Implementation of Single-Phase Shift (SPS) and Extended Phase Shift (EPS) for Dual Active Bridge (DAB)

Abstract

Objectives: To improve power transfer and efficiency in Dual Active Bridge (DAB) converters, this study compares and assesses the Single-Phase Shift (SPS) and Extended Phase Shift (EPS) control techniques. Methods: Using the Dual Active Bridge (DAB) arrangement, the research focuses on implementing SPS and EPS control methods to an Isolated Bidirectional Full-Bridge DC-DC Converter (IBDC). A comprehensive review of the IBDC's operating modes and the EPS's control concept is included in this study. Findings: In comparison with EPS, SPS control is limited by a smaller operating range, higher power loss, and higher circulating current. Conversely, EPS exhibits benefits such as decreased back power flow, increased Zero Voltage Switching (ZVS) range, and decreased current stress. These conclusions are supported by the simulation results, which show that EPS control outperforms SPS in terms of operational stability, harmonics, and efficiency. Under the SPS control at different phase shift minimums, THD is 15.06%; whereas, for EPS it is 12.90%. Novelty: This study demonstrates how EPS outperforms SPS in DAB converters, providing better operational range, THD, and efficiency. Keywords: Isolated Bidirectional Full-Bridge DC–DC Converters (IBDCs), Dual Active bridge (DAB), Single Phase Shift (SPS), Extended Phase Shift (EPS), Current Stress, Power Transmission