Universal Modulation Technique for Quasi-Hybrid Input based Dual-Active-Bridge Converter for Bidirectional V2G Applications

This paper introduces a universal modulation technique (UMT) for the bidirectional dual-active-bridge (DAB) converter that is supplied by a quasi-hybrid input (AC or DC). The presented UMT is versatile, adaptable, working smoothly with any inputs, and capable of supplying or drawing power for AC or DC grid. Out of eight high-frequency switches of DAB, the presented modulation eliminates turn-ON loss for all switches and turn-OFF loss for six switches. It is easy to realize due to the single control variable, offering power factor correction (PFC) during grid-to-vehicle (G2V). To realize this modulation technique, a quasi-single-stage (QS<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>) bidirectional DAB is selected which can operate in AC-to-DC or DC-to-DC mode. Further, to implement the UMT, two configurations for the QS<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> DAB are presented: one features a single port serving both AC and DC inputs, while the other includes two separate ports with power relay. For quasi-hybrid input, a control scheme applicable to both configurations with vehicle-to-grid (V2G) and G2V features is discussed. Additionally, design criteria are presented considering the real-world rating. The proposed idea has been tested and verified using a scaled-down prototype of 630 W.