Design and implementation of an LCL DC/DC converter prototype for DC grids

Abstract

This paper is focused on the design and implementation of an LCL DC/DC converter prototype. This inductor-capacitor-inductor (LCL) topology offers some promising properties as fault tolerant capability for DC grids, being able to step up the DC voltage without using any internal AC transformer. This prototype is to be included in a five terminal mock up DC grid located at the Electrical Engineering and Power Electronics Laboratory (L2EP) in Lille. This document presents the design of this converter, an advanced control method developed in a single synchronous frame linked with central capacitor voltage, and a new modulation scheme to reduce losses. Experimental results obtained with the developed prototype are presented.