P³R – Partial Power Post Regulator for DC Buildings Application

Series-resonant converters (SRCs) have gained attention for many applications, including power supply units, data centers, and smart transformers, due to their high and very flat efficiency curve. However, ideally, SRCs operate without voltage regulation, as implementing phase shift or frequency control can penalize the converter efficiency. This presents a significant drawback for certain applications such as dc buildings, nanogrids, and dc microgrids, where such converters must operate under droop control, resulting in a variable output voltage. To address this limitation and enable SRCs to operate under variable output voltage, this paper proposes a bidirectional partial power converter as a post regulator stage (P<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>R). The proposed converter is based on a current-fed topology, featuring fully controlled switches to allow bidirectional power flow and the capability to step-up or down the output voltage. Experimental results, showcasing the converter waveforms for a 5-kW prototype, are presented to evaluate the converter's viability for this application.