November 2023

Conference Paper

A Medium Voltage Three-Stage Power Converter Topology for Distribution Grid Scale Energy Storage Systems

By:
Chinthavali, Madhu Sudhan ; Adib, Aswad ; Pereira Pinto, Joao Onofre ; Wojda, Rafal P; Starke, Michael R
Page Number:
1-8
Book Title:
2022 IEEE Energy Conversion Congress and Exposition (ECCE)
Publication Date:
November 9, 2023
Publisher Location:
IEEE, New Jersey, United States of America
Conference Name:
IEEE Energy Conversion Congress and Exposition (ECCE) 2022
Conference Location:
Detroit, Michigan, United States of America
Conference Sponsor:
IEEE, IAS, PELS
View DOI Listing:
https://doi.org/10.1109/ECCE50734.2022.9947970

Abstract

This work proposes a three-stage converter topology with a medium frequency isolation transformer for direct integration of energy storage systems into medium voltage distribution grids. The distributed architecture of the topology, using standard AC/DC converters, has been developed with the aim of plug-and-play capability and voltage and power scalability. The medium frequency transformer facilitates improved power density, while its 20:1 voltage translation capability enables the use of limited voltage level (500 Vdc) of the commercially available batteries. This paper presents the topology structure and details how it can be scaled to reach the full range of the distribution grid voltages and the required power levels. A transformer design for 500 Hz rated frequency is discussed. The control scheme of the converter equipped with voltage support, frequency support, and black start capabilities is also presented. Control hardware-in-the-loop results using OPAL-RT, with converter switching models connected to a weak IEEE-4 node test feeder modified for the aforementioned grid services, are provided to show the topology feasibility.