Current stress minimization for isolated dual active bridge DC-DC converter

Area of Science:

• Electrical Engineering
• Power Electronics

Background:

• Isolated dual active bridge (DAB) DC-DC converters are crucial for power conversion.
• Traditional single-phase shift (SPS) modulation in DAB converters leads to high current stress and reduced efficiency due to reverse circulating power flow.
• Increasing control complexity is a concern when aiming for improved performance through more phase-shift angles.

Purpose of the Study:

• To introduce and evaluate a new phase-shift modulation technique for isolated DAB DC-DC converters.
• To minimize maximum current stress and thereby improve converter efficiency and reduce device losses.
• To offer a control strategy with enhanced performance and implementation simplicity compared to existing methods.

Main Methods:

• Development of a novel phase-shift modulation technique utilizing two degrees of freedom (two phase-shift angles).
• Control of converter power is achieved by adjusting the phase shift between the legs of the first and second bridges.
• Comparative analysis of the proposed modulation against the traditional single-phase shift (SPS) technique.

Main Results:

• The proposed modulation technique effectively reduces maximum current stress in the DAB converter.
• The new method demonstrates improved converter efficiency and lower device losses compared to SPS.
• The technique offers a balance between performance enhancement and control complexity, outperforming SPS.

Conclusions:

• The new two-phase-shift angle modulation is a superior control strategy for isolated DAB DC-DC converters.
• This technique significantly reduces current stress and enhances overall converter efficiency.
• It provides a practical and effective solution for improving DAB converter performance without excessive control complexity.