Bidirectional series-resonant DC-DC converter with fault-tolerance capability for smart transformer

Abstract

Abstract-The Series-Resonant dc-dc converter (SRC) is widely used in several application and it became very popular in Smart Transformer application. In this application, fault tolerance is a highly desired feature and it is obtained through redundancy. This paper proposes a reconfiguration scheme for the SRC for the case of failure in one semiconductor, which could drastically reduce the need of redundancy. Using the proposed scheme, the full-bridge based SRC can be reconfigured in a half-bridge topology, in order to keep the converter operational even with the failure (open circuit or short circuit) of one switch. The theoretical analysis is carried out for the unidirectional SRC and then extended to the bidirectional topology, since bidirectionality is required in smart transformer application. To verify the feasibility of the proposed scheme, the converter is tested experimentally in a 700 V to 600 V prototype with 10 kW of output power. A IGBT short-circuit fault is tested and the results confirms the effectiveness of the proposed approach.

Soft-Start Procedure for a Three-Stage Smart Transformer Based on Dual-Active Bridge and Cascaded H-Bridge Converters

“…The smart transformer (ST) is an intelligent distribution substation based on the power electronics which can be implemented on the basis of a solid state transformer (SST) or on the basis of a back-to-back converter plus a standard transformer. In the framework of smart grids, the ST concept has recently attracted the attention of industry for the capability to regulate the voltage, the frequency, the active and reactive power flow, and to allow meshed-operations of distributed feeders [1][2][3][4][5][6]. Considering the modular three-stage ST based on the cascaded H-bridge (CHB) converter and the dual active bridge (DAB) converters in Fig.…”

State of the Art of Solid-State Transformers: Advanced Topologies, Implementation Issues, Recent Progress and Improvements

“…According to [74], the system cost could be reduced by approximately 20%. SRC is configured either in half-bridge or full-bridge whereby the difference for both bridges is explained in [80]. Besides, SRC operates in discontinuous conduction mode (DCM) to reach the most efficient operating point [81] by achieving ZVS, zero-current switching (ZCS) and low current switching.…”

A Family of Series-Resonant DC–DC Converter With Fault-Tolerance Capability

“…The fault-tolerance capability of the SRC presented in the previous section for the unidirectional topology can also be easily extended to the bidirectional full-bridge topology [8]. In the topology depicted in Fig.…”

“…In this context, this paper proposes a fault tolerance solution with minimum of additional hardware and no impact on efficiency for the SRC converter, using the advantage of inherent fault tolerant capability of this topology. The proposed fault tolerant solution has been briefly introduced in [7] for the unidirectional topology of the full-bridge converter and in this paper it is extended to the SRC based on multilevel topologies and also to the bidirectional version [8].…”