Comparative Analysis of Multiple Active Bridge Converters Configurations in Modular Smart Transformer

Abstract

In this work, the quadruple active bridge dc-dc converter (QAB) is proposed to be used as a building block to implement the dc-dc stage of a Smart Transformer (ST). Different configurations (symmetrical, asymmetrical, rated for voltage/power) for this converter are considered for investigation. Four different architectures of ST, including one based on the Dual Active Bridge (DAB) converter as a benchmark and three based on the QAB converter, are presented and compared in terms of cost, efficiency, reliability and implementation complexity. As an additional contribution, different semiconductors technologies (silicon IGBT and silicon carbide MOSFETs) are evaluated in order to verify their impact on ST application. The design for each architecture is described and the results are compared. In order to validate the theoretical analysis developed in the paper, a 20 kW prototype was built and experimented.Index Terms-Dc-dc converter, multiple active bridge converter, multiwinding transformer, smart Transformer.

Comparative analysis of DC to AC conversion cells for application in PV‐linked grid‐connected modular multi‐level cascaded converters

“…A comparative study is presented in this section to select the proper conversion cell for the MAB converter. From an analytical point of view, any n ‐port MAB converter can be decomposed into n ( n − 1)/2 DAB converter [10]. Therefore, the DAB converter is used as a base topology to simulate and compare the characteristics and performance of the conversion cells.…”

“…The topology can be further extended to the multi‐active bridge (MAB) converter by connecting more active bridges to a multi‐winding transformer (MWT) [9]. The resultant topology leads to a reduced number of conversion cells and transformers which reduces the system size and cost of the system, while still preserves the same advantages [10]. The MWT operates as a common magnetic bus to integrate the energies in the form of magnetic flux [11–13].…”

“…The MWT operates as a common magnetic bus to integrate the energies in the form of magnetic flux [11–13]. The power flow in the MWT is controlled by a phase shift control technique [9–13]. The most common MAB converter topologies are triple‐active bridge (TAB) [12], and quadruple‐active bridge (QAB) [13].…”

“…However, increasing the number of bridges and transformer windings to more than four leads to the complexity in the structure and design of MWT [14, 15]. Application of MAB converter with different configurations in the modular smart transformers and the resulting advantages are studied in [10] and only the FB topology is considered as dc–ac conversion cell in the proposed systems. However, some other dc–ac conversion cells that are feasible for MAB converter application are suggested in [16].…”

Voltage Distribution in the Windings of Medium-Frequency Transformers Operated With Wide Bandgap Devices

“…The MFT is a transformer operated with Pulse-Width Modulation (PWM) voltage waveforms in the kilohertz range and MV level. The most common alternatives to connect the MFT to the power electronics are presented in [11]. The operating voltage level of the MFTs typically results in similar insulation requirements as LFTs, to guarantee the same operational safety within the MV grid.…”