Phase-Shift Keying-based Modulation of Talkative Dual-Active Bridge Converters

In dc interconnections such as dc microgrids or electric vehicle charging stations, a flexible management of the power flow is of greater importance. For that purpose, the exchange of information beside the power transfer is necessary. The dc output voltage of switching dc converters contains already information – the switching frequency itself which can be seen in the voltage ripple. This ripple is always there and and can be used to transfer further information. Modulating information onto the voltage ripple is called talkative power conversion (TPC). For that purpose, classical modulation techniques such as frequency-shift keying (FSK) and phase-shift keying (PSK) are used and can be modulated on top of the power modulation through pulse-width modulation (PWM). A suitable converter in dc microgrids or charging stations is the dual-active bridge (DAB) converter due to its bi-directionality and its high power density. The selection of a suitable TPC information modulation scheme depends on the requirement of plug-and-play capabilities and easy adoption.Thus, PSK is selected and analysed as a TPC strategy that can be adapted for TPC in DAB converters. In this work, the emerging challenges of PSK-TPC in DAB converters and the necessary modifications in the control and PWM of the thus talkative DAB converter are shown and explained.