge is formed in the NPC configuration. A detailed analysis on a semi-dual active bridge (S-DAB) has been presented in [12], where the primary and secondary bridges produce 2L and 3L voltage waveforms, respectively, which are phase-shifted to control the power flow. The concept of symmetric modulation for 2L-to-5L bridge voltages with an NPC-based secondary bridge has been introduced by the authors in [13], which has the advantage of having simple mathematical representation and a minimum number of parameters to define the voltage waveforms and to control the power flow through the ML-DAB.…”

A novel digital peak-current-mode self-sustained oscillating control (PCM-SSOC) technique for a Dual-Active Bridge DC/DC converter

“…SELF-SUSTAINED OSCILLATING CONTROL SCHEME vp and vs. The operating principles are given in [13] in detail. Fig.2 shows the conventional phase-shift control of the DAB DC/DC converter.…”