EnStadt:Pfaff – Innovative Photovoltaic DC Charging Infrastructure with Buffer Storage

Duration: January 2017 - December 2022
Contracting Authority/ Sponsors: Federal Ministry for Economic Affairs and Energy (BMWi), Federal Ministry of Education and Research (BMBF)  
Project Partners: City of Kaiserslautern; Pfaff-Areal Entwicklungsgesellschaft (PEG); Palatina Wohnbau; Fraunhofer-Institute for Experimental Software Engineering (IESE); Environmental-Campus Birkenfeld, Institute for applied  Material Flow Management (IfaS); University of Applied Sciences Kaiserslautern; University of Applied Sciences Fresenius
Website: https://pfaff-reallabor.de (only in German)
Project Focus:
Geplantes Reallaborzentrum.
© ASTOC/MESS
Geplantes Reallaborzentrum.

As the appreciable growth in charging infrastructure for electric vehicles can lead to local supply shortages in the distribution grids, particularly fast charging stations are increasingly being equipped with local storage buffers. In a solar carport with integrated buffer storage and fast charging infrastructure, the DC electricity generated by the PV system can be inverted and rectified up to four times on its route from the PV module via the buffer storage unit to the DC charging point, generating unnecessary conversion losses.

Within the "EnStadt:Pfaff" joint research project, Fraunhofer ISE is investigating and demonstrating purely DC-DC connected fast charging infrastructure. The goal is to increase the efficiency of this type of sector coupling significantly.

For this purpose, a DC grid consisting of innovative DC fast charging points, PV generators, a battery system with a high discharge power and a bidirectional inverter as a backup for grid connection were set up in the urban laboratory center in Kaiserslautern. This infrastructure will be evaluated and optimized as part of the demonstration.

Fraunhofer ISE supports industrial partners in identifying innovative solutions by designing, engineering, dimensioning and optimizing this type of conductive or also inductive fast charging systems with buffer battery storage for novel applications. These also include charging infrastructure for maritime and aviation applications, as well as electrification of local public transport systems.