Functional Features of Isolated AC/DC Converter Interface in Future Low-Voltage DC Microgrids | IEEE Conference Publication | IEEE Xplore

Functional Features of Isolated AC/DC Converter Interface in Future Low-Voltage DC Microgrids


Abstract:

In order to decouple dynamics of low-voltage DC microgrids and the AC utility grid and apply specific grounding configurations, it is required that the AC/DC converter in...Show More

Abstract:

In order to decouple dynamics of low-voltage DC microgrids and the AC utility grid and apply specific grounding configurations, it is required that the AC/DC converter interface features transformer galvanic isolation. This paper proposes a simple, bidirectional, two-stage converter topology with an active front-end AC/DC stage followed by an isolated, resonant DC/DC converter, operated as a DC transformer. The isolated AC/DC interface features droop control implemented using a minimized set of measurements and feedback loops. Theoretical considerations are backed up with simulation results for different power levels, justifying the feasibility of the proposed converter topology and the droop control strategy for the given purpose.
Date of Conference: 04-08 September 2023
Date Added to IEEE Xplore: 02 October 2023
ISBN Information:
Conference Location: Aalborg, Denmark

I. Introduction

Due to the increased penetration of distributed energy resources with inherent DC nature, such as photovoltaics (PV), battery energy storage systems (BESS) and electric vehicle batteries, but also DC loads, such as LED lights, microprocessors, laptop/cellphone batteries, etc., there is a growing interest in both academic and industry environments towards low-voltage (< 1500 Vdc) DC microgrids (DCMGs) (see Fig. 1), owing to numerous advantages of DC power distribution [1], [2]. Typical application cases involve commercial buildings, industrial plants, datacenters, EV charging stations and marine. The main motivation for introducing DC microgrids comes from expectedly increased power conversion efficiency due to reduction in number of the power conversion stages, which underpins the process of the power grids decarbonization. As described in [3], in industrial plants with energy recuperation, moving from the AC to DC distribution brings a measured efficiency improvement of 5.87 %. Further benefits involve potential cost reduction and more resilient operation of the system.

References

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